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otpeatY of CSC S'ibC U.S. DEPARTMENT OF COMMERCE NOAA COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE CHARLESTON, SC 29405-2413 FDER CM-64 (A2) Grant: Final Report Planning Department Monroe County Florida Funds for this project were provided by the Florida Department of Environmental Regulation, Office of Coastal Management, from a grant from the U.S. Department of Conutmerce, Office of Ocean and Coastal Resource Manacement, under the Coastal Zone Management Ac.t of 1.9'72, as amended r'� ~bsJ The format of this report will follow the Scope of Work for this grant, as amended by the second amendment dated September 28, 1984. TASK I. Revisions to the Coastal Zone Protection and Conservation Element. (1) Maps of Endangered Species. These maps are complete and are being transferred to sepia by the Department's draftsmen so they can be reproduced. They will be sent to DER under separate cover. The following section describes the maps and their use. The maps are drawn at a scale of 1:24,000 (1" = 2000'), which is the scale the County is using for all its Land Use Plan maps. They are drawn on a copy of the County's "Existing Conditions" Maps, which show all existing development and wetland or upland vegetation. Of the thirty endangered or threatened animal species in the Keys, there are sufficient data to map 16 species. Of these 16 species, 6 have been mapped by showing generalized ranges. For these species the range boundary is a solid line interrupted by the code number of the species with two stars. The arrows along the line point inward towards the range. The six species mapped in this manner are: 1) American Crocodile (code A204) - Range includes parts of Maps 5, 6 and 7. Within the range, the crocodile may inhabit open water (code 500), or mangroves (code 612, 620). 2) Key Largo Woodrat (code A401) - Range includes Upper Key Largo on Map 7. Within the range, the woodrat inhabits tropical hardwood hammocks (vegetation code 426). 3) Key Deer (code A402) - Two ranges are shown. The total range is delineated as described above, and includes areas on Maps 1, 2, and 3. The smaller range is delineated by a line with two arrows instead of one. Approximately 2/3 of the population is concentrated in this area. Within its range, the Key Deer utilizes all habitats and many developed areas. 4) Key Largo Cotton Mouse (code A404) - Range is same as Key Largo Woodrat, shown on Map 7. 5) West Indian Manatee (code A406) - Range includes bay waters along north and west side of Key Largo, on Maps 6 and 7. Within this range, the manatee inhabits open water, bays, creeks and canals. 6) Schaus Swallowtail Butterfly (code A502) - Range includes Upper Key Largo, shown on Map 7. Within this range, the Schaus Swallowtail inhabits tropical hardwood hammocks (vegetation code 426). Final Report October 29, 1984 Page Two Ten species are mapped by showing the locations of known populations and reported observations. The following species are mapped in this manner: 1) Big Pine Ringneck Snake (code A206) 2) Eastern Indigo Snake (code A208) 3) Key Mud Turtle (code A209) 4) Florida Brown Snake (code A211) 5) Miami Black Headed Snake (code A212) 6) Florida Ribbon Snake (code A213) 7) Eastern Brown Pelican (code A306) (Nesting colonies mapped). 8) Silver Rice Rat (code A403) 9) Key Vaca Raccoon (code A405) 10) Stock Island Tree Snail (code A501). For each of thesesspecies, a star is placed on the map at the center of the general area where it was observed. Please note that in many cases, the actual observation was somewhere within the vegetative community where the star is located, but it may not be directly under the star itself. At each star, there is a notation for the species code number(s), followed by a second number which is the County's number for that observation record. For example, A209-01 is the first observation record for the Key Mud Turtle. Attachment 1, of this report, is a print-out of the computer listing of all observa- tion records, giving a brief synopsis of the source and location. The final set of data for the endangered and threatened animals is the Table found in Attachment 2. This Table is used with the maps. All 30 species are listed with the County's species codes. As explained in the Table's footnote, an asterisk denotes the ten species for which observations are mapped, and a plus sign denotes the six species for which ranges are mapped. The "habitat" columns show the habitats where the species breeds or nests (B), feeds (F) and rests or roosts (R). The habitat columns are abbreviations of the names of the vegetation types mapped on the "Existing Conditions" maps, and the vegetation codes are also shown. For example, "SLP" stands for slash pinelands, which has the code 411 on the maps. The final column of this Table shows the geographic range of the species. Final Report October 29, 1984 Page Three TASK II. Interagency Agreements. I ~~~Attachment 3 is two letters initiating monthly meetings of County personnel with local representatives of the U.S. Army Corps of Engineers and Florida Department of Environmental Regulation. I ~Other agencies now represented at these meetings include U.S. Fish and Wildlife Service, Florida Department of Natural Resources, and Florida Game and Freshwater Fish Commission. I ~~~The County also participates in the Florida Keys Interagency Management Committee, chaired by DCA. TASK III. Ordinance Development. (1) Trees and Vegetation. Attachment 4 is the revision to this ordinance prepared by the Planning Department, along with a letter transmitting it to the I ~County's Land Use Plan consultants. Adoption may occur as part of the new Land Use Plan. 3 ~~~(3) Freshwater Wetlands. Attachment 5 is the definitions of the vegetation communities mapped on the County's "Existing Conditions" maps. Freshwater wet- lands are mapped with code 641, and a definition of this unit is included in Attachment 5. 3 ~~~(4) Mangrove Trimming. Staff determined that a mangrove trimming ordinance is not re- quired at present. The proposed revision to the Trees and Vegetation ordinance can address this problem, and the State has recently enacted an ordinance regulating mangrove trimming. TASK IV. Standards for Site Development. Attachment 6 is narrative descriptions and a sensitivity analysis I ~of the different natural communities of the Keys. This material will be used as the data base for the new Land Use Plan and site development regulations. Please note that the enclosed material, while it is being used for the development of planning scenarios, is still in a draft form. Revisions are anticipated as the program ad- I ~vances to subsequent phases. Final Report October 29, 1984 Page Four TASK V. Coral Reef. 5 ~~~One section of Attachment 5 addresses coral reefs. 3, ~TASK VI. Coordinate with DCA Land Use Plan Program. It should be evident that the entire focus of this grant pro- gram has been coordinated with the Land Use Plan effort of the County and DCA. I I t I 5 U I I X A T T A C H M E N T I I I ATTACHMENT1 I I l I I I I I Explanation of Index Entries Species Code: Record #: FNAI Element Occurence Code: Author/Observer: Citation: Location: Township - Range - Section: Key Vegation Code: Hammock Atlas Reference: I A207 01 AHRDB11011.002 Jun 10 77 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16a,b,c A207 02 AHRDB11011.003 May 26 77 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16d,e A207 03 AHRDB11011.004 1977 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16f A207 04 AHRDB11011.005 Jun 15 77 Weiner, A.H. Hammocks Survey 066S-029E: L113 426 L9/17 05 AHRDB11011.006 Jun 21 77 Weiner, A.H. Hammocks Survey 066S-028E: L113 426 L9/21 I A207 06 AHRDB11011.007 Jan 5 77 Weiner, A.H. Hammocks Survey 066S-028E: Ll10 426 L9/35 A207 07 AHRDB11011.011 Mar 24 82 Weiner, A.H. Hammocks Survey 063S-038E: L134 426 L4/1 A207 08 AHRDB11011.012 Dec 7 81 Weiner, A.H. Hammocks Survey 067S-030E: L116 426 L8/11 A209 01 Oct 5 78 Barbour, D. Bruce Letter to Paul Moler (5/2/79) 066S-028E-29: LIlO 426, 740.3 L9/35 A209 02 Oct 26 78 Barbour, D. Bruce Letter to Paul Moler (5/2/79) 066S-028E-31, 067S-028E-06: L109 426 L10/6a I A209 03 AHRAE01011.001 May 26 77 Weiner, A.H. Hammocks Survey 066S-029E-17: L114 426 L9/16d A209 04 AHRAE01011.001 May 26 77 Weiner, A.H. Hammocks Survey 066S-029E-17: L114 426 L9/16e A209 05 Nov 16 78 Barbour, D. Bruce Letter to Paul Moler (5/2/79) 066S-029E-31: L112 640 A209 06 Oct 26 78 Barbour, D. Bruce Letter to Paul Moler (5/2/79) 066S-028E-28: LllO 426, 640 L9/36 07 AHRAE01011.002 Sep 12 77 I Weiner, A.H. Hammocks Survey 066S-028E-29: LIlO 426, 740.3 L9/35 l A209 08 Lazelle, Skip Letter to FWS 067S-030E-06: L116 426 L8/11 A212 01 AHRDB35060.001 May 26 82 Achor, Karen L. Special Animal Field Report Form, 6/8/82 061S-039E-01,12: L135 640, near 426 L2/8 A212 02 AHRDB35060.006 I Sep 76 Specimen #JF-39064 SM 060S-040E: L136 prob. 426 A212 03 AHRDB35060.007 Jun 78 Porras, L. & L.D. Wilson New Distributional Records for Tantilla oolitica 065S-034E-19: L148 426 L6/2 A213 01 AHRDB36122.001 May 26 77 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16d,e A213 02 AHRDB36122.002 I 1977 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16f A213 03 AHRDB36122.003 Jan 5 77 Weiner, A.H. Hammocks Survey 426, 641 L9/35 A213 04 AHRDB36122.004 3 May 23 70 Christman, S.P. Specimen #UF-44325 SM 066S-029E: L116 411 A213 05 May 23 76 Keefer Specimen #UF-44326 SM 066S-029E: L116 411 I A213 06 Porras Specimen #UF-44327 SM 066S-029E: L116 411 A306 01 1968-1976 Williams, Lovett E., Jr. (ed.) Recovery Plan for the Eastern Brown Pelican, p.34 067S-026E-26: L161 ? A306 02 ABNDB01022.011 Jun 25 75 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 061S-038E: L149 ? A306 03 ABNDBO1022.012 Apr 19 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 062S-038E: L150 ? A306 04 ABNDB01022.013 Jul 78 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 061S-034E: L151 ? A306 05 ABNDB01022.014 May 14 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 066S-030E: L152 612 I A306 06 ABNDB01022.015 Feb 13 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 063S-035E: L153 ? I A306 07 ABNDB01022.016 May 27 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 ? :L154 ? A306 08 ABNDB01022.017 May 27 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 065S-028E: L155 ? A306 09 ABNDB01022.018 May 14 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 066S-032E: L156 426, 740.1 A306 10 ABNDB01022.019 May 27 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 066S-027E-04: L157 ? A306 11 ABNDB01022.020 Apr 19 76 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 063S-035E: L153 ? A306 12 1975-1976 Osborn, Ronald G. & Thomas W. Custer Herons & Their Allies: Atlas of Atlantic Coast Colonies, 1975 & 1976 066S-027E-04: L157 A306 13 1976-1978 Nesbitt, Steven A., et al. Florida Atlas of Breeding Sites for Herons & Their Allies:1976-1978 066S-027E-04: L157 A306 14 1968-1976 Williams, Lovett E., Jr. (ed.) Recovery Plan for the Eastern Brown Pelican, p.34 066S-030E-29: L162 612 A306 15 1968-1976 Williams, Lovett E., Jr. (ed.) Recovery Plan for the Eastern Brown Pelican, p.34 066S-031E-21, 22: L163 612,640 A306 16 1968-1976 Williams, Lovett E., Jr. (ed.) Recovery Plan for the Eastern Brown Pelican, p.34 066S-031E-19: L122 612 A306 17 1968-1976 Williams, Lovett E., Jr. (ed.) Recovery Plan for the Eastern Brown Pelican, p.34 065S-030E: L164 ? A401 01 AMAFF08011.001 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 059S-040E-13: L136 426 L1/5 A401 02 AMAFF08011.002 Sep 20 77 Weiner, A.H. Hammocks Survey 059S-040E-13,23,24: L136 426 L1/8 A401 03 AMAFF03081.004 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 059S-040E-23: L136 426 L1/9 A401 04 AMAFF03081.005 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 059S-040E-25: L136 426 L1/11 A401 05 AMAFF03081.006 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 060S-040E-10: L136 426 L1/14 A401 06 AMAFF03081.007 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 060S-040E-10: L136 426 L1/15 A401 07 AMAFF03081.008 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 060S-040E-16: L135 426 L2/1 A401 08 AMAFF03081.009 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 060S-040E-28: L135 426 L2/2B I A401 09 AMAFF08011.010 Sep 30 78 Weiner, A.H. Hammocks Survey 060S-040E-29: L135 426 L2/3 A401 10 AMAFF03081.012 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 059S-040E-24: L136 426 L1/lOB A401 11 AMAFF03081.013 Nov 82 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 059S-040E-24: L136 426 Ll/1OA A401 12 AMAFF03081.012 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 060S-040E-02: L136 426 L1/13 A401 13 AMAFF03081.016 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 059S-040E-35: L136 426 L1/12 A401 14 AMAFF03081.017 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 060S-040E-10: L136 426 L1/16 A401 15 78 Layne, James N. FCREPA: Mammals (Vol. I) 3 064S-036E-02,03: L139 426 L5/1 A401 16 Mar 84 Weiner, A.H. Hammocks Survey 059S-040E-26,35; 060S-040E-02,03: L136 426 L1/12 A401 17 Feb 84 Weiner, A.H. Hammocks Survey 060S-040E-02: L136 426 L1/13 A401 18 Feb 26 84 Weiner, A.H. Hammocks Survey 060S-040E-09,15: L136 426 L1/16 A401 19 Jan 84 Weiner, A.H. Hammocks Survey 060S-040E-29: L135 426 L2/4 A401 20 Dec 83 Weiner, A.H. Hammocks Survey 060S-040E-29,31,32: L135 426 L2/5 A403 01 AMAFF01030.001 Feb 7 73 Spitzer, Numi Thesis, telephone conservation w/ D. Jackson 066S-028E-29: Ll10 426, 740.3 L9/35 A403 02 Feb 80 Spitzer, Numi Status Report on Oryzomys argentatus, the Silver Rice Rat p.2 para. 3 065S-028E-29: L159 612 A403 03 AMAFF01030.001 Feb 8 73 Spitzer, Numi Thesis, telephone conservation w/ D. Jackson 066S-028E-29: LllO 426, 740.3 L9/35 A403 04 Nov 12 81 Spitzer, Numi Thesis 066S-028E-01: L113 612, 640 A403 05 Nov 22 81 Spitzer, Numi Thesis 066S-028E-01: L113 612, 640 A403 06 Nov 12 81 Spitzer, Numi Thesis 066S-028E-01: L113 612, 640 A403 07 Nov 18 81 Spitzer, Numi Thesis 066S-028E-01: L113 612, 640 A403 08 Nov 18 81 Spitzer, Numi Thesis 066S-028E-12: L113 612, 640 A403 09 Nov 20 81 Spitzer, Numi Thesis 065S-028E-35: L113 620, 640 A403 10 Oct 9 81 Spitzer, Numi Thesis 066S-030E-05: L143 A403 11 Oct 11 81 Spitzer, Numi Thesis 066S-030E-05: L143 A403 12 Nov 28 81 Spitzer, Numi Thesis 066S-029E-19: L114 620, 640 A403 13 Jan 19 81 Spitzer, Numi Thesis 065S-028E-29,32: L159 612, 640 A403 1 4 Jan 20 81 Spitzer, Numi Thesis 065S-028E-29,32: L159 612, 640 A403 1 5 rn 1976 Spitzer, Numi Thesis 065S-028E-29,32: L159 612, 640 A403 16 1980 Spitzer, Numi Thesis 065S-028E-29,32: L159 612, 640 A403 1 7 Oct 5 81 Spitzer, Numi Thesis 067S-027E-07,08: L107 612, 620, 640 A403 18 Nov 2 81 Spitzer, Numi Thesis 066S-028E-26: L111 620, 640 A403 19 Nov 4 81 Spitzer, Numi Thesis 066S-028E-23: Llll 620, 640 A403 20 Dec 1 81 Spitzer, Numi Thesis 066S-028E-23: Llll 620, 640 A403 21 Dec 6 81 Spitzer, Numi Thesis 066S-028E-23: Llll 620, 640 A403 22 Nov 8 81 Spitzer, Numi Thesis 066S-028E-26: Llll 620, 640 A403 23 Dec 6 81 Spitzer, Numi Thesis 066S-028E-26: Llll 620, 640 A403 24 Jan 2 81 Spitzer, Numi Thesis 065S-028E-26: L160 A403 25 Jan 9 81 Spitzer, Numi Thesis 065S-028E-26: L160 A403 26 Jan 19 81 Spitzer, Numi Thesis 065S-028E-26: L160 A403 27 1984 Spitzer, Numi Personal communication 066S-027E-08,09: L158 A404 01 AMAFF03081.001 Aug 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 060S-040E-16: L135 426 L2/1 A404 02 AMAFF03081.002 Jun 79 Humphrey, S.R. & D.B. Barbour Status & Habitats of 8 Endangered & Threatened Rodents in Fla. 059S-040E-26: L136 426 L1/11 A404 03 78 Layne, James N. FCREPA: Mammals (Vol. I) 064S-036E-02,03: L139 426 L5/1 A405 01 AMAJE02011.006 Jun 10 77 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16a,b,c A405 02 AMAJE02011.007 May 26 77 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16d,e A405 03 AMAJE02011.008 1977 Weiner, A.H. Hammocks Survey 066S-029E: L114 426 L9/16f I A405 04 AMAJE02011.009 Jun 21 77 Weiner, A.H. Hammocks Survey 066S-028E: L113 426 L9/21 A405 05 AMAJE02011.010 May 16 78 Weiner, A.H. Hammocks Survey 066S-028E: Little Knockemdown 426 L9/32 A405 06 AMAJE02011.012 Feb 11 82 Weiner, A.H. Hammocks Survey 066S-028E: LIlO 426 L9/38a,b A405 07 AMAJE02011.011 Feb 16 82 Weiner, A.H. Hammocks Survey 066S-030E: L117 426 L8/7 A405 08 AMAJE02011.005 Aug 15 77 Weiner, A.H. Hammocks Survey 066S-030E: L117 426 I L8/10 A405 09 AMAJE02011.004 Aug 1 77 Weiner, A.H. Hammocks Survey 066S-030E: L117 426 L8/9 A405 10 AMAJE02011.003 Aug 16 77 Weiner, A.H. Hammocks Survey 066S-030E: L117 426 L8/8 A405 11 AMAJE02011.002 Aug 6 77 Weiner, A.H. Hammocks Survey 066S-030E: L117 426 L8/6 A405 12 AMAJE02011.001 Jul 30 77 Weiner, A.H. Hammocks Survey 066S-030E: L117 426 L8/5 A501 01 ASGAS45011.001 80 Thompson, F.G. Final Report to USFWS on Stock Island Tree Snail, Orthalicus r. reses 067S-025E-27: L102 426, 740.1 I I I I I I I I I I ~~~A T TAC0H ME NT 2 I I I I I I -I I I __ - --- - ---- - - --- - - - - FISHES SPECIES NAME HABITAT RANGE LATIN NAME SLP THH OPW FRM SCM SMB FWW SGB B/B COR (COMMON NAME) 4111426 5006121620164016411645710 801 CODE I Menidia conchorum B Big Pine, Cudjoe, (Key Silverside) F F Key West A101 R R SLP:Slash pineland THH:Tropical hardwood hammock OPW:Open water FRM:Fringing mangrove SCM:Scrub mangrove SMB:Salt marsh-buttonwood association FWW:Freshwater wetland SGB:Seagrass bed B/B:Beach w/associated berm COR:Coral reef B:Breeding F:Feeding R:Resting *:Observations mapped +:Range mapped MONROE COUNTY PLANNING DEPARTMENT REPTILES SPECIES NAME HABITAT RANGE LATIN NAME SLP THH OPW FRM SCM SMB FWW SGB B/B COR (COMMON NAME) 411142615006121620|640641|645|710|801 CODE I Alligator mississippiensis I |B IB I Little Pine to Cudjoe (American Alligator) IF F F F I (inclusive) A201 I I I I I I I I I Caretta caretta caretta B Upper Matecumbe (Atlantic Loggerhead F F F (nesting), Lower Turtle) R Matecumbe (nesting), A202 all marine waters Chelonia mydas mydas B All marine waters (Atlantic Green Turtle) F F A203 R Crocodylus acutus B B Key Largo, Plantation, (American Crocodile) F F F Florida Bay, Little A204 + R R Pine to Big Pine (inclusive), Johnston, Sugarloaf Dermochelys coriacea All marine waters (Leatherback Turtle) F A205 R Diadophis punctatus acricus B ? No Name to Sugarloaf (Big Pine Ringneck Snake) F ? (inclusive) A206 * R ? Drymarchon corais couperi B B Key Largo, Plantation, (Eastern Indigo Snake) FF1 F1F2 F2 F2 F2 No Name to Sugarloaf A207 * R1 R1 (inclusive) [pan-Keys?] Eretmochelys imbricata B All marine waters imbricata F F F (Atlantic Hawksbill Turtle) R A208 ----- ----- ----- ---- ----- ----- ---- ----- ----- ---- ----- ----- - --- --- -- ----- ---- - ----- - - - - - - - - - --- - - - Kinosteron bauri bauri B Big Pine to Stock (Key Mud Turtle) F2 F2 F1 Island (inclusive) A209 * R2 R2 R1 Lepidochelys kempi All marine waters (Atlantic Ridley Turtle) F A210 R R Storeria dekayi victa B B Big Pine, No Name, (Florida Brown Snake) F F Sugarloaf Lower Keys population R R A211 * Tantilla oolitica B B I I I I I I I |Key Largo to Grassy Key (Miami Black-headed Snake) F1 F1 F2 F2 F2 (inclusive) A212 * R1 R1 R2 R2 R2 Thamnophis sauritus B B B B No Name to Cudjoe (Florida Ribbon Snake) F F F F (inclusive) Lower Keys population R R R R A213 * SLP:Slash pineland THH:Tropical hardwood hammock OPW:Open water FRM:Fringing mangrove SCM:Scrub mangrove SMB:Salt marsh-buttonwood association FWW:Freshwater wetland SGB:Seagrass bed B/B:Beach w/associated berm COR:Coral reef B:Breeding F:Feeding R:Resting *:Observations mapped +:Range mapped ___________________________________________________________________________________________ BIRDS SPECIES NAME HABITAT RANGE LATIN NAME SLP THH OPW FRM SCM SMB FWW SGB B/B COR (COMMON NAME) 41114261 5001612162016401641 64645710801 Charadrius alexadrinus B Middle Keys, Big Pine, tenuirostris F Florida Bay (Southeastern Snowy Plover) R A301 Columba leucocephala B Pan-keys (White-crowned Pigeon) F F A302 R R R Falco peregrinus Pan-keys (Peregrine Falcon) F F F F A303 R R Haliaeetus leucocephalus B B B B Little Pine to Key West (Bald Eagle) F2 F2 F1 F2 F2 F2 F2 F2 Florida Bay A304 R2 R1 R2 R2 Mycteria americana Key Largo, Florida Bay (Wood Stork) F F F F F F A305 R Pelecanus occidentalis B2 BI Pan-keys, Florida Bay, carolinensis F F Marquesas, Dry Tortugas (Eastern Brown Pelican) RI1 R R1 R2 A306 * Sterna albifrons B Pan-keys antillarium F (Least Tern) R A307 --- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - - -- -- -- B - Sterna dougalli dougallii B Crawl Key, Cocoplum (Roseate Tern) F Beach, islands off A308 R Seven-Mile Bridge, Key West Harbor, Dry Rocks, Dry Tortugas SLP:Slash pineland THH:Tropical hardwood hammock OPW:Open water FRM:Fringing mangrove SCM:Scrub mangrove SMB:Salt marsh-buttonwood association FWW:Freshwater wetland SGB:Seagrass bed B/B:Beach w/associated berm COR:Coral reef B:Breeding F:Feeding R:Resting *:Observations mapped +:Range mapped ___________________________________________________________________________________________ - ---I / I I m m- m m---------m-m MAMMALS SPECIES NAME HABITAT RANGE LATIN NAME SLP THH OPW FRM SCM SMB FWW SGB B/B COR (COMMON NAME) 4111426 50016121620 64016411645 7101801 CODE Neotoma floridana smalli B Upper Key Largo, Lignum (Key Largo Woodrat) F Vitae (introduced) A401 + R Odocoileus virginianus B Little Pine to clavium F F F F F F Sugarloaf (inclusive) (Key Deer) R R R R A402 + Oryzymus argentatus B B B B Little Pine to (Silver Rice Rat) F F F F Sugarloaf (inclusive) A403 * R R R R Peromyscus gossyupinus B Upper Key Largo allipaticola F (Key Largo Cotton Mouse) R A404 + Procyon lotor auspicatus B B Grassy Key to Cudjoe (Key Vaca Raccoon) F F F F F F F (inclusive) A405 * R R R R R R R Trichechus manatus B B Upper Keys, Florida Bay latirostris F F (West Indian Manatee) R R A406 + SLP:Slash pineland THH:Tropical hardwood hammock OPW:Open water FRM:Fringing mangrove SCM:Scrub mangrove SMB:Salt marsh-buttonwood association FWW:Freshwater wetland SGB:Seagrass bed B/B:Beach w/associated berm COR:Coral reef B:Breeding F:Feeding R:Resti.ng *:Observations mapped +:Range mapped ___________________________________________________________________________________________ -- -- - - -- -m- - --- INVERTEBRATES SPECIES NAME HABITAT RANGE LATIN NAME SLP THH OPW FRM SCM SMB FWW SGB B/B COR CODE Heraclides aristodemus B Upper Key Largo ponceanus F (Schaus' Swallowtail) R A502 + Orthalicus reses reses B Stock Island (Stock Island Tree Snail) F A501 * R SLP:Slash pineland THH:Tropical hardwood hammock OPW:Open water FRM:Fringing mangrove SCM;Scrub mangrove SMB:Salt marsh-buttonwood association FWW:Freshwater wetland SGB:Seagrass bed B/B:Beach w/associated berm COR:Coral reef B:Breeding F:Feeding R:Resting *:Observations mapped +:Range mapped ___________________________________________________________________________________________ I I I I I I I I I I A TT AC H ME NT 3 II I I I I I I BOARD OF COUNTY COMMISSIONERS CO~U NTY MONROE Wilhelmina Harvey, District 1 KEY WVEST, FLRDA 33040 MAYO Swiftenade, District 2 1305) 294 4641 EXt . 13 0MAOJerHrndzDsic3 Planning Department Alison Fahrer, District 4 5825 Jr. College Rd. West Mayor Pro tern Ken Sorensen, District 5 Key West, Fla. 33040 I ~August 25, 1983 E ~Mr. Gary Shaffer, Branch Office Manager Fla. Dept. of Environmental Regulation I ~11400 Overseas Highway, Suite 219 Marathon, Fla. 33050 3 ~Dear Mr. Shaffer: As you are aware, several government agencies have regulatory U ~jurisdiction over various aspects of dredging, filling and structural activities in the waters and wetlands of Monroe County. It is the feeling of this Department that the public and all the agencies could benefit from greater communication I ~and coordination. To this end, we would like to propose a first step towards greater coordination: specifically, that the local personnel of the agencies who are involved in the processing of permit applications meet on a regular basis. We think that one meeting a month would be a good start. We propose that a meeting be set up for the week of September 19-23 in order to discuss a schedule and format for future I ~meetings. Please contact the biologist in our Key West office, Mark Robertson (ext. 171), in order to arrange a meeting date 3 ~convenient for your staff. I hope that our proposal will benefit everyone involved. I look forward to your response. Sincerely, I effr o~yle, Ph.D. 3 Director I JD: cm cc: Mr. John Adams, U.S. Army Corps of Engineers Mr. Michael Silayton, U.S. Army Corps of Engineers I ~~Mr. Curtis Kruer, U.S. Army Corps of Engineers BOARD OF COUNTY COMMISSIONERS UNTY y MON ROE i Wilhelmina Harvey, District 1 KEY WEST, FLORMIDA 33040 Ed Swift, District 2 (305)294-464, Ext. 130 MAYOR Jerry Hernandez, District 3 Planning, Bldg. & Zoning Alison Fahrer, District 4 5825PJr.olange Bldg. Wet ZMayor Pro tern Ken Sorensen, District5 I ~5825 Jr. College Rd. West Key West, Fla. 33040 August 25, 1983 Mr. John Adams, Chief, Regulatory Division U.S. Army Corps of Engineers P.O. Box 4970 Jacksonville, Fla. 32232 Dear Mr. Adams: As you are aware, several government agencies have regulatory jurisdiction over various aspects of dredging, filling and structural activities in the waters and wetlands of Monroe County. It is the feeling of this Department that the public and all the agencies could benefit from greater communication and coordination. To this end, we would like to propose a first step towards greater coordination: specifically, that the local personnel of the agencies who are involved in the processing of permit applications meet on a regular basis. We think that one meeting a month would be a good start. We propose that a meeting be set up for the week of September 19-23 in order to discuss a schedule and format for future meetings. Please contact the biologist in our Key West office, Mark Robertson (ext. 171), in order to arrange a meeting date convenient for your staff. I hope that our proposal will benefit everyone involved. I look forward to your response. Sincerely, Jeffrey M. Doyle, Ph.D. Director JD:cm cc: Mr. Gary Shaffer, Fla. Dept. of Environmental Regulation Mr. Michael Slayton Mr. Curtis Kruer I I I I I I I I I I I I I I i I BOARD OF COUNTY Cf-MMISSIONERS OUNTY of MONIROE A1 Wilhelmina Harvey, District I KEY WEST, LFLOR'CIA 33040 . Ed Swift, District 2 ' : 051 294 4641 t MAYOR Jerry Harnandez, istrict 3 ..f *' *" ~ ~' '.. Alison Fahrer. District 4 Mvayor Pro tern Ken Srensen. District 5 July 7, 1984 Ms. Wendy U. Larsen Siemon, Larsen & Purdy 200 South Wacker Drive Suite 2110 Chicago, Illinois 60606 RE: Draft revisions to Chapter 18 of .Monroe County Code, "Trees and Vegetation." Dear Wendy: I am enclosing a copy of the proposed revisions to this ordinance that we discussed last week. For background, these revisions were prepared by Andy Hooten and myself as part of the County's FDER grant. We started with a revision from the Florida Keys Resource Planning and Management Committee, and then made further changes. We sent that draft to seventy individuals and organizations state-wide for review and comment. The reviewers represented a broad spectrum, including environmental advocacy groups, citizens' associations, attorneys representing primarily developers, and consulting firms. We received thirteen replies. These comments were incorporated into this final draft. Two points deserve special mention. First, we have had an ongoing debate about the advisability of a mangrove trimming ordinance. The County has received a number of applications to "trim" mangroves in order to provide a view of the water or increase breezes (cutting of wetland vegetation does not require ACOE or FDER permits). At present, the County's policy does not permit trimmming mangroves along natural shorelines, except for that which is required for water access (ie, around a dock). The logic behind this policy is that Chapter 4 of the Code specifies full protection for shoreline mangroves, and trimming would eliminate many of the functions that Chapter 4 is intended to protect (the "Coastal Zone Element" of the Comprehensive Plan also specifies a high degree of protection for shoreline mangroves). In addition, the County's new (1984) flood regulations specify no removal of mangroves that would Wendy U. Larsen, July 7, 1984. Page 2. increase the probability of flood damage. Finally, we envisioned a large enforcement problem associated with mangrove "trimming" permits. Our conclusion was that a separarce ordinance for mangrove trimming was not appropriate. We felt that the enclosed revisions to Chapter 18 world give the County sufficient criteria and guidelines to address applications for mangrove trimming; we have not explicity stated whether or not it is a "permittsble" activity. Second, I would like to mention that we prepared this revision prior to the County's current'program to totally revise all land use regulations. However, I think that there are a number of sections that are valuable in that they reflect our experience in the current permitting arena, and the input of a number of individuals. Please do not hesitate to call me if you have any questions or commments. Sincerely yours, -'/ /( 4/ '>2 X/c Mark L. Robertson, Biologist cc: Mr. Jerry Annas Mr. Charles Pattison, DCA FORMAT PROPOSED DELETIONS: [Words in brackets and underlined]. PROPOSED ADDITIONS: Words in boldface type. I~ ~ ~ ~~------------------ Ch. 18, Proposed Revisions; Page 1 Chapter 18 TREES AND VEGETATION Art. I. In General, && 18-1 - 18-15. Art. II. Land clearing, && 18-16 - 18-24. ARTICLE I. IN GENERAL Secs. 18-1 - 18-15. Reserved. ARTICLE II. LAND CLEARING Sec. 18-16. Definitions. As used in this article, the following terms shall have the meanings indicated in this section: COUNTY BIOLOGIST: A person employed by the Monroe County Building, Planning and Zoning Department in the capacity of "Biologist", as set forth in the job description of the County Personnel Section. For the purpose of enforcing this ordinance the county biologist shall be a code inspector as defined in Section 6-285 of this code of ordinances. DESTRUCTION OF VEGETATION means the removal of all or parts of vegetation by any means; specific actions which cause vegetation to die, including but not limited to damage inflicted upon the root system by heavy machinery or lethal substances; changing the natural grade above the root systems or around the trunks (specifically trees), damage inflicted on the vegetation permitting infection or pest infestation, application of herbicidal or other lethal chemicals, paving over the root system, or arson. DEVELOPMENT means the carrying out of any building operation or the making of any material change in the use or appearance of any structure, and for the purpose of this article, shall include: (1) The placement or construction of any structure on land; (2) The reconstruction, alteration of the size, or material change in the external appearance, of a structure on the land; (3) Alteration of a shore or bank of a seacoast, including any coastal construction as defined in section 161.021, Florida statutes, 1975; Ch. 18, Proposed Revisions; Page 2 (4) Demolition of a structure; (5) [Clearing of land or removal of any vegetation] Destruction of vegetation, as defined in this ordinance, or; (6) Deposit of refuse, solid or liquid waste, or fill on a parcel of land. LAND CLEARING PERMIT means a permit issued by Monroe County authorizing the destruction of vegetation, as defined in this ordinance. NO DESTRUCTION OF VEGETATION STATEMENT means a notarized statement signed by the property owner or his authorized agent stating that destruction of vegetation, as defined in this ordinance, shall not occur as a consequence of proposed development on the property. TROPICAL HARDWOOD HAMMOCK means a [characteristic combination] community of plant species repeated in numerous stands, which contain, [predominantly] but are not limited to, the following tree species: Pigeon Plum (Coccoloba diversifolia) Strangler Fig (Ficus aurea) Shortleaf Fig (Ficus citrifolia) Torchwood (Amyris elemifera) Wild Tamarind (Lysiloma latisiliqum) Jamaica Dogwood (Piscodia piscipula) Willow Bustic (Bumelia salicifolia) Black Ironwood (Krugiodendron ferreum) Lancewood (Nectandra coriacea) Gumbo Limbo (Bursea simaruba) Crabwood (Ateramnus lucidus) Poisonwood (Metopium toxiferum) Spanish stopper (Eugenia foetida) Wild Lime (Zanthoxylum fagara) Blolly (Guapira discolor) West Indian Mahogany (Swietenia mahagoni) Wild Dilly (Manilkara bahamensis) VEGETATION, for the purposes of this ordinance, means the following plants: (1) All plants with woody stems; (2) All shrubs, bushes, grasses and vines greater than 3 feet in height; or H ~~Ch. 18, Proposed Revisions; Page 3 I ~~~(3) All plants, no matter what size, that are listed as Endangered or Threatened under state or Federal laws; or are listed as Endangered or I ~~Threatened for Monroe County by the Florida Committee on Rare and Endangered Plants and Animals, as found in the most recent edition of "Rare and Endangered lBiota of Florida, Volume Five, Plants" MINOR LANDSCAPING MAINTENANCE means the care and trimming I ~~of: (1) Vegetation planted or propogated for landscaping purposes; or (2) Naturally occurring, individual plants and trees, or small isolated groups of vegetation maintained as landscaping on properties developed in conformance with Monroe County ordinances. Sec. 18-17. Purposes. The purposes of this article are to: 3 ~~~(1) To promote and encourage the protection of unique and biologically important natural resources, prevent the adverse effects to adjacent properties caused by the indiscriminate [clearing of land] destruction of vegetation, aid in the implementation of ot he r requirements for shoreline and [tree] plant protection, and minimize potential adverse impacts upon water quali ty. (2) To promote and encourage the protection and conservation of biologically unique vegetation (associations] communities known as tropical hardwood hammocks, protect certain rare or aesthetically desirable [tree] plant species found within these hammocks, provide performance oriented criteria for the protection of these tropical hammocks and specific (trees] plants in recognition of their importance and I ~~~contributions to the promotion of the health, safety and welf are of the community through carbon dioxide absorption, oxygen release, protection from storm I ~~winds, microclimate modi~fication, wind and surface drainage improvement and stabilization. (3) To protect the vegetation comprising the habitats I ~~of the native fauna of Monroe County, particularly those species listed as Endangered or Threatened by 3 ~~~State or Federal agencies. Ch. 18, Proposed Revisions; Page 4 H ~See. 18-17.5. Admininstration. The Zoning Official, as defined in this code of ordinances, I ~~shall be responsible for the administration of this chapter. Sec. 18-18. Land clearing permit - required, [exceptions]. (a) It shall be unlawful and an offense against the county for any person, either individually or through agents, employees or independent contractors, to [clear, by mechanical or any other means]I, cause the destruction of vegetation on any land or wetlands located within the unincorporated areas of the county I ~~~without having first applied for and obtained a land clearing permit from the building department of the county, subject to specific exemptions to this I ~~~requirement. [(b) A land clearing permit shall be required for the removal of all or parts of naturally occurring vegetation in the county.] [(c) Review and approval of development site plans I ~~~which results in the issuance of a development order shall constitute compliance with the requirements of this section. In such cases the land clearing permit will be issued in conduction with the building permit.] [(d) THIS SECTION SUBSTANTIALLY REVISED AND MOVED TO SECTION 18-19.1 [Sec. 18-19. Same - Application; field check, verification, 3 ~prerequisite to issuance.] [THIS SECTION DELETED AS CURRENTLY WRITTEN.] Sec. 18-19. Exemptions and undesirable plant species. (a) A land clearing permit shall not be required for: I ~~~~(1) Minor landscaping maintenance, as defined In this ordinance; 3 ~~~~(2) Minimal clearing of lines less than four (4) feet wide and not lower than one (1) foot above existing ground level for surveying conducted by a 3 ~~~~registered, professional land surveyor; Ch. 18, Proposed Revisions; Page 5 (3) Removal of trees or parts thereof which threaten to cause disruption of public or private utility services or threaten to pose a hazard in an emergency condition. (b) The following plant species are hereby declared to be undesirable plant species: Asiatic Colubrina (Colubrina asiatica) Australian pine (Casuarina equisitifolia, Casuarina lepidopholia), Brazilian pepper (Schinus terebinthifolius), Paper tree (Melaleuca quinquinervia). (1) The Building, Planning and Zoning Department shall waive the requirements and fees of this ordinance for the removal of these species, after the property owner has filed an application for a land clearing permit and the county biologist has made a written finding that the proposed destruction of vegetation will not significantly affect plant species other than the above-named undesirable plant species. (2) No person shall plant, propogate or sell these undesirable species in Monroe County. Sec. 18-20. An application for a land clearing permit filed with the building department shall be accompanied by a fee [of ten dollars ($10.00) for each individual site under one acre and twenty dollars ($20.00) for each individual site over one acre proposed for clearing] established by the Board of County Commissioners. Such fees are hereby declared to be necessary for the purpose of processing the application and making the necessary inspections for the administration and enforcement of this section. [Sec. 18-21. Same - Approval.] [THIS SECTION COMPLETELY DELETED AS CURRENTLY WRITTEN.] Sec. 18-21.1. Land clearing permit; procedures. (a) As a precondition to the application for or receiving of a building permit from the Building Department, the owner of a property shall apply to the Building Department for a land clearing permit, or shall file a "No Destruction of Vegetation Statement" with the Building Department. Ch. 18, Proposed Revisions; Page 6 I ~~(THIS ENTIRE PAGE IS A PROPOSED ADDITION) (b) A land clearing permit or "No Destruction of Vegetation Statement" shall not be required when applications for the following building permits are * ~~~filed: (1) Additions, renovations, improvements or alterations to existing single family residences, duplexes, mobile homes, and travel trailers. (c) The request for a land clearing permit shall be filed on an application form provided by the building department and shall include the following information: (1) The name and address of the owner of the land for which the land clearing permit is requested; (2) The name and address of the person that will * ~~~~physically clear the land; (3) A statement of the purpose(s) for which the I ~~~~land clearing permit is requested; (4) The legal description and street address, if any, of the land for which the permit is requested; (5) A map, drawn to scale, of the vegetative communities found on and adjacent to the site. I ~~~~The vegetation map shall identify the different vegetative communities, such as tropical hardwood hammock, mangroves, buttonwood, salt marsh, pinelands, freshwater wetlands. The map shall be accompanied by a descriptive narrative that lists the species of plants that are present in each vegetative community, by scientific names and common names, and specifically identifies any unusual or outstanding natural features of the site. On properties that are one-quarter (1/4) I ~~~acre or more In size, the vegetation map and accompanying narrative shall be prepared by a qualified person with a working knowledge of the I ~~~~flora and fauna of the Florida Keys. A natural vegetation list and names and addresses of individuals qualified to identify the native flora and fauna may be obtained from the the Monroe County Planning and Zoning Department. I ~Ch. 18, Proposed Revisions; Page 7 I ~(THIS ENTIRE PAGE IS A PROPOSED ADDITION) (6) An overall site plan, drawn to scale, of the I ~~~land for which the land clearing permit is requested, showing the areas to be cleared, the areas to be left uncleared, and any proposed structures or improvements. (d) The County Biologist shall conduct a site survey to verify the accuracy and completeness of the information supplied with the land clearing permit application. If the County Biologist determines that the application for a land clearing permit does not include the information required by this ordinance, the applicant shall be notified in writing of the deficiencies and there shall be no further review or processing of the application until the deficiencies have been corrected by the applicant. (e) (1) The Zoning Official shall review all -land clearing permit applications using the standards and criteria set forth in this ordinance. A written report or written recommendation by the County Biologist shall be part of the review by the Zoning Official. I ~~~~(2) The Zoning Official shall not issue any land clearing permits that are not consistent with the purposes, standards and criteria of this I ~~~~ordinance. The Zoning Official is empowered to require modifications to a land clearing permit application, including but not limited to relocation or restoration of vegetation, In order to insure compliance with the purposes, standards and criteria of this ordinance. (1) The decision to issue or deny a land clearing permit application shall be made by the Zoning Official within thirty (30) days of the date of receipt of said application, unless the application is deemed to be incomplete by the County Biologist. In that case, the decision by I ~~~~the Zoning Official shall be made within thirty (30) days of the date when the deficiencies are * ~~~~corrected. Ch. 18, Proposed Revisions; Page 8 3 ~~(THIS ENTIRE PAGE IS A PROPOSED ADDITION) (2) The Zoning Official's decision shall take one of three forms: land clearing permit is approved; I ~~~land clearing permit is approved subject to specific modifications or conditions; or land clearing permit is denied. In the case of a I ~~~~denial, the applicant shall be notified in writing of the reason(s) for the denial. (g) On sites where the proposed land clearing is for I ~~~development that requires building permits, the land clearing permit shall be issued only in conjunction * ~~~with the appropriate building permit. Sec. 18-21.5. Same; standards and criteria. 3 ~~~(a) Criteria. The Zoning Official shall authorize the issuance of a land clearing permit if one or more of the following conditions exists: 1 ~~~~(1) The vegetation is located in an area where a structure or improvements may be placed according to a plan that otherwise meets the standards and I ~~~~purposes of this ordinance, and other provisions of the County Code; and the vegetation cannot be relocated on or off the property because of age, species or size. (2) The vegetation is diseased, injured, in danger of falling, too close to existing or porposed structures, or creates unsafe vision clearance for vehicular traffic. 3 ~~~~(3) It is in the welfare of the general public that the vegetation be removed for reason(s) other than set forth above. I ~~~(b) Standards. The Zoning Official shall consider significant adverse Impacts in the following areas on the urban and natural environments, in reviewng a land clearing permit application: (1) Ground stabilization. Whether the proposed destruction of vegetation will substantially impact the ability of the vegetation to stabilize soils and control erosion. Ch. 18, Proposed Revisions; Page 9 I ~~(THIS ENTIRE PAGE IS A PROPOSED ADDITION) (2) Water quality and/or aquifer recharge. Whether the proposed destruction of vegetation I ~~~~will substantially lessen the natural assimilation of nutrients, chemical pollutants, heavy metals, silt and other noxious substances from ground and surface waters. (3) Ecological impacts. Whether the proposed destruction of vegetation will substantially lessen the balance and viability of surrounding biological communities through impacts upon functions such as microclimate modification, food I ~~~~chains or the ability to withstand natural or man-made stresses (eg, hurricances, fires, disease, salt spray, etc.). (4) Noise pollution. Whether the proposed destruction of vegetation will significantly increase ambient noise levels to the degree that a nuisance is anticipated to occur. (5) Storm protection. Whether the proposed I ~~~destruction of vegetation will significantly lessen the ability of the vegetation to decrease property damage or loss of life from tropical storms and hurricanes. (6) Air Quality. Whether the proposed destruction of vegetation will significantly I ~~~~lessen the natural cleansing of the atmosphere by vegetation through particulate matter interception, and the production of oxygen as a I ~~~~by-product of photosynthesis. (7) Wildlife habitat. Whether the proposed destruction of vegetation will significantly reduce available habitat for wildlife existence and reproduction, or result in the emigration of wildlife from adjacent or associated ecosystems. (8) Aesthetic degradation. Whether the proposed destruction of vegetation will have an adverse I ~~~~affect on the public interest in maintaining an aesthetically pleasing environment. Ch. 18, Proposed Revisions; Page 10 (THIS ENTIRE PAGE IS A PROPOSED ADDITION) (c) Standards for tropical hardwood hammocks. in all I ~~~cases where an application is made for a land clearing permit on a site vegetated by tropical hardwood hammock, as defined in this ordinance, the proposed plan or development shall incorporate the maximum I ~~~possible protect-ion of the tropical hardwood hammock. Protection of such tropical hardwood hammocks as intact areas shall be required in all development, as oppossed I ~~to the selective removal of individual plants, or destruction of understory vegetation, or removal of soil and roots. The spatial arrangement of proposed structures and other impervious surfaces shall reflect design considerations which provide maxiumum protection of tropical hardwood hammock communities. The Zoning Official shall not approve any land clearing I ~~permits on sites vegetated by tropical hardwood hammock, unless the proposed land clearing incorporates the maximum possible protection for such tropical hardwood hammock communities. Sec. 18-21.2. Same - expiration. (a) A land clearing permit shall expire and become null and void if work authorized by such permit is not commenced within thirty (30) days from the date of the I ~~~permit issuance or if such work, when commenced, is suspended or abandoned at any time for a period of ninety (90) days. (b If the work covered by the land clearing permit has not commenced or has been commenced and been suspended or abandoned, the Zoning Official may extend such permit for a single period of sixty (60) days from the date of expiration of the initial permit, if the request for extension is made prior to the expiration date of the initial permit. (c) If the work covered by the permit has commenced, is in progress, has not been completed and is being carried on progressively In a substantial manner, the permit shall be In effect until completion of the job. I ~~~(d) If work has commenced and the permit becomes null and void or expires because of lack of progress or abandonment, a new permit covering the proposed I ~~destruction of vegetation shall be applied for and obtained before proceeding with the work. Ch. 18, Proposed Revisions; Page 11 Sec. 18-22. Notification o f completion o f clearing; certificate of completion. I~~~~ (a) Within [f orty-eight (48) hours] two (2) working days after the work [contemplated under] authorized by the land clearing permit [required by section 18-18] I ~~~has been completed, the holder of the permit shall notify the building department of such completion, after which the county biologist shall [again field check] conduct a survey of the clearing site. If no violations of the land clearing permit have occurred, the [Building Department) Zoning Official shall issue a certificate of completion to the holder of the permit. If violations of the permit have occurred, a certificate of completion [will] shall not be issued until the site has been restored with native Keys flora I ~~~[or other appropriate vegetation] as outlined in a restoration plan approved by the [Building, Planning and Zoning Department] Zoning Official. No further activity of any nature shall commence on the land that is the subject matter of the land 'clearing permit untilI such certificate has been issued. I ~~(b) A certificate of occupancy, as described in Section 6-38 of this code of ordinances, shall not be issued for any building on a site which is subject to a I ~~~land clearing permit, until a certificate of completion has been issued by the Zoning Official. [See. 18-23. Tree protection.] [THIS SECTION COMPLETELY DELETED AND REPLACED AS FOLLOWS.] Sec. 18-23. Plant protection. To the maximum extent, individuals of species listed as Endangered or Threatened by State or Federal agencies, or by the Florida Committee on Rare and Endangered Plants and Animals as found In the most recent edition of "Rare and Endangered Biota of Florida, Volume Five, Plants", shall be protected, whether they occur naturally or have been 5 ~Dimensional variances from lot setback lines may be granted by the board of adjustment to protect threatened or endangered plants, and to otherwise enhance the purposes and 3 ~intent of this article. Ch. 18, Proposed Revisions; Page 12 U ~~See. 18-24. Scope of this article. This article shall not apply to any municipality located in I ~~the county. [Sec. 18-25. Penalties.) [THIS SECTION DELETED AND REPLACED AS FOLLOWS.] 5 ~Sec. 18-25. Penalties. Upon conviction in court, a violator of any provision hereof shall be subject to a fine not to exceed five hundred I ~dollars ($500.00) or imprisonment in the county jail for a period not to exceed sixty (60) days, or by both such fine and imprisonment, in the discretion of the court; and each I ~~plant, bush and tree cut down, destroyed, removed or moved shall constitute a separate offence. In addition to the fine, the violator shall be required to restore the site with native Keys vegetation as outlined in a restoration plan approved by the Zoning Official. 3 ~See. 18-26. Civil remedies. in addition to any other remedies provided by this article the county shall have the following judicial remedies available for violations of this article or any permit issued under this article. (a) The county may institute a civil action in a court of competent jurisdiction to establish liability and to recover damages for any injury caused by the destruction of vegetation in contravention of the terms of this article. (b) The county may institute a civil action in a court of competent jurisdiction to impose and recover a civil penalty for each violation in an amount of not more than five thousand dollars ($5,000.00) per offense. However, the court may receive evidence in mitigation. I ~~Each tree, bush or other plant unlawfully removed or destroyed under the provisions of this article shall constitute a separate offense hereunder. (c) The county may institute a civil action in a court of competent jurisdiction to enforce compliance with this article, to enjoin any violation hereof, and to seek injunctive relief to prevent irreparable injury to vegetation or properties encompassed by the terms of 5 ~~~this article. I I I I I I I I I A T T A C H M E N T 5 I I I I I I I I l DRAFT - Sept. 7, 1984. Page 1 . VEGETATION AND NATURAL FEATURES: DEFINITIONS AND BACKGROUND MONROE COUNTY PLANNING DEPARTMENT ------------------------------------------------------ The following vegetation types and natural features have been mapped: CODE NAME 411 Slash Pineland 426 Tropical Hardwood Hammock 500 Open Water 612 Fringing Mangroves 620 Scrub Mangroves 640 Salt Marsh and Buttonwood Associations 641 Freshwater Wetlands 710 Beach with Associated Berm 740.0 Disturbed (Bare/Vegetation Unknown) 740.1 Disturbed with Hammock 740.2 Disturbed with Mangrove 740.3 Disturbed with Salt Marsh and Buttonwood 740.4 Disturbed Beach/Berm 740.5 Disturbed with Exotics 740.6 Disturbed with Slash Pine The definitions of these mapping units follow. __________________________________ Slash Pineland (411). This is an upland forest community with an open canopy dominated by the native slash pine, Pinus elliottii var. densa. Plant species that are commonly present include (but are not limited to): Byrsonima cuneata Locust Berry Cassytha filiformis Love vine Coccothrinax argentata Silver Palm Crossopetalum ilicifolium Christmas Berry Croton linearis Pineland Croton Morinda royoc Yellow Root Pinus elliottii Slash Pine Randia aculeata White Indigo Berry Thrinax morrissii Keys Thatch Palm Sorghastrum secundum Indian grass. DRAFT - Sept. 7, 1984. Page 2 Slash pinelands are a fire climax community; that is, in the absence of fires they will be replaced by tropical hardwood hammock (map code 426). This is a gradual process that can complicate the distinction between slash pinelands and tropical hoardwood hammock. The separation of these two communities should be made on the basis of dominance by plants that are characteristic of one or the other community. Slash pinelands occur only in the Lower Keys. Tropical Hardwood Hammock (426). This is an upland, hardwood forest community that is characterized by a number of West Indian tree species. This community may contain (but is not limited to) the following species: Amyris elemifera Torchwood Ateramnus lucidus Crabwood Bumelia salicifolia Willow Bustic Bursera simaruba Gumbo Limbo Coccoloba diversifolia Pigeon Plum Eugenia foetida Spanish Stopper Ficus aurea Strangler Fig Ficus citrifolia Shortleaf Fig 3uapira discolor Blolly Krugiodendron ferreum Black Ironwood Lysiloma latisiliquum Wild Tamarind Metopium toxiferum Poisonwood Nectandra coriacea Lancewood Piscidia piscipula Jamaica Dogwood Swietenia mahagoni West Indian Mahohany Zanthoxylum fagara Wild Lime. Tropical hardwood hammocks are found throughout the Florida Keys. The appearance and species mix varies widely among the hammocks of the Keys. Open Water (500). These are areas of open water with no discernible emergent vegetation. This category includes "salt ponds", which are shallow, enclosed basins with very restricted tidal influence and generally having extremely variable salinity and temperature regimes (Coastal Coordinating Council, 1974). DRAFT - Sept. 7, 1984. Page 3 The maps show two types of mangrove communities: fringing mangroves (map code 612) and scrub mangroves (map code 620). The definitions of these communities follow. Fringing Mangroves (612). These are wetland communities subject to tidal influence, where the vegetation is dominated by three species of mangroves, specifically: Avicennia germinans Black mangrove Laguncularia racemosa White mangrove Rhizophora mangle Red mangrove. Other vascular plant species that may be present include (but are not limited to): Batis maritima Saltwort Lycium carolinianum Christmas Berry Monanthochloe littoralis Key grass Salicornia spp. Glasswort Sesuvium portulacastrum Sea Purslane Sporobolus virginicus Dropseed Suaeda linearis Sea Blite. In general, the trees in fringing mangrove communities have crowns that are sufficiently dense and close-spaced so as to present a closed canopy. In addition, the trees are generally greater than 1.5 meters (4.9 feet) in height (Lugo and Snedaker, 1974). Scrub Mangroves (620). These are wetland communities subject to tidal influence, where the vegetation is dominated by the same three species of mangroves found in fringing mangrove communities. Other vascular plants, such as those listed for fringing mangrove communities, may also be present in scrub mangrove communities. Scrub mangroves are distinguished from fringing mangroves by two characters. First, scrub mangroves are generally smaller; on the average they are less than 1.5 meters (4.9 feet) in height (Lugo and Snedaker, 1974). Second, scrub mangroves do not, on the average, have dense, closely spaced crowns that result in a closed canopy. In some scrub mangrove areas there may be isolated clumps of mangroves more properly classified as fringing mangroves, which probably occur as a result of edaphic (i.e., soil) conditions. These clumps are, in many cases, mapped as part of the surrounding scrub mangrove zone due to the overall character of the area and their small area relative to the scale of the maps. DRAFT - Sept. 7, 1984. Page 4 The most widely used classification system for mangroves is that developed by Lugo and Snedaker (1975), and further described by Odum et al. (1982). The two types of mangrove communities mapped by Monroe County correspond, in general, to Lugo and Snedaker's classifications as follows. Lugo & Snedaker (1974) Monroe County Maps Fringe Forest Fringing Mangroves (612) Riverine Forest " " " Overwash Forest " " " Basin Forest* " " " Dwarf Forest Scrub Mangroves (620) * - Not well represented in the Florida Keys. In both types of mangrove communities there may be areas of open water that have been mapped as part of the mangroves. This is due to either the small size of the water body, or that the overall coverage of mangroves is greater that forty percent (40%) throughout the area (Environmental Effects Laboratory, U.S. Army Corps of Engineers, 1978). Fringing mangroves and scrub mangroves are found throughout the Keys. However, scrub mangroves are more common in the Lower Keys than in the Middle and Upper Keys. Salt Marsh and Buttonwood Associations (640). This mapping unit encompasses two plant associations that are sometimes collectively or individually referred to as the "transitional zone." The salt marsh community is a wetland area subject to tidal influence where the vegetation is dominated by non-woody groundcovers and grasses. The salt marsh is usually present in the more waterward portion of this mapping unit. The vegetation may include (but is not limited to) the following non-woody species: Batis maritima Saltwort Distichilis spicata Salt grass Fimbristylis castanea Chestnut sedge Monanthocloe littoralis Key grass Salicornia spp. Glasswort Sesuvium portulacastrum Sea purslane Spartina spp. Cordgrass Fimbristylis castanea Chestnut sedge. DRAFT - Sept. 7, 1984. Page 5 Woody vegetation that may be present includes the three species of mangroves, as well as buttonwood (Conocarpus erectus). However, the salt marsh community is distinguished by the dominance of non-woody plants, the woody species have a coverage of less than forty percent (40%; Environmental Effects Laboratory, U.S. Army Corps of Engineers, 1978). The salt marsh community may be associated and intermixed with areas of almost bare ground, where the vegetation may be limited to mats of periphyton (i e., algae). These areas, which are also known as "saltwater coastal flats", "salt flats" or "salt barrens" (Environmental Effects Laboratory, U.S. Army Corps of Engineers, 1978) have generally been included in this mapping unit (map code 640) on the Monroe County maps. The buttonwood association is the second plant association that is part of this mapping unit (map code 640). This association is usually present in the more landward zone of this mapping unit, and may intermix with more upland communities. Depending on the relatve dominance of plant species and other factors, the entire buttonwood association or a portion thereof may be classified as wetlands under State and Federal regulations. The vegetation may include (but is not limited to) the following species: Borrichia spp. Sea oxeye daisy Bumelia celastrina Saffron plum Coccoloba uvifera Sea grape Conocarpus erectus Buttonwood Zrithalis fruticosa Black torch Fimbristylis castanea Chestnut sedge Jacquinia keyensis Joewood Lycium carolinianum Christmas berry Maytenus phyllanthoides Mayten Spartina spp. Cordgrass. The buttonwood association is distinguished from the salt marsh association by the dominance of buttonwood trees, usually occuring as an open stand that permits the growth of an understory of groundcovers and shrubs. The buttonwood association is, in turn, distinguished from more upland communities by the presence of grasses and fleshy, halophytic groundcovers under its open canopy, and generally by the lack of an appreciable layer of humus and leaf litter. Salt marsh and buttonwood associations are found throughout the Florida Keys. I DRAFT - Sept. 7, 1984. Page 6 Freshwater wetlands (641). These are wetland areas with either standing water or saturated soil, or both; where the water is either fresh or of very low salinity. The vegetation is characterized (but not limited to) the following species, which are capable of growth and reproduction in saturated soil conditions: Cladium jamaicensis Saw grass Conocarpus erectus Buttonwood Eleocharis celluosa Spike rush Laguncularia racemosa White mangrove Rhizophora mangle Red mangrove Typha spp. Cattail. Freshwater wetlands are found only in the Lower Keys. It should be noted that some of the freshwater wetlands are one (1) acre or less in size, and thus are too small to appear on these maps. This is particularly true of cattail marshes. Many of these smaller areas occur in tropical hardwood hammocks or pinelands. Beach with Associated Berm (710). This mapping unit is distinguished by its geomorphological characteristics rather than its vegetation. A beach is an area of bare, unvegetated sand along a shoreline. A berm is a mound or ridge of unconsolidated sand that is immediately landward of, and usually parallel to, the shoreline and beach. A berm is higher in elevation than both the beach and the area landward of the berm. In the Florida Keys, the sand is calcareous material that is the remains of marine organisms such as corals, algae, molluscs, etc. In some locations there are berms without a beach being present along the shoreline. Instead, there is a narrow band of fringing mangroves along the waterward edge of the berm. These areas are mapped as Beach with Associated Berm (map code 710), as the mangrove fringe is too narrow to be distinguished on these maps. The height and width of berms in the Keys is highly variable. They may range in height from slightly above mean high water to more than seven (7) feet above mean sea level. The width of berms in the Keys varies from tens of feet to more than 200 feet. The vegetation on berms, which is dependent on their elevation and width, is also highly variable. There may be only groundcovers such as sea oats (Uniola paniculata), cordgrass (Spartina spp.), Keys spider lily (Hymenocallis latifolia) and various wetland groundcovers. Other berms may support tropical hardwood hammock vegetation. On the wider berms various plant associations may exist as bands running generally parallel to the shoreline. I DRAFT -Sept. 7, 1984. Page 7 Within some fringing mangrove forests along open water shorelines there are very low and narrow storm berms that are vegetated exclusively by I mangroves and associated wetland vegetation. Because of their small size and enclosure by the mangrove forest, these features are mapped as mangroves rather than berms. I Beaches and berms occur from Upper Matecumbe Key through the Lower Keys. I~~~~~------------------- Disturbed (Bare/Vegetation Unknown - 740.0). These are areas that I have been disturbed by human activities (e.g., deposition of fill) land clearing) on which there are large areas of bare substrate, or where the site is obviously disturbed but the vegetation could not be determined by ground-truthing because the site was not accessible to County personnel. This mapping unit also includes disturbed areas where a groundcover of grasses is maintained by mowing. I~~~~~------------------- Disturbed with Hammock (740.1). These are areas that have been disturbed by human activities, on which the vegetation is dominated by tropical hardwood hammock, as described earlier. The vegetation may either be a remnant of the vegetation that existed prior to the disturbance, or has colonized the site after the disturbance. Examples of these areas are sites that have been partially or completely cleared and the vegetation is pioneering hammock, or hammock areas which have * been extensively divided by roadways for a subdivision. �------------------ 3 ~~Disturbed with Mangrove (740.2). These are areas that have been disturbed by human activities, on which the vegetation is dominated by mangrove communities, as described earlier. The vegetation may be e ither a remnant of what existed prior to the disturbance or has recolonized the site after the disturbance. An example of such an area would be a mangrove community that was impounded by fill and cut off 3from tidal flow, and the mangroves have suffered a noticeable decline. ------------------- DRAFT - Sept. 7, 1984. Page 8 . Disturbed with Salt Marsh and Buttonwood (740.3). These are areas that have been disturbed by human activities, on which the vegetation is dominated by salt marsh and buttonwood associations, as described earlier. The vegetation may be either a remnant of what existed prior to the disturbance, or has colonized the site after the disturbance. An example of such an area would be a wetland site that had been filled, and the vegetation that regrew on the fill is dominated by salt marsh and buttonwood species, due to either the salt content of the fill, its low elevation relative to tides or other factors. Disturbed Beach/Berm (740.4). These are beaches or berms that have been disturbed by human activities. Possible disturbances include bulkheading, deposition of limerock fill, excavation or introduction of non-native plants such as Australian pine (Casuarina spp.) and Brazilian pepper (Schinus terebinthifolius) that now dominate the site. Disturbed with Exotics (740.5). These are areas that have been disturbed by human activities where the vegetation is now dominated by exotic (i.e., non-native) plant species such as Australian pine (Casuarina spp.) or Brazilian pepper (Schnius terebinthifolius). Disturbed with Slash Pine (740.6). These are areas that have been disturbed by human activities (e.g., partial or complete land clearing) where the vegetation is dominated by slash pineland species, as described earlier. The vegetation may be either a remnant of what existed prior to the disturbance, or has recolonized the site after the disturbance. I DRAFT - Sept. 7, 1984. Page 9 I ~~~~BACKGROUND OF MONROE COUNTY VEGETATION MAPPING The vegetation mapping program utilized two pre-existing sets of I vegetation maps as its data sources: 1) The Florida Keys Hardwood Hammock Atlas, developed in 1977 as part of a project sponsored by the Florida Cooperative Extension Service and the National Audubon Society; 2) Vegetation base maps for the Florida Keys Coastal Zone I Management Study, developed in 1974 by the Florida Coastal Coordinating Council. Both of these map sets were drawn at a scale of 1"=2,OOO', which is the I same scale as the County's land use base maps. Because both of these map sets are somewhat outdated with regards to development, the current extent of developed lands was taken from more recent maps from the Department of Community Affairs, also drawn at the 3 same scale (1"=2,o0O'). The resulting maps of vegetation and natural features were extensively Ichecked and revised by the Planning Department's biologists, who are familiar with the vegetation in many areas of the Keys as a result of work experience. Available aerial photography (black and white, 1"=bOO', Real Estate Data, Inc.) was also used as another source of Einformation. A program of ground-truthing was conducted throughout the Keys by the I biologists in order to visit a number of areas where the vegetation appeared to be In error on the original data maps and could not be resolved from available aerial photography. DRAFT - Sept. 7, 1984. Page 10 REFERENCES Environmental Effects Laboratory. 1978. Preliminary Guide to Wetlands of Peninsular Florida - Major Associations and Communities Identified. U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss. Technical report Y-78-2. 66 pages (plus appendices). Florida Coastal Coordinating Council. 1974. Florida Keys Coastal Zone Management Study. Fla. Dept. of Natural Resources. Tallahassee, Florida. 138 pages. Lugo, A.E. and S.C. Snedaker. 1974. The Ecology of Mangroves. Annual Review of Ecology and Systematics. 5:39-64. Odum, W.E., C.C. McIvor and T.J. Smith, III. 1982. The Ecology of the Mangroves of South Florida: A Community Profile. U.S. Fish and Wildlife Service, Office of Biological Services, Washington, D.C. FWS/OBS-81/24. 144 pages. I I I I I I I I I I ~~~A TT A CH ME NT 6 I I I I I I I I I, MON-TITLE #7sce 09/29 TENTATIVE DRAFT NO. 1 FLORIDA KEYS GROWTH MANAGEMENT PLAN Background Data Elements SIEMON, LARSEN & PURDY CHARLES L. SIEMON, Project Manager 200 South Wacker Drive Chicago, Illinois 60606 (312) 876-1560 LANE KENDIG, INC. LANE KENDIG, Principal 472 Killarney Pass Mundelein, Illinois 60060 Thomas Patton Barton-Aschman Ham-ner, Siler, & Associates & Associates George & Associates P. 0. Box 12692 2901 W. Busch Blvd. 1111 Bonifant Street Gainesville, Florida Suite 1010 Silver Spring, Tampa, Florida 33416 Maryland 20910 MON-1 #8sce 09/29 TENTATIVE DRAFT NO. I DRAFT BACKGROUND DATA ELEMENTS OF A GROWIT MANAGEMENT PLAN FOR THE FLORIDA KEYS THIS DOCUMENT CONTAINS A SERIES OF BACKGROUND DATA ELEMENTS PREPARED BY THE MONROE COUNTY PLANNING STAFF AND THE COUNTY' S GROWTH MANAGEMENT CONSULTANTS. THE WORKING TABLE OF CONTENTS FOR THE PROPOSED IS INCLUDED; HOWEVER, ONLY THOSE ELEMENTS SET OUT IN ALL CAPS AND BOLD TYPE ARE INCLUDED IN THIS DRAFT. THE DATA IS BEING PUBLISHED IN DRAFT FORM IN ORDER THAT ITS ACCURACY CAN BE CONFIRMED OR CORRECTED THROUGH PUBLIC INPUT AND PARTICIPATION. A SERIES OF PUBLIC WORKSHOPS WILL BE CONDUCTED ON SEPTEMBER 18, 19 AND 20 AT PLANTATION KEY, MARATHON AND KEY WEST RESPECTIVELY. CORRECTIONS, QUESTIONS OR CONCERNS SHOULD BE DIRECTED TO: Mr. Ty Symroski, Acting Senior Planner Monroe County Growth Management Plan Project Team 2nd Floor Old Administration Building Truman Annex City of Key West, Florida 33040 (305) 294-9614; or Mr. Charles L. Siemon Growth Management Plan Project Manager Siemon, Larsen & Purdy 200 South Wacker Drive Chicago, Illinois 60606 (312) 876-1560 MON-I #9sce 10/01 FLORIDA KEYS GROWTH MANAGEMENT PLAN LAND USE TABLE OF CONTENTS VOLUME 1* PAGE CHAPTER I. THE ENVIRONMENT A. NATURAL ENVIRONMENT. (1) GEOMORPHOLOGICAL AND CLIMATE OVERVIEW OF THE FLORIDA 1 (2) CORAL REEFS (3) SEAGRASS ECOSYSTEM 34 (4) MANGROVES 40 (5) TRANSITIONAL HABITATS 47 (6) SALT PONDS; 54 (7) BEACHES AND BERMS 58 (8) TROPICAL HARDWOOD HAMMOCKS 66 (9) PINELANDS 73 (10) FRESHWATER WETLANDS 78 (11) PLANT AND ANIMAL SPECIES OF SPECIAL STATUS 81 (12) EVALUATION AND RANKING OF FLORIDA KEYS HABITATS 85 REFERENCES 97 B. BUILT ENVIRONMENT. (1) Existing land use; (a) existing uses; (b) intensity; (c) subdivisions (d) COMMUNITY CH-ARACTER. (e) PLANNING AREAS (f) EXISTING COMMUNITY CHARACTER * NOTE: This is a working Table of Contents for the land use volume of the Florida Keys Growth Management Plan. Only those portions which are indicated in bold and capitals are included in this draft. MON-I #8sce 09/29 (2) TRANSPORTATION; (a) ROADS; (b) AIRPORTS; AND (c) MARINAS. (3) POTABLE WATER; (4) WASTEWATER TREATMENT; (5) SOLID WASTE MANAGEMENT; (6) ELECTRICAL; (7) POLICE; (8) FIRE & EMS; (9) MEDICAL SERVICES; (10) SCHaOLS; (11) LIBRARIES; (12) HURRICANE PROTECTION; (13) PARKS AND WILDLIFE REFUGES; (14) GENERAL GOVERNMENTAL SERVICES; (15) MILITARY FACILITIES; (16) HISTORIC RESOURCES C. POPULATION AND GROWTH TRENDS. (1) POPULATION (a) POPULATION (b) MILITARY - RELATED POPULATION (c) NON-MILITARY POPULATION (d) SEASONAL POPULATION (e) PEAK (f) POPULATION BY COUNTY SUBAREA (2) HOUSING (a) HOUSEHOLD TRENDS AND PROJECTIONS (b) 1-HOUSING DEMAND (i) CHARACTERISTICS OF THE EXISTING STOCK (ii) STRUCTURE TYPE (iii) TENURE (iv) VACANCY RATES (v) DISTRIBUTION BY COUNTY SUBAREA (vi) PROJECTED DEMAND (v i i) DEMAND BY STRUCTURE TYPE (3) EMPLOYMENT AND COMMERCIAL DEVELOPMENT (a) EMPLOYMENT (b) TOURISM (c) U.S. NAVAL BASE KEY WEST (d) MARINE INDUSTRIES (e) EMPLOYMENT PROJECTIONS MON-I #Ssce 09/29 (f) COERCIAL DEMAND (g) HOTEL ROOMS (h) CAMPGROUND SPACES D. ECONOMICS. (1) Existing conditions (a) income levels; (b) income sources; (c) real estate transactions; (i) type of product; (ii) per unit value; aa) single-family residential bb) multi-family residential cc) hotel/resort dd) commercial, and ee) industrial; and (iii) purchaser identification. aa) ages bb) household character, and cc) existing or prior residency; and (d) Public revenues; (2) Trends; (a) income levels; (b) income sources; (c) real estate transactions: (i) type of product; (ii) per unit value; aa) single-family residential bb) multi-family residential cc) hotel/resort dd) commercial, and ee) industrial; and (d) public revenues. (3) Forecast: (a) income levels; (b) income sources; (c) real estate transactions: MON-I #8sce 09/29 (i) type of product; (ii) per unit value: aa) single-family bb) multi-family cc) hotel/resort dd) corrmnercial, and ee) industrial; and (iii) purchaser identification. aa) ages bb) household character, and cc) existing or prior residency; and (d) public revenues. CHAPTER II. POLICIES A. Environmental Protection 1. Coastal waters 2. Wetlands a. Tidal b. Perched c. Disturbed 3. Upland Vegetation a. Hammocks b. Cactus Hamocks c. Pinelands d. Disturbed Harrmocks 4. Threatened and endangered species a. Plants b. Animals B. Comunity Character 1. Tourist economy 2. Tropical image 3. Natural character 4. Native densities 5. Building character a. height b. scale c. mass d. materials - iv- IMON-I #8sce 09/29 d. materials e. bulk 6. Landscaping 7. Open space 8. Scenic vistas C. Adequate Facilities 1. Potable water 2. Wastewater treatment 3. Roads 4. Parks 5. Public safety D. Employment E. Housing Chapter III. IMPLEMENTING REGULATIONS Article 1. Purpose and Applicability Article 2. Definitions and Rules of Interpretation Article 3. Decisionmaking and Administrative Bodies Article 4. Planning Documents and Official Map Sec. 4-101 Comprehensive Plan Sec. 4-102 Capital Improvements Program Sec. 4-103 Land Use Designation Map Article 5. Development Review Division I. General Division 2. Development Permitted as of Right Division 3. Conditional Uses Division 4. Impact Analysis 1. Procedure a. application b. contents c. certification 2. General Standards 3. Limitations Article 6. Variances to the Plan and Map, and Appeals Article 7. Plat Approval Article 8. Nonconformities Article 9. Vested Rights v I MON-1 #8sce 09/29 Article 10. Use Categories Article 11. Density Options 1. Urban 2. Sub-urban 3. Sparsely settled 4. Native Article 12. Development Standards 1. Urban 2. Sub-urban 3. Sparsely Settled 4. Native Article 13. Development Right Allocations 1. Tidal wetlands 2. Perched wetlands 3. Harrmock 4. Scarified land 5. Improved land Article 14. Use of Development Rights Article 15. Development Monitoring 1. Building permits 2. Inspections 3. Certificates of Occupancy - vi I-A-1-3 #6sce 09/30 I. THE ENVIRONMENT A. NATURAL ENVIRONMENT (I) GECMORPHOLOGICAL AND CLIMATIC OVERVIEW OF THE FLORIDA KEYS Discovered by Ponce de Leon on May 12, 1513, the Keys have always fascinated those who have come in contact with them. Lying along the New World trade routes and blessed with a semi-tropical climate, their history has been intimately tied to the ocean from which they arose. The Florida Keys proper are an elongate, arcuate chain of low lying islands over 220 miles in length, extending from the southeastern tip of the Florida Peninsula, more properly called the Florida Plateau or Florida Platform. They extend from Soldier Key at the northernmost end of the chain, to the Dry Tortugas to the south and west at the other end. They are bounded by the Straits of Florida on the Atlantic side and sepa- rated from the mainland by Biscayne Bay, Barnes Sound, Blackwater Sound and Florida Bay (White, 1970; Brooks, 1982). Physiographically, the Keys belong to what has been called the Southern Zone of the Coastal Lowlands by the Florida Geological Survey (See Figure 1), also referred to as the Gold Coast and Florida Bay (Brooks, 1982). This area lies south and southeast of Lake Okeechobee, is primarily underlain by Pleisto- cene limestones and is characterized by low relief, poor drainage and extensive areas of coastal mangrove swamps (See Figure 2) (Brooks, 1982). The highest point in the Keys, only 18 feet above sea level, lies on Windley Key. Because of its generally low ele- vation, mostly less than 5 feet above sea level, most of the islands are bordered by mangrove swamps, particularly on the lower energy Florida platform side. Sandy beaches are less com- mon and are mostly restricted to the higher energy beaches on the Atlantic side of the larger islands. All told, mangroves cover nearly half of the total area of the Keys (Hoffmeister, 1974). Geologically and physiographically, the Florida Keys can be div- ided into three main areas: the Coral Reef Keys, more corrmonly known as the Upper Keys; the Oolitic Keys, better known as the Lower Keys; and, some 50 miles to the west, the Dry Tortugas (White, 1970). Miami Beach, Virginia Key and Key Biscayne are barrier islands which receive their sediment supply from the mainland. Being geologically different, they are not considered part of the Florida Keys (Brooks, 1982). I-A-1-3 #4col 9/7/84 Figure I: PH)YSIOGRAPHIC DIVISIONS OF THE FLORIDA PENINSULA TIDE. FLORIDA GEOGRAPHICAL SURVEY. II ALABAM~ MARIJANNA LOWLANDS NORTHe 6 EG0 GEO I A I .9~~j C04S~~jlvc LLED 1-~~~~~~~~7 0 .. I~. C, O ;t~~~-x cis I IO i I; TAMPA SOUTHERN ZONE I~~~~~~~~~~~~~~~~~~~~~M~~ 2 - I. I %. - - - - C I~~~~~t)Sc-PIP I~~~~ ,~� pE I ~~ ~ .� I -2- ~ SUTER I~~~~~~~~~~~~~I_ I-A-1-3 #4coI 9/7/84 Figure 2: PHYSIOGRAPHIC DIVISION IN I , ~ ~~~SOUTH FLORIDA REPRODUCED FROMv BROOKS, 1982. PY1GAeDIVIIN RI a - Sir" ATL^-Ar= BA~I 2-a 5 Selvap- Bicsf- Man ~sh D A 0 2c3Sttark River R14e- ou"d SI2dh 2 d Tda% Thouts-,rt Tz k;rhts I 2~I Cbral Rc4 Kf-s 2 2c-2 Ocd~fit emi * 2eA Florida 8ay 2 -- Am AEA 3' -Sawn w s-r*p.PN FLATWOO) . 1C4 *~~~~~~~~~~~~~~~~~~~~~~~~--- - -- -- V~~e3 e2- :76-~ ~ ~~0 ------------ ------ ----- --------------~ ~ ~ ~ ~ ~~~* I-A-1-3 #6sce 09/30 I ~The Upper Keys As their other name impl ies , the Coral Reef IKeys are a I ~linear chain of islands made up primarily of limestone coral rock. The main axis of the islands lies parallel to the axis of the chain. They extend f rom Soldier Key to the North, to the lower (southern) end of the Big Pine Key. On their seaward side lies a well developed reef tract composed of an outer fringe reef which borders the inner edge of the narrow continental shelf that averages a mere 4 miles in width. Between the Keys and this I ~relatively continuous outer fringe reef, shallower banks and deeper channels dotted with patch reefs run parallel to the is- lands. These living reefs, unique in the United States, are best I ~developed in the Upper Keys area. Because corals are exceedingly sensitive to turbidity, their development is favored by the long orientation of the islands and the limited number of channels between them. This particularly fortunate combination of circum- stances acts to block the influx of carbonate muds from the bays and prevents silting of the reef tract (Brooks, 1982; Hoffmeis- 3 ~ter, 1974). The Lower Keys 3 ~~~The Lower Keys are primarily composed of oolites, small spherical grains of calcium carbonate, cemented together to form a limestone. The axis of the islands runs at right angles to the general trend of the chain rather than parallel to it as in the I ~Upper Keys. The islands are separated by numerous long narrow channels. They extend from Big Pine Key (excepting) the southern tip of the island which belongs to the Upper Ke ys) to the Mar- I ~quesas. The modern coral reefs associated with the Lower Keys Ilie mos tlIy to the sou th of the i slIands and are Iles s well develI- oped than the northern reefs, no doubt owing to the fact that the channels which separate the islands provide ready transfer of the carbonate muds f rom the GulIf to the reef tract. The constant presence of mud increases the turbidity in the water and inhibits 3 ~reef growth somewhat. The Dry Tortugas 3 ~~~~Some seventy miles to the west of Key West, the Dry Tortugas represent the last outlier islands of shallow sediments of the Florida Platform. They are primarily composed of carbon- ate sands and mud of biological origin which overlie an under- pinning of Key Largo limestone. 5 ~A. Geology and Stratigraphy Little is known of the earliest history of the southern part of the State of Florida as data are notably absent due to I ~the paucity of deep wells. It is known that basement rocks in the central and northern part of the state range in depth from 3,000 feet in the northern part of the state to some 12,000 feet 3 ~near Lake Okeechobee. In character they resemble rocks associa- -4- I-A-1-3 #5sce 09/29 I ~ted with the Appalachians. In the southern part of the state, however, the deepest non-sedimentary rocks penetrated are basal- tic submarine volcanics (See Figure 3) (Bass, 1969). They are I ~overlain by a wedge of sedimentary rocks that rapidly thickens southwardly and exceeds a thickness of 20,000 feet in the Keys. It is worthy of note that such volcanics are corrronly associated with areas where the crustal plates separate. Reconstructions of Pangea, the giant land mass that existed before the present con- tinents assumed their modern shape and location, shows that the boundary between North America and Africa crossed the tip of I ~Florida. If such reconstructions are correct, the abrupt deepen- ing of the basement rocks in South Florida would mark the line of separation between these two continents when Pangea broke up. I ~The presence of submarine volcanics would therefore confirm such an interpretation. In any case, it is generally accepted that South Florida is an area where sediments prograded over oceanic 3 ~crust. (See Figure 4) (Shurbet, 1968) Although Mesozoic sediments represent thicknesses well in excess of 10,000 feet (Puri and Vernon, 1964), only the more recent Cenozoic sediments have a direct bearing on the history and the formation of the Keys. Of these the most important are the sediments deposited since Miocene time. Although these sedi- 3 ~ments give us an excellent record of the past environments of South Florida, much controversy still surrounds their age and in some cases their exact stratigraphic relationships. Reconstruc- tion of the past is further complicated by the fact that the relationship between land and sea has not been static. (See * ~~~~It is well known that the advent of glaciation in higher latitudes affected sea level. During glacial periods, when water accumulates on land in the form of ice, sea level drops. Con- versely, during periods of climatic amelioration, sea level rises as water is returned to the sea. It is generally estimated that if all the water presently tied up in glaciers were returned to the oceans, sea level would rise by some 200 feet. Conversely, I ~during glacial maxima, sea level dropped by as much as 350 below present level. It is easy to see that an area such as the Keys which ties but a few feet above present sea level would be mark- 3 ~edly affected by the 500+ foot oscillations which have affected the world's coasts since Middle Tertiary Miocene times. These fluctuations are relatively rapid when measured against geologic t ime. Indications are that sea level has risen some 8 to 10 I ~inches during this past century alone. Other evidence, such as the presence of peat under Crane Key 4 to 10 feet below present sea level indicates a much lower sea level a mere 4000 years ago. Some 20,000 years ago, sea level may have been as low as 450 feet below present level (See Figure 6). Although the gen- erlsequence of events is relatively clear, there is still con- I ~siderable argument as to the precise age of a specific event (Brooks, 1973; Alexander, 1974; Fairbrige, 1974). U -~~~~~~~~~~~~~5- I-A-1-3 iI4coI 9/7/84 Figure 3: BASE-MENT MAP OF THE GULF OF MEXICO AND ADJOINING STATES (BROOKS - 1972) BASEMENT MAP OF THE GULF OF MEXICO AND (1972) ADJOINING STATES Alter P. T. Flawn(1967). P1 . Applin (1951) . M. 4. Bass (1969) C. Milton and V. I. Hutst (1965). ).W. Anloine (1968). C. Milton and R. GrVast (1969. . 1.LGough (1967). E.0. Shurbity (1968) contour interval 4000 ft. on too of Pre- urassic, jassavot of carbovato Platform gpbasrogadtio o Ordovician and Silurian sedimentary roc k s crbolae, Bak ove lJ1~9~d paleoloic melamerphic and igneous rocks of Piedmont Rhyalites. tuffs.and rloclrl~-5)n in. diabalic sills and diligs.49-133m.1 oceanic Cr ust~8t I _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _~~~~~~~~ I ~~I-A-1I-3 #4col 9/7/84 Figure 4: GENERALIZED GEOLOGIC CROSS SECTION THRU FLORIDA (Fla. State Geol. Surv. Bull. 5). U I~~~A X'i SEA co -104/1 lox7 ~~ 7: kQ N \' JURSC? FLO~~~~~~~~RINIYAGE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~IC? F ~~~~~~~~~~~~~~.00I3 II -7- I-A-1-3 #4col 9/7/84 Figure 5: STRATEGIRAPHIC RELATIONSHIP BETWEEN THE NIT (Purl and Vernon 1964) ~~~~~~~~~~~~~~,a Fort Thompsonq -8- J I-A-1-3 Y/4col 9/7/84 Figure 6: GLACIAL EUSTATIC SEA LEVEL I ~~~~~CHRONOLOGY BASED UPON STRATIGRAPHIC EVIDENCE IN FLORIDA (Brooks, 1963, 1972). LATE PLIOCENE PLEISTOCENE a ~~~~~~~~~~~~~~~~~~~Pro-glacial 'ciss, 3 Oboo~~~~~~~~~~~~fe~oVl::. ,., lac * ii S~~~~~~~~~~ame ami. F. ictec Jeack 1Fe. -100 NOT A0s1 aaa Cvoldo Mimi eaed Rey Larg aete$ Iit*I CIC qtiplaw I~~ ~~~~~~~~~~t b I.1bamos" New Cols.. Mill Hmmock Wm. -200~ ~ ~ ~ ~ ~ ~~1WW14"o $oda "atwls #6070. ~ ~ ~ ~~~~11,8 Aw cooli4s81goe StateOinl,.~ .6 61*10042~~~~~~~~~~~~~~~~ * goal 9~~~~~~~~~~~~~~~~~~ I-A-1-3 #6sce 09/30 The most important formations having a bearing on the geologic history of the Keys are, in decreasing order of age: the Tamiami Formation; the Caloosahatchee-Fort Thompson forma- tion; the Miami Limestone, the Key Largo Limestone; and the Key West Limestone. Although the age relationship between the first three formations is quite clear, it is less certain that the last three formations represent clearly distinct events rather than nearly contemporaneous environmentally controlled facies (See Figures 7 and 8) for the surface distribution of these forma- tions. The Tamiami Limestone The Tamiami Limestone is the oldest formation that out- crops in South Florida and underlies much of this part of the state. It is a tan to light grey limestone, quite variable in appearance, ranging from dense, to sandy, clayey and shelly, with some sandy units and some reef rock units. Near Miami, it reaches a maximum thickness of 150 feet (Parker, et al., 1955). Westward, it thins rapidly. In its upper portion, some 15 feet thick in the Miami area, it is one of the most permeable and prolific formations of the Biscayne Aquifer (Parker, et. al., 1955; Stringfield, 1966; Parker and Cooke, 1944). According to Dubar (1974) the upper portion is separated from the lower portion by an unconformity. It is not clear whether this stratigraphic separation corresponds to a hydrologic separation as well. In the Miami area the upper productive zone is composed of permeable limestones, underlain by relatively impermeable marls and limestones of the Lower Tamiami and Hawthorne Formations, which, in part, form the confining beds between the deeper Floridan Aquifier and the shallower Biscayne Aquifier. Although the Floridan has sufficient water pressure to allow artesian flow in the Keys, the high concentration of dis- solved materials renders the water unfit for public consump- tion. Pennekamp Spring on Key Largo is a 6-inch artesian well 1,300 feet deep into the Florida Aquifer. It has a chloride concentration of 2,440 mg/lI, nearly ten times the recommended U.S. Public Health Service levels (Rosenau, et al., 1977). The Tamiami Limestone has generally been assigned a Miocene age, but more recent faunal correlations suggest that it may be Pliocene (Brooks, 1982; Dubar, 1974). The Caloosahatchee-Fort Thompson Formation Like the Tamiami Formation, these formations thicken coastward. In the areas of the Keys, these formations, if indeed there are more than one, are primarily represented by the Fort Thompson Formation. They represent an extremely complex series of interbedded clastic and shell deposits formed during the vari- ous transgressions and regressions of the sea associated with Pleistocene glacial events. - 10 - I-A-1-3 #4col 9/7/84 Figure 7: GEOLOGIC MAP OF SOUTHERN FLORIDA (H1-offmeister, 1974). LA rma MIAMI LIMESTONE 5 3 ANASTASIA FORMATION En; KEY LARGO LIMESTONEX 3 FT. THOMPSON FORMATION I -tuf'*^ X CALOOSAHATCHEE MARL 3 TAMIAMI FORMATION .~< a , "~- SCALE IN MILES 3 . ; 0 10 20 30 i * - S I ,*':* -ljj-J-- - -l J-- ***'J4 :3 -, 0 P w. a. r 0' J** * ,.. %0.- I \i:i 0 I --j--- 'I I - I I ,:::::" I; : J".--r 'I * a V I * j. IiI *1I - V I *!- * 0 I .EZI IA 'j U -. I.. **I* j , ' Iijii!i I * !3 .11 I ':y 0 . I I * -.12- I-A-1-3 #5sce 09/29 Up to 70 feet thick near Miami, it thins southward and westward (Dubar, 1974). Although locally productive, the dense, hard limestones and intercalated muds and marls of the Fort Thompson render it somewhat less permeable than overlying and underlying units (Parker and Cooke, 1944; Stringfield, 1966). No doubt some of the Fort Thompson formation is contemporaneous with the strata which will be discussed below and merely represents different environmental conditions. However, exact contempor- anity has not been determined at present time (Brooks, 1973, 1982; Dubar, 1974). The Miami Limestone The Miami Limestone is the main rock outcrop in the southeastern part of the Florida peninsula. It is the medium to hard limestone, white to yellowish in color, oolitic in places, rich in bryozoans in part, and may also contain some quartz sand. It underlies most of the Florida Bay where it is covered by varying thicknesses of calcareous mud derived from the disin- tegration of calcareous algae. This limestone is primarily rep- resented by two environmental facies -- the oolitic and the bryo- zoan. The bryozoan facies underlies much of the oolitic; but landward of the Miami area, the oolite thins and disappears while the bryozoan facies persists. Eastward, towards the Upper Keys, the bryozoan facies interfingers with the Key Largo Limestone. Presumably when water was higher than at present, the environment was similar to the present environment of the Bahamas, where today we also find oolitic mounds on the oceanic side of the platform with bryozoans thriving behind the mound. The presence of the reefs of the Key Largo Limestone acting as a barrier en- couraged the formation of oolites in the waters behind this bar- rier, while further back, protected by the reef and the accum- ulating ridge of oolites, bryozoans flourished. When sea level dropped during an ensuing glacial episode, these bryozoan and oolitic beds of the Miami Limestone were exposed subareally and the sediments were cemented as rainwater deposited calcite be- tween the grain spaces. Similarly, in the Lower Keys, a second mound of oolite developed on the Florida Bay side of the Key Largo Limestone reef. As the mound increased in size because of extensive precipitation of calcium carbonate, it slowly over- whelmed the reef. The contact between these two formations (i.e. Key Largo Limestone and Miami Oolite) can be seen in Big Pine Key. From there, the Miami Oolite progressively thickens west- ward to reach 35 feet near the west end of the lower Keys (Hoff- meister, et al., 1964; Hoffmeister, 1974; Dubar, 1974). As in the North, in the Miami area, subsequent exposure due to lowering of sea level allowed the oolite mound to harden. However, be- cause this mound was not protected by a reef line as in the North, when sea level rose again it concentrated its erosional energy along the relictual tidal channels which had formed at the t.ime of dposition of the oolitbankKand cut the long parallel c annels now separae the Lower eys. - 13 - I-A-1-3 #6sce 09/30 Both the Miami Limestone and the Key West Limestone (if indeed they are distinct) are porous limestones, containing numerous vertical solution features most likely formed during the Pleistocene. Because these features are not corrmonly connected, water does not move laterally as readily as in the Key Largo Limestone and they provide an excellent supply of fresh water (Parker and Cooke, 1944; Parker, et al., 1955). The Key Largo Limestone The Key Largo Limestone outcrops at the surface from Soldier Key to the southernmost end of Big Pine Key, over a dis- tance of 110 miles. However, subsurface drillings indicate that it originally extended over twice its exposed length, from Miami to the Dry Tortugas. It varies in thickness from 70 to over 170 feet. It is a fossil coral reef whose main structure is a net- work of coral heads with intervening spaces filled with detrital reef material. Star coral, and less corrmnonly brain corals, are the dominant species found in the exposed Key Largo Limestone indicating that the reef that can now be seen was a patch reef. Drilling seaward of the presently exposed part of the Key Largo Limestone reveals the presence of moose horn coral, a species characteristic of present fringe reefs. No doubt, the lowering of the sea which allowed cementation of the Miami Limestone also killed the reef as it emerged. The subsequent rise of the sea which reshaped the oolitic limestone of the Lower Keys, also destroyed most of the outer fringe reef. Only the inner patch reef is visible today and forms the backbone of the Upper Keys. (See Figure 9). The Key Largo Limestone is a very porous coralline lime- stone. It is riddled with solution features and voids, allowing water ready passage, both vertically and horizontally. Although potentially an excellent aquifer, it contains very little fresh water because its permeability allows ready outflow (Hoffmeister and Multer, 1968; Hoffmeister, 1974; Parker, et al., 1955). The Key West Limestone There is doubt in some authors' minds whether the oolitic limestone which forms the lower Keys is in fact distinct from the Miami Limestone. Those (starting with Sellars (1909)) who have maintained that it is not, have insisted that the oolite which covers the lower Keys is a separate formation and have therefore given it the name of Key West Limestone (see Brooks, 1982). Although there is argument as to the contemporaneity of the events discussed, or the specific formations present, there is little or no disagreement as to the environmental conditions which prevailed or the mode of formation of these deposits. -14- 3 ~~~~Figure 9: Ax RECONSTRUCTION OF ENVIRONMENT DURING KEY LARGO LIMESTONE FORWATION TIME (above); PRESENT CONDITIONS (below) (Hoffmneister, 1974). U ~~~~~~~Poak ReeIs ODrisal We Level of Keys 1101 larp line) 3 ~~~~~~~~~~~~patch Post# ...... 021.r Reef---, ~~~~~~~~~IO * b~~~~~~~~~b -SCALE; Ke Large Las. Io IS FEE15 VT o;km I USA FI~~~aIDA KE~(kt" -" Odoing Sea LeLl" puI& Reef* ' ~ . SCALE-~ * \...... poo Lag La ee Ue Lrge Re.? 3 -~~~~~~~~~~~~15- I-A-1-3 #5sce 09/29 B. Groundwater in the Keys Although the Miami area has a relatively ample supply of fresh water (albeit increasingly depleted by ever-growing de- mand), such is not the case in the Keys despite similar regional geology. Surrounded as they are by salt water, their fresh water resouces are meager at best, and too often nonexistent. Fresh water lenses of the Biscayne Aquifer exist primarily on Big Pine Key and Key West, as well as on No Name, Cudjoe and Upper Sugar- loaf Keys. Dependent as they are on rainfall for recharge, local supplies are further limited by runoff, evaporation and transpir- ation and outflow from the aquifier (Parker, et al., 1955; Klein, 1970; Hanson, 1980). Although the Upper Keys receive more rainfall than the Lower Keys, they have virtually no fresh water supplies. Because the voids in the underlying Key Largo Limestone are intercon- nected horizontally, percolating rainwater is not confined later- ally, resulting in increased outflow. For the same reason, salt- water readily rises and passes through the aquifier in response to tidal influences. This results in increased mixing and dis- sipation of the fresh water (Parker, et al., 1955; Chesher, 1974). Because the Miami (or Key West) Oolite in the Lower Keys has fewer lateral connections than the Key Largo Limestone, out- flow is slower. Tidal amplitude is lower as well resulting in less mixing (Parker, et al., 1955; Cheshner, 1974; Hanson 1980). Cementation crusts within the oolite also tend to limit evaporation. Despite the presence of some fresh water lenses, it is not expected that groundwater supplies of the Keys will ever provide a significant amount of fresh water. Nevertheless, large withdrawals would severely impact the limited supply available with concomnitant salt water intrusions. Additionally, ditching such as that reported by Alexander and Dickson (1972) provide ample evidence of the portentially adverse effect of human inter- ference. C. Tides Tides effect nearly one million acres of estuaries and tidelands in Florida, and their rise and daily and secular varia- tions intimately affect natural ecosystems and human activities alike. The knowledge that tides are linked to the motion of the sun and the moon has been known since antiquity. However, the basic explanation for tides, namely the interaction between the gravitational forces of the Earth-Moon-Sun system, did not come forth until Newton's time. Because the moon is the closer body to the Earth, its influence is preeminent. Bodies of water which face the Moon are closer to it and therefore are subjected to - 16 - I-A-1-3 #.5sce 09/29 greater forces. Being less rigid than the solid earth, the body of water facing the Moon is subjected to greater acceleration than the remainder of the system and bulges towards the Moon. I ~Oceans on the opposite side of the Earth, being farthest away, will experience a lower gravitational gradient than the Earth and, experiencing less accleration, will bulge away from the Earth. Thus, interaction of gravitational forces will give rise to two bulges, once facing the Moon, the other at its anti- podes. As the Moon passes a given point on the surface of the Earth 50 minutes later each day, each point on the surface should experience two high tides and two low tides during each tidal day of 24 hours and 50 minutes. The attraction of the Sun, albeit weaker than that of I ~the Moon because of its greater distance from the Earth, will have a similar effect on bodies of water. Depending on the rela- tive positions of the three bodies, the gravitational pull of the I ~Sun may reinforce that of the Moon to cause the greater than normal tides called spring tides. During periods when they par- tially cancel each other lower than average tides called neap tides occur. These effects are further complicated by a host of fac- tors. Because the planetary bodies travel in elipses rather than circles, Earth-Sun and Earth-Moon distances vary continually. Furthermore, the angle between the Earth's Equator and the Sun varies by 47 degrees over a period of a year. Similarly, the U ~Moon's position will shift from 28.5 north to 28.5 south of the Equator over a period of a month. To complicate matters even further, tidal bulges are not free to move over the surface of the Earth as the various oce an basins are separated by conti- U ~nents. Further, tides in a given locality are affected not only by hegross topography (Gross, 1977). Once put into motion, the water in a particular basin will begin to oscillate with a fre- quency natural to that basin. Apparently, the natural frequency of the Gulf of Mexico is 24 hours. As such it naturally responds more readily to diurnal tidal forces and the Gulf is character- I ~ized by a diurnal regime of one high and one low tide per tidal day (Mariner, 1954). in contrast, the Atlantic basin exhibits two high tides and two low tides of nearly equal amplitude per tidal day. Such a regime is referred to as semi-diurnal (See Figure to). It is not surprising that Key West, lying as it does at I ~the edge of both basins, will exhibit a mixed tide pattern (See Figure 10). Although there are two highs and lows per tidal day, they are of inequal amplitude. In the Keys proper, tides are semi diurnal north of Key Largo and below Key Largo they are of the mixed type. The amplitude of tides tends to be lower in low latitudes and indeed the tidal range at the Miami station is only on the order of 2.5 feet (Mariner, 1954; Provost, 1973). Further- more, the tidal range along the continental slope break decreases southward along the Keys to Key West where it is on the order 1.1 feet (Provost, 1973). -17 - I-A-1-3 #4col 9/7/34 Figure IQ: TIDE CURVES, MIAMI 13EACH AND KEY WEST, JUNE 23-30, 1948 (Marmer, 1954). 23 24 25 26 27 28 29 30 FEET 1.0- A A - Key West 0.Q\VJ V VVVVwUV V V \ 7VV .0- FEET I I.O- 23 24 -5 26 27 28 29 30 Ioopq A A U~~tA U -JV Ivvs-d I-A-1-3 II5sce 09/29 * ~~~There is a marked delay in tides between the east and west side of the Keys which is con-nonly attributed to friction (Enos, 1977). No doubt it is also related to local topography and to the characteristics of Florida Bay. Because it is a small shallow restricted basin, Florida Bay does not exhibit large tides; in f act ,the ir amplIi tude is on the order of 0.5 feet, leading to a marked water gradient between the two sides of the I ~Keys. Consequently, at high tide there is substantial water in- flow into Florida Bay from the Atlantic. The magnitude of this difference is related to the number of openings between the two I ~systems. In the Upper Keys where the islands act as a barrier, and few openings connect the Atlantic to Florida Bay, the water gradient is quite marked. In the Lower Keys where the islands lie parallel to the tidal flow direction and where the openings are corrmon, the gradient is much less (Enos, 1977). Tidal amplitudes are also influenced by meteorological I ~conditions. Changes in barometric pressure influence the height of the water column. Theoretical calculations indicate that tidal height may rise up to one foot for every one inch decrease I ~of barometric pressure. Even greater than barometric effects are changes in tides induced by the wind. In shallow areas, the wind may force a large amount of water against a coastline inducing not only a greater amplitude in the tides but also tidal currents as the water is forced to move laterally in response to the grav- itational gradient. Both these effects are corrmon during hurri- canes where the tidal surges up to 25 feet have been recorded. Lastly, tide amplitude is also affected by long range variations in sea level. Careful record-keeping indicates that amelioration of climate has led to an historical rise in sea level. Along the Atlantic Coast, sea level has crept up at the rate of one foot every 72-125 years approximately averaging one foot per century. This rise seems slower in Key West where the I ~average rise is closer to one foot in 143 years (Provost, 1973). Little is known, however, about the causes of these vari- I ~ations. D. Climate Lying in the zone of the trade winds, the Keys exper- I ~ience a subtropical savanna type climate characterized by warm surrrers and mild dry winters (Bradley, 1972). The mean annual sunshine is 3,300 hours, ten percent more than the peninsula to the north, and average daily solar energy reaching the Keys has been calculated at 447 langleys (Dames and Moore, 1978). 3 ~~~The mean annual temperature ranges from 77 degrees F in the Lower Keys to 76 degrees F in the Upper Keys. The mean temp- erature for January, the coldest month, is 69 degrees F, while August, the hottest month, has a mean of 84 degrees F (Thomas, 1974). (See Figure 11) One striking aspect of the isotherms is how closely they follow the coastline from the Dry Tortugas to - 19 - 3 I-A-I-3 #4col 9/7/84 Figure MEAN TEMPERATURE FOR JANUARY AND AUGUST, (Thomas 1974). I I I I I I _________ I I U I I I I 2 I _____ a. 2 - I - 20 - I I-A-1-3 #5sce 09/29 1 ~Ft. Pierce. This is primarily due to the meliorative effect of the warm marine waters which bathe the Keys, and the presence of the warm Gulf Stream along the coast (Jordan, 1973). Yearly rainfall in the Keys ranges from 35-45 inches, although it may be as little as 20 inches or as much as 60 inches in a given year. Most of the rainfall comes during the wet sea- son, the sum-ner months from May to October, and has a pronounced biomnodal distribution (Thomas, 1974). Most of the rain falls during May, June, September and October. (See Figures 12 and 13) I ~During these months, the Keys lie in a low pressure through area between two anti-cyclonic cells. As this trough shifts into the Gulf during July and August, rainfall decreases. Thunderstorms are the primary source of water during the wet season. Ninety percent of the 60 to 80 storms which occur each year form during the wet season when approximately 35% of the days report thunder- storms due in large part to convective processes (Jordan, I ~1973). As the moist, oceanic air heats up over the land during hot sun-mer days, it becomes unstable and rises. Moisture con- denses forming thunderstorms. This process is favored by the I ~orientation of the Keys virtually at right angles to the prevail- ing easterlies. Occasionally, tropical cyclones will also add to the water budget of the Keys (See Section on Hurricanes). I ~~~During the dry winter season, most of the rainfall is due to cold f ronts, which pass over the area on the average of once a week. Winter rainfall, however, accounts for less than one third of the precipitation in the area (Thomas, 1974). There is a net decrease in precipitation southward, presumably for two reasons. Winter cold fronts do not pass into the Lower Keys as often as they do in the Upper Keys. Further, convective thunderstorms do not develop as readily over small islands as they do over the mainland. This also accounts for the fact that the Lower Keys show less marked seasonal differences than the Upper Keys. B ~~~Winds are relatively mild, averaging 11-12 knots throughout the year, with highest winds occurring during the winter months (November through April) and decreasing during the sunmer, although wind velocities nearing 250 mph were associated with the great hurricane of 1935 (Jordan, 1974; Gentry, 1974) . (See F igu re 14 ) Becau se t he Key s lI e i n t he a rea o f t he t rades , wind direction is generally easterly. An excellent synopsis of the general climate of the area can be found in Schomer and Drew, * ~E. Hurricanes No climatic discussion would be valid without mentioning tropical cyclones. Almost invariably spawned in the latitudes from 5 to 20 N, these areas of low pressure vary in intensity and degree of organization. Cyclones with poorly defined circulation 3 ~and winds of less than 38 mph are called tropical disturbances or -21 - I-A-I-3 II4col 9/7/84 5 ~~~~~~Figure 12: AVERAGE ANNUAL RAINFALL IN 'NCHES (Thomas, 1974). 1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-50 I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~IM I~~~~~~~~~~~~~~~~~~~~~~4 - 5"';s/MIM I~~~~~~~~~~~~~~~~05 -22- I-A-I-3 #4col 9/7/84 Figure 13 AVERAGE MONTHLY RAINFALL FOR THREE REPRESENTATIVE STATICNS IN STUDY AREA (Schorner and Drew, 1982). 0 1 ~~9- ,&Tavorrier El Key West ORoyal Palm A-- -A Rangy' Station I I i7- A/I z 2~~~~~~~~~2 a/ / jDN 1 r~~~~~~~ -/ z 1 I ~~~~ Fe g trMyfn u'yAr ~ ~ b I I-A-i-3 #4col 9/7/84 Figure fj': SEASONAL DISTRIBUTION OF MEAN MONTHLY WIND SPEED (Jordan, 1973). SUMMARY AREA �-- ~~TAMPA I~~~~~I MEAN WIND SPEED OCEY WEST ETS ~~~~~~~~~~~~TAMPA APALACHCOLA TALLAH4ASSEE S a AM I I I~ I-A-1-3 #5sce 09/29 depressions. If the circulation pattern becomes closed, and the maximum winds exceed 38 mph the depression is reclassified as a tropical storm. When the maximum winds exceed 74 mph the storm becomes a hurricane. Should the maximum sustained winds exceed 125 mph, it is referred to as a great hurricane (Gentry, 1973). Hurricanes con-nonly begin as a wave or disturbance in the trade winds. If this wave intensifies, a counterclockwise circulation cell begins. As it gains energy from the condensa- tion of moisture carried upward in the center of circulation, the pattern intensifies into a tight spiral extending hundreds of miles outward from a central low pressure zone (called the eye) conrnonly 10 to 20 miles wide. In the eye, where pressures may be as low as 940 millibars, the winds are relatively calm (20 mph or less) and the sun may even break through the clouds. Virtually without transition as one leaves the eye, wind velocity jumps to over 200 mph in some of the great hurricanes. Torrential rains and severe thunderstorms ring the eye to heights of 40,000 feet and some 30 miles outward. Winds often reach 50 mph even 100 miles out from the eye, and the circulation system may extend over 300 miles from the center. Thus, a single storm may affect the entire Keys (Miller, 1971). Dependent, as these cyclones are, on warm moist air for their energy supply, it is not surprising that they are most corrmon during the surfmer months. In the area of the Keys, there were 38 hurricanes from 1901-1971 (Jordan, 1973). Nearly 80% occurred during the months of August, September and October, while the months of November through May accounted for only 10% of all the hurricanes. October alone accounted for 37% of these hurricanes. Similar data for the North Atlantic confirm this pattern. It should be noted that although yearly patterns are clear, no long range pattern has been detected. Hurricanes release tremendous amounts of energy. A single storm may release 300-400 billion kwh per day. During the same period of time, 10-20 billion tons of water will fall in the form of rain during the average nine day life of a hurricane (Miller, 1971). On the average, 6-12" of rain will fall on a given location; although some storms are virtually dry, one trop- ical cyclone dropped 35" of rain in Trenton, Florida in three days in 1941 (Gentry, 1973). Much depends of course on the path and characteristics of a particular storm. On the average, they move over the surface at the rate of 12 mph. They tend to be slower below 30 degress N latitude while steered West or North- west by the easterly trades. Once they enter the westerlies, they tend to veer to the northeast and commonly accelerate. Forward speeds up to 50 mph have been reported. As the storm moves over the colder waters of the North Atlantic or over land, less moisture becomes available, the storm loses energy and co- herency and ultimately dissipates. - 25 - I-A-1-3 #5sce 09/29 I ~~~Because of their large size, their cornmon occurrence and the enormous amount of energy they release, hurricanes pose a particular danger to all the areas they affect. In coastal areas such as the Keys three primary effects are associated with hur- ricans; wind, waves and storm surges. 3 ~~~Wind: As the dynamic pressure of the wind increases with the square of the wind velocity, tremendous pressures are exerted on vegetation and structures. A hurricane with winds of 75 to 100 mph can generate pressures of 75 lb/sq ft., enough to I ~destroy mobile homes and cottages. As the wind flows around structures it creates pressure differentials which are sufficient to collapse them. The passage of the intense low pressure center over sealed buildings can have a similar effect (Stursa, 1973). Waves: Because of the intense winds and the long dura- tion of these storms, they generate large waves corrmonly 35 feet in height, but reaching up to 50 feet. As these waves reach the shoreline, they erode beaches, highways, undermine structures and rework sediments. Developed coastal areas where beach berms have been removed and canals that have been cut to the shore are par- ticularly vulnerable to storm wave action. 5 ~~~Storm Surges: Perhaps the greatest danger to low lying areas such as the Keys is the storm surge which may be associated with any hurricane that approaches or crosses a coast. The storm surge is corrmonly composed of three elements that reinforce each other. First, as the low pressure center passes over an area, sea level will bulge below the low pressure area by as much as two feet because of the decreased barometric pressure. Second, I ~because the shoreline acts as a barrier, the water is piled up against land by winds. Third, high tides may combine their am- plitude with the rise in water from the other factors. In Pass I ~ ~Christian, Louisiana, in 1969, the storm surge reached 25 feet, the highest surge recorded in the Keys reached near 18 feet dur- ing the "Labor Day" Hurricane of 1935 (Gentry, 1973; Sursa 1973). While such a rise is extreme, surges in excess of ten I ~feet are not uncorrron and if one visualizes storm waves up to 20 f eet in height superimposed on these surges, one can readily understand the potential destructiveness of a large hurricane. I ~Associated with tidal surge flooding and wave pounding are surge currents which are responsible for sediment reworking and trans- port . Although surges are corrrnon phenomena, their amplitude and destructive potential are difficult to predict, depending as they are on a host of factors such as wind speed, direction, fetch, water depth, basin and coastal shape as well as currents, tides and seiches, to name but a few. Secondary effects of hurricanes may include damage to vegetation as well as marine biota because of sudden changes in I ~temperature and salinity, as well as direct effect on the aquifer by flooding recharge areas (Stursa, 1973; Craighead and Gilbert, 1962). In extreme cases, entire coastlines have been obliter- 3 ~ated. It should be borne in mind, however, that hurricanes are -26 - I-A-1-3 #5sce 09/29 natural parts of ecosystems and water budgets of many areas. With the passing of the years and a better understanding of these severe storms, loss of life has drastically decreased, even though because of increased development of the coastlines prop- erty damage continues to rise steadily. The effects of hurricanes on the Keys' natural ecosys- tems can be devastating. The storm surge and associated wave action especially impact shoreline systems such as salt ponds, beaches, berms and mangrove corrmunities. Hurricane Donna sub- stantially changed shorelines throughout the Upper Keys. Some smaller Keys were practically obliterated, some were severed, and in many areas low dune ridges were stripped of vegetation (Craighead and Gilberg, 1962). The effect of such disturbance is to return these systems to a pioneer seral stage. Craighead and Gilbert (1962) further noted that these forces dispersed Red Mangrove (Rhizophora mangle) seeds several miles inland and cer- tainly represented the source of the extensive inland stands of this species. The winds of severe hurricanes will directly uproot much of the vegetation in the path of the eye and defoliate most of the remainder. While much defoliated vegetation produces new foliage, some species, especially mangroves, may be characterized by high mortality for reasons that are unclear, although high soil hydrogen sulfide generated by anaerobic decomposition of newly deposited organics may be a major factor (Craighead and Gilberg, 1962). While mangroves were often decimated by hurricanes, some species of upland vegetation fared much better. Especially wind- resistant species are: Cabbage Plain Sabal palmetto Royal Palm Roystonea elata Live Oak Quercus virginiana Strangler Fig Ficus Aurea Mastic Sideroxylon foetidissimum Lysiloma Lysiloma bahamensis Slash Pine Pinus elliottii Areas affected by storm surges may be temporarily dam- aged by the increased salinity of water or soil. If drainage is poor, as in some wetland areas, recovery may take several years (Stursa, 1973), but the torrential rains that accompany hurri- canes tend to offset this damage and the region's high annual rainfall tends to leach away deposited salts and promote a faster recovery in most plant cormnunities. Since hurricanes are recurring natural phenomena, most Keys biota have evolved some degree of accomodation. Conse- quently, a fairly predictable successional sequence tends to generate anew the destroyed system. One factor that can compli- cate this recovery, however, is the introduction of propagules of - 27 - I ~~I-A-1-3 #6sce 09/30 exotic plant species. M4any such species, especially Brazilian Pepper (Schinus terebinthefolius) and Australian Pine (Casuarina I ~~ecuisetioia) are opportunistic forms that rapidly colonize dis- turbed sites and may delay or adversely affect ultimate recov- ery. Further, the latter species is very salt tolerant and tends I ~~to suffer less than many native species when exposed to subse- quent storm surges (Alexander, 1968). Another major impact of hurricanes on upland systems is I ~~the removal or reduction of the thin humus layer that overlies the limestone. The significance of this humus is discussed else- where but it can be stated here that its diminution sets back the I ~~successional sequence to an earlier seral stage in which many environmental variables (temperature, surface moisture) become * ~~more extreme. (2) CORAL REEFS * ~~~Coral Reefs are among the Earth's most complex and productive natural systems. These shallow water ecosystems rest on a limestone substratum of their own production in stable I ~~environmental conditions. The saltwater environment is warm (above 70 degrees F.) and transparent enough to access to the intense bright light required by many reef inhabitants. The structural framework of coral reefs is composed of colonies of tiny organisms collectively called coral. These organisms extract calcium and carbonate ions from seawater to I ~~secrete calcareous chambers within which they live. The growth of a coral reef, therefore, represents the collective actions of the many individuals comprising these colonies and is a slow I ~~process. This structural framework provides food and/or habitat for a vast number of organisms. The principal extant reef builders are hermatypic corals I ~~(DiSalvo & Odum, 1974) whose symbiosis with unicellular algae called zoosanthellae provides a mechanism for maximizing reef growth. The algal species occur in the endodermal tissue of I ~~their host where they are protected by its calcareous skeleton, which is spacially oriented to insure illumination. This advantage is maximized in associations with the many corals whose I ~~polyps are extended out of this structure during daylight hours (Wainwright, 1967). These algae provide their host with oxygen as a metabolic byproduct of photosynthetic activity and organics (Muscatine, 1967.) The coral reefs of the Florida Keys are at the northern edge -28- of the geographic range of these systems. Consequently, their structural organization may differ somewhat from the classic patens observed in most Caribbean reefs where physical conditions are more constant. Nonetheless, the pattern of Keys reefs approaches the "barrier reef" model originally advanced by 3 ~~Charles Darwin. The most seaward component of this barrier complex is an outer reef system that develops at the crest of an escarpment (See Figure 8) at the outer edge of the shallow continental shelf that occurs along the Atlantic edge of the Keys. Because of the linear regularity of this geomorphological feature, outer reefs tend to be linear systems that parallel the Keys. Landward of the outer reef lies a shallow lagoon system that is characterized by less structural regularity of its coral components. These patch reefs are of scattered and irregular distribution, shape and size. Differences in the physical environments of the barrier and patch reefs are reflected in the differing morphologies of their dominant coral species. The patch reefs of the lagoon area live in shallow water that is more strongly influenced by wave action that can increase turbidity, 3 ~~and by weather changes that can result in a range of thermal variation unknown in the deeper waters of the outer reef. The evolutionary accomodation to these conditions has been the 3 ~~Predominance in the patch reefs of mas~sive boulder-shaped corals whose morphology is better able to withstand the high wave energy and concommitant turbidity. I ~~~The corals along the outer reef do not experience such stressful conditions. Here the thermal condition is stabilized by the influence of warm Gulf Stream waters and sediments that could contribute to turbidity are instead transported into the a ~~ocean's depths by the zone's many sand channels. As a consequence, the outer reef is inhabited by many corals with 3 ~~branched and plated morphologies. Further, there exist discontinuities in Keys barrier reef I ~~istribution that reflect geographic discontinuities in the archipelago itself. The chain of islands that comprise the Upper Keys constitute a continuous barrier to the exchange of water between Florida Bay and the Atlantic. Consequently, the Gulf Stream's thermally moderating influence is more constant here than in the Lower Keys where the archioelago is fragmented and seasonal thermal variations are more profound. Further, these passages in the Lower Keys indirectly allow the generation of turbid water. The conseauence of these differences is that major reef development in the lower Keys are limited to the "shadow zone" south of major islands (e.g., the Samba reefs south of Looe Ke)where environmental conditions are more constant. 3 -~~~~~~~~~~~29- Biota There are over 6000 patch reefs between Miami and the Marquesas Keys (Schomer & Drew, 1982). Most occur in areas of sand, mud, or rock substrate located in a band two to four miles from the islands between Hawk Channel and the outer reefs (Marszalek, et al., 1977). There are two basic types of patch reefs (Marszalek, et al., 1977; Jaap, 1982)--dome patch reefs and linear patch reefs. Dome patch reefs usually occur in clusters in water depths of less than 30 feet and vary in size from a few meters to more than 700 meters (Schomer & Drew, 1982). They are typically circular or eliptical and are surrounded by a halo of barren substrate. The community's biota varies greatly depending on reef age and environmental condition (Jaap, 1982), but typically consists of scleractinian and alcyonarian corals, other coelenterates, mostly erect sponges, echinoderms crustaceans, molluscs, red and green algae, and a variety of fishes. Jones (1977) described a successional sequence for dome patch reefs in which the pioneer corals are likely to be Porites porities, Manicina areolata, and Favia Fragum. These forms are replaced by massive primary reefbuilding corals like the starlet coral (Siderastrea siderea), the brain corals (Diploria labrinthiformis and D. strigosa), star corals (Montastrea annularis, and M. cavernosa), the finger corals (Porites porites and P. Furcata), and Colpophyllia natans. The coral assemblage of linear reefs is similar to that of patch reefs, but elkhorn coral (Acropora palmata) joins Montastrea annularis as a principal reefbuilder. Linear reefs usually occur seaward of dome patch corals and lie roughly in a chain parallel to the outer reefs. Both types of reefs commonly have the algae Gonialithon sp. and Halimeds opuntia, numerous erect sponges, bivalves of the genera Arca, Lithophaga, and Barbatia, the gastropods Strombus gigas and Corallophils abbreviata, spiny lobsters (Panulirus argus), stone crabs (Menippe Mercenaria), the echinoids Diadema antillarium and Echinometra lucunter, numerous ostracods, bryozoans, foramini- fera, ostracods, and fishes (Enos, 1977; Multer, 1977, Jaap, 1982). Table 1 lists some of the common fish species of patch reefs. Outer reefs are located at or near the shallow shelf break. The elongated reefs form a discontinuous belt that is best developed seaward of Key Largo and the lower Keys. The biota of the outer reefs include Porites astreoides, Lettuce Coral (Agaricia agericites), Clubbed Finger Coral Porites porites), Siderastres sidera, Elkhorn Coral (Acropora palmata), Staghorn Coral (A. cervicornis), Pillar Coral (Dendrogyra cylindrus), - 30- I Gorgonia ventalina, Plexaura complanata, Diploria clivos, the alcyonarians Plexaura flexuosa, Pterogorgia citrina, and Eunicea mammosa, the hydrozoan Millepora complanata, the green algae Halimeda, the brittle stars Ophiothrix orstedii and Ophocnida sp., and coralline algae. These are a small fraction of the total species assemblage of outer reefs. Kissling (1977) identified from nine outer reefs off the Lower Keys over 350 macrobenthic species including 42 species of stony corals, 41 species of soft corals, and 21 species of brittle stars. It is further estimated that over 300 fish species inhabit these reefs. Some of the more commonly occurring fish species are listed in Table 1. Few other vertebrates occur with regularity. Three species of sea turtle may occur with varying frequency in coral reef although all utilize other habitats. These are the atlantic Ridley (lepiochelys kempi), Atlantic Green Turtle (Chelonia mydas mydas), and Atlantic Loggerhead (Caretta caretta caretta). Bottle-nosed Dolphins (Tursiops Truncatus) may also be occasionally observed in or near reefs, but it is not a principal habitat for this species. All four of these vertebrates are listed by federal and/or state agencies as threatened/endangered. TABLE 1. Common fish species of Keys coral reefs. Outer Reef Creole Wrasse Clepticus parrai Blue Chromis Chromis cyanea Brown Chromis Chromis multilineata Rock Beauty Holacanthus tricolor Parrotfish Scarus spp. Hogfish Lachnolaimus maximus Sargeant Major Abedefduf saxatilis Bluehead Thalassoma bifasciatum Striped Grunt Haemulon striatum Smallmouth Grunt Haemulon chrysargyreum Bluestriped Grunt Haemulon Scirus French Grunt Haemulon flavolineatum Spanish Grunt Haemulon macrostomum Grey Angelfish Pomacanthus arcuatus Grey Snapper Lutjanus griseus Glassy Sweeper Pempheris schombergki Porkfish Anisotremus virginicus Bicolor Damselfish Pomocentrus partitus Flamefish Apogon maculatus Squirrelfish Holocentrus ascensionis Pearly Razorfish Hemipteronotus novacula Siminole Goby Microgobius carri Slendor Mojarra Eucinostomus pseudogula - 31 - Eyed Flounder Bothus ocellatus Ballyhoo Hemiramphus brasiliensis Scaled Sardine Harengula pensacolae Lane Snapper Lutjanus synagris Yellow Stingray Urolophus jamaicensus Gag Grouper Mycteroperca microlepis Nassau Grouper Epinephelus striatus Snowy Grouper Epinephelus nireatus Jewfish Epinephelus itajara Yellowtail Snapper Ocyurus chrysurus Barracuda Sphyraena barracuda Spanish Hogfish Bodianus rufus Patch Reef Sergeant Major Abedefduf saxatilis Bluehead Thalassoma bifasciatum Parrotfish Scarus spp. French Angelfish Pomacanthus paru Black Grouper Mycteroperca bonaci Blue Tang Acanthurus coeruleus Bluestriped Grunt Haemulon sciurus Black Grouper Mycteroperca bonaci Gag Grouper Mycteroperca microlepis Nassau Grouper Epinephelus striatus Snowy Grouper Epinephelus nireatus Jewfish Epinephelus itajara Yellowtail Snapper Ocyurus chrysurus Barracuda Sphyraena barracuda Spanish Hogfish Bodianus rufus Impacts The great diversity of coral reef biota is either directly or indirectly dependent on a stable physiochemical environment. Any modification of these conditions can be expected to result in changes in the function and structure of reef ecosystems. Of Particular significance are possible modifications of temperature, salinity, light intensity, and sedimentation patterns. Great mortality of reef biota has been recorded as a result of exposure to high temperatures and to the atmosphere in shallow reef systems during extremely low tides (Mayer, 1914; Glynn, 1968). Similar man-induced reef disturbance has been documented and is attributable to thermal effluents from a power plant in Biscayne Bay that caused coral death as far as 1-1/2 Kilometer away (Kaplan, 1982). - 31 a - :I Most of the processes that damage reefs, however, may be I ~~exacerbated by human development in or modification of the Keys upland or shore habitats. Dredge and fill operations, for example, generate large amounts of sediments that may reach reefs * ~~and kill or damage coral and other sedentary animals and plants that are unable to clean their surfaces. Upland development also indirectly generates sediments that can damage reefs. Clearing I ~~of terrestrial habitats directly exposes soil to the actions of wind and water, whereas an anastomosing network of roots holds soil in place in unaltered habitats. Ultimately, most lost sediment will find its way into offshore waters. Nonetheless, it is unlikely that the impact of such human activities can generate levels of turbidity that approach those associated with the wave energies of s~evere storms. In particular, the soil of upland I ~~areas is such a meager resource that it can contribute little to such processes. Some inwash from terrestrial areas, especially from Florida Bay, has always occurred naturally, and severe U ~~weather can similarly increase siltation regimes, but the location of the Keys' living coral reefs represents an accomodation to these influences that has been reached through geologic time. Changes in the rate of sediment generation and release into offshore waters may upset an equilibrium that will not be reestablished for centuries. 3 ~~~Upland development also indirectly generates sediments that can damage reefs. Clearing of terrestrial habitats directly exposes soil to the actions of wind and water, whereas an anastomosing network of roots holds soil in place in unaltered habitats. Ultimately, most lost sediment will find its way into offshore waters. I ~~~An associated problem is the concommitant loss to coral reefs of nutrients that promote eutrophication in all aquatic systems. This process, which is exacerbated by nutrient release I ~~from septic tanks, promotes "blooms" of microorganisms that can cloud the water and reduce light penetration for days at a time. The devastating effects of these processes have been documented for Hawaiian reef systems (Banner, unpubl. ins.) where there occurred a decimation of reef biota. State and County regulatory legislation now exists to prevent or mitigate many of the I ~aforementioned environmental damage. In addition to such indirect damage caused by modifications in the physical environment, direct damage constitutes a major I ~problem to Keys coral reefs. The increased presence of humans in these areas resulting from tourism and Keys population growth has impacted these systems in several unfortunate ways. Because coral growth is so extremely low, any direct damage to the reef infrastructure may be viewed as simipermanent. Corals broken by collectors and ship anchors or ship hulls, for instance, ~~~~~~~~~~32 -32 represent aspects of this problem that have been worsened by the high level of human presence here. The potential for extensive physical damage was realized earlier in 1984 when a commercial vessel became grounded on a Keys reef system. Extensive breakage of the reef structure was caused by both the impact of the vessel's hull and its chain and anchor, as well as those of rescue vessels, during attempts to free it. Physical damage may result as well from natural forces such as high wind and associated waves (Glynn, et al., 1964). Selective removal of fish (by spearfishing) and mollusc shells can also produce changes in reef trophic structure. Oil spills may also adversely affect coral reefs. Laboratory studies have shown that floating oil can disrupt the normal feeding and cleaning activities of corals (Reimer, 1975), and physical contact for more than a few hours causes tissue death (Bak & Elgershuizen, 1976). The ability of corals to recolonize after disruption is greatly reduced by such exposure (Fishelson, 1973) and coral growth rate is reduced by short-term exposure (Birkeland, et al., 1976). Diaz-Pifferer (1962) noted that corals in oil spill areas showed a "bleached" appearance. In other areas of such coral discoloration, the cause has been found to be the loss of the symbiotic zooxanthellae that are so critical to coral metabolism and growth. -33- I-A-1-3 #6sce 09/30 (3) THE SEAGRASS ECX)SYSTEM A. Introduction. The seagrass comrnunity is a highly productive, faunally rich system that covers a larger area than any other ecosystem in Monroe County. Seagrass "meadows" provide abundant food and shelter for a myriad specis of fish, sea turtles, and inverte- brates and thus probably represent the richest nursery and feed- ing grounds in South Florida's coastal waterways. Because many corrrnercially important species depend on this system at some point during their life cycle, the continued health of seagrass meadows is critical to the long-term economic wellbeing of the Monroe County community. While mangroves and coral reefs rarely abut, vast sea- grass beds freely intermingle with both systems and bridge the areas between these divergent systems. As transitional habitats, they are important to many species of both adjacent ecosystems either seasonally, as a nursery area, or for regular nocturnal feeding (as in snappers and grunts). In addition to representing a primary resource for grazers, seagrasses provide vast amounts of energy via detritus which may cycle internally or be exported to mangrove or coral reef corrmunities. Seagrass meadows also are important in stabilizing sedi- ments that woudl otherwise exist as shifting sand and mud. As such, they represent a critical element in preventing or at least regarding the loss of continental materials that would otherwise be lost by erosion to the ocean's depth. To fully appreciate the functional importance of sea- grass cormmunities one must recognize the huge extent of their geographical range in southern Florida. Of the 10,000 Km2 (3,860 mi2) of seagrass in the Gulf of Mexico, over 8,500 Km2 (3,280 mi2) are in Florida waters, primarily in Monroe County (Zieman, 1982). Seagrasses cover over 80% of the sea floor in an area bounded by Cape Sable, north Biscayne Bay and the Dry Tortugas, an area of over 5,500 Km (2,120 mi) (Zieman, 1982). In an inven- tory of the estauries of Florida's Gulf Coast, McNulty et al. (1972) estimated that almost half of the region of Florida Bay west of the Keys and landward to the freshwater line to Cape Sable was submerged vegetation. By comparison, less than 7% of the area consisted of mangroves. B. Biota. Worldwide, there are approximately 45 species of sea- grasses. In Monroe County, there are six species representing 4 genera and 2 families (See Table 1) While these comprise a small percentage of the hundreds of plant and animal species found in seagrass communities, they are clearly the most important forms because the other inhabitants depend, in some way, upon the pres- ence of these seagrass species. -34 - I-A-1-3 #5sce 09/29 Turtle Grass (Thalassia testudinum) is the most robust and widespread of the seagrasses, forming extensive meadows throughout its range. Manatee Grass (Syringodium filiforne) is more surficially rooted than Turtle Grass and rarely forms exten- sive meadows occurring most commonly mixed with other species of in small dense monospecific patches. Shoal Grass (Halodule wrightii) is found primarily in disturbed areas that are devoid of Turtle Grass or Manatee Grass and is an important early colon- izer of such sites. Overall, it is the most eurycious of the principal seagrass species in that it thrives in waters too shal- low or too deep for the other species and is the most tolerant of all species to variations in temperature and salinity (Zieman, 1982). The three species of Halophila are small forms that are sparsely distributed in seagrass communities, seldom comprising an important trophic component. All other plant species of seagrass communities are of considerably less trophic consequence. Only a few types of algae are capable of colonizing the bottom sediments, notably members of the genera Halimeda, Penicillus, Caulerpa, Rhipocephalus, and Udotea. Still other species of algae attach directly to the leaves of seagrasses. TABLE 1 SEAGRASSES OF MONROE COUNTY (After Zieman, 1982) Family and Species Common Name Hydrocharitaceae Thalassia testuctinum Turtle Grass Halophila decipiens Halophila engelmanni Halophila johnsonii Potamogtonacea Syringodium filiforne Manatee Grass Halodule wrightii Shoal Grass The successional sequence which generates a seagrass climax has been documented (Zieman, 1982) in "blowout" areas. These denuded areas may originate as a result of a sea urchin overgrazing, a large anchor dragging or a major storm. The ini- tial scar is enlarged by water flow into a bare crescentic sur- face up to 10 meters wide. Pioneer colonizers of this unconsoli- dated surface are rhizophytic algae, especially species of Hali- meda and Penicillus. Because their sediment-binding capacility is limited to their rhizoidal base, they never affect an area - 35 - I-A-1-3 #5sce 09/29 greater than a few centimeters away, but produce small consoli- dated sediment balls (Williams, 1981). After this initial sedi- ment consolidation, a succession of seagrasses colonize the blow- out surface. The first is Shoal Grass. In some sequences, Mana- tee Grass will next appear: it may be mixed with Shoal Grass at one edge and Turtle Grass (from undisturbed colony) at the other. However, Manatee Grass is the least constant member of this sequence and is frequently absent altogether. Thereafter, Turtle Grass colonizes the area and the climax is restored. The time required for recovery will vary depending on the size of the disturbance, wave intensity, and other factors but in Barbados, blowout restabilization took 5 to 15 years (Patriquin, 1975). A large invertebrate fauna inhabits seagrass ecosys- tems. Conspicuous among epibenthic forms are the Queen Conch (Strombus gigas), the Spiny Lobster (Panulirus argus), the Baha- miam Starfish (Oreaster reticulata), and numerous sea urchins, most notable Lytechinus variegatus and Tripneustes ventricosus. Numerous epiphytic invertebrates glean a livelihood from seagrass areas by preying on the algae that grow on the leaves of sea- grasses. Principal among these are a variety of gastropods (not- ably Cerithium mascarum, C. eburnum, Anachis sp., Astrea spp., Modulus modulus, Mitrella lunata and Bittium varium) and small crustanceans (especially Cymadusa coompta, Gamnarus mucronatus, Melita nitida, Grandidierella bonnieroides, Palaemonetes pugio, P. vulgasis, P. intemedius, and Periclimenes longicaudus). Many invertebrates including the Pine Shrimp (Penaeus duorarum) and the Spiny Lobster utilize seagrass meadows for nurseries. Diverse and abundant fish faunas also inhabitat seagrass corrmunities. While few, if any, of the many permanent residents forms are of direct commercial value, these ecosystems are impor- tant nurseries and feeding areas for such species. These include the Sea Bream (Archosargus rhomboides), the Sheepshead (A. pro- batocephalus), the Gap Grouper (Mycteroperca microlepis), and the Redfish (Scriaerops oscellata). Other fish that extensively utilize seagrasses as nursery areas are: Pinfish, Lagodon rhomboides Spotted Seatrout, Cynoscion nebulosus Spot, Leiostomus xanthurus Silver Perch, Bairdiella chrysura Pigfish, Orthopristi chrysoptera White Grunt, Haemulon plumeri Ocean Sturgeon, Acanthurus bahianus Doctorfish, Acanthurus chirurgus Spotted Goatfish, Pseudupeneus maculatus Yellow Goatfish, Mulloidicthys martinicus Gray Snapper, Lutianus griseus Lane Snapper, Lutjanus Synagris Mutton Snapper, Lutianus Analis Dog Snapper, Lutianus jocu Yellowtail Snapper, Ocyurus chrysurus Bucktooth Parrotfish, Sparisoma radians 36 I-A-1-3 #5sce 09/29 Redtail Parrotfish, S. chrysopterum Stoplight Parrotfish, S. viride Redfin Parrotfish, S. rubripine Striped Parrotfish, Scarus croicensis Rainbow Parrotfish, S. guacamaia Midnight Parrotfish, S. coeruleus Emerald Parrotfish, Nicholsina usta In areas where seagrass meadows abut coral reefs, many prominent species of reef fish move into seagrass areas to feed at night. Principal among them are members of the families Poma- dasyidae, Lutjanidae, and Holocentridae. The only reptile to whom seagrass constitutes a princi- pal feeding habitat is the Green Sea Turtle (Chelonia mydas). Human predation has reduced Chelonia populations to a level esti- mated at between .1% and 1% of their pre-Columbian abundance and have brought them to the verge of extinction. Presently, it is classified as a federal endangered species. Thus it is critical that all habitat critical to their survival, including seagrass meadows, be afforded protection from degradation. Large numbers of birds are known to feed extensively in shallow seagrass meadows including the endangered (Federal Status) Brown Pelican, Pelecanus occidentalis. These are listed in Table 2. Two aquatic mammals known to corrmmonly utilize seagrass communities are the Caribbean Manatee (Trichechus manatus) and the Bottlenose Dolphin (Tursiops truncatus). While Bottlenose Dolphins are common in South Florida waters generally, they are not especially commnon in shallow seagrass meadows (such as in Florida Bay) because the extreme shallowness precludes swimming for such a large ma-mnal. Caribbean Manatees are an exceedingly rare form whose low total population has resulted in their desig- nation as an endangered species. Formerly the range of the Caribbean Manatee was considerably greater but the population now seems to be centered around the protected regions of Everglades National Park. A survey of the Everglades' Caribbean Manatee population by Odell (1976) found a total of 772 individuals; 46% were sighted in Whitewater Bay, 20% in the Gulf of Mexico, 23% in inland waters, and only 1% in Florida Bay. A later study (Odell, 1979) reported no sightings in Biscayne Bay. - 37- I-A-1-3 #5sce 09/29 TABLE 2 BIRDS THAT USE SEAGRASS FLATS IN SOUTH FLORIDA (After Zieman, 1982) Preferred Cormmon Name Species Name Feeding Tide Waders-primary: Great Blue Heron Ardea herodias Low Great White Heron A. herodias Low Great Egret Casmerodius albus Low Reddish Egret Egretta rufescens Low Waders-secondary: Louisiana Heron E. tricolor Low Little Blue Heron E. caerulea Low Roseate Spoonbill Ajaia ajaja Low Willet Catoptrophorus semipalmatus Low Swirrmers: Double-crested Phalacrocorax Cormorant auritus High White Pelican Pelecanus (winter only) erythrorhynchos High Crested Grebe (winter) Red-breasted Merganser (winter) Mergus serrator Flyers-plungers: Osprey Pandion haliaetus High Bald Eagle Haliaeetus leucocephalus High Brown Pelican Pelecanus occidentalis High - 38 - I-A-1-3 #5sce 09/29 C. Disturbances. The principal naturally occurring damage to seagrass corrmunities results as a consequence of the tense wave action brought by hurricanes. The successional colonization of the resulting "blowouts" may require a decade or more as was dis- cussed previously. The greatest amount of direct damage to seagrass corrmu- nities has come as a result of dredge-and-fill operations. Filled areas, of course, become the sites of developed features and cease to function as natural systems. But dredged areas as well are severely damaged by the change in sediment characteris- tics making them unsuitable for seagrass recolonization for long periods (Sieman, 1975). The indirect adverse effects of such activities include increased turbidity and depletion of dissolved oxygen. The former reduces light penetration and thereby re- stricts productivity of surrounding systems and congests the feeding apparatus of filter feeding animals. Oxygen depletion, a consequence of the oxidation of suspended organic materials, makes the system less hopitable to allaerobic organisms. Because dredged sediments are unconsolidated and easily suspended, the banks of fill areas can represent source areas for such turbidity for long periods. The ultimate ecological consequence of such activities is the destabilization and impoverishment of the af- fected ecosystems and significant economic loss for fisheries and recreation industries (Taylor and Soloman, 1968). Zieman (1976) considers cuts from boat propellers to be the most corrmon type of disturbance of South Florida's seagrass beds. Typically, 2 to 5 years are required for recolonization of such areas in turtle grass beds. Eutrophication of seagrass corrnunities may occur through the addition of nutrients from sewage or industrial wastes. The profusion of algal growth fostered by such enrichment increases turbidity and thereby reduces the photosynthetic efficiency of seagrasses. Further, the increased deposition of dead organic matter (algae, seagrass leaves) reduces the concentration of dissolved oxygen on the sea floor and thereby adversely affects the seagrass rhizones. In some cases (Taylor et al., 1973; McNulty, 1970) seagrass populations are severely reduced or eliminated by these processes. Other documented declines in seagrass populations have been caused by oil spills (Zieman, 1982) and thermal pollution from power generating facilities (Zieman and Wood, 1975). -39- I-A-1-3 #6sce 09/30 (4) MOVES A. Introduction Mangroves and the mangrove corrmunity have long been of special interest to naturalists and scientists. Literature on mangroves dates back to Theophrastus (305 B.C.), Plutarch (A.D. 70), Pliny (A.D. 77) and Arrian (A.D. 136). A significant body of literature, describing mangroves throughout the world, has accumulated since this early period. Recent research has in- volved efforts by numerous scientists of disciplines ranging from ecology and biogeography to molecular biology and microbiology. Comprehensive reviews of this work have been published by Lugo and Snedaker (1974) and by Odum et al (1982). The more recent research has been directed towards de- termining the functional role of the mangrove corrmunity in marine ecosystems. This effort, in part, is a response to development pressures which have resulted in the elimination or degradation of many thousands of acres of Florida's wetlands. Consequently, a large and accessible data base is now available for use in land planning and resource management decisions. B. Biota The "mangrove cormmunity" is composed of a diverse asso- ciation of salt tolerant plants that provide food and habitat for a characteristic fauna. The major environmental conditions that characterize this system are: I. Loose, wet, saline soils. 2. Periodic tidal submergence. 3. Occasional tropical storms and/or hurricanes. 4. Low energy wave and current regimes. The dominants of this association are the mangroves of which, in South Florida, there are three species. Red Mangrove (Rhizophora mangle) has characterisitc stilt, prop and aerial roots and bears the cigar-shaped, viviparous seedlings. Black Mangrove (Avicennia germinans) has "pneumatophore" breathing roots and gray-green leaves encrusted with excreted salts. White Mangrove (Laguncularia racemosa) has rounded leaves with a pair of salt glands on the petiole. The Buttonwood (Conocarpus erec- tus) is often associated with the mangroves but is not a domi- nant. It occurs more frequently in what is termed the "transi- tional zone" which lies on slightly higher ground between the mangroves and upland systems. Other plants comnonly associated with the mangroves include a number of fleshy halophytes, e.g. Saltwort (Batis maritima), Glasswort (Salicornia virginica), etc. - 40 - I-A-l-3 #5sce 09/29 In Florida, the Black Mangrove enjoys the most wide- spread distribution, ranging from St. John's County on the east coast and along the entire Gulf coast. Red and white Mangroves are less widely distributed; they range from Cedar Key on the west coast to north of the Ponce de Leon Inlet (Volusia County) on the east coast. The distributional range of Buttonwood is similar to that of the White and Red Mangroves. At the limit of their respective ranges, these plants do not form the type of dense association as is typical of the South Florida populations, but occur as scattered small trees. In some areas the mangrove association is replaced by Juncus or Spartina marshes. According to Odum et al (1982), the four major factors that limit the distribution of mangroves and determine the extent of mangrove ecosystem development are 1) climate, 2) salt water 3) tidal fluctuation and 4) substrate. Odum cites work which shows that mangroves do not develop where the annual average temperature is below 66 degrees F or where water temperatures exceed the 107-113 degree F range. Contrary to popular belief, mangroves do not require salt water but are "facultative halo- phytes", i.e. they do not develop in freshwater environments only because they are not able to successfully compete with other plants. Although tidal flow is not an essential for mangroves, it benefits them by carrying nutrients into the system, prevent- ing excessive salt loading of soils and dispersing their propagu- les. According to both Odum et al. (1982) and Davis (1940), man- groves grow best in depositional envrionments with low wave ener- gy since high wave energies prevent establishment of propagules, stress the root system and prevent accumulation of fine sedi- ments. Wrack accumulations also tend to smother propagules and prevent their establishment. The historically accepted pattern of mangrove zonation was initially described by Davis (1940). The seaward zone of the intertidal area is dominated by Red Mangroves occurring as a pure stand. Moving landward, Black and White Mangroves mix with the Reds in varying proportions and, on the higher ground, Buttonwood increases in frequency. This zonation scheme was also accepted as the successional sequence leading to the climax forest, the tropical hardwood harrmock, with each zone equivalent to a seral stage. More recently, ecologists (Odum et al., 1982; Ball, 1980) have disputed this hypothesis and suggest these zonation patterns appear to result from the differential influence of physical factors on the competitive abilities of the mangrove species. Lugo and Snedaker (1974) have classified mangrove sys- tems into six types based upon their physical structure. The five that occur in the Florida Keys are overwash forest, fringe forest, riverine forest, basin forest, and scrub or dwarf forest. Overwash forests are found on small keys or peninsu- las. In many cases overwash forest is the only conrnunity which -41- I-A-1-3 #5sce 09/29 occurs on a small island. These forests are regularly overwashed by tides and often contain no land which rises above mean high water. All three mangrove species may be present, but Red Man- groves are usually the dominant form with canopy height ranging from 20 to 25 feet. Because of the regular tide sheet overflow, litter dows not accumulate and organic export rates are high. These are the preferred roosting and nesting areas for a number of birds since they are isolated from most predators of eggs and young, e.g. rats, raccoons and feral cats. Along low energy shorelines mangroves form fring forests of variable width and canopy height ranging from 20-30 feet. The zonation pattern of fringe forests closely approximately the classical scheme. Low tide and current velocities allow for colonization by these trees and for the import and subsequent accumulation of sediments. The prop roots of Red Mangrove and the pneumatophores of Black Mangrove are particularly effective in sediment accumulation. Fringing forests which face open bodies of water to the north accumulative vast amounts of detri- tus, much of which is generated by the productive, nearshore seagrass conrnunities. The rich, organic sediments, which accumu- late within the fringe forest, are often strongly anaerobic. In these soils, Black Mangroves tend to dominate probably because their pneumatophores or air roots allow access by underground portions of the tree to atmospheric grases. These root systems enable mangroves to withstand the wind and wave energies of trop- ical storms and provide substrate for marine algae and inverte- brates and sanctuary for small fish. In fringe forests, popula- tion of succulent, salt tolerant plants often form a dense ground cover. The two most corrmon species are Saltwort and Glasswort (Salicornia spp.). Here, the soil is elevated above mean sea level so that these plants are only wetted by high tides. The soils are often a mixture of organic sediments and coarse, cal- careous sand. The trees are usually medium to large and widely spaces; there is no mid-story . There is apparently enough light on the forest floor to support the prolific growth of these suc- culents. This dense association of low-growing plants, in com- bination with pneumatophores of the Black Mangroves, acts to entrap sediments and litter, thus accelerating the elevation of this zone above the influence of the tide. In this case, one can perceive the future succession to an upland seral stage. This association has recently been recognized as habitat for the en- dangered (Florida) Silver Rice Rat (Oryzomys argentatus). The best developed riverine forests occur along creeks and rivers on the mainland. In the Keys, this forest occurs only along tidal creeks. All three species of mangroves may occur, but the dominant form is usually Red Mangrove. On the mainland, this forest contains the largest trees of all the forest types, with canopy heights in excess of 60 feet but in the Keys, the structure is similar to that of the fringe forest. High rates of productivity and nutrient export are attributable to the daily tidal flushing. Mangroves growing along tidal creeks are well protected from storms and other external influences. -42- I-A-1-3 #5sce 09/29 Basin forests also are not well represented in the Keys. On South Peninsular Florida, these forests occur inland along drainage depressions where upland runoff is channeled to- ward the coast. In the Keys, they are where large,shallow de- pressions in the caprock fosters the accumulation of soil and channelize tidal flow. Forest structure is similar to overwash forests but the Red Mangrove does not dominate the system to the same extent. Black and White Mangroves occur with greater fre- quency with increasing soil elevations and diminishing tidal influence. Scrub or dwarf forest are best developed in the Lower Keys. These cormunities fail to achieve the tree size and pro- ductivity characteristic of the other forest types. Both the scrub and dwarf (known locally as "spider" mangroves) associa- tions are characterized by small trees with an understory of scattered, salt tolerant shrubs, herbs and graminoids. The scrub community generally contains all three species of mangrove but is usually dominated by Black. The trees are widely spaced and often appear stunted; dwarf mangrove associations contain trees less than five feet in height with less distance between trees than in scrub forest. These small trees, usually Red Mangroves, are not juveniles but rather dwarfed forms of this species. Both the scrub and dwarf forests occur in intertidal areas which do not enjoy daily tidal flushing. Dwarf mangroves appear to occur on slightly lower elevations than scrub mangroves. In many areas of the Lower Keys, where the forests oc- cur, e.g. Sugarloaf, Saddlebunch, and Torch Keys, the oolitic caprock is emergent, providing limited opportunity for soil ac- cumulation. Where soils do occur, they are characteristically thin, saline marls within shallow caprock depressions. Due to lack of regular tidal flushing, soils often become hypersaline during the dry season and dilute during the wet season. More- over, propagules are less likely to reach these areas since they are dispersed by tide. All of these factors make it difficult for mangroves to colonize and survive in these areas, and a num- ber of researchers believe that the scrub and dwarf forests may also be nutrient limited. In some rocky, intertidal areas conditions are so severe as to preclude the growth of woody plants. Where soils are thin and hypersaline and tidal impacts minimal, salt marshes or salt flats represent the dominant community. These associations are vegetated by salt tolerant graminoids, shrubs and fleshy succu- lents. There is usually a mangrove fringe forest waterward of the marsh. In striking contrast to the scrub and dwarf forests, there occur, within these infrequently flooded areas, occasional small strands of very large Black Mangroves. These isolated pockets are reminscent of cypress domes of bay heads in the Big Cypress Swamp and Everglades. These trees appear to flourish because they are growing within deep solution depressions in the - 43- I-A-l-3 #5sce 09/29 caprock. These sinkhole-like formations accumulate substantial amounts of organic soil or peat and are thus able to retain mois- ture throughout the year. Although they receive tidal input with the same frequency as the adjacent scrub conTnunity, the soil conditions support much higher levels of productivity and tree growth. The fact that these stands are dominated by Black Man- groves may be indicative of anaerobic and saline soil. Similar, although smaller, solution formations in this zone support stands of Red Mangrove larger than those scrub forms on the adjacent higher grounds. These shallow depressions also accumulate organic soils and thus retain soil moisture better than the thin, marl soils that cover the caprock of the scrub zone. The importance of mangrove systems both to man and to other natural corrmunities cannot be underestimated. Although the research that has documented this fact has been, for the most part, conducted outside of the Florida Keys, it would certainly be reasonably to extrapolate some of these values to the mangrove systems of this area. Mangroves protect shorelines from ero- sional damage by tropical storms and hurricanes. This not only protects upland systems but also human conrmunities. Riverine, frining and overwash forests act as "nursery areas" for a variety of finfish and invertebrates. Many of these are of economic importance to the conrmercial and sport fishing industries of the Keys as well as to the tourist economy. These forests provide both food and sanctuary from predators for larvae and juve- niles. Mangroves accelerate the deposition and stablization of particulate sediments thereby maintaining water clarify in ad- jacent open waters and enhance the ability of marine filter feed- ing organisms to obtain food by lowering the energy output re- quired to filter out inedible particulates. Marine seagrasses and algae can photosynthesize more efficiently in clear water and snorkelers and divers enjoy a better recreational experience. A number of food webs are based on primary production of the mangroves and their associated epiflora. Energy flows stem- ming from mangrove-derived carbon begin their movement through these food webs as detritus or as the products of direct graz- ing. Other pathways involve bacteria, fungi, macroalgai and phytoplankton associated with mangroves. This energy is often transferred to the human comnunity by the tourist, sport and cormmercial fishing industries. Mangroves also provide feeding, nesting and roosting habitat for numerous wading and fishing birds. Not only is the intrinsic value of this avifauna inestimable, but it augments tourism. Further, mangrove forests accumulate various nutrients and pollutants derived from upland sources. Nutrients are con- verted to plant biomass and exported in particulate or dissolved form. An undetermined portion may be tied up in the sediments or within the living corrmunity. Thus, mangrove systems act as - 44 - I-A-1-3 #5sce 09/29 natural filters, cycling some nutrients through the environment and storing othes. Mangrove-dependent Keys reptiles and marrmals with "special status" include: American Crocodile Crocodylus acutus Mangrove Terrapin Malaclemys terrapin rhizophorarum Key Deer Odocoileus virginianus clavium Silver Rice Rat Oryzomys argentatus Key's Raccoon Procyon lotor auspicatus C. Impacts Adverse human impacts upon mangrove systems in the Keys have been widespread and destructive. Ever since the period of early colonization of the archipelago by European settlers, man- grove areas have been perceived as pestilential, mosquito-breed- ing swamps which represented a barrier to settlement. Moreover, fringing mangrove forests are located on those portions of the Keys which are most valuable as homesites--open, breezy, water- front locations. Thus, the history of development in the Keys has been one of dredge and fill in mangrove areas. These activi- ties by developers clear waterfront lots and provide navigational access via dredged channels. The fill is utilized to elevate lots above tidal influence and to create access roads. These activities totally destroy mangrove forests. The construction or roads in and adjacent to mangrove areas has both direct and indirect impacts upon the coastal eco- system. Clearing and filling of roadways devastates the on-site cormunity while impoundment may isolate tidal wetlands from tidal sheet flow, drastically altering the physio-chemical character of their enviornment. Salinity regimes change, nutrient exchange is blocked, export of organic is prevented and fish and inverte- brates lose their avenues of access to the sea. The long term results of impoundment include: 1) loss of biotic divesity; 2) diminished wetlands productivity; 3) loss of wildlife habitat; and 4) diminished secondary productivity of nearshore marine systems. In cases where roads do not toally impound wetlands, these adverse impacts do not occur until a storm washes huge quantities of seawater into the impoundment and man-made con- straints on flushing prevent the release of this stormwater back to sea. Subsequent evaporation of the freshwater component leaves the impoundment with a hypersaline condition resulting in death of some populations. Hurricanes are the greatest impact of any natural force on all of the Keys' terrestrial corrmunities. Severe storms may completely destroy a mangrove corrmunity and, in some cases, (Craighead, 1971), the subsequent successional sequence may gen- erate a different corrmunity type. -45 - I-A-1-3 #5sce 09/29 The effects of human settlement adjacent to mangrove areas is most profound on wildlife populations. Birds, such as White-crowned Pigeons, are easiliy disturbed by human activity and will not nest near urbanized areas. Secondary impacts in- clude predation on wildlife, such as lizards and birds, by domes- tic animals (i.e. cats and chickens), molestation of wildlife by dogs, attraction of edificarian species, such as Black and Norway Rats (which feed on nesting birds), and introduction of exotic plants, such as Brazilian Pepper. Trimming of mangroves to increase breeze, improve views or eliminate mosquitos is a conmmon practice in the Keys. This diminishes primary productivity, eliminates bird habitat and changes air flows in the i-mnediately upland natural conrnunity. This last effect may negatively impact hardwood han-mocks by al- lowing salt spray and drying winds into a forest which is very sensitive to moisture and salt. -46- I-A-4-5 #6sce 09/30 (5) TRANSITIONAL HABITATS In the Florida Keys, the term "zone of transition" is that area which generally lies landward of the mangrove fringe and seaward of an upland cormnunity not normally influenced by tides. Within this zone, two basic types of corrmunities are recognized, the salt marshes are transitional wetlands and the buttonwood (Conocarpus erectus) are transitional upland corrmun- ities. The transitional wetland corrmunities include all tidaly influenced wetlands that are not dominated by large, fringing mangroves or areas of "spider mangroves". The transitional up- lands or buttonwood zones include the shrub corrmunity between the salt marsh zones and the higher upland habitats such as hammocks and pinelands which are not influenced by tides, not dominated by large, fringing mangroves or areas of "spider mangrove" and the buttonwood-hardwood transition." In transitional habitats several of the most important environmental factors that control species distribution occur along a gradient or "cline". These are functions of tidal in- fluence and are linearly related to distance from mean high water. They include a) duration of submergence, b) duration of exposure, and c) frequency of submergence. Thus, the position of an individual plant or invertebrate population within the transi- tional zone is an adaptive response to this complex of environ- mental gradients. In the case of animal populations, the avail- ability of food and cover also influence distribution. The Florida Keys experience mixed, semidiurnal tides of low amplitude (3 feet), with two unequal high and low tides each tidal day. Because of the low amplitude of Keys' tides, the inundation of the transition zone may be affected by several other factors including wind direction and velocity as well as shoreline exposure and slope. Microrelief is another determinant of vegetation patterns in the transitional zone since areas of exposed caprock do not accumulate soils as do shallow, eroded de- pressions in the rock. These depressions may be acres in size or only large enough to support a single plant. Elevation of the substrate, and thus drainage patterns, may also affect large or very small areas. The resulting vegetation pattern in Keys' transitional zone is a "mosaic" of plant populations. Biota Organisms living in the seaward portion of the transi- tion zone are subject to tidal inundation more frequently and of longer duration than those higher up. A species' response to the ratio of submergence/exposure and the salinity regime of its habitat may be morphological, physiological or, in the case of animal populations, behavioral. Some plants, for example, have glands which excrete the salts which enter through the roots, whereas others become succulent thereby diluting the salts. Saltgrass (Distichlis spicata), an exceptionally widespread com- 47 - I-A-4-5 #5sce 09/29 ponent of coastal marshes, is extremely salt tolerant and has a fast-growing rhizome system which allows it to colonize and res- pond to substrate fluctuations rapidly. Crustaceans, such as fiddler crabs (Uca sp.) and molluscs, such as the peanut snail (Cerion sp.), move vertically with the tide. Tidal marshes are among the world's most productive ecosystems. Southern marshes may annually produce up to ten tons of marsh grass per acre whereas Northeastern U.S. marshes produce biomass in the range of 3 to 7 tons (Niering and Warren, in Clark, 1977). Much of this plant production becomes available as organic detritus which provides the chief food base for the coas- tal fish and shell-fish populations of corrnercial importance (Darnell, 1976). Coastal marshes further provide food, shelter and nesting sites for numerous species of waterfowl and wading birds and habitat for a variety of small marrrnals and reptiles. Marshes act as nutrient traps and pollution filters thereby main- taining high water quality in nearshore waters. Marsh systems also slow down runoff and trap particulates which would otherwise reduce offshore water clarity and create stress for marine filter feeders as well as for large predators. The transitional habitats of the Keys contain species representative of the adjacent plant corrrnunities. Salt marshes and Buttonwood scrub forests are distinguished from adjacent mangrove and upland hantmock associations because the "dominant" elements differ from the latter in terms of "frequency of occur- rence" and/or coverage. Although Buttonwood occurs quite often in both mangrove and low hanrmocks, it is not the dominant ele- ment. Buttonwood, especially the larger trees, occurs on ground which is slightly higher than that of the fringing mangrove com- munity. Buttonwood scrub usually occurs as an open stand with an understory of salt tolerant succulents and small shrubs, e.g. Saitwort (Batis martima), Sea Daisy (Borrichia frutescens) and Dropseed (Sporobolus virginicus). Upland, the Buttonwood asso- ciation grades into low hammock, where it also occurs with some frequency, but is not dominant. Olmstead, et al (1981) point out that in the coastal area of Everglades National Park, between Flamingo and Joe Bay, Buttonwood stands and hammocks intergrade and it is difficult to delineate between them. Salt marshes, distinguished from adjacent associations by their low stature and lack of woody vegetation, are dominated by salt tolerant herbs, shrubs and grasses. Howard's (1950) description of the "salicornia tidal flats" of Bimini closely approximates that of Keys' salt marshes. These marshes are often found in association with areas of bare ground known as "barrens" that are devoid of macrophytic vegetation and commonly contain only mats of periphyton. Davis (1940) believes that these zones of virtually bare ground are shallow depressions in the substrate wherein high salinities (80 ppt) eliminate plant life. There is little question that Keys' salt marshes are a transitional com- munity wherein soils display highly variable levels of salinity. -48 - I-A-4-5 #5sce 09/29 The type of transitional association that develops in the Keys is a result of the primary interaction between tide and topography. In the middle and upper Keys, there is a relatively steep slope to the high ground which is elevated above normal tidal influence. In these areas, a harrmock is often found within a short distance from the high water mark. On the Florida Bay side of Vaca and Fat Deer Keys, for instance, there is a narrow, rocky, intertidal zone with scattered mangrove, Buttonwood, herbs and grasses which grades into a zone of small shrubs and trees which tolerate sea spray. This "thorn scrub" or "low hamnock" protects the upland hammock. On the ocean side of Key Largo, the slope of the intertidal is not as great and one finds a wider zone of transitional, salt tolerant vegetation landward of the mangroves. In the lower Keys, where the pitch of the intertidal zone is slight, one finds the broadest expanse of transitional zones. On Sugarloaf, Cudjoe, Big Torch, Little Torch, and on a number of other islands, transitional zones occupy areas hundreds of feet in width. On these keys, much of the eroded, oolitic caprock is exposed, creating a "karst-like" substrate with dis- junct, shallow depressions containing marl soils. The majority of these areas is wetted only by the highest normal tides and by storm tides. In the most seaward subzone of these broad, rocky trans- itional areas, one usually finds "scrub mangrove" communities dominated by small Red and Black Mangroves with an understory of Glasswort (Salicornia spp.). Salt Grass (Distichilis spicata), Key Grass (Monanthochloe littoralis) and Sea Daisy (Borrichia frutescens). Moving upland, there is a change to a more diverse plant community with fewer mangroves. Depending on drainage and soil, this association can be either the Buttonwood scrub asso- ciation or the salt marsh. Some salt marshes are mixtures of fleshy halophytes including glasswort (Salicornia virginica and S. bioelovii), Purslane (Sesuvium portulacastrum) and Saltwort with occasional Sea Daisy and small mangrove. Other marshes are dominated by grasses including Salt Grass, Key Grass, Dropseed and occasional (Fimbristylis castanea), Sea Daisy, Saltwort, Buttonwood and small mangrove. These graminoids and herbs occur as small, dis- junct populations forming a mosaic.. In some cases a single population will occupy an area of about a half acre, whereas in others, the same species might be represented by only a few indi- viduals. This distributional pattern is probably a function of the area's microrelief which determines drainage and soil salin- ity. On slightly higher ground, on Sugarloaf, Big Pine, Water, Crab and several other keys, pure stands of Chestnut Sedge or Cordgrass occur. These areas are somewhat reminiscent of the marshes of the middle Atlantic coast, but on a much smaller scale. - 49- I-A-4-5 #5sce 09/29 The most landward subzone generally contains the most diverse flora because of its proximity to the upland hamnock forest. Here Buttonwood becomes abundant, generally associated with an understory of Sea Daisy, Dropseed, Sea Oxeye (Borrichia arborescens), Cordgrass, Chestnut Sedge, Christmas Berry (Lycium carolinanum) and other small shrubs, herbs and graminoids. The open aspect of this association resulting from the widespread branching habit of the Buttonwoods allows much sunlight into the lower story and generates abundant vegetation beneath these trees in areas with adequate soil accumulations. A frequent epiphyte on these trees is the bromeliad Tillandsia circinnata which actu- ally requires high exposure and is very resistant to desicca- tion. The yellow-flowered Wild Allamanda (Urechites lutea) and White-flowered Rubber Vine (Rhabdadenia biflora) are also often found on Buttonwoods in this association. Moving upland the transitional uplands grade into ham- mock with its dense association of trees and shrubs, closed can- opy, vertical structure and absence of graminoids and fleshy halophytes. The landward extent of the tides is marked by the accumulation of litter on the forest floor which generally cor- responds to the hammock boundary. Often, there are small islets of low hammock within the transitional zone vegetated by small, salt tolerant trees and shrubs, e.g. Joewood (Jacquinia keyen- sis), Wild Dilly (Manilkara bahamensis), mayten (Maytenus phyl- lanthoides), Black Torch (Erithalis fruticosa), Saffron Plum (Blumelia celastrina), and Poisonwood (Metopium toxiferum). These plants are cotmmon elements of the low hammock association. Plants occurring in transitional zone that have been categorized by state and/or federal agencies as endangered or threatened include: Golden Leather Fern Acrostichum avieum Leather Fern Acrostichum danaeifolium Geiger Tree Cordia sebestena Dollar Orchid Encyclia boothiana Butterfly Orchid Encyclia tempensis Joeweed Jacquinia Kenensis Pride of Big Pine Strumpfia maritimn Bay Cedar Suriana maritima Twisted Airplant Tillandsia circinata Banded Wild Pine Airplant Tillandsia utriculata Worm Vine Orchard Vanilla barbellatus While not presently so designated, the Tamarindillo (Acacia choriophylla) should similarly be afforded endangered status in the Keys as its population is comprised of a single mature specimen and several seedlings in a transitional wetland on Sugarloaf Key. The transitional zone support a fauna somewhat different from that of the mangrove systems but there are a number of ani- mals that feed in both tidal areas. The most frequently observed - 50 - I-A-4-5 #5sce 09/29 invertebrates are various species of insects, molluscs and crus- tanceans. Of the latter, the fiddler crab (Uca spp). is often found in the salt marshes and barrens where there is adequate woil for burrowing. The white peanut snail (Cerion spp.) is often found in large numbers on the marsh floor or climbing through the low-lying vegetation, and Ram's horn snails, and the gastropods Cerithidea and Melampus are also very commnon in the marsh. The herpetofauna of Keys transitional wetlands include: Green Anole Anolis carolinensis Key West Anole Anolis sagrei stejnegeri Six-lined Racerunner Cnemidophorous s. sexlineatus Black Racer Coluber constrictor Diamondback Rattlesnake Crotalus adamanteus Cuban Treefrog Hyla septentroinalis Rough (Keeled) Green Snake Opheodrys aestivus A number of mammals utilize transitional wetlands as habitat. The endangered Key deer (Odocoileus virginianus clav- ium), and the endemic Key Vaca Raccoon (Procyon lotor auspica- tus), listed as threatened by the state, feed in salt marshes and Buttonwood scrub. The habitat of the recently described (Spitzer and Lazall, 1978) Silver Rice Rat (Oryzomys argentatus, state endangered) has been redefined to include the low intertidal zone, salt marshes, and the Buttonwood transitional comnunity (Spitzer, unpublished M.S.). Results obtained from Spitzer's recent (1984) trapping studies indicate that this rodent forages and nests in transitional wetlands, as does the endemic Keys' marsh rabbit, Sylvilagus palustris Lefner (Lazell, 1984). The importance of Keys' wetlands to wading bird popu- lations has long been recognized by wildlife biologists. Vir- tually every wading bird species resident in the archipelago forages in tidal wetlands. Scientists from the National Audobon Society have been studying Keys' birds for over 40 years and are presently continuing a three year study on Florida wading bird ecology. This study is providing documentation for the impor- tance of transitional wetlands to these birds. The unpublished results (Sprunt and Powell, Pers. Con-rn.) demonstrates that: ". . . water cycles characteristic of Florida Bay place an exceptionally high level of im- portance on transition zone habitats through- out the Keys for the survival of wading birds. The topography of Florida Bay and extreme South Florida in general restricts water flow between the Keys, the Atlantic Ocean and the Gulf of Mexico. As a result, water levels in Florida Bay fluctuate season- ally and the Bay remains continually flooded for several weeks and even months of the year. During these periods, most wading birds -51 - I-A-4-5 #5sce 09/29 are unable to feed in their usual feeding areas because the water is too deep for them to wade. Consequently, they are forced to seek alternative feeding sites and therefore, move into the high marsh and transition zone habitats which are generally covered by shal- low water at that time. During these periods, the existence of undisturbed transition habi- tat is critical to the survival of birds that at other times feed on seagrass meadows adja- cent to the Keys. This seasonal dependence on habitats that are available primarily on the main line keys is illustrated in the data we have collected on wading bird abundance in Florida Bay. During the months of September and November, when Florida Bay water levels were high, the birds were absent fromthe Bay and were feeding instead in transitional zone habitats." Wading birds of "special status" that feed in transi- tional wetlands include: Roseate Spoonbill Ajaia ajaja Great White Heron Ardea herodias accidentalis Great Egret Casmerodius albus Little Blue Heron Egretta eaerulea Snowy Egret Egretta thula Reddish Egret Egretta rufexens Tricoloned Heron Egretta tricolor White Ibis Eudocimus albus Black-crowed Night Heron Nycticorzx nycticorax Yellow-crowned Night Heron Nyctanassa violacea Glossy Ibis Plegadis falcinellus Impacts The ecological history of Keys' wetlands is often a reflection of disturbance and the biota's collective response to these extreme environmental pulses. Salt marshes are often formed by the action of storms and hurricanes which create natural impoundments on the periphery of these islands. The impounded wetlands contain saline, marl soils which are subse- quently wetted by storm overwash or seasonal rains. The most destructive disturbance is that of hurricanes. Hurricanes often reset the time line of ecological succession as in the case of the 1960 hurricane Donna. According to Craighead (1971), who reported the effects of Donna on Everglades National Park: "...the seed of batis imrrmediately germinated and formed an almost continuous ground cover throughout the entire saline zone on low tidal - 52 - I-A-4-5 #Ssce 09/29 lands where the mangrove stands had been killed and sunlight reached the new soil left by the storm tide. Batis is a light-demanding plant that was relatively scarce before Hurri- cane Donna in all well stocked mangrove forest areas. The seeds float and were widely dis- tributed in the fresh mud deposits. By the end ofthe second sunmmary following this storm, pratically the entire area of destruction could be distinguished from the air by the yellowish-green ground cover of this scrubby plant. The stems of batis loop over and intertwine to reach a height of 2 to 3 feet, making a tangle that is very difficult to penetrate. This mat is an effective hindrance to the growth of mangrove seedlings. A similar phenomenon occurs when mangroves are removed or impounded by man. The fleshy halophytes suppress mangrove development but are eventually "shaded out" once the mangroves become re-established. If, on the other hand, the soils of the impounded area remain hypersaline, mangroves will not survive and a salt marsh or barren will result. Buttonwood areas of the Keys and Everglades National Park, which had been cleared for charcoal production, now contain a flora dominated by graminoids, herbs and small shrubs. The Buttonwoods are now recolonizing and the pre-existing sere will return. A less dramatic disturbance occurs in salt marshes as a result of compacting of the vegetation and soils by heavy equip- ment or off-road vehicles. Salt marsh plants have shallow root systems which form a rhizosphere only a few inches below the soil surface. This confines the feeding rootlets to the zone wherein salinities are less than that of the deeper soil. This strati- fication results from the leaching action of rainwater which percolates downward, or drains off, carrying with it the accumu- lated salt load. Moreover, the shallow marl soils tend to com- press under loan, diminishing the interstitial speace between soil particles, which is important for gas, water and nutrient exchange. Thus, one finds persistent tracks or scars in salt marshes which are the impact marks of vehicles which have killed the vegetation and created conditions inimical for recoloniza- tion, a situation quite similar to the "prop-scarring" of marine seagrass beds by power boats. Filling areas adjacent to transitional wetlands can produce adverse impacts by interrupting tidal flow and possibly changing salmity. Impoundments in adjacent areas may have simi- lar effects. Examples include construction of roads and subdivi- sion between transitional wetlands and the source of tidal sheet flow for these areas. -53- I ~I-A-4-5 ll6sce 09/30 1 ~(6) SALT POMJS I ~~~~Salt ponds occur throughout the Florida Keys created both naturally and as byproducts of human activity. Some, like the famous Key West salt ponds, are remnants of former open water I ~~areas that have not been completely filled. Salt ponds are cut off from surface tidal action by storm-built berms and/or fill structures such as roads. In a topographic sense, they are actu- I ~ally shallow impoundments, receiving seawater during intense storm events and rainwater on a regular, seasonal basis. The Florida Coastal Coordinating Council, in their 1974 report on the 5 ~Florida Keys, identified salt ponds as: "Shallow, enclosed basins with very restricted tidal influence and generally having extremely variable salinity and temperature. This char- acteristic is directly related to the season of he earand the rainfall/evaporation bud- ger. Due to these extremes in salinity and temperature, conditions are adversse for most organi1sms found in coastal wetlands. For these reasons such areas have populations I ~~~~restricted to specialized organisms able to tolerate the rigorous environment. Such popu- lations tend to change with salinity fluctua- I ~~~tions caused by alternating periods of rain- fall and drought." In the Keys, salt ponds range in size from less than one I ~acre to tens of acres. The best known are located in Key West, Cudjoe, Little Torch and Long Keys. Seasonally variable water depths range from 2 feet to occasionally dry in the late I ~spring. Salinity of pond waters has been measured at 6 ppt to 66.3 ppt and sediment salinities in some ponds probably exceed this latter f igure and at the end of the dry season. Tempera- I ~~tures of the small volumes of water contained in these ponds approach those of the ambient air, which are reported to range from 69.4 to 84.9 F (monthly mean, Key West). In the smal ler ponds, and in the larger ponds during periods of dry-down, water I ~temperatures probably experience a daily range considerably dif- ferent from these reported monthly averages. In these cases, 3 ~peak summer values undoubtedly exceed 90 F. Salt ponds sediments are generally a mixture of organic mud marlI (a mud precipitated by plants, consisting of mostly calcium carbonate), and coarser-grained, calcereous skeletal elements derived from marine organisms. These sediments often have a reddish color. Their composition reflects a history of both in situ deposition and storm deposition. In some ponds, I ~there is only a thin (1-2 inches) marl layer over the caprock, wehreas in others, sediment depths exceed a foot and are often 3 ~anaerobic. I -~~~~~~~~~~~54- I-A-4-5 #5sce 09/29 Biota. The extremes of temperature, salinity, exposure and edaphic conditions, provide an explanation for the depauperate flora and low plant biomasss of these ponds. Vascular plants and marcoalgae are most frequently represented by the green algae Bataphora aerstedii and Acetabularia crenulata on coarse sub- strates and Widgeon Grass (Ruppia maritima) and Spike Rush (Eleo- charis cellulosa) rooted in the sediments. Occasional Black Mangrove (Avicennia germinans) and, less frequently, Red Mangrove (Rhizophora mangle) are to be found in the ponds, especially on their periphery. The smaller ponds often contain little or no macroscopic vegetation whatsoever. In larger ponds the Spike Rush and occasional mangroves are restricted to the pond margins and the central area usually contains no emergent vegetation. It appears, therefore, that these ponds may be filling in from the perimeter. The seasonal fluctuations and extremes of temperature, salinity and exposure characteristic of these salt ponds are inimical to the seagrasses which normally occur in shallow water bodies in the Keys. Seagrasses are usually abundant in similar areas which are regularly influenced by surface tidal flow. Turtle Grass (Thalassia testundinum) withstands temperatures of 91-95 F, but growth falls off rapidly if these temperatures are sustained. Shoal Grass (Halodule wrightii) prefers 68-86 F, but is somewhat more eurythermal than Turtle Grass. Turtle Grass can survive salinites of 3.5-60 ppt but can tolerate these extremes for only short periods; below 20 ppt this species loses leaves. Shoal Grass is the most euryhaline (Zieman, 1982). Exposure of normally submerged aquatic plants to the desiccating influences of atmospheric air represents an extreme stress, especially when the duration of exposure is greater than a tidal cycle. According to Zieman (1982): "The seagrasses of south Florida are all sub- tidal plants that do not tolerate exposure well. Exposed leaf surfaces will lose water constantly until dry, and there is not con- straint to water loss that would limit dry- ing. Although exposure to the air definitely occurs at certain low tides on shallow turtle grass or shoal grass flats, unless it is ex- tremely brief, the exposed leaf surfaces will be killed." Probably the best adapted biotic element of the salt ponds is the periphyton, an association of microalgae, primarily blue-greens, which form mat-like structures composed of fine, algal filaments. In wetland areas which periodically dry out, these mats appear as black crusts on the surface of the caprock or sediment. These seemingly dead algal mats come to life when wetted in a manner similar to that of the epiphytic Resurrection - 55- I-A-4-5 #6sce 09/30 Fern (Polypodium polypodioides). The periphyton is now believed to be a significant component of shallow, wetlands areas. On the Florida mainland, the periphyton is found abundantly in all three of the Water Conservation Areas, Everglades National Park, the Big Cypress Swamp and inland prairies of the southeast coast. It is a food source for caddisflies, mayflies, stoneflies, scurds, zooplankton and fish (Gleason and Spackman, in Gleason, 1974). The blue-grass algal constituent of the periphyton is believed to be important to the percipitation of the calcitic mud (marl) which forms much of the sediment in salt ponds. The synergistic effects of periodic exposure, hyper- salinity, high water temperature and sub-optimal edaphic condi- tions severely limits or excludes seagrasses and mangroves from salt ponds. Those forms which have evolved the adaptations which enable them to withstand these stresses, for example, Widgeon Grass and blue-grass algas, are among the few survivors. Salt tolerant seeds and seedlings of mangroves are herbaceous plants, for example, Saltwort, Glasswort, and others, accompany the storm surge into the ponds. The seasonal occurrence of hurricanes coincides with the fruiting period of mangroves, thus ensuring a large seed/seedling supply for dispersal. If the ponds receive enough mud to elevate their buttoms above standing water, and if soil salinities are not excessive, a saltmarsh or mangrove system may result. If soil salinities exceed the tolerance of marsh plants or mangroves, then "salt flats" or "salt pans" develop. These areas generally contain a sparse association of halophytes and a ground cover of periphyton. In the long term absense of a storm event, the ponds will fill in, from their periphery inward, as a result of the in situ deposition of plant detritus, that is eutrophication. The subsequent seral stages would then progress through a marsh or mangrove system and possibly climax in a hard- wood hammock. A severe drought would undoubtedly delay this progression for an indeterminate period of time. Although the flora of salt ponds is depauperate, especi- ally when compared to other Keys' wetlands, the fauna is di- verse. Raccoons, insects, snakes and a great diversity of migra- tory and resident birds utilize the food resources of salt ponds. Within the ponds are found a variety of small fish, crus- taceans and mollusks. Mollusks found in considerable abundance include the genera Cerithium and Modulus. Fish species fre- quently reported to occur include the Sheepshead Minnow (Cyprinodon variegatus), killifish (Fundulus spp.), Rainwater Killifish (Lucania parva), Mosquitofish (Gambusia affinis), and Sailfin Molly (Poecilia latipinna). Birds know to utilize Keys salt ponds as feeding habitat include: Great Blue Heron Great White Heron Great Egret Snowy Egret Tricolored Heron Little Blue Heron White Ibis Roseate Spoonbill - 56 - U I-A-4-5 #i5sce 09/29 Reddish Egert Green Heron Willet Greater Yellowlegs Lesser Yellowlegs Dowitcher Dunlin Blue-winged Teal Brown Pelican Herring Gull Laughing Gull Ring-billed Gull Royal Tern Corrmon Tern Forster's Tern Semipalmated Plover Western Sandpiper Black-bellied Plover Semiplamated Sandpiper Yellow-crowned Night Heron Those listed by the Florida Corrmittee on Rare and Endangered Plants and Animals are underlined in the above list. Species of Fundulus, Cyprinodon, and Poecilia are the primary food fishes of the rare Roseate Spoonbill (Ogden, in Pritchard, v. 2, 1978) and the White Ibis (Kushlan, 1979). Similarly, the rare Reddish Egret is reported by R.T. Paul (Pers. Corrmn.) to feed primarily on Killifish. Impacts The most direct human impact upon salt ponds is that of filling for development, an activity that destroys the entire system. Development adjacent to a pond, although not affecting the pond's structure, diminishes its functional integrity through adverse impacts upon resident wildlife. Feral and domestic ani- mals, which invariably accompany residential developments, harass wildlife, especially birds and the close proximity of human acti- vity often discourages birds from foraging, roosting and/or nest- ing, thereby limiting reproductive success and ultimately dimin- ishing populations. - 57 - I-A-6 #5sce 09/30 3 ~(7) BEACHES AND BERMS A. Introduction Beaches, or beach-like systems, are not especially com- mon in the Florida Keys. Their frequency increases from the upper to the lower region of the archipelago. Keys with a large percentage of land mass composed of beach are to be found in the Marquesas, Tortugas and Sand Keys. In the lower Keys, beaches occur on Key West, lower Sugar loaf, Big Pine, the Newfound Harbor U ~Keys and Bahia Honda Key. On these islands the beaches front the waters of Hawk Channel and the channels that flow into it. On the Gulf side of the lower keys, noteworthy beaches can be found on the Content and Sawyer Keys. Moving up the Keys, beaches occur on Boot Key, Key Colony Beach, Grassy Key, Long Key and on the Atlantic side of the Matecumbes. There are no natural 3 ~beaches in the upper Keys. Beach systems in the Keys are generally composed of two components. The most seaward component is the "beach" which is I ~defined as "the unvegetated part of the shoreline formed of loose material, usually sand, that extends from the upper berm to the low water mark" (Clark, 1977). The "berm", as defined by this author, is "a ridge or ridges on the. backshore of the beach, formed by the deposit of material by wave action, that marks the upper limit of ordinary high tides and wave wash; berms have sharply sloping leading edges." The Florida Natural Areas Inven- I ~tory abstracts state that "many dune-like sites in the Keys and along the Gulf coast of the peninsula are actually storm-deposit 3 ~ridges classified as 'coastal berm'." Beaches form when the proper combination of source material, topography, wave energy and currents coincide. In the Keys, this harmony of physical factors does not occur nearly as I ~often as on the Florida mainland. Here, there are no streams bearing sediments generated by the erosion of upland areas, nor are there strong longshore currents importing sands from upshore I ~sources. Moreover, the shallow, gently sloping bottoms adjacent to these islands reduce the effectiveness of waves carrying sand landward. Further offshore, the coral reefs of the Florida Reef Tract dissipate the energies of large oceanic waves and swells by causing them to break miles from the beaches. In most areas of the Keys, wave energies are so low that beaches never form; in- stead, if water depths are shallow, mangrove systems or mud flats I ~develop. As a result of the normally low wave energies which impact Keys' beaches, the active beach zone is quite narrow, standing in sharp contrast to the wide beaches of Daytona Beach I ~or Fort Lauderdale. The width, slope and zonation of a beach system are functions of wave energy, direction, and near-shore current as well as the characteristics of the sand itself. Waves impacting the shore contribute sand to the beach, whereas waves which break 3 ~at an angle cause sand to be transported offshore. The slope of -58 - I-A-6 #4sce 09/29 a beach represents the topographic response to wave energy and direction. Large storm waves erode a beach, thereby increasing the slope angle, while gentle waves generate an accumulation of sand which decreases beach slope. The broad surface of a gently sloping beach absorbs wave energies preventing their impact fur- ther inland. When winter storms remove sand from a beach, it is replaced by material from the berm. "It is the capacity of the berm-and dune system to store sand and yield it to the adjacent submerged bottom that gives this system its outstanding ability to protect the shorelands." (Clark, 1977) Immnediately seaward of the beaches of several Keys (e.g. Long Beach, Big Pine Key, Content Keys) there is a broad, shallow sloping, rocky ledge that parallels the entire shoreline. This intertidal area separates these beaches from deeper waters off- shore and acts as a buffer to waves in a manner similar to thatof wide, shallow sloping beaches found in other areas of the Keys such as Bahia Honda and Smathers Beach, Key West. It is very likely that gently sloping sand beaches covered these rocky, intertidal areas. This sand was probably deposited in the berm by storms, leaving the exposed rock. The sands which form Keys beaches and berms are composed primarily of the calcareous remains of the marine organisms which live in shallow offshore waters. Foremost of the contributors to these sands are mollusks, stony corals, echinoids and green algae such as Halimeda and Penicillus. The framentary remains of these organisms are generally coarse and angular in constrast to the fine particles of silica which form the sands of most northern beaches. This coarse fraction of sediments is sorted from the fine by the action of wave and current. Coarse material is deposited in the higher energy areas such as beaches and slope tops of channels, whereas the fine muds end up in quiescent areas such as mud banks, shallow embayments and mangrove fringes. Subsequent to the deposition of this material on the beach, it is either carried upward to the berm by stormwaves or transported offshore by nearshore currents. Because of its rela- tively large size and angularity, this sand is not readily trans- ported by the wind as are the siliceous sands of mainland beaches. This explains the absence in the Keys of the shifting or high dunes characteristic of beaches in the middle Atlantic seashore. Thus the narrow beaches characteristic of the Keys are created by an interaction of low wave energy and coarse sand. The berms or sand ridges result from storm waves which transport sand from the shallow submerged bottoms and beach zones landward. The physical environment of beaches is one of ex- tremes. Beaches are subject to high soil temperatures, persis- tent wind, occasional severe storms, intense sunlight, salt spray and periodic inundation by seawater. The coarse, calcareous sands of Keys beaches have little capability for moisture-reten- tion. Excellent drainage, high temperatures and constant air movement result in high rates of percolation and evaporation of -59- I-A-6 #4sce 09/29 soil moisture. During the numerous cloudless days, light levels are intense due to both direct sunlight and light reflected from the sand and surf. Storms and high winds have erosive effects on the substrate occasional ly causing "blow-outs" of sections of beach. All of these factors combine to make the beach a harsh environment for both plants and animals. Soil salinity is also an important limiting factor to plants since sale represents a I ~physiological stress. A transect study of Barbados beaches has shown that soil water increases landward and soil salts de- crease (Gooding, 1947) and this would presumably be true for * ~Keys beaches as well. B. Biota U ~~~In spite of these conditions, beaches support a rich biota which is specifically adapted to this environment. More- over, these animals and plants not only tolerate this harsh en- vironment, but also stablize and maintain its physical struc- ture. Plants which become established on loose sand and are able to grow upward at a rate exceeding deposition, stabilize it by preventing wind and water erosion. Roots easily penetrate these coarse calcareous sands so that fast-growing plants with deep root systems can reach below the dry top soils. In addition, the lants add an organic component to the calcareous sand by contri- I ~buting leaves and other plant parts (humus). Thus, both the amount and distribution of berm soils and their ability to retain moisture are directly related to the amount and type of resident vegetation. According to Furley and Newey (1979), "the distribution of plant corm-unities appears to show a very close relationship to the character of soils which in turn strongly reflect the nature of the topography. Soil moisture appears to play a significant part in the composition of the vegetation ..."1 Soil factors have I ~a controlling influence on the kinds of plants that occur on the strand, their zonation and the successional sequence leading from bare substrate to a mature climax conmmunity. Wind affects beach vegetation both mechanically and physiologically. High wind causes direct injury to plants through defoliation and breakage of woody parts. Plants exposed I ~to excessive and/or constant wind tend to lose water from their tissues (evapotranspiration) at a rate faster than it can be replaced. These plants become desiccated and either die entirely I ~or in part. This results in assymetric growth since new growth is protected on the leeward side and new windward growth is sub- ject to desiccation and death (windpruning). This is thought to explain the "shearing" effect observed on dunes and mangrove islands. Emergent vegetation that would rise otherwise above the canopy, or protrude seaward, is sheared off by wind effect re- sulting in a flat-topped canopy with a landward slope to the I ~vertical aspect of the woody vegetation. it has been hypothe- sized that this streamlined profile deflects the force of hurri- I ~canes and prevents uprooting of trees. -60- I-A-6 #i4sce 09/29 The biota characteristic of beach systems throughout the world occurs in generalized zones or associations. Each zone is a band running parallel to the shoreline occupied by a distinct assemblage of plants and animals that are adapted morphologic- ally, physiologically and behaviorally to the environmental con- ditions of that zone. The boundary between zones may be well-defined or obscure. The physicochemical factors which in- teract with the biota to create these zones include: 1. TOPOGRAPHY a. Vertical elevation of the berm. b. Slope c. Distance from shore d. Orientation to prevailing winds. 2. SOILS a. Moisture b. PH c. Nutrients d. Salinity 3. LIGHT and TEMPERATURE a. Angle and duration of exposure to sunlight b. Shading effects 4. RAINFALL Precipitation decreases linearly from the upper Keys to the Tortugas. Because Keys beaches are xeric (dry habitats), many plants show "xeromorphic" adaptations to this condition. These include succulence, rapid growth, deep roots, cutinized, and/or involuted leaves, reduced leave size, epidermal hairs, etc. Sea Oats (Uniola paniculata), a con-mon beach grass, is quite important to their stability and possess a number of these adaptations. Oosting and Billings (1942) described Uniola as "a fast growing, rhizomatous pioneer which can grow and reach opti- mum development under constant influence of wind and salt spray at a maximum distance from the water table. It dominates the ocean side of the force dune and crest of the rear dune." Other xeromorphic plants commnonly found on Keys shores include Cord- grass (Spartina Paten), Sea Purclane (Sesuvium portulacastrum) and Sea Lavender (Tournefortia gnapholodes. -61- I-A-6 #4sce 09/29 Four distinct zones on Keys beaches are generally recog- nized (Davis, 1942). These are: 1. A strand-beach association of pioneer halophytic (salt tolerant) species. 2. An essentially herbaceous strand-dune association, on the fore part of the low dunes. 3. A strand-scrub association. 4. A strand-hanmmock association. This generalized zonation scheme is typically found only on the most highly developed beach systems such as on the keys between Key West and the Tortugas. For the remaining islands, this distinct zonation, with some variation, occurs on Bahia Honda, lower Sugarloaf, Big Pine, the Newfound Harbor Keys and the Conte Keys. On other keys, this zonation complex is not as well developed. The strand-beach association is dominated by plants which are salt tolerant, root quickly, germinate from seed rapidly and can withstand wave wash and shifting sand. Commonly found species include Sea Purslane (Sesuvium portulacastrum), Railroad Vine (Ipomoea pes-caprae), Beach Grass (Panicum amaru- lum), Sea Oats (Uniola paniculata), Sea Lavender (Tournefortia gnapholodes), Coastal Ragweed (Ambrosia hispida), Bay Cedar (Suriana maritma), Cenchrus and Chamaesyce. On most Keys beaches this association occurs only at the base of the berm since the beach zone is very narrow. These plants also occupy the most seaward portion of the berm and continue some distance land- ward. On a number of Keys beaches, mangroves and Buttonwood (Conocarpus erectus) have become established in this zone. In the Content Keys, for instance, there is a narrow band of Red (Rhizophora mangle) and Black (Avicennia germinans) Mangroves just landward of the intertidal, bare, caprock bottom. This mangrove fringe, which is only 1-3 trees in width, grades into the sandy, foreshore zone of the beach. This zone of the beach is especially important to shore- birds since it accumulates vast amounts of decomposing organic material which supports a myriad of small invertebrates such as amphipods, isopods, crabs, mollusks, worms and others. Fre- quently observed birds in this zone include sandpipers, plovers, Ruddy Turnstones, Sanderlings, Killdeer, Dowitchers, Willets, Dunlins, and gulls. These birds feed on these small inverte- brates. The next zone, Davis' "strand-dune" association, begins with a steep and distinct increase in slope upward from the beach. This sloping portion fo the berm receives the effects of the highest spring tides as well as storm-generated wave wash. The berm may be elevated only several inches or as much as sev- -62- I-A-6 #4sce 09/29 eral feet above the level of the beach and may extend landward hundreds of feet as flat-topped plateau or beach ridge. On sec- tions of the Bahia Honda and Marquesas beaches, there are series of parallel ridges separated by shallow swales. The foreslope of the berm is vegetated primarily by the above-listed species of the beach association. Grasses and her- baceous plants, which stabilize this area, are most coomnon. As one proceeds landward, these pioneer species are joined by other species such as Chaff Flower (Alternanthera maritima), Sea Daisy (Borrichia frutescens), Cordgrass (Spartina patens), Beach Orach (Atriplex arenaris), Spider Lily (Hymenocallis latifolia), and Sea Rocket (Cakile lanceolata). On a number of Keys beaches, Australian Pines (Casuarina equisetifolia) have become estab- lished in this zone effectively competing with the native vegeta- tion. It is quite possible that the extensive root systems of these trees interferes with marine turtle nesting. Another exotic, Leatherleaf (Colubrina asiatica), has also become estab- lished on Keys beaches forming dense thickets in the seaward portion of the berm. If the berm is narrow, as on Content and Sawyer Keys, the grass and herb-dominated association covers the majority of the zone. If, however, the berm is a wide feature, as on Long Beach and Bahia Honda, both "strand-scrub" and "strand-hamnock" associations develop. Davis (1942) states that a minimum width of 75 yards is required for the simultaneous occurrence of all three stages of this succession. However, on a number of Keys' beach systems these two associations occur on berms that are not this wide. In these cases, either the scrub has developed with- out a haramock or both corrmunities develop as narrow zones. An additional exception to Davis' scheme occurs in areas where a mangrove fringe fronts a narrow dune ridge. In such cases, as on No Name Key, a scrub or hammock association develops without a beach. The strand-scrub association is generally considered a transition zone between strand-dune and hamnock forest. Shrubs and occasional trees occur more frequently here and become more abundant as one proceeds landward. Species often found include Seagrape (Coccoloba uvifera), Wild Sage (Lantana involucrata), Seven-year Apple (Casasia clusiifolia), Blolly (Guapira dis- color), Gray Nicker (Caesalpina crista), Blackbeac (Pithecello- bium guadalupense), Nightshade (Solanum bahamense), and the Prickly Pear Cactus (Opuntia stricta). Occasional larger trees include Buttonwood, large Seagrape, Blolly, Gumbo Limbo (Bursear simaruba), and Jamaica Dogwood (Piscidia piscipula). Vegetation occurring as an understory or in open areas includes many of the previously-mentioned graminoids and herbs as well as Natal Grass (Rhynchelytrum repens), Spanish Needles (Bidens alba) and Yellow- top (Flaveria linearis). This transitional association is the seral stage which preceeds the succession to climax hammock forest. The most landward zone on the berm is occupied by tropi- cal hardwood hammocks, which are described elsewhere. - 63 - I-A-6 #4sce 09/29 Animals inhabiting Keys beach systems include species which are endemic to the archipelago and/or listed as "en- dangered," "threatened," "rare" or of "special conern." En- dangered marine turtles have been reported to nest on Keys beaches with the most recent sightings on Long Beach, Big Pine Key and Lower Matecumbe Key. Urbanization and the establishment of Australian Pines on nesting beaches are factors resulting in the loss of this critical habitat. The Marsh Rabbit (Sylvilagus palustris) has been ob- served on the berm on Long Beach apparently utilizing the open, grassy areas. This endemic subspecies (Lazell, 1984) is also found in Chestnut Sedge (Fimbristylis castanea) dominated marshes. It is apparently present only on the Lower Keys. The Red Rat Snake (Elaphe guttata guttata) and the Eas- tern Indigo Snake (Drymarchon corais couperi) are threatened species that have been frequently observed on Keys beach sys- tems. These snakes feed on small rodents and on the abundant Anolis lizards (A. carolinensis and A. sagrei steinegeri) found in both the open areas of the berm and in the hamnocks. A number of endangered/threatened plants occur on Keys beaches including: Silver Plam Coccothrinax argentata Geiger Tree Cordia sebestena Golden Creeper Ernodea littoralis Joewood Jacquinia keyensis Sea Lavender Tournefortia gnapholodes Scaevola Scaevola plumieri Pride of Big Pine Strumpfia maritima Bay Cedar Sunriana maritima Key Thatch Palm Thrinax morrisii Yellowwood Zanthoxylum flavum C. Impacts Disturbances which affect beach systems may be natural or manmade. The most obvious of the former are hurricanes, the effects of which can be most dramatic. According to Craighead (1971), many miles of beach shoreline on the southern tip of Florida were once a mangrove fringe. This deforestation was caused by hurricanes of 1935 and 1960. Craighead believes that the mangroves did not become re-established because of tide and wrack accumulations. The establishment of exotic vegetation on beach systems in the Keys is a widespread phenomenon. Australian pines and leatherleaf are found on most beaches. In some dune hammocks, Brazilian Pepper (Schinus terebinthefolius) has also become es- tablished, often forming dense thickets. All of these plants are invasive and displace native vegetation, especially following - 64 - L I-A-6 #5sce 09/30 I~~clearing or other disturbances. Australian Pine is believed by Austin (1978) to be both an effective competitor and an imnpedi- ment to the nesting of sea turtles and the American Crocodile (Crocodylus acutus). He also believes that it opens beaches and dunes to erosion because it inhibits the growth of native plants which stabilize the sand. I ~~~Disturbance of indigenous beach vegetation either selec- tively or by total removal, has disasterous consequence for the entire system. The most obvious result is the destabilization of I ~the substrate which then is subject to rapid erosional loss lead- ing to "blow outs" of entire sections of beach under storm condi- tions. If, in fact, the structure of the system is diminished, natural and/or man-made systems which depend upon the beach for protection may be in jeopardy from storm effects. Elimination of shrubs and trees changes the wind regime thereby increasing the drying of soils and the degree of desication suffered by the I ~remaining plants. All of these factors impede the successional sequence. Further, the removal of plants diminishes the amount of food and cover for animal inhabitants. Consequently, only I ~smaller populations can be supported -- a major concern in cases where species are endangered, threatened and/or rare. I~~~~~~~~~~~~6 I-A-7-11 #6sce 09/30 (8) TROPICAL HARDWOOD HAMMOCK Tropical hardwood harrmocks represent the climax com- munity of South Florida and the Keys. These forest systems occur as isolated stands of hardwoods amid freshwater or saltwater wetlands. The flora of these corrmunities is largely derived from tropical species from the West Indies rather than the temperate forms that characterize the plant conmnunities of the Florida peninsula generally. In the Everglades, these tree islands may be seasonally flooded but elsewhere they tend to remain above water except after severe storms or hurricanes. The "soil" of these hartmocks, consists mostly of a layer of partially decomposed organic matter resting directly on a porous limestone substrate. This thin film of organics is the principal physical resource that enables ham- mocks to accorrmodate a flora that is adapted to mesic -- and not xeric -- conditions. The maintenance of this organic layer is therefore critical to the existence of tropical hardwood ham- mocks. The closed canopy of harmmocks is insulative, moderating thermal extremes (Olmstead and Loope, 1984) and reducing the loss of soil moisture. Key harrmocks are also characterized by a heterogeneity that is indirectly attributable to periodic fire and hurricanes. These natural impacts interrupt succession in all or a portion of the hanmock to produce a mosaic or seral stages within or among hamocks. Within the harrmocks, most plant species occur as "clumps" rather than being characterized by random or uniform distribution. There is a positive correlation between degree of clumping and rarity (Hubbell, 1979) which means that very rare forms may occur only in one or two places and thus are inordi- nately susceptible to elimination. Biota South Florida's tropical hardwood hanrmocks have been subcategorized as high hamrocks and low harrmocks (Davis, 1943; Alexander, 1958) on the basis of their elevation. In the Keys, low harrmocks occur approximately plus or minus 1-2 meters above sea level and high harrmocks approximately plus or minus 2-5 meters. Thus one harrmock type may grade into the other at their corrmon edge. In Monroe County, high hammocks occur primarily in the upper Keys and are rare elsewhere. Mature high hanrmocks are extremely rare, with the most mature apparently being limited to North Key Largo and Lignum Vitae Key. A typical high hamhock canopy ranges from 4-10 meters high with taller canopy species such as Mahogany (Swietenia mahagoni) protruding 3-7 meters above the canopy. Other canopy emergents include Poisonwood (Metopium Piscidia piscipula), Shortleaf Fig (Ficus citrifolia), and Wild Tamarina (Lysiloma latisiliguum). Shorter canopy species include - 66 - I-A-7-11 #5sce 09/29 Pigeon Plum (Coccoloba diversifolia), Willow Bustle (Sumelia salicifolia) and Black Ironwood (Krugiodendron Ferreum). Smaller trees like White Stopper (Eugenia axillaris) and Crabwood (Ater- amnus lucidus) may be part of the canopy or a discontinuous shrub layer. The sparse ground cover includes Snowberry (Chiococca parvifolia), Passionflower (Passiflora suberosa) and other her- baceous forms. Various bromeliads, orchids, and ferns occur as epiphytic forms. Low hammock species tend to be smaller than those of high hammocks and the canopy is correspondingly lower. The can- opy may be so low (2-3 m), in fact, that there is little distinc- tion between canopy and subcanopy. Beard (1955) attributees this and also the high occurrence of thorny species and/or forms with small, simple, stiff leaves to decreased soil moisture. In low hammocks, Buttonwood (Conocarpus erecta) joins the canopy and species such as Wild Dilly (Manikara bahamensis), Jamaica Caper (Caparis cynophallophora), and Saffron Plum (Bumelia celastrina) are usually found only in low hammock systems. Species such as Prickly Pear Cactus (Opuntia stricta) Sea Grape (Coccoloba uvi- fera) and Cabbage Palm (Sabal palmetto) are restricted primarily to low hammocks but can occur in the upper edge of transitional wetlands. Low hammocks may be further subcategorized on the basis of plant composition and substrate. Cactus hammocks are low hammocks with understories dominated by cacti of the genera Opun- tia and Cereus. While some species such as Barbed Wire Cactus (Ce-reus pentagonus), Prickly Pear Cactus (Opuntia stricta var. dillenii), and Prickly Apple Cactus (Cereus gracilis) are commnon in cactus hammocks, others are extremely rare. Tree Cactus (Cereus robinii) for instance is known from fewer than a half dozen sites in the Keys. Examples of cactus hammocks are L5/5* on Long Key and "The Cactus Hammock" on the southern extension of Big Pine Key. Palm Hamnocks are another type of low hammock. These are dominated by palms such as Florida Thatch Palm (Thrinax radi- ata), Cabbage Palm, Silver Palm (Coccothrinax argentata), or Keys Thatch Palm (Thrinax morrissii). Palm hammocks occur in the middle keys. Examples are L7/2 and L7/3 which are visible from U.S. I just north of Marathon. The third type of low hammock is the dune hammock. As the name implies, these are low hammocks which develop on dunes and they may be dominated by hardwoods or palms. Dune hammocks are found on Sugarloaf Key and a few others. * Unnamed hammocks are labeled with the numbering system used by Weiner (1979). - 67 - I-A-7-11 #5sce 09/29 Of the many plant species native to the tropical hard- wood hamn-mocks of the Keys, 37 are classified by state and/or federal agencies as endangered or threatened. These are shown on Table 1. Two species that are apparently endemic to Keys ham- mocks are Blodgett's Sage (Salvia blodgettii) and Cyperus blod- gettii (Avery and Loope, 1980). Cyperus was originally found on Upper Matecumbe and in the Lower Keys; Boldgett's Sage was re- corded from Key West. Both are inconspicuous plants, and no recent sightings are known. The environment provided by the flora of tropical hard- wood harmnocks is a major determinant of the assemblage of animal species that inhabitat these ecosystems. Because of their uni- queness and restricted occurrence, tropical hardwood harmnocks harbor many endemic or very restricted forms including several of the Keys threatened or endangered species. While amphibians are not abundant in Keys hammocks, many reptiles may be found. These include the Box Turtle (Terrapene carolina lauri), Key Mud Turtle (Kinosternon bauri bauri), the endemic Keys Mole Skink (Eumeces egregius egregius), Coral Snake (Micrurus fulvius fulvius), Eastern Diamondback Rattlesnake (Crotalus adamanteus), Big Pine Key Ringneck Snake (Diadophis punetatus acricus), Eastern Indigo Snake (Drymarchon corais couperi), Florida Brown Snake (Storeria dekayi victa), Miami Black-headed Snake (Tantilla politica), and the Florida Ribbon Snake (Thamnophis sauritus sackeni). While some of these rep- tiles apparently occur throughout the Keys, others are restricted to only a portion of the archipelago. The coral snake, for in- stance, is apparently limited to upper Keys hamnnocks. Many species of birds utilize tropical hardwood ham- mocks. Those known to nest in Keys hammocks are: Swallow-tailed Kite Elanoides forficatus Red-shouldered Hawk Buteo lineatus Osprey Pandion haliaetus Mourning Dove Zenaidura macroura Ground Dove Columbigallina passerina Mangrove Cuckoo Coccyzus minor Yellow-billed Cuckoo Coccyzus americanus Screech Owl Otus asio Chuck Will'w Widow Caprimulgus carolinensis Pileated Woodpecker Dryocopus pileatus Corrrmmon Flicker Colaptes auratus Red-bellied Woodpecker Centurus carolinus Gray Kingbird Tyrannus dominicensis Great-crested Flycatcher Myiarchus crinitus Carolina Wren Thryothorus ludavicianus Mockingbird Mimus polyglottus Brown Thrasher Toxostoma rufum White-eyed Vireo Vireo griseus Black-whiskered Vireo Vireo altiloguus Red-winged Blackbird Agelaius phonicius - 68 - I-A-7-11 #5sce 09/29 Common Grackle Quiscalus guiscula Cardinal Richmondena cardinalis Within the Keys, the range of some species is quite limited. The Pileated Woodpecker and Carolina Wren, for instance, are known only from Key Largo. Endangered or threatened bird species using tropical hardwood hammocks include the Peregrine Falcon (Falco pere- grinus), which hunts along the hammock edge or treetops and the White-crowned Pigeon (Columba leucocephala). The latter is a spring and summer resident of the Keys that is not found else- where in the United States. They nest in mangroves but feed in hammocks. Mammals that utilize Keys tropical hardwood hammocks include the Opossum (Dildelphis marsupialis), Gray Squirrel (Sciurus carolinensis matecumbei), Raccoon (Procyon lotor), Marsh Rabbit (Sylvilagus palustris), Hispid Cotton Rat (Sigmodon hispi- dus), Least Shrew (Cryptotis parva), the Bobcat (Lynx rufus). Four species of subspecies of mammals that inhabit Keys hamrrmocks are classified by state and/or federal agencies or endangered or threatened. These are: Key Largo Woodrat Neotoma floriana smalli Key Largo Cotton Mouse Peromyscus gossypinus allapaticola Key Vaca Raccoon Procyon lotor auspicatus Key Deer Odocoileus virginianus davium Originally the Key Largo Woodrat and Key Largo Cotton Mouse were apparently limited to hardwood hammocks in North Key Largo. Both were introduced to Lignum Vitae Key in 1970 where they appear to be prospering. The Key Vaca Raccoon is known from Grassy Key to Key West. The Key Deer is found only on the lower Keys at present. Key Deer utilize several communities for feeding but show a pref- erence for open harrmocks and pinelands (Layne, 1974). Of the many invertebrates inhabiting Keys harrmocks, two are endangered forms. These are the Stock Island Tree Snail (Orthalicus reses reses) and the Schaus Swallowtail Butterfly (Heraclides aristodemus ponceanus). The former was originally restricted to Stock Island and Key West while the latter is known only from North Key Largo and Elliott Key where it deposits its eggs primarily on Torchwood. Some color forms of the Florida Tree Snail (Liquus fasciatus) are restricted to specific ham- mocks, and it appears that collectors have eliminated some forms. - 69 - I-A-7-11 #5sce 09/29 Impacts Impacts which affect hanTnocks on the Keys are varied and include natural activities such as hurricanes and fires. Man-induced impacts include activities such as land clearing, dredging, ditching, filling and the introduction of exotic plants. The nature of these impacts depends on the integrity and size of the harrmock and its wildlife. Recovery from the impacts depends on the condition, size and amount of surrounding hammocks and wetlands or the type of development in adjacent land. Due to the intricate relationships of hammock species, seemingly insignificant impacts can result in extensive repercus- sions. For instance, loss of a large Mahogany adversely affects the Mahogany Mistletoe (Phoradendron rubrum) which grows only on the tops of mature Mahogany trees. Hurricanes are probably the most important natural force that impacts terrestrial ecosystems in the Florida Keys. The degree of disturbance, of course, varies with hurricane intensity but severe hurricanes can devastate hardwood hammocks and many years or even decades may be required for recovery. The sloping outline of a mature hammock canopy may deflect winds (Craighead, 1974). Thus, hurricane impact is more severe if the hammock edge is not intact. Fires, too, can alter hammocks for long periods since they may destroy the shallow organic "soil" that is essen- tial for the structure and function of these ecosystems. Eventu- ally, however, successional changes will reestablish the species assemblage characteristic of the original system. This is at- tributable largely to the fact that such natural catastrophes are recurring phenomena to which target species have evolved a gene- tic accomodation. The currmulative impact of these adaptations generates a regular and orderly successional recovery following such events. Alterations mediated by humanity are usually more en- during and sometimes permanent. By 1974, over 50% of South Florida's tropical hardwood hammocks had been destroyed (Robert- son & Kushlan, 1974). Land clearing, dredging, ditching, and filling modify the edaphic conditions that are essential to ham- mock restoration. Further, these activities remove the propa- gules that constitute the gene base for successional recovery. The extensive introduction of exotic plants further complicates the prospects of recovery from natural or human-caused impacts since some of these tend to out-compete and eventually replace some native species that are links in the seral recovery sequence that would otherwise generate a harrmock climax. Brazilian Pepper (Schinus terebinthifolius) is one such troublesome weed. While it seems incapable of establishing a toehold in unmodified ham- mocks, it rapidly invades altered hammock areas and may delay or even prevent recovery depending on the severity of disturbance. In part, the vulnerability of hammocks is attributable, as men- tioned, to the easily destroyed meager soil resource that is the edaphic foundation of its fragile trophic structure. But this - 70 - I-A-7-11 #5sce 09/29 vulnerability is further attributable to their isolation and discontinuity which can make recruitment of successional forms difficult and thereby retard or prevent reestablishment of a hanmmock climax. The speed and likelihood of recovery are in- versely proportional to distance separating the altered area from an unaltered system from which recruitment can occur. The incidence of filling uplands appears to be increas- ing. It is likely that recolonization of abandoned fill sites will result in a species assemblage that differs from the biota of the original hammock because of differences in substrate. Mosquito control activities also result in the degrada- tion of harrmocks. Mosquito ditches provide avenues for saltwater intrusion and invasion by exotics. Mosquito spraying may affect pollinators as well as mosquitoes. Road construction has seriously affected hammocks both directly and indirectly. In addition to the direct destruction of harrmock acreage, road construction dissects and thereby frag- ments these systems. On North Key Largo for example all hammocks are dissected by U.S. I or C-905, most through (or close to) the center. The increased access thus provided to hammocks results in further indirect environmental damage by increasing storm damage, invasion of exotics, soil dessication, collecting, il- legal dumping, fire vandalism, and wildlife mortality. Removing the understory and ground cover from hammocks is becoming a common practice in the Keys. This practice, loc- ally called "grubbing out," provides visual access, increased airflow and space for planted colorful exotics. This severely degrades hammocks by direct elimination of smaller plants (in- cluding the young of canopy species), reduction of wildlife habi- tat and increased exposure to the dessicating influences of wind and light. -71- I-A-7-11 #5sce 09/29 Table 1: Species of Keys hammocks that are presently listed as Endangered or Threatened on state or federal lists* include: Scientific Name Commnon Name Acrostichum aureum Golden Leather Fern Acrostichum danaeifolium Leather fern Chrysophyllum oliviforme Satinleaf Cereus gracilis Prickly apple cactus Cereus pentagonus Barbed-wire cactus Cereus robinii Tree cactus Clusia rosea Balsalm apple Coccothrinax argentata Silver Palm Cordia sebenstena Geiger tree Cupania glabra Cupania Encyclia boothiana Dollar Orchid Encyclia tampensis Butterfly orchid Eugenia confusa Redberry stopper Guaiacum sanctum Lignum vitae Hippomane mancinella Manchineel Jacquinia keyensis Joeweed Opuntia stricta Prickly pear cactus Polypodium heterophyllum Vine Fern Polypodium phyllitides (Campyloneuron) Strap fern Pteris longifolia var. bahamensis Ladder brake Salvia blodgettii Blodgett's sage Swietenia mahagoni Mahogany Thrinax morrissii Keys thatch palm Thrinax radiata Florida thatch palm Tillandsia balbisiana Reflexed wild pine Tillandsia circinata Twisted air plant Tillandsia fasciculata Wild pine Tillandsia flexuosa Banded wild pine Tillandsia setacea Needle leaved airplant Tillandsia utriculata Giant wild pine Tillandsia valenzuela Soft-leaved wild pine Vanilla barbellata Vanilla orchid Vittaria lineata Shoestring fern *Endangered status is shown in the Table on "Threatened and En- dangered Plants of the Florida Keys." - 72 - I I-A-7-11ll #6sce 09/30 (9) PINELANDS Pinelands are fire-climax systems dominated by pines. In the absence of fire, pinelands ultimately are transformed into hardwood harrmocks--a process that may require several decades (Alexander and Dickson, 1970). Although pinelands formerly existed in the Upper Keys (Alexander, 1953), their occurrence in Monroe County is presently limited to the Lower Keys, primarily on Little Pine Key, Big Pine Key, No Name Key, Cudjoe Key, Sugar- loaf Key and on neighboring Keys (Weiner, 1979; Robertson, 1955). Biota Pinelands are seral systems that are less easily charac- terized biotically than climax hardwood hammock. Caribbean Pine (Pinus elliottii var. densa) is the canopy dominant and Silver- palm (Coccothrinas argentata), Black-bead (Pithecellobium keyense) and the Keys Thatch Palm (Thrinax morrisiia) are the primary midstory forms. Species composition of the understory is less easily characterized since it changes as succession pro- gresses. Understory plants of rather general occurrence in pine- lands are Long-stalked Stopper (Psidium longipes), Pisonia (Pisonia rotundata), and Locustberry (Byrsonima lucida). In the absence of fire, Poisonwood (Metopium taxiferum) and other hard- wood hammock forms invade pineland understory. The ground cover consists of a large number of species (Alexander & Dickson, 1970); the most important are Golden Creeper (Eonodea littonalis), Sand Flax (Linum arenicola), Pine Pik (Bletia purpurea), Pine Fern (Anemia adiantifolia), Star Rush (Dichromena floridensis) and Andropogon virginicus. As a consequence of frequent fires, the leaf litter of pinelands is shallow and discontinuous. This, and the open nature of the canaopy, generates a drier environment with more thermal extremes than occurs in the hardwood hammocks of Ever- glades National Park (Robertson, 1955; Olmsted, 1984) and ap- parently in the Keys). In the absence of fire, pinelands understories tend to develop a subcanopy of hardwood species that eventually expands to replace the pine canopy. Nonetheless, the successional se- quence is prolonged enough and fires frequent enough to allow continuous presence of Keys pinelands for periods long enough to generate several endemic plants species (Table I). Examples are the Keys Senna (Cassia keyensis), two spurges (Chamaesyce del- toidea var. serpylludm and C. porteriana var. keyensis), Gerardis keyensis, and Schizachyrium sericatum. At least 11 keys pine- lands plants are presently listed as threatened or endangered by state or federal agencies. These are: - 73 - I� I-A-7-11 #6sce 09/30 Golden Leather Fern Acrostichum aureum Leather Fern Acrostichum danaefolium Pine Fern Anemia adiantifolia Keys Senna Cassia keyensis Small-flowered Lily Thorn Catesbaea parviflora Silver Palm Coccothrinax argentata Michaux Orchid Habenaria quinquesta Ladder Brake Fern Pteris longifolia var. bahamensis Pride of Big Pine Strumpfia maritima Keys Thatch Palm Thrinax morrisii Vanilla Orchid Vanilla barbellata In the absence of fire, a pineland in the southern peninsula of Florida may be replaced by hardwood hammock after about 25 years (Alexander, 1967); in the lower Keys, 50 years (Alexander & Dickson, 1970). The pinelands of some of the lower Keys presently have almost succeeded to hardwood hammock. In the Pinelands of Cudjoe Key, for example, there exists a hardwood understory 6 meters or more high and ground cover species typical of pinelands are absent. Pinelands are the home of many animal species including several forms endemic to the Keys. Endemic reptiles that utilize the pinelands include the Keys Mole Skink (Eumeces egrigius egrigius), the Big Pine Key Ringneck Snake (Diadophis punctatus acricus) and Florida Brown Sanke (Storeria dekayi victa). An- other endemic snake, the Florida Ribbon Snake (TThamnophis sauri- tus sackeni), is a denizen of wetlands that is sometimes found in pinelands, especially at points on interface with wetlands. The Eastern Indigo Snake (Drymarchon corais couperi) is a threatened form that regularaly utilizes pinelands and another threatened form, the American Alligator (Alligator mississippiensis) util- izes pinelands as corridors from one freshwater hole to another (Don Kosin, pers. comrr.). While there are no bird species endemic to the Florida Keys, many threatened or endangered forms occur here and a species are known to rest here. Species that utilize pinelands include the Bald Eagle (Haliaeetus leucocephalus Peregrine Falcon (Falco peregrinus tundrius), and White-crowned pigeon (Columba leucocephala). With the exception of the West Indian Manatee (Trichechus manatus latoristris) all endangered/threatened mam- mals of the Florida Keys are endemic (mostly subspecific) forms. Two of these that regularly utilize pinelands are the Key Deer (Odocoileus virginianus caluium) and Key Vaca Raccoon (Pro- cyon lotor auspicatus). While Key Vaca Raccoons are versatile animals that adapt well to moderate environmental modification, Key Deer populations have been severely diminished by human im- pacts. Development has reduced to discontinuance patches the open hammocks and pinelands they prefer and has thereby generated increased contact with traffic, dogs and humans. - 74 - I-A-7-11 #5sce 09/29 Impacts The most significant natural phenomena that disturb all terrestrial ecosystems in the Keys are hurricanes and fires. As a consequence of recurring exposure, pinelands have become adapted to these disturbances and fully recover from such im- pacts. Fires, in fact, are essential to the maintenance of pine- lands since, as mentioned, these are seral and not climax commun- ities. Consequently, fire exclusion in pinelands eventually generates a proliferation of hardwood species that culminates in a tropical hardwood hammock climax. Since humans discourage fire in the vicinity of habitations, development tends to secondarily reduce the extent of pinelands whose perpetuation entails peri- odic burning. Disturbances caused by humans are more varied and fre- quently more enduring. By far the most damaging impacts are those associated with building and farming. Clearing destroys pinelands outright and subsequent construction on the site pre- cludes their reestablishment indefinitely, perhaps permanently. Indirect effects associated with development may similarly damage pinelands. The establishment of roadways, for instance, directly destroys pinelands and indirectly may reduce populations of its animal inhabitants (Key Deer for example) via road kills. Simi- larly, dogs harass and kill Key Deer and other pinelands fauna. Impoundments within pinelands can drastically change the local soil moisture regime and cause the suffocation of roots and the corresponding death or dieback of plants. Following a hurri- cane, these impoundments may hold saltwater for periods long enough to cause damage to plants. Another secondary impact of development is the intro- duction of exotic plants and animals. In some cases, as with landscape plants for instance, introductions are purposeful. The major offenders, however, are exotic species that prefer dis- turbed sites and consequently tend to characterize the environs of developed features. Brazilian Pepper (Schinus terebinthi- folius), and Australian Pine (Casuarina equisetifolia) are the most invasive forms in Monroe County. Unfortunately, exotic species that populate disturbed sites constitute a reservois from which these invasive forms can colonize unmodified pinelands when natural forces (such as fire or hurricane) rekindle the succes- sional sequence. Another adverse impact associated with development is the excavation of wells, canals and mosquito control ditches. Here the potential damage is more subtle and less easily quanti- fied. On the larger keys a freshwater "lens" -- a subterranean reservoir of rainwater that has percolated through the overlying soil and limestone -- rests above the denser saltwater that has seeped in laterally. The principal impact of wells is to dimi- nish these lenses through the direct withdrawal of fresh water. Canals and mosquito control ditches carry away fresh water that - 75 - I 3 ~~I-A-7-11 #5sce 09/29 3 ~would otherwise provide recharge and also provide an avenue whereby saltwater can reach and contaminate these lenses. It is reasonable to assume that such reductions of groundwater availa- bility will adversely affect overlying ecosystems, including pinelands, although this has not been demonstrated. Mosquito spraying in pinelands can severely reduce the I ~population of their insect inhabitants including species essen- tial to pollination. The damage attributable to such spraying is compounded by the openness of the pineland canopies that allows extens ive penet rat ion. There exists another dimension to the extent of damage inflicted by humans on pinelands and other terrestrial ecosystems U ~~in the Florida Keys. This is the reduction of large natural expanses to small isolated patches of habitat. This destabilizes the habitat type by complicating recovery from disturbance (since I ~source areas for floral or faunal repopulation may be distant) and reducing the populations of wid ranging forms. Key Deer, for instance, may move between the remnants of a formerly contiguous ecosystem and thereby be exposed to traffic (the primary source of mortality), dogs, hunters and other limiting influences. I~~~~~~~~~~~~7 I-A-7-11 #5sce 09/29 TABLE 1 ENDEMIC PLANTS OF SOUTH FLORIDA PINELANDS Species found in the Florida Keys* Species Habitat Range Argythamniablodgettii pinelands Keys and mainland Cassia keyensis pinelands Keys** Chamaesyce deltoidea var. serpyllum pinelands Keys** C. garberi pinelands, hammocks sand dunes Keys and mainland C. porteriana var. keyensis pinelands, dunes Keys** C. porteriana var scoparia pinelands Keys, possibly Big Cypress Croton arenicola pinelands, dunes Keys and mainland Evolvulus sericeus var averyi pinelands Keys and mainland Gerardia keyensis (Agalinis) pinelands Keys** Linum arenicola pinelands Keys and mainland Melanthera parvifolia pinelands Keys and mainland Phyllanthus pentaphyllys var floridanus pinelands Keys and mainland Schizachyrium sericatum pinelands Keys** Tragia saxicola pinelands Keys and mainland I * according to Avery and Loope (1980) ** endemic to the Keys only - 77 - I-A-7-11 #6sce 09/30 (10) FRESHWATER WETLANDS Small expanses of freshwater wetlands occur, primarily in the Lower Keys, as vestiges of the more expansive systems that existed prior to the 1950's. The diminution of these wetlands has resulted from filling for development and draining for mos- quito control. Biota Both Cowardin (1979) and Clark (1977) characterize freshwater wetlands by the presence of erect, graminoid vegeta- tion rooted in poorly drained, saturated soils which are rich in organics. Wetlands are flooded either permanently or for a suf- ficient period each year to support communities of waterdependent plants. Two types of freshwater wetlands occur in the Keys. The most extensive is the Sawgrass (Cladium jamaicense) - dominated marsh. Keys' sawgrass marshes are quite different from the vast sawgrass marshes of the Everglades where a tall (6-10 foot) dense monoculture of sawgrass occurs on deep ( 2 feet), peaty soils which are covered by water for most of the year. In the Keys, small, disjunct, sawgrass-dominated associations occur on much shallower soils are individual plants are much smaller. Other species comrnon to Keys' sawgrass marshes include: Saw Sedge (Cyperus ligularis), White-top Sedge (Dichromena floridensis), Leather Fern (Acrostichum sp.), False Foxglove (Agalinis spp.), Aster (Aster tenuifolius), Broom Sedge (Andropogvon glomeratus) and Buttonwood (Concocarpus erectus). Two vines--Mangrove Rubber Vine (Rhabdadenia biflora) and Wild Allamanda (Urechites lutea) -- as well as a variety of bromeliads, occasionally occur on the Buttonwoods. Sawgrass occurs ubiquitously in both fresh and brackish wetlands. In areas which contain brackish water or slightly saline soils, the association often includes other salt tolerant forms including the sedges Fimbristylis castanea and F. spatha- cea, and the grasses Sporobolus virginicus and S. domingensis. In these areas, Buttonwood and mangroves frequently occur. In small, shallow solution depressions on Big Pine, No Name, Cudjoe and Sugarloaf Keys, dense stands of Saw Palmetto (Serenoa repens) are found closely associated with sawgrass. The other type of freshwater wetland found in the Keys is the Cattail marsh. This marsh occurs much less frequently than the Sawgrass association but occurs on Knockemdown, Big Pine, Little Torch, Middle Torch, Sugarloaf and Cudjoe Keys. Narrow, linear stands of Cattail (Typha sp.), established in mosquito ditches, occur throughout the Lower Keys. These marshes are flooded by freshwater during the wet season and contain wet to moist soils throughout the year since their deep, organic layer has a high water-holding capacity. - 78 - I-A-7-11 #5sce 09/29 It appears that the portions of this habitat which have the deepest, organic soils support almost pure stands of Cat- tail. On the higher periphery of the marsh, Spike Rush (Eleocha- ris cellulosa) and Sawgrass occur. The Spike Rush often occurs in pure stands just a few inches below the Sawgrass and is also found in brackish salt ponds. Buttonwoods and occasional man- groves occur on the borders of the marsh supporting mixed popula- tions of bromeliads, i.e. Tillandsia spp. and, at one time or- chids, e.g. Encyclia teampensis, which require a high relative humidity. Because cattail marshes naturally occur well within the confines of haramocks protected from the xeric atmospheric conditions characteristic of more open areas of the Keys, they are probably subjected to saline influences only during hurri- canes. Freshwater marshes normally support a highly diverse and abundant fauna which includes fish, invertebrates, amphibians, reptiles, birds and mammnals. On the mainland of South Florida, they are critical to the reproductive success of animal popula- tions which bear young during the dry season. Here, they are habitat for the threatened American Alligator (Alligator missis- sippiensis) and the endangered (state) endemic Key Mud Turtle (Kinosternon bauri bauri). The recently described Silver Rice Rat (Oryzomys arentatus) was originally discovered in a Cattail marsh on Cudjoe Key (Spitzer & Lazell, 1978). According to Jacobsen (1983), the small, isolated popu- lation of alligators in the lower Keys (Big Pine, Little Pine and No Name Keys) is dependent upon preservation of freshwater habi- tats in this area. Lazell (Pers. Corm.) believes that the opti- mal habitats of the mud turtle are small fresh or slightly brack- ish ponds in or at the edges of hardwood han-mocks. The various frog species of the Keys as well as the Florida Ribbon Snake (Thamnophis sauritus sackeni) require freshwater habitats during at least a portion of their life history. The federally-endangered Key Deer (Odocoileus virgini- anus clavium) is only found on those islands which contain both food and fresh water. Although this animal moves out from Big Pine/No Name Keys (population center) during the wet season, it returns here during the drier months. Maintenance of above- ground, freshwater resources in undeveloped areas is therefore critical to its survival. Freshwater marshes are important to both resident and migratory bird populations. During the dry season, freshwater wetlands are the only natural sources of water for the Key Deer. Impacts The impact of hurricanes on freshwater wetlands can be devastating. In addition to the outright destruction of the system's biota, the deposition of salt water can have an indirect adverse effect on its flora. Hurricane impact is discussed more fully in the section dealing with tropical hardwood hammocks. - 79 - I-A-7-11 O.sce 09129 Human impacts which most affect freshwater wetlands include filling, mosquito ditching and the dredging of upland canals and borrow pits. While filling directly eliminates this habitat, dredging is believed to diminish surface freshwater I ~resources. The blasting and dredging, which accompanies canal and borrow pit construction, exposes shallow, water-containing strata of bedrock to salt water intrusion and evaporation. This lowers freshwater levels in ponds and marshes thereby decreasing the size of this habitat and diminishing, or making unpalatable, drinking water supplies available for wildlife. This problem is especially important to the Key deer populations on No Name and Big Pine Keys, islands with the archipelago's largest fresh, groundwater resources. I ~~~Mosquito ditches, which are widespread in the lower Keys, have had disastrous consequences for freshwater wetlands. The ditches were intended to drain or bring in tidewater to up- I ~land areas which contained standing water, which were believed to be mosquito breeding areas. As a consequence, numerous fresh- water wetlands were drained or subjected to saltwater intrusion, thereby creating a brackish mixture in what was historically a freshwater habitat. Ultimately, salt tolerant vegetation dis- placed freshwater-dependent species and much freshwater wildlife habitat was lost. Ironically, many of these ditches, since they I ~are not maintained, have become cut off from surface tidal in- fluence, and therefore contain freshwater during the wet season-- the period of maximum mosquito activity. These ditches also tend I ~to trap deer fawns. The ditches do, however, provide limited habitat for Cattails and Leather Fern as well as alligators and small fish. I-A-7-11 #6sce 09/30 (11) PLANTS AND ANIMAL SPECIES OF SPECIAL STATUS Table 1: PLANT SPECIES OF THE FLORIDA KEYS WITH SPECIAL STATUS STATUS: SCIENTIFIC NAME COMMON NAME STATE FEDERAL FCREPA Acrostichum aureum Golden Feather Fern THR None Rare Acrostichum danaeifolium Leathern Fern THR None None Anemia adiantifolia Pine Fern THR None None Campyloneurum phyllistidis Strap Fern THR None None * Cassia Keyensis Big Pine Partridge END UR THR Pea (Key Cassia) Catesbaea parviflora Small Flowered Lily END END END Thorn Cereus gracilis Prickly Apple Cactus END UR THR Cereus pentagonus Barbed Wire Cactus THR None None Cereus robinii Tree Cactus END END END Chrysophyllum oliviforme Satin Leaf THR None None Clusia rosea Balsam Apple (USA) END None EXTINCT Coccothrinax argentata Silver Palm END None THR Cordia sebestena Geiger Tree THR None None Cupania glabra Cupania END None END Enclyclia boothiana Dollar Orchid END UR None Encyclia tampensis Butterfly Orchid THR None None Eugenia confusa Redberry Stopper THR None None Guaiacum sanctum Lignum Vitae END None None Habenaria quinquesta Michaux's Orchid Hippomane mancinella Manchineel THR None THR Jacquinia Keyensis Joewood THR None None Mallotonia gnapholodes Sea Lavendar END None THR syn: Tournefortia gnaphalodes Micrograrrma heterophylla Vine Fern syn: Polypodium heterphyllum Opuntia spinosissima Semaphore Cactus Pseudophoenix sargentii Buccaneer Palm THR None END Pteris longifolia Ladder Brake THR None None var. bahamensis Scaevola plumieri Scaevola END None None Strumphfia maritima Pride of Big Pine END None END Suriana maritima Bay Cedar END None None Swietenia mahagoni Mahognay THR None None Thrinax morrisii Florida Thatch THR None THR Palm Thrinax radiata Key Thatch Palm THR None THR Tillandsia balbisiana Reflexed Wild THR None None Pine Airplant Tillandsia circinata Twisted Airplant THR None None syn. paucifolia Tillandsia fasciculata Wild Pine END None None Airplant - 1 I-A-7-11 #5sce 09/29 Tillandsia Flexuosa Banded Wild Pine THR None THR Airplant Tillandsia setacea Needle-leaved THR None None Airplant Tillandsia utriculata Giant Airplant THR None None Tillandsia valenzuelana Soft-leaved Wild Pine Vanilla barbellata Worm Vine Orchid THR None THR Vittaria lineata Shoestring Fern THR None None KEY: FCREPA = Florida Corrmittee on Rare and Endangered Plants and Animals END = Endangered THR = Threatened UR = Under Review = Endemic to Florida Keys - 82 - I-A-7-11 i5sce 09/29 Table 2: ENDANGERED AND THREATENED FAUNA OF THE FLORIDA KEYS STATUS: SCIENTIFIC NAME CCOtION NAME STATE FEDERAL FISHES: *Menidia conchorum Key Silverside END None AMPHIBIANS AND REPTILES: Alligator American Alligator (SSC) THR mississippiensis Caretta caretta carretta Atlantic loggerhead THR THR turtle Chelonia mydas mydas Atlantic green turtle END END Crocodylus acutus American crocodile END END *Diadophis punctatus Big Pine Key ringneck THR UR acricus snake Dermochlys coriacea Leatherback turtle END END Drymarchon corais couperi Eastern indigo snake THR THR Eretmochelys imbricata Atlantic hawksbill END END imbricata turtle *Kinosteron bauri bauri Key mud turtle END UR Lepidochelys kempi Atlantic ridley turtle END END *Storeria deKayi victa Florida brown snake THR UR (Lower Keys only) Tantilla oolitica Miami black-headed snake THR UR *Thamnophis sauritus Florida ribbon snake THR None sackeni (Lower Keys only) BIRDS: Charadrius aleandrinus Southeastern snowy END UR tenuirostris plover Columba leucocephala White-crowned pigeon THR UR Falco peregrinus Peregrine falcon END END Haliaeetus leucocephalus Bald eagle THR END Mycteria americana Wood stork END UR Pelecanus occidentalis Eastern brown pelican THR END carolinesis Sterna dougallii Roseate tern THR UR Sterna antillarum Least tern THR None MAMMALS: *Neotoma floridana Key Largo wood rat END END smalli - 83 - I I-A-7-11 #5sce 09/29 *Odocoileus virginianus Key deer THR END clavium *Oryzomys argentatus Silver rice rat END UR *Peromyscus gossyupinus Key Largo cotton mouse END END allipaticola *Procyon lotor Key Vaca raccoon THR UR auspicatus Trichechus manatus West Indian Manatee END END latoristris INVERTEBRATES: *Heraclides aristodemus Schaus' swallowtail END END ponceanus butterfly *Orthalicus reses Stock Island tree snail THR THR KEY: END = Endangered THR = Threatened UR = Under Review SSC = Species of Special Concern * = Endemic to Florida Keys - 84 - I I-A-7-11 #6sce 09/30 I ~(12) EVALUATION AND RANKING OF FLORIDA KEYS HABITATS The Florida Keys Habitats were broken down into ten I ~groups for the purposes of evaluation of impacts. Three matrices were developed. The first (Table A) is an impact matrix on habi- tat structure and function which categorizes the activities with- in and adjacent to the particular type habitat types which exist on the Keys. The second and third matrices (Tables B and C) are sensitivity matrices involving habitat type and an evaluation of the potential for impacts for each system. The impact matrix on I ~habitat structure and function presents the detailed level of evaluation of impacts while the sensitivity matrices provide an evaluation of a variety of parameters which may affect each habi- tat type. Impact Matrix on Habitat Structure and Function I ~~~Habitat types in this matrix (Table A) were broken down into eight groups with mangroves treated as a single type and freshwater wetlands also classed as a single type. Activities I ~which were deemed important to these systems were listed and numerical levels assigned to each. The numerical ratings were as follows: 3 = high impacts, 2 = moderate impacts, I =low !m- I ~pacts, 0 = not applicable. This numerical arrangement provides the opportunity for ranking the particular habitats according to the specific impacts of all possible activities which occur with- in or adjacent to these sites. A general discussion of each activity or impact is presented below along with a discussion of individual impacts in each habitat characterization. I ~~~~Impact Activities in Florida Keys Habitats Dredging Dredging activities or the excavation of ma- terials from all habitat types produce significant impacts. Once removed, habitats which have been dredged out become very diffi- cult to reestablish. In the Keys most of the habitats are very fragile and any significant dredging within these sites produces I ~effects which are often deleterious. Adjacent activities are generally less destructive to habitat types, however, in the case of habitats such as freshwater wetlands and pinelands, the im- pacts can be very severe due to lowering of the water table. Filling_. Filling of habitats within the Keys basically destroys all existing plant corrmunities. Also, most fill material does not match the soil type of the area which is being filled resulting in the production of an unsuitable substrate for 3 ~any restoration potential of the particular type of habitat. In the case of mangroves, elevational increases due to filling often lead to other habitat types such as uplands. In I ~most cases fill materials serve as substrates for exotic plants such as Brazilian Pepper. After colonization by exotic species, succession to endemic communities generally does not occur on the * ~Keys. I~~~~~~~~~~ -85 - I-A-7-11 #5sce 09/29 Impoundment. impounding water on upland habitats such as pinelands and hamrmocks generally results in severe impacts due to the increased water regime on these sites. This is also true for the impounding of water on mangroves and transitional habi- tats and by disruption of the food web in these systems. Impacts are generally less in the transitional habitats and mangroves due to less reliance of the plant species in these areas on insect pollenators and tidal pulses which generally dilute the pesti- Road Construction. Road construction involves both the movement of dirt and filling operations in allI types of habi- tats . Some grading and ditching operations may also result in either impoundment or drainage of habitat types. Road construc- I ~tion is generally more servere in freshwater wetlands, salt ponds and beaches and berms since these activities can seriously dis- 3 ~rupt these habitats. In the case of harrmocks and transitional habitats, road construction can result in the removal of the existing vegetation and, where deposition or grading occurs, lead to invasion by exotic species. In general, an opening of the harmmock habitat upsets the delicate climatological regime within these areas, thus leading to the general demise of the system. In the case of I ~mangroves, some impacts may occur on these areas either from the filling or deposition of materials. Road construction activities generally result in a change in grade or elevation of these sites I ~which either increases or reduces the intertidal regime for these sites. This action can lead to different commn-unity types de- pending on final elevations. Utilities. Utility construction in wetland areas generally results in little impacts. Some clearing may be neces- sary for the initial right-of-way construction; however, the I ~vegetative corrrunities which dominate in both the fresh and salt- water wetlands are usually not high enough to interfere with powerlines. Digging and refilling for underground utilities I ~should result in littlg longterm impacts if elevations are re- stored to preconstruction levels in these habitats. In the case of pinelands and hammrocks, utility construc- tion results in severe impacts in these areas due to removal of the canopy trees to prevent interference with powerlines and root * ~growth over pipelines. Utility construction in adjacent areas generally leads to little impacts except for moderate impacts in ham-nocks. Agains, any changes brought about such as opening of the canopy can produce significant impacts away from the actual construction site. Land Clearing.Land clearing in any type of habitat resul ts in irrmediate destruction of the vegetative corrmunities and subsequent loss of habitat for faunal species which occupy -86 - I-A-7-11 #5sce 09/29 these areas. In many cases, the amount of time for revegetation of cleared sites is extremely long due to the successional seres through which many of the cormiunities have to undergo to reach a climax state. In the case of clearing of pines and harrmocks it is likely that heavy invasion by exotics would preclude any re- vegetation of the sites by many endemic species. Land clearing in adjacent sites generally has little impact on the habitats in surrounding areas, however, fragile beach and berm overstories and harrmock overstories may be signif- icantly affected by microclimate changes in surrounding sites. Sewage disposal. In general, sewage disposal would have little effect on the plant cormmunities in wetland areas except for salt ponds. In these areas the fragile balance of hypersaline conditions can be upset by the introduction of water from sewage disposal. This activity can result in the decreased salinities leading to more freshwater systems. Some impacts would also be serious in areas such as hantmocks and possibly pinelands where increased fresh water into these systems can change the soil moisture regimes and lead to succession to a wetter habitat such as a freshwater marsh. Sewage disposal in adjacent areas generally would have little impact on any of the conmmunities or habitat types found in the Florida Keys. Landfill operations. Landfill operations in any habi- tat results in the obliteration of existing corrrnunities and also generally provides higher elevations. Any increase in elevation obviously completely wetland areas to nonwetland sites. In the Keys, disposal is generally by landfill buildup with some material placement over the site. If allowed to revegetate, any of these areas would generally succeed to upland corrmunities; however, the invasion of exotics into these sites should be sig- nificant and upset any normal successional regime which would naturally occur on these sites. Disposal operations in adjacent areas should result in little impact to any of the habitat types in the Keys. Debris-Solid waste disposal. In many parts of the Keys a significant amount of debris can be found from haphazard dis- posal operations which have occurred in the past and are still continuing today. Disposal within hammocks generally would re- sult in the addition of combustible materials which could in- crease fire hazards in these areas and areas such as pinelands and beaches and berms. In the case of freshwater wetlands and salt ponds, any addition to these sites could cause significant impacts. Also, disposal operations in many of the habitat types could open up the canopy or cover the existing vegetation and introduce seed stock of exotic species which often outcompete endemic plants. -87 - I-A-7-11 #5sce 09/29 Consumptive water use - Domestic. Consumptive water use in all habitats found on the Keys should generally r es ulIt in insignificant impacts except for those particular areas such as pinelands which depend upon the fragile balance of water for maintaining plant succession. Usually removal of freshwater for septic tank systems results in return flows back into the ground producing little net change in water balance for a particular site. The impacts of consumptive use of water in adjacent areas would probably be low for most habitats, however, if very small freshwater systems are impacted, animals in adjacent areas may be deprived of water sources. For example, many animals such as the Key deer may travel fairly long distances to a particular I ~freshwater area for water. Moderate impacts could generally be expected from disposal of water in adjacent areas to habitats such as pinelands which could suffer from higher water tables. For individuals utilizing water from the pipeline and subsequently disposing in septic tanks, the impacts could be more significant in drier habitats such as pinelands and hamrrocks due to the net increase in freshwater to these sites. Consumptive water use - Cornmercial. Any significant amount of water which would be utilized from freshwater wetlands on a corrmercial basis could severely impact these areas, whether the water is taken from within the site or from adjacent sites. I ~Net losses of water from freshwater wetlands could quickly reduce these areas to dry habitats; however, the likelihood of any sig- nificant conrmercial use from any of these areas is very small. In adjacent areas , the impacts of consumptive use of water would probably be low; however, if very small freshwater systems are impacted, animals in adjacent areas could be deprived of water sources. Settlement. Settlement activities generally involve both the direct loss of habitat and the introduction of people and pets to these sites. Direct loss of habitat from settlement is generally severe since structures placed over the existing habitat, if not permanent, result in long-term loss. Settlement I ~in adjacent areas may often result in significant impact due to the introduction of domestic pets, especially dogs, which can severely deplete or have an impact on deer populations and other species such as rabbits. Vehicular traffic (on road). Activities from vehicular traffic on roads are related to the increased encounter of both people and automobile with animal species in the areas. In gen- eral, the most significant impacts would be related to vehicular traffic through pinelands where species such as the endangered I ~Key deer may be impacted both within its habitat range and within adjacent areas due to encounters with automobiles. -88- l-A-7-11 OIsce 09/29 * ~~~Freshwater wetlands may also be significantly impacted by vehicular traffic due to the possible close proximity to these sites and possible impac ts on faunal species which t ra velI to these sites for water. Areas such as transitional habitats and uplands and mangroves would be least impacted by these areas. Salt ponds would also suffer little impact except for disturbance to wading birds which utilize these sites. Recreation. Recreation impac ts can be generally severe in those areas for which there are small acreages of habi- I ~~tat remaining on the Keys. Any kind of recreational activity such as the use of all terrain vehicles, and even hiking, plant collecting, and other activities can result in the significant degradation of habitats. When man enters these areas, his move- I ~ment through these sites can change commnunity succession and r e sulItin an upset in the successional sere f or these sites. Animal populations which occupy these areas can also be signifi- I ~cantly impacted such as the impact on the Key Largo woodrat in trans itional habitats. Recreational activities in adjacent areas generally would provide little impact except for areas such as freshwater wetlands and salt ponds of which the faunal constituency could be impacted by greatly increased contact with recreationists. Toxic wastes. Toxic waste disposal activities in areas such as freshwater wetlands, salt ponds and beaches and berms I ~could be very significant due to the small amount of habitat which exists of these areas. Also any toxic waste which would be introduced into freshwater wetlands, the source of drinking water for many endangered species and other faunal components, would greatly affect these areas. In general, toxic waste disposal in areas away f romn I ~sites or adjacent to habitat types would result in minimal im- pacts unless some transport of the toxic waste occurred through overland flow or other means into surrounding corrmunities. In I ~the case of freshwater wetlands and salt ponds any small amount of toxic waste which could be transported or would flow into these areas could result in significant environmental impacts. Ranking of Impacts on Habitat Structure and Function. The bottom of Table A shows the ranking of the particular habi- tats found on the Florida Keys according to the within/adjacent I ~~activities which may affect these sites. The sites which could potentially suffer the most serious impacts or be most sensitive to most impacts include pinelands, freshwater wetlands and ham- I ~ ~mocks. These fall into the category of high impact. Those in the moderate category include salt ponds and beaches and berms. Those ranked according to the least potential for impact activi- ties include transitional habitats and mangrove corrrunities. -89 - I-A-7-11 #5sce 09/29 Sensitivity of Florida Keys habitats to impacts. Tables B and C are primary sensitivity matrices for Florica Keys habi- tats. In Table B the ten habitat types are presented according to rarity of the systems, resilience, restoration potential and the number of threatened and endangered plant and animal species which are found in these areas. Freshwater wetlands were divided into typha marshes and cladium marshes in the sensitivity ma- trices due to the dissimilarities and general functions of these sites. Typha marshes make up only a very small percentage of the conmnunities in the Florida Keys. Mangroves were also divided into scrub mangroves and fringing mangroves in the sensitivity matrix. As for freshwater wetlands, significant differences exist between the scrub and fringing mangrove communities. Also, some of the impacts for these sites can vary due to differences in tidal amplitudes and differences in primary producitivities of these conrmunities. The resilience factor is based on the impact matrix in Table A on habitat structure and function. The ratings for habi- tats are broken down into very rare, rare, moderately rare and common for the rarity index; low, moderate and high for resil- ience index; and low, moderate and high for restoration potential of these sites. The total number of threatened and endangered species is given for each habitat unit. Rarity. The rarity of the habitat types within the Keys was ranked according to very rare, rare, moderately rare and contmon or on the basis of acreages of the habitats which occur on the Keys. The rarest corrmunity types consist of the typha marshes and the beach and berm communities. Only a very small acreage of typha marsh exists on the Florida Keys and should likely be considered in a category of its own, however, beaches and berms are also very rare and fragile systems which occur on the Keys. Those types falling into the rare category are the cladium marshes, saltponds and pinelands. Transitional wetlands and harmmocks are considered to be moderately rare or basically in between the common or frequently occurring mangroves and corrmuni- ties such as pinelands. Resilience. The resilience of communities to impact activities both within and adjacent was ranked according to the impact matrix on habitat structure and function in Table A. Those areas with the lowest resilience or ability to withstand impacts include pinelands, hammocks, and typha and cladium marshes. Those with the highest resilience or the potential to withstand impacts were transitional uplands and the mangrove corrmunities. Restoration potential. The restoration potential for the habitats which are found on the Keys relates to the ability to restore these areas to their original or natural conditions after impact activities have occurred. In the case of areas such as pinelands, beaches and berms, hammocks and typha marshes, re- storation would be very difficult. For example, pinelands would -90- I-A-7-11 #5sce 09/29 be difficult to restore to their successional sere due to the potential for invasion of sites by exotics. It is very unlikely that any pineland corrmunity could ever be restored from a prisere situation again in the Keys due to exotic. Han-mocks would also be difficult to restore due to exotic invasion and the difficulty of obtaining propagule sources for replanting sites of this type. Typha marsh communities on the Keys would also very likely be difficult to restore due to the fragile nature and the very rare occurrence of these areas on the Keys. On the other hand, cladium marshes occur in much greater numbers and different physical settings on the Keys; therefore, restoration should be easier for these sites. Salt ponds and transitional habitats also have some restoration potential, however, it is difficult to judge the potential for salt pond restoration. Any inability of the soil or substrate to hold water would prevent restoration of a salt pond. Also, the physical features and elevations surrounding these sites would likely be difficult to duplicate. Transitional uplands or buttonwood communities are often invaded by exotics are disturbance. This factor would likely preclude succession back to transitional habitats. Transitional habitats or salt marsh communities could be established given enough time and money which could be devoted to the effort; how- ever, exacting requirements of final elevations within the tidal regime make reestablishment of these areas more difficult than mangrove systems which occupy greater tidal ranges than Key salt marshes. Mangroves have the highest restoration potential for the Keys due to the physical setting for these sites. In the case of mangroves, it is very likely that restoration could be complete in many cases where final elevations and tidal exchange could be accomplished. Propagule sources are readily available for these areas and a significant amount of research on establishment has been conducted for these habitats. Threatened and endangered species. Plant and animal species which were listed as either threatened or endangered by either the State of Florida or the U. S. Department of Interior are also shown in Table B. Hanrmocks rank much higher than the other habitat types due to the large number of threatened and endangered plants which occur in these areas. Thirty eight species occur in this habitat type. Other areas which ranked high are transitional uplands and pinelands. These are followed by beaches and berms which the other habitat types ranking down to salt ponds which have no endangered plants and only three endangered animals which utilize these areas. Sensitivity ranking of Florida Keys habitats. Table C is a numerical rating for all of the factors which were con- sidered in Table B. The numerical system is based on a ranking -91 - I-A-7-1l I/sce 09/29 3 ~ ~~ of totals of the rarity, resilience, restoration potential and threatened and endangered species. The habitats with the highest potential and threatened and endangered species. The habitats with the highest potential for impacts are the hanmmocks and pine- lands. These sites would be very difficult to restore and have low resilience to the classes of impacts which were considered in this study. As previously discussed, restoration or natural succession to mature habitats of these two types would be very difficult if not impossible under most settings in the Keys. 5 ~~~~~~Beaches and berms ranked second in the potent ial f or impacts, again due to their rarity and low restorat ion poten- tial. These areas are often dependent upon a single storm event for either creation and/or nourishment. Many years would elapse before these sites would be restored, if ever. Typha marshes also rank high in the potent ial f or im- pact s. As was previously noted only a very small acreage of these wetlands exist on the Keys and any significant activity could completely eliminate these sites. These sites also serve I ~as the only substantial sources of freshwater for species such as the endangered Key deer during extremely dry periods. This fac- tor adds greatly to their importance. I ~~~Those habitats ranking intermediate in potential for impacts include freshwater cladium marshes, transitional uplands and salt ponds. These areas generally rank intermediate in re- silience and in threatened and endangered species (except f or transitional uplands). Restoration potential of these sites is also moderate. In the case of salt ponds and cladiumn marshes, these areas are quite rare; however, they also can be restored if engineering techniques for restoration can be developed in the future. I ~~~Those habitats ranking lowest on the impact' scale in- clude transitional wetlands and fringing and scrub mangrove com- munities.. As for the impact matrix on habitat structure and I ~function (Table A) these sites generally rank lower in all cate- gories for potential for impacts. These areas are generally low in number of endangered and threatened species and have high 3 ~restoration potential and resilience to impacts. In the case of the mangrove corriunities, the acreage of these habitats on the Florida Keys is much greater than any of I ~the other habitat types. A great deal is known about these sites f r om the standpoint of productivity and functional capacity; however, when viewed solely on the potential for sensitivity and I ~from an overall environmental viewpoint, these sites rank highest for development potential of the Keys habitats. -92 - - - - - m - m - - - - -M Table A. Impact matrix on habitat structure and function, Florida Keys (NOTE - The two numbers in each space correspond to impacts as follows: Activity occurring within habitat/Activity occurring adjacent to habitat). Activities Habitat TvDes Within/ FW Salt Beaches & Pine- Trans. Trans. Adlacent Wetla Ponds Berms lands Hammook Wetla nds Up-lands Mangroves Dredge 3/3 3/1 3/1 3/3 3/2 3/1 3/1 3/1 Fill 3/1 3/1 3/1 3/1 3/1 3/2 3/1 3/2 Impoundment 1/1 2/1 0/0 3/2 3/2 3/2 3/2 3/1 Mosquito Ditching 3/3 3/1 3/1 3/2 3/1 2/1 2/1 1/1 Mosquito Spraying 3/2 3/2 2/2 3/1 2/1 1/1 2/1 1/1 Road Construction 3/1 3/1 3/1 2/1 3/2 3/1 2/1 3/2 Utilities 1/1 1/1 1/1 3/1 3/2 1/1 1/1 1/1 Land Clearing 3/1 0/2 3/2 3/1 3/2 3/1 3/1 3/1 Sewage 1/1 3/1 1/1 2/1 3/1 1/1 1/1 1/1 Landfill 3/1 3/1 3/1 3/1 3/1 3/1 3/1 3/1 Debris- Solid Waste 2/1 2/1 2/1 2/1 2/1 1/1 1/1 1/1 Consumptive Water Use. Domestic 1/1 0/0 0/0 2/2 1/1 0/0 0/0 0/0 Consumptive Water Use. Commercial 3/3 0/0 0/0 2/2 1/1 0/0 0/0 0/0 Table A. Impact matrix on habitat structure and function, Florida Keys (concluded) Activities Habitat TvDes Within/ FW Salt Beaches & Pine- Trans. Trans. Adjacent Wetlands Ponds Berms lands Hagk Wetl Uand s Mangrove Settlement 3/2 3/2 3/2 3/3 3/2 3/2 3/2 2/1 Vehicular Traffic (on-road) 3/2 1/1 2/1 3/3 2/1 1/1 1/1 1/1 Recreation 3/2 3/2 3/1 3/1 2/1 3/1 3/1 1/1 Toxic Waste 1/2 1/2 I/1 1/1 1/1 1/1 1/1 1/1 Totals: 42/28 36/20 35/17 44/27 41/23 32/18 32/17 28/17 Ranks 2 4 5 1 3 6 7 8 3 = High; 2 = Moderate; 1 = Low; 0 = Not Applicable Ranked according to sensitivity to impacts Table B. Primary sensitivity matrix of Florida Keys habitats Potential for Imoacts Restoration Threatened & Endangered spp. Habitat TvDe Rarity Resilience* Potential Plants Animals Totals T E T FW wetlands Typha marsh very rare low low 0 2 2 1 5 FW wetlands Cladium marsh rare low moderate 0 2 2 1 5 Beaches and Berms very rare low low 3 0 2 3 8 Salt Ponds rare moderate moderate 0 0 3 0 3 Pinelands rare low low 3 3 4 3 13 Hammocks mod. rare low low 7 20 5 6 38 o Un Trans. Uplands mod. rare moderate moderate 1 8 2 1 12 Trans. Wetlands mod. rare moderate moderate 1 0 3 1 5 Scrub Mangroves common high high 0 0 5 0 5 Fringing Mangroves common high high 0 0 5 1 6 Based on impact matrix on habitat structure and function High=44/27-41/23; Moderate=40/22-33/19; Low=32/18-28/17 Table C. Primary sensitivity numerical matrix of Florida Keys habitats Potential for Imoacts/Rank Threat. & Restoration Endangered Habitat TvDe Raritv Resilience* Potential SDecies Totals Ranrk* Pinelands 3 3 3 3 12 1 Beaches & Berms 4 2 3 2 11 2 Hammocks 2 3 3 4 12 1 FW wetlands Typha marsh 4 3 3 1 10 3 FW wetlands Cladium marsh 3 3 2 1 9 4 Salt Ponds 3 2 2 1 8 5 Trans. Uplands 2 1 2 3 8 5 Trans. Wetlands 2 2 2 1 7 6 Fringing Mangroves 1 1 1 2 5 7 Scrub Mangroves 1 -1 1 1 4 8 Very Rare=4 Low=3 Low=3 16-38=4 Rare=3 Moderate=2 Moderate=2 11-15=3 Mod. Rare=2 High=1 High=l1 6-10=2 Common=l1 0-5=1 Based upon impact marricor h'a.t-at,- -tpurtre. and... un-tio ....... 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