[Federal Register Volume 81, Number 189 (Thursday, September 29, 2016)]
[Rules and Regulations]
[Pages 66842-66865]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-23546]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2015-0137; 4500030113]
RIN 1018-AZ95


Endangered and Threatened Wildlife and Plants; Endangered Species 
Status for Chamaecrista lineata var. keyensis (Big Pine Partridge Pea), 
Chamaesyce deltoidea ssp. serpyllum (Wedge Spurge), and Linum arenicola 
(Sand Flax), and Threatened Species Status for Argythamnia blodgettii 
(Blodgett's Silverbush)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine 
endangered species status under the Endangered Species Act of 1973 
(Act), as amended, for Chamaecrista lineata var. keyensis (Big Pine 
partridge pea), Chamaesyce deltoidea ssp. serpyllum (wedge spurge), and 
Linum arenicola (sand flax), and threatened species status for 
Argythamnia blodgettii (Blodgett's silverbush), all plant species from 
south Florida. The rule adds these species to the Federal List of 
Endangered and Threatened Plants.

DATES: This rule is effective October 31, 2016.

ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov. Comments and materials we received, as well as 
supporting documentation we used in preparing this rule, are available 
for public inspection at http://www.regulations.gov. Comments, 
materials, and documentation that we considered in this rulemaking will 
be available by appointment, during normal business hours at: U.S. Fish 
and Wildlife Service, South Florida Ecological Services Field Office, 
1339 20th Street, Vero Beach, FL 32960; telephone 772-562-3909; 
facsimile 772-562-4288.

FOR FURTHER INFORMATION CONTACT: Roxanna Hinzman, U.S. Fish and 
Wildlife Service, South Florida Ecological Services Field Office, 1339 
20th Street, Vero Beach, FL 32960; telephone 772-562-3909; facsimile 
772-562-4288. Persons who use a telecommunications device for the deaf 
(TDD) may call the Federal Information Relay Service (FIRS) at 800-877-
8339.

SUPPLEMENTARY INFORMATION: 

Executive Summary

    Why we need to publish a rule. Under the Endangered Species Act, a 
species may warrant protection through listing if it is endangered or 
threatened throughout all or a significant portion of its range. 
Listing a species as an endangered or threatened species can only be 
completed by issuing a rule.
    The basis for our action. Under the Endangered Species Act, we may 
determine that a species is an endangered or threatened species based 
on any of five factors: (A) The present or threatened destruction, 
modification, or curtailment of its habitat or range; (B) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting its continued existence. We have determined that the threats 
to Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii consist 
primarily of:
     Habitat loss and modification through urban and 
agricultural development, and lack of adequate fire management (Factor 
A); and
     The proliferation of nonnative, invasive plants; 
stochastic events (hurricanes and storm surge); maintenance practices 
used on roadsides and disturbed sites; and sea level rise (Factor E).
    Existing regulatory mechanisms have not been adequate to reduce or 
remove these threats (Factor D).
    Peer review and public comment. We sought comments from independent 
specialists to ensure that our determination is based on scientifically 
sound data, assumptions, and analyses. We invited these peer reviewers 
to comment on our listing proposal. We also considered all other 
comments and information we received during the comment period.

Previous Federal Actions

    Please refer to the proposed listing rule for Chamaecrista lineata 
var. keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, 
and

[[Page 66843]]

Argythamnia blodgettii (80 FR 58536; September 29, 2015) for a detailed 
description of previous Federal actions concerning these species.

Background

    Please refer to the proposed listing rule (80 FR 58536; September 
29, 2015) for the complete discussion of each plant's description, 
habitat, taxonomy, distribution, population estimates, climate, 
historical range, current range, status, and biology.
    Below, we present only revisions to the discussions in the 
Background section of the proposed listing rule based on new 
information from peer review and public comments; as such, not every 
plant, or every topic for a plant, will be discussed below.
    Chamaecrista lineata var. keyensis (Big Pine partridge pea)

Species Description

    Please refer to the ``Species Description'' section of the proposed 
rule for the complete discussion. We make one minor editorial revision 
to our description of the plant's fruit, as follows: The fruit is an 
elongate pod, roughly similar to that of a pea, 33-45 millimeters (mm) 
(1.3-1.8 inches (in)) long and 4.5-5.0 mm (0.19-0.17 in) wide, with a 
soft fuzzy texture, which turns gray with age and eventually splits 
open to release seeds (Irwin and Barneby 1982, p. 757; Small 1933, pp. 
662-663).

Habitat

    Please refer to the ``Habitat'' section of the proposed rule for 
the complete discussion. In the Pine Rocklands discussion, we correct 
the following names of species: Quercus elliottii (running oak) is 
corrected to Quercus elliottii (running oak), and Psidium longipes 
(longstalked stopper) is corrected to Psidium longipes (longstalked 
stopper). We also correct the reference to hardwoods in the pine 
rocklands of the lower Florida Keys; the hardwoods in the subcanopy 
include species such as Byrsonima lucida and Mosiera longipes (Bradley 
2006, p. 3).

Current Range, Population Estimates, and Status

    Please refer to the ``Current Range, Population Estimates, and 
Status'' section of the proposed rule for the complete discussion. We 
make minor editorial revisions to the first sentence of the third 
paragraph of that section, as follows: A second indicator, the 
frequency with which Chamaecrista lineata var. keyensis occurred in 
sample plots on Big Pine Key from data collected in 2005, 2007, and 
2013, also shows a decline.
Linum arenicola (sand flax)
Habitat
    Please refer to the ``Habitat'' section of the proposed rule for 
the complete discussion. Under Roadsides and Other Disturbed Sites, we 
make minor editorial corrections concerning the plant's persistence on 
roadsides, as follows: Linum arenicola was at one time more common in 
pine rocklands in Miami-Dade County, but a lack of periodic fires in 
most pine rocklands fragments over the last century has pushed this 
species into the more sunny, artificial environments it prefers 
(Bradley and Gann 1999, p. 61).
    Please refer to the ``Current Range, Population Estimates, and 
Status'' section of the proposed rule for the complete discussion. We 
make the following corrections to that discussion:
    (1) We correct the description of the current distribution of Linum 
arenicola in Miami-Dade County, as follows: In Miami-Dade County, the 
current distribution of Linum arenicola is from just north of SW 184 
Street (in the Martinez Pinelands Preserve), south to the intersection 
of Card Sound Road and the C-102 canal, and west to SW 264 Street and 
177 Avenue (Everglades Archery Range at Camp Owaissa Bauer).
    (2) We correct our description of the compilation of all survey 
work to include a missed citation for Possley (2016, pers. comm.). The 
corrected sentence reads: Based on a compilation of all survey work 
through 2016, including Austin (1980), Kernan and Bradley (1996, pp. 1-
30), Bradley and Gann (1999, pp. 61-65), Hodges and Bradley (2006, pp. 
37-41), Bradley and Saha (2009, p. 10), Bradley (2009, p. 3), Hodges 
(2010, pp. 4-5, 15), Bradley and van der Heiden (2013, pp. 6-12, 19), 
Bradley et al. (2015, pp. 28-29), and Possley (2016, pers. comm.), of 
26 historical population records for Linum arenicola, 12 populations 
are extant and 14 are extirpated (see Table 3), a loss of roughly 54 
percent of known populations, from the early 1900s to the present.
    (3) Under Miami-Dade County, we correct the location of the seventh 
population of Linum arenicola, as follows: A seventh small population, 
located in 2014 at Zoo Miami, (Possley 2016, pers. comm.) is located on 
county land.
    (4) As a result of the corrections described in (1) through (3), 
above, we present a revised version of the proposed rule's Table 3 
(note: in the following table, USFWS stands for U.S. Fish and Wildlife 
Service; FWC stands for Florida Fish and Wildlife Conservation 
Commission; HARB stands for Homestead Air Reserve Base; and SOCSOUTH 
stands for Special Operations Command South Headquarters):

              Table 3--Summary of the Status and Trends of the Known Occurrences of Linum arenicola
----------------------------------------------------------------------------------------------------------------
                                                    Most Recent
          Population               Ownership        Population          County                  Trend
                                                     Estimate
----------------------------------------------------------------------------------------------------------------
                                                Extant 12 records
----------------------------------------------------------------------------------------------------------------
Big Pine Key.................  USFWS, FWC, TNC   2,676 (2007) \1\  Monroe..........  declining.
                                \12\, Private.
Upper Sugarloaf Key..........  FDOT \13\, USFWS  73 (2010) \2\...  Monroe..........  insufficient data.
Lower Sugarloaf Key..........  FDOT \13\, USFWS  531 (2010) \2\..  Monroe..........  stable.
Big Torch Key................  FDOT \13\,        1 (2010) \2\....  Monroe..........  declining.
                                Private.
Zoo Miami....................  Miami-Dade        56 (2014) \5\...  Miami-Dade......  insufficient data.
                                County.
Martinez Pineland............  Miami-Dade        100-200 (2013)    Miami-Dade......  insufficient data.
                                County.           \6\.
Everglades Archery Range.....  Miami-Dade        23 (2012) \7\...  Miami-Dade......  insufficient data.
                                County.
HAFB \15\ 1--S of Naizare      DOD \14\, Miami-  24,000 (2013)     Miami-Dade......  stable.
 BLVD.                          Dade County.      \7\.
SOCSOUTH (HAFB 2--NW side of   DOD \14\ (leased  74,000 (2009) 7   Miami-Dade......  stable.
 Bikini BLVD).                  from Miami-Dade   10.
                                County).
HARB (SW 288 St. and 132 Ave)  DOD \14\........  37 (2011) \7\...  Miami-Dade......  insufficient data.
C-102 Canal SW 248 St. to      SFWMD \11\......  1,000-10,000      Miami-Dade......  insufficient data.
 U.S. 1.                                          (2013) \7\.

[[Page 66844]]

 
L-31E canal, from SW 328 St.   SFWMD \11\......  Plants occur      Miami-Dade......  insufficient data.
 to Card Sound Road.                              along 14 km
                                                  (8.7 mi) of
                                                  levee (2013)
                                                  \7\.
----------------------------------------------------------------------------------------------------------------
                                              Extirpated 14 records
----------------------------------------------------------------------------------------------------------------
Middle Torch Key.............  FWC, FDOT\13\...  3 (2005) \3\....  Monroe.           ...........................
Ramrod Key...................  FDOT\13\........  110 (1979) \4\..  Monroe.           ...........................
Park Key.....................  FDOT\13\........  unknown (1961)    Monroe.           ...........................
                                                  \3\.
Boca Chica...................  DOD\14\, other    unknown (1912)    Monroe.           ...........................
                                (unknown).        \3\.
Camp Jackson.................  unknown.........  unknown (1907)    Miami-Dade.       ...........................
                                                  \9\.
Big Hammock Prairie..........  unknown.........  unknown (1911)    Miami-Dade.       ...........................
                                                  \9\.
Camp Owaissa Bauer...........  Miami-Dade        10 (1983) \7\...  Miami-Dade.       ...........................
                                County.
Allapatah Drive and Old        Private.........  256 (1996) \8\..  Miami-Dade.       ...........................
 Cutler Road.
Bauer Drive (Country Ridge     Miami-Dade        8 (1996) \8\....  Miami-Dade.       ...........................
 Estates).                      County.
Silver Green Cemetery........  Private.........  47 (1996) \8\...  Miami-Dade.       ...........................
Palmetto Bay Village Center..  Private.........  12 (1996) \8\...  Miami-Dade.       ...........................
HAFB (Community Partnership    DOD\14\, Miami-   unknown (2010)    Miami-Dade.       ...........................
 Drive).                        Dade County.      \7\.
Coco Plum Circle (corner of    Private.........  75 (1996) \8\...  Miami-Dade.       ...........................
 Robles Street & Vista Mar
 Street).
George Avery Pineland          Private.........  ``small colony''  Miami-Dade.       ...........................
 Preserve.                                        (2002) \7\.
----------------------------------------------------------------------------------------------------------------
\1\ Bradley and Saha 2009, p. 10.
\2\ Hodges 2010, p. 10.
\3\ Hodges and Bradley 2006, pp. 39-48.
\4\ Austin et al. 1980 in FNAI.
\5\ Possley 2016, pers. comm., p. 11.
\6\ Possley 2014, pers. comm.
\7\ Bradley and Van Der Heiden 2013, pp. 6-11.
\8\ Kernan and Bradley 1996, p. 9.
\9\ Bradley and Gann 1999, p. 65.
\10\ Bradley 2009, p. 3.
\11\ South Florida Water Management District (SFWMD).
\12\ The Nature Conservancy (TNC).
\13\ Florida Department of Transportation (FDOT).
\14\ Department of Defense (DOD).
\15\ Homestead Air Force Base (HAFB; decommissioned).

Biology
    Please refer to the ``Biology'' section of the proposed rule for 
the complete discussion.
    We revise the Life History and Reproduction discussion to read:
    Life History and Reproduction: Little is known about the life 
history of Linum arenicola, including pollination biology, seed 
production, or dispersal. Reproduction is sexual, with new plants 
generated from seeds. L. arenicola is apparently self-compatible 
(Harris 2016, pers. comm.). The species produces flowers nearly year 
round, with maximum flowering from April to September, with a peak 
around March and April. L. arenicola population demographics or 
longevity have not been studied (Bradley and Gann, 1999, p. 65; Hodges 
and Bradley 2006, p. 41; Hodges 2007, p. 2; Harris 2016, pers. comm.).
    Argythamnia blodgettii (Blodgett's silverbush)
Species Description
    Please refer to the ``Species Description'' section of the proposed 
rule for the complete discussion. We clarify the description of the 
leaves of Argythamnia blodgettii, as follows: The leaves, arranged 
alternately along the stems, are 1.5 to 4.0 centimeters (cm) (0.6 to 
1.6 in) long, have smooth (or rarely toothed) edges, are oval or 
elliptic in shape, and often are colored a distinctive, metallic bluish 
green when dried.
Taxonomy
    Please refer to the ``Taxonomy'' section of the proposed rule for 
the complete discussion.
    To the end of the first paragraph, we add the following: Ingram 
(1952) indicates the distribution of Argythamnia argothamnoides 
(including Florida material) as Florida and Venezuela. As such, the 
Service accepts the treatment of Argythamnia blodgettii as a distinct 
species and therefore does not find a compelling justification to 
remove the species from consideration for listing under the Act.
Current Range, Population Estimates, and Status
    Please refer to the ``Current Range, Population Estimates, and 
Status'' section of the proposed rule for the complete discussion. We 
make the following corrections to that discussion:
    (1) We correct the data in Table 4, presented below. (Note: In the 
following table, USFWS stands for U.S. Fish and Wildlife Service; FWC 
stands for Florida Fish and Wildlife Conservation Commission; DOD 
stands for Department of Defense; and ENP stands for Everglades 
National Park.)
    (2) Because of the corrections presented below for Table 4, the 
text preceding the table in the proposed rule is now incorrect. Based 
on the data presented below in Table 4, there are 50 records for 
Argythamnia blodgettii in Miami-Dade and Monroe Counties. Twenty 
populations are extant, 15 are extirpated, and the status of 15 is 
uncertain because they have not been surveyed in 15 years or more.

[[Page 66845]]



          Table 4--Summary of the Status and Trends of the Known Occurrences of Argythamnia blodgettii
----------------------------------------------------------------------------------------------------------------
                                                    Most recent
          Population               Ownership        population          County                  Trend
                                                     estimate
----------------------------------------------------------------------------------------------------------------
                                                Extant 20 records
----------------------------------------------------------------------------------------------------------------
Plantation Key, Snake Creek    FWC.............  101-1,000 (2005)  Monroe..........  Insufficient data.
 Hammock.                                         \2\.
Lower Matecumbe Key--Klopp     FDEP \6\........  11-100 (2000)     Monroe..........  Insufficient data.
 Tract.                                           \2\.
Lignumvitae Key..............  FDEP \6\........  101-1,000 (2005)  Monroe..........  Insufficient data.
                                                  \2\.
Big Munson Island............  Private (Boy      1,001-10,000      Monroe..........  Insufficient data.
                                Scouts of         (2005) \2\.
                                America).
North Key Largo..............  DOD, FDOT.......  No estimate       Monroe..........  Insufficient data.
                                                  (2005) \8\.
Key Largo--Dove Creek Hammock  FWC, FDOT.......  11-100 (2005)     Monroe..........  Insufficient data.
                                                  \2\.
Vaca Key (Marathon)--Blue      FWC, FDOT.......  11-100 (2005)     Monroe..........  Insufficient data.
 Heron Hammock.                                   \2\.
Windley Key--State Park......  FDEP \6\........  11-100 (2005)     Monroe..........  Insufficient data.
                                                  \2\.
Boca Chica KWNAS \7\ Runway    DOD.............  1,001-10,000      Monroe..........  Insufficient data.
 25.                                              (2004) \2\.
Boca Chica Key KWNAS \7\       DOD.............  200 (2004) \2\..  Monroe..........  Insufficient data.
 Weapons Hammock.
Big Pine Key.................  USFWS, FWC,       ~2,200 (2005)     Monroe..........  Insufficient data.
                                private.          \2\.
ENP Long Pine Key Deer         NPS \5\.........  2,000 (2015) \4\  Miami-Dade......  Insufficient data.
 Hammock area (Pine Block A),
 Turkey Hammock area (Pine
 Block B), Pine Block E.
Fuch's Hammock...............  Miami-Dade        12 (2008) \ 1\..  Miami-Dade......  Insufficient data.
                                County.
Owaissa Bauer Addition.......  Miami Dade Parks  377 (2014) \9\..  Miami-Dade......  Insufficient data.
                                and Recreation.
Camp Owaissa Bauer...........  Miami Dade Parks  878 (2009) \9\..  Miami-Dade......  Insufficient data.
                                and Recreation.
Ned Glenn Pineland Preserve..  Miami Dade Parks  8 (2016) \10\...  Miami-Dade......  Insufficient data.
                                and Recreation.
Camp Choee...................  Private (Girl     3 (2005) \3\....  Miami-Dade......  Insufficient data.
                                Scout Council
                                of Tropical
                                Florida).
Florida Power and Light        Private.........  7 (2015) \9\....  Miami-Dade......  Insufficient data.
 Easement adjacent to Ludlam
 Preserve.
Larry and Penny Thompson Park  Miami Dade Parks  5,700 (2009) \9\  Miami-Dade......  Insufficient data.
                                and Recreation.
Boystown Pineland............  Private.........  No estimate       Miami-Dade......  Insufficient data.
                                                  (2005) \3\.
----------------------------------------------------------------------------------------------------------------
                                              Uncertain 15 records
----------------------------------------------------------------------------------------------------------------
Crawl Key, Forestiera Hammock  Private.........  10 (1982) \3\...  Monroe..........  Insufficient data.
Long Key State Park..........  FDEP............  No estimate       Monroe..........  Insufficient data.
                                                  (1999) \2\.
Stock Island.................  Private.........  No estimate       Monroe..........  Insufficient data.
                                                  (1981) \2\.
Boot Key.....................  Private.........  11-100 (1998)     Monroe..........  Insufficient data.
                                                  \2\.
Deering Estate...............  State of Florida  11-100 (1991)     Miami-Dade......  Insufficient data.
                                                  \1\.
Castellow Hammock............  Miami Dade Parks  11-100 (1991)     Miami-Dade......  Insufficient data.
                                and Recreation.   \1\.
Pine Ridge Sanctuary.........  Private.........  2-10 (1992) \1\.  Miami-Dade......  Insufficient data.
County Ridge Estates.........  Private.........  11-100 (1999)     Miami-Dade......  Insufficient data.
                                                  \1\.
Epmore Drive pineland........  Private.........  2-10 (1999) \1\.  Miami-Dade......  Insufficient data.
Gifford Arboretum Pineland...  Private.........  2-10 (1999) \1\.  Miami-Dade......  Insufficient data.
Ned Glenn Nature Preserve....  Miami Dade Parks  11-100 (1999)     Miami-Dade......  Insufficient data.
                                and Recreation.   \1\.
Natural Forest Community #317  Private.........  2-10 (1999) \1\.  Miami-Dade......  Insufficient data.
Old Dixie pineland...........  Private.........  11-100 (1999)     Miami-Dade......  Insufficient data.
                                                  \1\.
Castellow #33................  Private.........  12 (1995) \ 3\..  Miami-Dade......  Insufficient data.
Castellow #31................  Private.........  30 -50 (1995)     Miami-Dade......  Insufficient data.
                                                  \3\.
----------------------------------------------------------------------------------------------------------------
                                              Extirpated 15 records
----------------------------------------------------------------------------------------------------------------
Upper Matecumbe Key..........  unknown.........  No estimate       Monroe.           ...........................
                                                  (1967) \ 3\.
Totten Key...................  NPS.............  No estimate       Monroe.           ...........................
                                                  (1904) \1\.
Key West.....................  City of Key West  No estimate       Monroe.           ...........................
                                                  (1965) \1\.
SW 184th St. and 83rd Ave....  Private.........  0 (2016) \10\...  Miami-Dade......  Insufficient data.
Tropical Park Pineland.......  Miami Dade Parks  0 (2016) \9\....  Miami-Dade.       ...........................
                                and Recreation.
Crandon Park--Key Biscayne...  Miami Dade Parks  0 (2008) \9\....  Miami-Dade.       ...........................
                                and Recreation.
Brickell Hammock.............  unknown.........  Extirpated 1937   Miami-Dade.       ...........................
                                                  \1\.
Carribean Park...............  Miami-Dade        Extirpated 1998   Miami-Dade.       ...........................
                                County.           \1\.
Coconut Grove................  Miami-Dade        Extirpated 1901   Miami-Dade.       ...........................
                                County.           \1\.
Coral Gables area............  unknown.........  Extirpated 1967   Miami-Dade.       ...........................
                                                  \1\.
Miller and 72nd Ave..........  unknown.........  Extirpated 1975   Miami-Dade.       ...........................
                                                  \1\.

[[Page 66846]]

 
Orchid Jungle................  Miami-Dade        Extirpated 1930   Miami-Dade.       ...........................
                                County.           \1\.
Palms Woodlawn Cemetery......  Private.........  Extirpated 1992   Miami-Dade.       ...........................
                                                  \1\.
South of Miami River.........  unknown.........  Extirpated 1913   Miami-Dade.       ...........................
                                                  \1\.
Naranja......................  Private.........  No estimate       Miami-Dade.       ...........................
                                                  (1974) \3\.
----------------------------------------------------------------------------------------------------------------
\1\ Bradley and Gann 1999, p. 6.
\2\ Hodges and Bradley 2006, pp. 10-17.
\3\ FNAI 2011b.
\4\ Sadle 2015, pers. comm., p. 1.
\5\ National Park Service (NPS).
\6\ Florida Department of Environmental Protection (FDEP).
\7\ Key West Naval Air Station (KWNAS).
\8\ Henize and Hipes 2005, p. 25.
\9\ Possley 2016, pers. comm.
\10\ Lange 2016, pers. comm.

Summary of Comments and Recommendations

    In the proposed rule published on September 29, 2015 (80 FR 58536), 
we requested that all interested parties submit written comments on the 
proposal by November 30, 2015. We also contacted appropriate Federal 
and State agencies, scientific experts and organizations, and other 
interested parties and invited them to comment on the proposal. 
Newspaper notices inviting general public comment were published in the 
Miami Herald and Key West Citizen. We did not receive any requests for 
a public hearing. All substantive information provided during the 
comment period has either been incorporated directly into this final 
determination or is addressed below.

Peer Reviewer Comments

    In accordance with our peer review policy published on July 1, 1994 
(59 FR 34270), we solicited expert opinion from three knowledgeable 
individuals with scientific expertise that included familiarity with 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii and their 
habitats, biological needs, and threats. We received responses from all 
three peer reviewers.
    We reviewed all comments received from the peer reviewers for 
substantive issues and new information regarding the listing of 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii. The peer 
reviewers generally concurred with our methods and conclusions, and 
provided additional information, clarifications, and suggestions to 
improve this final rule.
    (1) Comment: One peer reviewer and one public commenter provided 
new information about the status of various populations of Linum 
arenicola and Argythamnia blodgettii within Miami-Dade County 
preserves. The peer reviewer suggested that the Service may be 
overestimating the number of extant populations of A. blodgettii, 
referring to outdated data for Tropical Park, Martinez Preserve, and 
Crandon Park. The reviewer also suggested the rule should identify the 
separate parcels within the Richmond Pinelands complex (i.e., Ram 
Development Corporation, Martinez Pineland Preserve, Larry and Penny 
Thompson Park, Zoo Miami, University of Florida, and those owned by the 
Department of Defense (DOD)).
    Our Response: The Service appreciates the new information. We have 
updated the tables, and associated text, summarizing the status and 
trends of the known occurrences of Linum arenicola and Argythamnia 
blodgettii (Tables 3 and 4, above).
    (2) Comment: Two peer reviewers and one public commenter identified 
a recent publication by Ramirez-Amezcua and Steinman (2013) that 
included a treatment of the Argythamnia subgenus Ditaxis in Mexico, 
stating that the range of A. argothamnoides includes Florida, which may 
bring into question the validity of A. blodgettii as a valid taxon. One 
reviewer concluded that after reading the published information on the 
subject, he did not find compelling information to suggest that Florida 
A. blodgettii populations are synonymous with Argythamnia spp. outside 
of Florida. This reviewer also recommended that the Service treat A. 
blodgettii as a distinct species, endemic to Florida.
    Our Response: The Service has reviewed Ramirez-Amezcua and Steinman 
(2013) and additional literature relating to the taxonomy of 
Argythamnia blodgettii. As stated in the ``Taxonomy'' sections of this 
rule and the proposed rule, there is a history of changes to the 
classification of this plant, with many based on studies that do not 
include samples from across the plant's range, including the recent 
publication suggesting that Argythamnia blodgettii is synonymous with 
the wider ranging Ditaxis argothamnoides. However, the Service accepts 
the treatment of A. blodgettii as a distinct species and therefore does 
not find a compelling justification to remove the species from 
consideration for listing under the Act.
    (3) Comment: One reviewer commented on the need to include 
information about genetic studies in the document.
    Our Response: No genetic studies of Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, or 
Argythamnia blodgettii have been conducted.
    (4) Comment: One reviewer disagreed with our statement that there 
is no regulatory protection for State-listed plants on private lands 
through Florida Administrative Code (FAC) 5B-40.
    Our Response: The Service apologizes for mischaracterizing the 
regulatory protections provided through FAC 5B-40. We have corrected 
this, and describe the protections in detail in this final rule under 
Factor D. The Inadequacy of Existing Regulatory Mechanisms, below.
    (5) Comment: One reviewer suggested future research in best 
practices for mowing areas that support Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and 
Argythamnia blodgettii.
    Our Response: The Service agrees that the best mowing practices 
should be investigated to support the species. This is a topic that 
will be addressed in the recovery planning process.

[[Page 66847]]

    (6) Comment: One reviewer provided new information from an ongoing 
study about the direct and indirect effects of mosquito insecticide 
spray on flower visitors and reproductive fitness of Chamaecrista 
lineata var. keyensis and Linum arenicola in the lower Florida Keys. In 
addition, two public commenters took issue with the section of the 
proposed rule that discussed mosquito control pesticide applications as 
a factor affecting pollinators of Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia 
blodgettii. They asserted that the Service made incorrect statements 
regarding the frequency and amount of mosquito control adulticide 
treatments in South Florida. These public commenters requested that any 
mention of pesticide effects on pollinators be removed from this final 
rule.
    Our Response: The Service appreciates the new information provided 
by the peer reviewer. Data from ongoing studies in the lower Florida 
Keys of L. arenicola flower visitor observations show that sites not 
treated with adulticides had slightly higher fruit set rates than 
treated sites and pollinator-excluded experimental trials. Several 
species of small bees were observed frequenting flowers at untreated 
sites, while visitation was much less frequent at the treated site. 
Extensive studies in the Florida Keys suggest that broad spectrum 
insecticides negatively affect nontarget invertebrates, including 
pollinators (Hennessey 1991; Eliazar and Emmel 1991; Kevan et al. 1997; 
Salvato 2001; Bargar 2011; Hoang et al. 2011). In addition, pesticides 
have been shown to drift into adjacent undisturbed habitat that serves 
as a refuge for native biota (Hennessey 1992; Pierce et al. 2005; Zhong 
et al. 2010; Bargar 2011). These pesticides can be fatal to nontarget 
invertebrates that move between urban and forest habitats, altering 
ecological processes within forest communities (Kevan and Plowright 
1989, 1995; Liu and Koptur 2003).
    The Service believes that pesticide spraying may be a factor 
affecting the reproductive success of Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and 
Argythamnia blodgettii. However, we acknowledge that pesticide spraying 
practices by the Florida Keys Mosquito Control District (FKMCD) at 
National Key Deer Refuge (NKDR) have changed over the years to reduce 
pesticide use. Since 2003, expanded larvicide treatments to surrounding 
islands have significantly reduced adulticide use on Big Pine Key, No 
Name Key, and the Torch Keys. In addition, the number of aerially 
applied naled (Dibrom[supreg]) treatments allowed on NKDR has been 
limited since 2008 (FKMCD 2012, pp. 10-11). Zones that include the core 
habitat used by pine rockland butterflies, and several linear miles of 
pine rocklands habitat within the Refuge-neighborhood interface, were 
excluded from truck spray applications (no-spray zones) (Anderson 2012, 
pers. comm.; Service 2012, p. 32). These exclusions and buffer zones 
encompass over 95 percent of extant croton distribution on Big Pine 
Key, and include the majority of known recent and historical Florida 
leafwing population centers on the island (Salvato 2012, pers. comm.).
    Accordingly, the Service commends the FKMCD for its cooperation in 
recovering endangered butterflies and plants. Nevertheless, we are 
proceeding cautiously and have initiated a multi-year research project 
to further investigate the level of impact pesticides have on these 
four plants.

Federal Agency Comments

    (7) Comment: The U.S. Navy expressed interest and a commitment to 
work proactively with the Service to coordinate on the proposed listing 
of Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii under the Act. 
Naval Air Station (NAS) Key West, Florida, is subject to the NAS Key 
West Integrated Natural Resources Management Plan (INRMP). The Navy 
noted that the NAS Key West INRMP was acknowledged in the proposed 
listing rule as providing a conservation benefit to Argythamnia 
blodgettii habitat. The 2013 INRMP update identified several Monroe 
County rare species, including Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, and Linum arenicola, that do not 
occur on NAS Key West properties. The Navy requested that the Service 
coordinate with it prior to proposing critical habitat on Navy land for 
any of these species and to fully consider the benefits imparted to 
these species through INRMP implementation.
    Our Response: We appreciate the U.S. Navy's interest and commitment 
to work proactively with the Service to conserve Argythamnia 
blodgettii. In particular, NAS Key West has been proactive in surveying 
for these species and updating the NAS Key West INRMP to include 
conservation measures for Argythamnia blodgettii. The Service will 
coordinate early with NAS Key West regarding any critical habitat 
proposal for Chamaecrista lineata var. keyensis, Chamaesyce deltoidea 
ssp. serpyllum, Linum arenicola, or Argythamnia blodgettii.

Comments From the State

    We received comments from a peer reviewer who is employed by the 
Florida Forest Service. Those comments are addressed above under Peer 
Reviewer Comments in our responses to Comments (3) and (4).

Public Comments

    (8) Comment: One commenter opposed the proposed listing of the 
plants on Big Pine Key, Florida. While the commenter generally agreed 
with the field data for the Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia 
blodgettii, the commenter asserted the habitat can no longer sustain 
these and other federally protected endangered species going forward. 
The commenter described several alterations, including drainage canals 
and shallow wells for drainage, that they asserted have permanently 
damaged the freshwater lens (convex layer of groundwater on top of a 
layer of denser saltwater) in the Florida Keys. These alterations and 
sea level rise have permanently changed the natural lens and the amount 
of freshwater available to these species, particularly in times of 
drought or following a major hurricane event.
    Our Response: The Service acknowledges the challenges faced by the 
Florida Keys due to salinization and sea level rise. These factors are 
discussed at length in this final rule under Factor E. Other Natural or 
Manmade Factors Affecting Its Continued Existence, below. In addition, 
the Service agrees habitat loss or degradation is a factor that 
threatens Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii. However, we 
disagree that habitat on Big Pine Key can no longer sustain these or 
other federally protected endangered species going forward. Canals, 
which occur throughout a large portion of Big Pine Key, have allowed 
saltwater intrusion into upland areas of the island for decades, 
threatening upland ecosystems. However, habitat restoration is ongoing 
across Big Pine Key, particularly within the pine rocklands and 
rockland hammocks. These restoration efforts are attempting to protect 
the freshwater lens required by native vegetation; this includes 
filling or plugging drainage canals to reduce or halt seawater 
intrusion into upland areas.

[[Page 66848]]

Summary of Changes From the Proposed Rule

    None of the new information we received during the comment period 
on the proposed rule changes our determinations in this final rule for 
these four plants. Most of the changes are editorial in nature, and are 
described above in the Background section of this rule. However, based 
on comments we received from peer reviewers and the public, we make the 
following substantive changes:
     We update the status of several populations of Linum 
arenicola and Argythamnia blodgettii;
     We update the discussion of the taxonomy of A. blodgettii 
to take into consideration a recent publication; and
     We update our discussion of pesticide applications and 
pollinators to reflect current application limitations now in effect on 
Big Pine Key.

Summary of Factors Affecting the Species

    The Act directs us to determine whether any species is an 
endangered species or a threatened species because of any one of five 
factors affecting its continued existence. In this section, we 
summarize the biological condition of each of the plant species and its 
resources, and the factors affecting them, to assess the species' 
overall viability and the risks to that viability.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

    Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii have experienced 
substantial destruction, modification, and curtailment of their 
habitats and ranges. Specific threats to these plants under this factor 
include habitat loss, fragmentation, and modification caused by 
development (i.e., conversion to both urban and agricultural land uses) 
and inadequate fire management. Each of these threats and its specific 
effects on these plants are discussed in detail below.
Human Population Growth, Development, and Agricultural Conversion
    The modification and destruction of the habitats that support 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii has been extreme 
in most areas of Miami-Dade and Monroe Counties, thereby reducing these 
plants' current ranges and abundance in Florida. The pine rocklands 
community of south Florida, in which all four plants primarily occur, 
is critically imperiled locally and globally (FNAI 2012, p. 27). 
Destruction of pine rocklands and rockland hammocks has occurred since 
the beginning of the 1900s. Extensive land clearing for human 
population growth, development, and agriculture in Miami-Dade and 
Monroe Counties has altered, degraded, or destroyed thousands of acres 
of these once abundant ecosystems.
    In Miami-Dade County, development and agriculture have reduced pine 
rocklands habitat by 90 percent in mainland south Florida. Pine 
rocklands habitat decreased from approximately 74,000 hectares (ha) 
(183,000 acres (ac)) in the early 1900s, to only 8,140 ha (20,100 ac) 
in 1996 (Kernan and Bradley 1996, p. 2). The largest remaining intact 
pine rocklands (approximately 2,313 ha (5,716 ac)) is located on Long 
Pine Key in Everglades National Park (ENP). Outside of ENP, only about 
1 percent of the pine rocklands on the Miami Rock Ridge have escaped 
clearing, and much of what is left are small remnants scattered 
throughout the Miami metropolitan area, isolated from other natural 
areas (Herndon 1998, p. 1).
    Similarly, most of the pine rocklands in the Florida Keys (Monroe 
County) have been impacted (Hodges and Bradley 2006, p. 6). Pine 
rocklands historically covered 1,049 ha (2,592 ac) of Big Pine Key 
(Folk 1991, p. 188), the largest area of pine rocklands in the Florida 
Keys. Pine rocklands now cover approximately 582 ha (1,438 ac) of the 
island, a reduction of 56 percent (Bradley and Saha 2009, p. 3). There 
were no estimates of pine rocklands area on the other islands 
historically, but each contained much smaller amounts of the habitat 
than Big Pine Key. Remaining pine rocklands on Cudjoe Key cover 72 ha 
(178 ac), Little Pine has 53 ha (131 ac), No Name has 56 ha (138 ac), 
and Sugarloaf has 38 ha (94 ac). The total area of remaining pine 
rocklands in the Florida Keys is approximately 801 ha (1,979 ac). 
Currently, about 478 ha (1,181 ac) (82 percent) of the pine rocklands 
on Big Pine Key, and most of the pine rocklands on these other islands, 
are protected within the NKDR and properties owned by the Nature 
Conservancy, the State of Florida, and Monroe County (Bradley and Saha 
2009, pp. 3-4). Based on the data presented above, the total remaining 
acreage of pine rocklands in Miami-Dade and Monroe Counties is now 
8,981 ha (22,079 ac) (approximately 8,140 ha (20,100 ac) in Miami-Dade 
County, and 801 ha (1,979 ac) in the Florida Keys (Monroe County)).
    The marl prairies that also support Linum arenicola have similarly 
been destroyed by the rapid development of Miami-Dade and Monroe 
Counties. At least some of the occurrences reported from this habitat 
may be the result of colonization that occurred after they were 
artificially dried-out due to local or regional drainage.
    Likewise, habitat modification and destruction from residential and 
commercial development have severely impacted rockland hammocks, and 
coastal berm, that support Argythamnia blodgettii. Rockland hammocks 
were once abundant in Miami-Dade and Monroe Counties but are now 
considered imperiled locally and globally (FNAI 2010x, pp. 24-26). The 
tremendous development and agricultural pressures in south Florida have 
resulted in significant reductions of rockland hammock, which is also 
susceptible to fire, frost, hurricane damage, and groundwater reduction 
(Phillips 1940, p. 167; Snyder et al. 1990, pp. 271-272; FNAI 2010, pp. 
24-26).
    Pine rocklands, rockland hammock, marl prairie, and coastal 
habitats on private land remain vulnerable to development, which could 
lead to the loss of populations of these four species. As noted 
earlier, all four plants have been impacted by development. The sites 
of Small's 1907 and 1911 L. arenicola collections in Miami-Dade County 
are now agricultural fields (Kernan and Bradley 1996, p. 4). A pine 
rocklands site that supported L. arenicola on Vistalmar Street in Coral 
Gables (Miami-Dade County) was cleared and developed in 2005, as part 
of the growing the Cocoplum housing development. A second pine 
rocklands site that supported L. arenicola, located on private land on 
Old Cutler Road, was developed into the Palmetto Bay Village Center. L. 
arenicola has not been observed at either site since they were 
developed. A former marl prairie site supporting a sizable population 
of L. arenicola near Old Cutler Road and Allapatah Drive (SW 112 Ave) 
in Miami-Dade County was extirpated when the site was developed in the 
1990s (Bradley and van der Heiden 2013, pp. 6-12, 19). The Boca Chica 
Key population of L. arenicola was also likely lost due to development 
(Hodges and Bradley 2006, p. 48).
    Bradley and Gann (1999, p. 6) list 12 populations of Argythamnia 
blodgettii in Miami-Dade County that were lost when the site that 
supported them was developed. An A. blodgettii population on Key West 
was likely lost due to the near complete urbanization of the island 
(Hodges and Bradley 2006, p. 43). Any

[[Page 66849]]

development related to the Boy Scout camp on Big Munson Island is a 
potential threat to the largest population A. blodgettii.
    The largest Linum arenicola population in Miami-Dade County is 
located on property owned by the Miami-Dade County Homeless Trust. U.S. 
Special Operations Command South Headquarters (SOCSOUTH), a unified 
command of all four services of DOD, has entered into a 50-year 
agreement with Miami-Dade County to lease this 90-ac (36.4-ha) area, 
where they are building a permanent headquarters on approximately 28 ac 
(11.3 ha) (DOD 2009, p. 1). As stated above, the population of L. 
arenicola is spread across the site and was estimated at 74,000 plants 
in 2009 (Bradley 2009, p. 3). In consultation with the Service, the DOD 
developed a plan that avoided the majority of the population with 
accompanying protection and management of approximately 57,725 
individuals of sand flax (about 78 percent of the estimated onsite 
population) (Service 2011, p. 13). The plan will manage 5.95 ha (14.7 
ac) of habitat, though most of it is scraped, and only a small portion 
has a pine canopy (Van der Heiden and Johnson 2013, p. 2). An 
additional 1.3 ha (3.2 ac) is being managed and supports 13,184 
individuals of sand flax (about 18 percent of the estimated onsite 
population) (Service 2011, p. 13).
    Currently there are plans to develop a 55-ha (137-ac) privately-
owned portion of the largest remaining area of pine rocklands habitat 
in Miami-Dade County, the Richmond pine rocklands, with a shopping 
center and residential construction (RAM 2014, p. 2). Bradley and Gann 
(1999, p. 4) called the 345-ha (853-ac) Richmond pine rocklands, ``the 
largest and most important area of pine rockland in Miami-Dade County 
outside of Everglades National Park.'' Populations of Argythamnia 
blodgettii and Linum arenicola, along with numerous federally listed 
species, occur in habitat adjacent to the area slated for development. 
The Miami-Dade County Department of Regulatory and Economic Resources 
(RER) has completed a management plan for county-owned portions of the 
Richmond pine rocklands (Martinez Pineland Preserve, Larry and Penny 
Thompson Park) under a grant from the Service and is leading the 
restoration and management of these areas (Bradley and Gann 1999, p. 
4). The developer has proposed to enter into a habitat conservation 
plan in conjunction with their plans to develop their portion of the 
site and was required by Miami-Dade County Natural Forest Community 
(NFC) regulations to set aside and manage 15 ha (39 ac) of pine 
rocklands and 2 ha (4 ac) of rockland hammock. A second project that 
would result in the loss of pine rocklands habitat is also proposed for 
the Richmond pine rocklands. It includes expanding the Miami Zoo 
complex to develop an amusement park and large retail mall.
    Approximately 25 percent of extant Linum arenicola occurrences (3 
of 12 sites), and 40 percent of extant Argythamnia blodgettii 
occurrences (14 of 35 sites), are located on private land; no extant 
populations of Chamaecrista lineata var. keyensis or Chamaesyce 
deltoidea ssp. serpyllum are located entirely on private land. It is 
possible that the plants on private lands will be lost from most of 
these sites in the future with increased pressure from development and 
the other threats described below.
    Argythamnia blodgettii is the only one of the four plant species 
that occurs in ENP, where a population of over 2,000 plants is stable, 
and prescribed fire and other management activities that benefit A. 
blodgettii are conducted on a regular basis.
    Most pine rocklands and rockland hammock habitat is now limited to 
public conservation lands, where future development and habitat 
alteration are less likely than on private lands. However, public lands 
could be sold off (or leased) in the future and become more likely to 
be developed or altered in a way that negatively impacts the habitat. 
For example, at the SOCSOUTH site noted above (leased to DOD by Miami-
Dade County), ongoing development of headquarters buildings SOCSOUTH 
has resulted in the loss of L. arenicola and pine rocklands habitat 
(Bradley and van der Heiden 2013, pp. 8-10). Construction of visitor 
facilities such as parking lots, roads, trails, and buildings can 
result in habitat loss on public lands that are set aside as preserves 
or parks.
    Roadside populations of Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia 
blodgettii are vulnerable to habitat loss and modification stemming 
from infrastructure projects such as road widening, and installation of 
underground cable, sewer, and water lines. The Lower Sugarloaf Key 
population of Linum arenicola was impacted by repaving of the road, 
which placed asphalt on top of and adjacent to the population (Hodges 
and Bradley 2006, p. 41).
    Although no entire populations of Chamaecrista lineata var. 
keyensis or Chamaesyce deltoidea ssp. serpyllum have been extirpated by 
habitat loss due to development, the size and extent of these 
populations have been reduced on Big Pine Key (and surrounding islands 
for Chamaecrista lineata var. keyensis). The total area of pine 
rocklands on Big Pine Key has decreased by 56 percent from 1955 to the 
present (Bradley and Saha 2009, p. 3).
    The human population within Miami-Dade County is currently greater 
than 2.4 million people, and is expected to grow to more than 4 million 
by 2060, an annual increase of roughly 30,000 people (Zwick and Carr 
2006, p. 20). Overall, the human population in Monroe County is 
expected to increase from 79,589 to more than 92,287 people by 2060 
(Zwick and Carr 2006, p. 21). All vacant land in the Florida Keys is 
projected to be developed by then, including lands currently 
inaccessible for development, such as islands not attached to the 
Overseas Highway (U.S. 1) (Zwick and Carr 2006, p. 14). However, in an 
effort to address the impact of development on federally listed 
species, Monroe County implemented a habitat conservation plan (HCP) 
for Big Pine and No Name Keys in 2006. In order to fulfill the HCP's 
mitigation requirements, the County has been actively acquiring parcels 
of high-quality pine rocklands, such as The Nature Conservancy's 20-
acre Terrestris Tract on Big Pine Key, and managing them for 
conservation. Although the HCP has helped to limit the impact of 
development, land development pressure and habitat losses may resume 
when the HCP expires in 2023. If the HCP is not renewed, residential or 
commercial development could increase to pre-HCP levels.
    While Miami-Dade and Monroe County both have developed a network of 
public conservation lands that include pine rocklands, rockland 
hammocks, marl prairies, and coastal habitats, much of the remaining 
habitat occurs on private lands as well as publicly owned lands not 
managed for conservation. Species occurrences and suitable habitat 
remaining on these lands are threatened by habitat loss and 
degradation, and threats are expected to accelerate with increased 
development. Further losses will seriously affect the four plant 
species' ability to persist in the wild and decrease the possibility of 
their recovery or recolonization.
Habitat Fragmentation
    The remaining pine rocklands in the Miami metropolitan area are 
severely fragmented and isolated from each other by vast areas of 
development. Remaining pine rockland areas in the Florida Keys are 
fragmented and are located on small islands separated by

[[Page 66850]]

ocean. Habitat fragmentation reduces the size of plant populations and 
increases spatial isolation of remnants. Barrios et al. (2011, p. 1062) 
investigated the effects of fragmentation on a pine rocklands plant, 
Angadenia berteroi (pineland golden trumpet), which is recognized by 
the State of Florida as threatened, and found that abundance and 
fragment size were positively related. Possley et al. (2008, p. 385) 
studied the effects of fragment size on species composition in south 
Florida pine rocklands, and found that plant species richness and 
fragment size were positively correlated (although some small fragments 
supported nearly as many species as the largest fragment). Composition 
of fragmented habitat typically differs from that of intact forests; as 
isolation and edge effects increase, there is increased abundance of 
disturbance-adapted species (weedy species; nonnative, invasive 
species) and lower rates of pollination and propagule dispersal 
(Laurence and Bierregaard 1997, pp. 347-350; Noss and Csuti 1997, pp. 
284-299). The degree to which fragmentation threatens the dispersal 
abilities of Chamaecrista lineata var. keyensis, Chamaesyce deltoidea 
ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii is unknown. 
In the historical landscape, where pine rocklands occurred within a 
mosaic of wetlands, water may have acted as a dispersal vector for all 
pine rocklands seeds. In the current, fragmented landscape, this type 
of dispersal would no longer be possible for any of the Miami-Dade 
populations. While additional dispersal vectors may include animals and 
(in certain locations) mowing equipment, it is likely that 
fragmentation has effectively reduced these plants' ability to disperse 
and exchange genetic material.
    While pollination research has not been conducted for Chamaesyce 
deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii, 
research regarding other species and ecosystems, including Chamaecrista 
lineata var. keyensis (discussed below), provides valuable information 
regarding potential effects of fragmentation on these plants. Effects 
of fragmentation on pollinators may include changes to the pollinator 
community as a result of limitation of pollinator-required resources 
(e.g., reduced availability of rendezvous plants, nesting and roosting 
sites, and nectar/pollen); these changes may include changes to 
pollinator community composition, species abundance and diversity, and 
pollinator behavior (Rathcke and Jules 1993, pp. 273-275; Kremen and 
Ricketts 2000, p. 1227; Harris and Johnson 2004, pp. 30-33). As a 
result, plants in fragmented habitats may experience lower visitation 
rates, which in turn may result in reduced seed production of the 
pollinated plant (which may lead to reduced seedling recruitment), 
reduced pollen dispersal, increased inbreeding, reduced genetic 
variability, and ultimately reduced population viability (Rathcke and 
Jules 1993, p. 275; Goverde et al. 2002, pp. 297-298; Harris and 
Johnson 2004, pp. 33-34).
    In addition to affecting pollination, fragmentation of natural 
habitats often alters other ecosystems' functions and disturbance 
regimes. Fragmentation results in an increased proportion of ``edge'' 
habitat, which in turn has a variety of effects, including changes in 
microclimate and community structure at various distances from the edge 
(Margules and Pressey 2000, p. 248), altered spatial distribution of 
fire (greater fire frequency in areas nearer the edge) (Cochrane 2001, 
pp. 1518-1519), and increased pressure from nonnative, invasive plants 
and animals that may out-compete or disturb native plant populations. 
Liu and Koptur (2003, p. 1184) reported decreases in Chamaecrista 
lineata var. keyensis's seed production in urban areas of Big Pine Key 
due to increased seed predation, compared with areas away from 
development.
    The effects of fragmentation on fire go beyond edge effects and 
include reduced likelihood and extent of fires, and altered behavior 
and characteristics (e.g., intensity) of those fires that do occur. 
Habitat fragmentation encourages the suppression of naturally occurring 
fires, and has prevented fire from moving across the landscape in a 
natural way, resulting in an increased amount of habitat suffering from 
these negative impacts. High fragmentation of small habitat patches 
within an urban matrix discourages the use of prescribed fire as well 
due to logistical difficulties (see ``Fire Management,'' below). Forest 
fragments in urban settings are also subject to increased likelihood of 
certain types of human-related disturbance, such as the dumping of 
trash (Chavez and Tynon 2000, p. 405). The many effects of habitat 
fragmentation may work in concert to threaten the local persistence of 
a species; when a species' range of occurrence is limited, threats to 
local persistence increase extinction risk.
Fire Management
    One of the primary threats to Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia 
blodgettii is habitat modification and degradation through inadequate 
fire management, which includes both the lack of prescribed fire and 
suppression of natural fires. Where the term ``fire-suppressed'' is 
used below, it describes degraded pine rocklands conditions resulting 
from a lack of adequate fire (natural or prescribed) in the landscape. 
Historically, frequent (approximately twice per decade), lightning-
induced fires were a vital component in maintaining native vegetation 
and ecosystem functioning within south Florida pine rocklands. A period 
of just 10 years without fire may result in a marked decrease in the 
number of herbaceous species due to the effects of shading and litter 
accumulation (FNAI 2010, p. 63). Exclusion of fire for approximately 25 
years will likely result in gradual hammock development over that time 
period, leaving a system that is very fire-resistant if additional pre-
fire management (e.g., mechanical hardwood removal) is not undertaken.
    Today, natural fires are unlikely to occur or are likely to be 
suppressed in the remaining, highly fragmented pine rocklands habitat. 
The suppression of natural fires has reduced the size of the areas that 
burn, and habitat fragmentation has prevented fire from moving across 
the landscape in a natural way. Without fire, successional climax from 
pine rocklands to rockland hammock is rapid, and displacement of native 
species by invasive, nonnative plants often occurs. Understory plants 
such as Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii are shaded out 
by hardwoods and nonnatives alike. Shading may also be caused by a 
fire-suppressed pine canopy that has evaded the natural thinning 
effects that fire has on seedlings and smaller trees. Whether the dense 
canopy is composed of pine, hardwoods, nonnatives, or a combination, 
seed germination and establishment are inhibited in fire-suppressed 
habitat due to accumulated leaf litter, which also changes soil 
moisture and nutrient availability (Hiers et al. 2007, pp. 811-812). 
This alteration to microhabitat can also inhibit seedling establishment 
as well as negatively influence flower and fruit production 
(Wendelberger and Maschinski 2009, pp. 849-851), thereby reducing 
sexual reproduction in fire-adapted species such as Chamaecrista 
lineata var. keyensis, Chamaesyce deltoidea ssp. serpyllum, L. 
arenicola, and A. blodgettii (Geiger 2002, pp. 78-79, 81-83).
    After an extended period of inadequate fire management in pine

[[Page 66851]]

rocklands, it becomes necessary to control invading native hardwoods 
mechanically, as excess growth of native hardwoods would result in a 
hot fire, which can kill mature pines. Mechanical treatments cannot 
entirely replace fire because pine trees, understory shrubs, grasses, 
and herbs all contribute to an ever-increasing layer of leaf litter, 
covering herbs and preventing germination, as discussed above. Leaf 
litter will continue to accumulate even if hardwoods are removed 
mechanically. In addition, the ashes left by fires provide important 
post-fire nutrient cycling, which is not provided via mechanical 
removal.
    Federal (Service, NPS, FFS (Florida Forest Service)), State (FDEP, 
FWC), and County land managers (Miami-Dade RER and NAM (the Natural 
Areas Management division of Department of Parks, Recreation and Open 
Spaces), and nonprofit organizations (Institute for Regional 
Conservation (IRC), The Nature Conservancy (TNC)) implement prescribed 
fire on public and private lands within the ranges of these four 
plants. While management of some County conservation lands includes 
regular burning, other lands remain severely fire-suppressed. Even in 
areas under active management, some portions are typically fire-
suppressed.
    Miami-Dade County: Implementation of a prescribed fire program in 
Miami-Dade County has been hampered by a shortage of resources, as well 
as by logistical difficulties and public concern related to burning 
next to residential areas. Many homes have been built in a mosaic of 
pine rocklands, so the use of prescribed fire in many places has become 
complicated because of potential danger to structures and smoke 
generated from the burns. Nonprofit organizations such as IRC have 
similar difficulties in conducting prescribed burns due to difficulties 
with permitting and obtaining the necessary permissions as well as 
hazard insurance limitations (Gann 2013a, pers. comm.). Few private 
landowners have the means or desire to implement prescribed fire on 
their property, and doing so in a fragmented urban environment is 
logistically difficult and may be costly.
    All occurrences of Linum arenicola and Argythamnia blodgettii in 
Miami-Dade County are affected by some degree of inadequate fire 
management of pine rocklands and marl prairie habitat, with the primary 
threat being the modification and loss of habitat due to an increase in 
shrub and hardwood dominance, eliminating suitable conditions for the 
four plants, and eventual succession to rockland hammock.
    In Miami-Dade County, Linum arenicola occurred along the south edge 
of Bauer Drive on the northern border of a pine rockland owned by 
Miami-Dade County. The property is occupied by a communications tower, 
and is not a managed preserve. Kernan and Bradley (1996) reported eight 
plants. At the time (1992 through 1996), the road shoulder was 
dominated by native grasses. Since then, native canopy hardwoods have 
invaded the site and eliminated the sunny conditions required by L. 
arenicola. It has not been seen since, despite multiple surveys between 
1997 and 2012, and is considered to be extirpated. L. arenicola was 
discovered at Camp Owaissa Bauer by George N. Avery in 1983. Since that 
time, the pine rocklands habitat where he found the plants in the park 
suffered extremely heavy hardwood recruitment due to fire suppression. 
Despite recent hardwood control and reintroduction of fire, no plants 
have been relocated. Bradley and Gann (1999, pp. 71-72) suggested that 
the lack of fires in most forest fragments in Miami-Dade County during 
the last century may be one of the reasons why L. arenicola occurs 
primarily in disturbed areas.
    Monroe County (Florida Keys): Fire management of pine rocklands of 
the lower Florida Keys, most of which are within NKDR, is hampered by a 
shortage of resources, technical challenges, and expense of conducting 
prescribed fire in a matrix of public and private ownership. 
Residential and commercial properties are embedded within or in close 
proximity to pine rocklands habitat (Snyder et al. 2005, p. 2; C. 
Anderson 2012a, pers. comm.). As a result, hand or mechanical 
vegetation management may be necessary at select locations on Big Pine 
Key (Emmel et al. 1995, p. 11; Minno 2009, pers. comm.; Service 2010, 
pp. 1-68) to maintain or restore pine rocklands. Mechanical treatments 
may be less beneficial than fire because they do not quickly convert 
debris to nutrients, and remaining leaf litter may suppress seedling 
development; fire has also been found to stimulate seedling germination 
(C. Anderson 2010, pers. comm.). Because mechanical treatments may not 
provide the same ecological benefits as fire, NKDR continues to focus 
efforts on conducting prescribed fire where possible (C. Anderson 
2012a, pers. comm.). However, the majority of pine rocklands within 
NKDR are several years behind the ideal fire return interval (5-7 
years) suggested for this ecosystem (Synder et al. 2005, p. 2; Bradley 
and Saha 2011, pp. 1-16). Tree ring and sediment data show that pine 
rocklands in the lower Keys have burned at least every 5 years and 
sometimes up to three times per decade historically (Albritton 2009, p. 
123; Horn et al. 2013, pp. 1-67; Harley 2012, pp. 1-246). From 1985 to 
1992, prescribed burns were conducted in the NKDR mainly for fuel 
reduction. There was no prescribed burning by Service staff in the NKDR 
from 1992-1997, in part because not enough was known about the 
ecological effects of prescribed fire in this system (Snyder et al. 
1990, p. 2).
    All occurrences of Chamaecrista lineata var. keyensis, Chamaesyce 
deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii 
in the Florida Keys are affected by some degree of inadequate fire 
management of pine rocklands habitat, with the primary threat being the 
modification and loss of habitat due to an increase in shrub and 
hardwood dominance, eliminating suitable conditions for the four 
plants, and eventual succession to rockland hammock.
    Prescribed fire management over the past decade has not been 
sufficient to reverse long-term declines in Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, or Linum arenicola on 
Big Pine Key. Prescribed fire activity on Big Pine Key and adjacent 
islands within NKDR appears to be insufficient to prevent loss of pine 
rocklands habitat (Carlson et al. 1993, p. 914; Bergh and Wisby 1996, 
pp. 1-2; O'Brien 1998, p. 209; Bradley and Saha 2009, pp. 28-29; 
Bradley et al. 2011, pp. 1-16). As a result, many of the pine rocklands 
across NKDR are being compromised by succession to rockland hammock 
(Bradley and Saha 2009, pp. 28-29; Bradley et al. 2011, pp. 1-16).
Conservation Efforts To Reduce the Present or Threatened Destruction, 
Modification, or Curtailment of Habitat or Range
    Miami-Dade County Environmentally Endangered Lands (EEL) Covenant 
Program: In 1979, Miami-Dade County enacted the Environmentally 
Endangered Lands (EEL) Covenant Program, which reduces taxes for 
private landowners of natural forest communities (NFCs; pine rocklands 
and tropical hardwood hammocks) who agree not to develop their property 
and manage it for a period of 10 years, with the option to renew for 
additional 10-year periods (Service 1999, p. 3-177). Although these 
temporary conservation easements provide valuable protection for their 
duration, they are not considered under the discussion of Factor D, 
below, because they are voluntary agreements and not regulatory

[[Page 66852]]

in nature. Miami-Dade County currently has approximately 59 pine 
rocklands properties enrolled in this program, preserving 69.4 ha (172 
ac) of pine rocklands habitat (Johnson 2012, pers. comm.). The program 
also has approximately 21 rockland hammocks properties enrolled in this 
program, preserving 20.64 ha (51 ac) of rockland hammock habitat 
(Joyner 2013b, pers. comm.). The vast majority of these properties are 
small, and many are in need of habitat management such as prescribed 
fire and removal of nonnative, invasive plants. Thus, while EEL 
covenant lands have the potential to provide valuable habitat for these 
plants and reduce threats in the near term, the actual effect of these 
conservation lands is largely determined by whether individual 
landowners follow prescribed EEL management plans and NFC regulations 
(see ``Local'' under Factor D discussion, below).
    Fee Title Properties: In 1990, Miami-Dade County voters approved a 
2-year property tax to fund the acquisition, protection, and 
maintenance of natural areas by the EEL Program. The EEL Program 
purchases and manages natural lands for preservation. Land uses deemed 
incompatible with the protection of the natural resources are 
prohibited by current regulations; however, the County Commission 
ultimately controls what may happen with any County property, and land 
use changes may occur over time (Gil 2013b, pers. comm.). To date, the 
Miami-Dade County EEL Program has acquired a total of approximately 313 
ha (775 ac) of pine rocklands, and 95 ha (236 ac) of rockland hammocks 
(Guerra 2015, pers. comm.; Gil 2013b, pers. comm.). The EEL Program 
also manages approximately 314 ha (777 ac) of pine rocklands, and 639 
ha (1,578 ac) of tropical hardwood and rockland hammocks owned by the 
Miami-Dade County Parks, Recreation and Open Spaces Department, 
including some of the largest remaining areas of pine rocklands habitat 
on the Miami Rock Ridge outside of ENP (e.g., Larry and Penny Thompson 
Park, Zoo Miami pinelands, Navy Wells Pineland Preserve), and some of 
the largest remaining areas of tropical hardwood and rockland hammocks 
(e.g., Matheson Hammock Park, Castellow Hammock Park, Deering Estate 
Park and Preserves).
    Conservation efforts in Miami's EEL Preserves have been underway 
for many years. In Miami-Dade County, conservation lands are and have 
been monitored by Fairchild Tropical Botanic Garden (FTBG) and IRC, in 
coordination with the EEL Program, to assess habitat status and 
determine any changes that may pose a threat to or alter the abundance 
of these species. Impacts to habitat (e.g., canopy) via nonnative 
species and natural stochastic events are monitored and actively 
managed in areas where the taxon is known to occur. These programs are 
long-term and ongoing in Miami-Dade County; however, programs are 
limited by the availability of annual funding.
    Since 2005, the Service has funded IRC to facilitate restoration 
and management of privately owned pine rocklands habitats in Miami-Dade 
County. These programs included prescribed burns, nonnative plant 
control, light debris removal, hardwood management, reintroduction of 
pines where needed, and development of management plans. One of these 
programs, called the Pine Rockland Initiative, includes 10-year 
cooperative agreements between participating landowners and the 
Service/IRC to ensure restored areas will be managed appropriately 
during that time. Although most of these objectives have been achieved, 
IRC has not been able to conduct the desired prescribed burns, due to 
logistical difficulties as discussed earlier (see ``Fire Management,'' 
above).
    Connect to Protect Program: FTBG, with the support of various 
Federal, State, and local agencies and nonprofit organizations, has 
established the ``Connect to Protect Network.'' The objective of this 
program is to encourage widespread participation of citizens to create 
corridors of healthy pine rocklands by planting stepping stone gardens 
and rights-of-way with native pine rocklands species, and restoring 
isolated pine rocklands fragments. By doing this, FTBG hopes to 
increase the probability that pollination and seed dispersal vectors 
can find and transport seeds and pollen across developed areas that 
separate pine rocklands fragments to improve gene flow between 
fragmented plant populations and increase the likelihood that these 
plants will persist over the long term. Although these projects may 
serve as valuable components toward the conservation of pine rocklands 
species and habitat, they are dependent on continual funding, as well 
as participation from private landowners, both of which may vary 
through time.
    National Wildlife Refuges: The National Wildlife Refuge System 
Improvement Act of 1997 (16 U.S.C. 668dd note) and the Fish and 
Wildlife Service Manual (601 FW 3, 602 FW 3) require maintaining 
biological integrity and diversity, require comprehensive conservation 
planning for each refuge, and set standards to ensure that all uses of 
refuges are compatible with their purposes and the Refuge System's 
wildlife conservation mission. The comprehensive conservation plans 
(CCPs) address conservation of fish, wildlife, and plant resources and 
their related habitats, while providing opportunities for compatible 
wildlife-dependent recreation uses. An overriding consideration 
reflected in these plans is that fish and wildlife conservation has 
first priority in refuge management, and that public use be allowed and 
encouraged as long as it is compatible with, or does not detract from, 
the Refuge System mission and refuge purpose(s). The CCP for the Lower 
Florida Keys National Wildlife Refuges (NKDR, Key West National 
Wildlife Refuge, and Great White Heron National Wildlife Refuge) 
provides a description of the environment and priority resource issues 
that were considered in developing the objectives and strategies that 
guide management over the next 15 years. The CCP promotes the 
enhancement of wildlife populations by maintaining and enhancing a 
diversity and abundance of habitats for native plants and animals, 
especially imperiled species that are found only in the Florida Keys. 
The CCP also provides for obtaining baseline data and monitoring 
indicator species to detect changes in ecosystem diversity and 
integrity related to climate change. The CCP provides specifically for 
maintaining and expanding populations of candidate plant species, 
including Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii, all four of 
which are found in this refuge complex.
    Department of Defense Lands: The Sikes Act requires the DOD to 
develop and implement integrated natural resources management plans 
(INRMPs) for military installations across the United States (see also 
Factor D discussion, below). INRMPs are prepared in cooperation with 
the Service and State fish and wildlife agencies to ensure proper 
consideration of fish, wildlife, and habitat needs. The DOD has an 
approved INRMP for Key West Naval Air Station (KWNAS) on Boca Chica Key 
that includes measures that will protect and enhance Argythamnia 
blodgettii habitat, including nonnative species control (DOD 2014, p. 
69). Furthermore, DOD is currently preparing an INRMP for Homestead Air 
Reserve Base (HARB) and SOCSOUTH. A previous biological opinion 
(Service 2011, entire) required SOCSOUTH to protect and manage 7.4 ha 
(18.3 ac) of pine rocklands habitat

[[Page 66853]]

and 70,909 individuals of Linum arenicola (approximately 96 percent of 
the estimated onsite population) based on 2009 survey data. A 
conservation easement was established over the protected areas, and DOD 
has provided funds for management of the site, including fencing and 
nonnative species control.
Summary of Factor A
    We have identified a number of threats to the habitat of 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii that have 
operated in the past, are impacting these species now, and will 
continue to impact them in the future. Habitat loss, fragmentation, and 
degradation, and associated pressures from increased human population, 
are major threats; these threats are expected to continue, placing 
these plants at greater risk. All four plants may be impacted when pine 
rocklands are converted to other uses or when lack of fire causes the 
conversion to hardwood hammocks or other unsuitable habitat conditions. 
Any populations of these species found on private property could be 
destroyed by development; the limited pine rocklands, rockland hammock, 
and coastal berm habitat on public lands can also be affected by 
development of recreational facilities or infrastructure projects. 
Although efforts are being made to conserve publicly and privately 
owned natural areas and apply prescribed fire, the long-term effects of 
large-scale and wide-ranging habitat modification, destruction, and 
curtailment will last into the future, while ongoing habitat loss due 
to population growth, development, and agricultural conversion 
continues to pose a threat. Therefore, based on the best information 
available, we have determined that the threats to the four plants from 
habitat destruction, modification, or curtailment are occurring 
throughout the entire range of the species and are expected to continue 
into the future.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The best available data do not indicate that overutilization for 
commercial, recreational, scientific, or educational purposes is a 
threat to Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, or Argythamnia blodgettii. Threats to these 
plants related to other aspects of recreation and similar human 
activities (i.e., not related to overutilization) are discussed under 
Factor E, below.

Factor C. Disease or Predation

    No diseases or incidences of predation have been reported for 
Chamaesyce deltoidea ssp. serpyllum or Argythamnia blodgettii.
    Key deer are known to occasional browse plants indiscriminately, 
including Chamaecrista lineata var. keyensis and Linum arenicola. Key 
deer do not appear to feed on Argythamnia blodgettii, probably due to 
potential toxicity (Hodges and Bradley 2006, p. 19).
    Seed predation by an insect occurs in Chamaecrista lineata var. 
keyensis, and seems to be exacerbated by habitat fragmentation. 
Individuals at the urban edge suffer higher insect seed predation than 
those inside the forest (Liu and Koptur 2003, p. 1184).
    While seed predation and occasional Key deer browsing may be a 
stressor, they do not appear to rise to the level of threat at this 
time. Therefore, the best available data do not indicate that disease 
or predation is a threat to Chamaecrista lineata var. keyensis or Linum 
arenicola.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    Under this factor, we examine whether threats to these plants are 
discussed under the other factors are continuing due to an inadequacy 
of an existing regulatory mechanism. Section 4(b)(1)(A) of the Act 
requires the Service to take into account ``those efforts, if any, 
being made by any State or foreign nation, or any political subdivision 
of a State or foreign nation, to protect such species.'' In relation to 
Factor D under the Act, we interpret this language to require the 
Service to consider relevant Federal, State, and tribal laws, 
regulations, and other such mechanisms that may minimize any of the 
threats we describe in threat analyses under the other four factors, or 
otherwise enhance conservation of the species. We give strongest weight 
to statutes and their implementing regulations and to management 
direction that stems from those laws and regulations. Examples are 
State governmental actions enforced under a State statute or 
constitution, and Federal actions authorized by statute.
    Having evaluated the impact of the threats as mitigated by any such 
conservation efforts, we analyze under Factor D the extent to which 
existing regulatory mechanisms are inadequate to address the specific 
threats to the species. Regulatory mechanisms, if they exist, may 
reduce or eliminate the impacts from one or more identified threats. In 
this section, we review existing Federal, State, and local regulatory 
mechanisms to determine whether they effectively reduce or remove 
threats to Chamaecrista lineata var. keyensis, Chamaesyce deltoidea 
ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii.
Federal
    As Federal candidate species, the four plants are afforded some 
protection through sections 7 and 10 of the Act and associated policies 
and guidelines. Service policy requires that candidate species be 
treated as proposed species for purposes of intra-Service consultations 
and conferences where the Service's actions may affect candidate 
species. Other Federal action agencies (e.g., NPS) are to consider the 
potential effects (e.g., prescribed fire, pesticide treatments) to 
these plants and their habitat during the consultation and conference 
process. Applicants and Federal action agencies are encouraged to 
consider candidate species when seeking incidental take for other 
listed species and when developing habitat conservation plans. However, 
candidate species do not receive the same level of protection that a 
listed species does under the Act.
    Populations of Argythamnia blodgettii within ENP are protected by 
NPS regulations at 36 CFR 2.1, which prohibit visitors from harming or 
removing plants, listed or otherwise, from ENP. However, the 
regulations do not address actions taken by NPS that cause habitat loss 
or modification.
    As discussed above under Factor A, the CCPs for the Lower Florida 
Keys National Wildlife Refuge and the Crocodile Lake National Wildlife 
Refuge provide for Chamaecrista lineata var. keyensis, Chamaesyce 
deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii. 
Linum arenicola occurs on DOD lands at HARB and SOCSOUTH. L. arenicola 
and A. blodgettii may occur on Federal lands within the Richmond Pine 
rocklands, including lands owned by the U.S. Coast Guard.
    As discussed under Factor A, above, the DOD has an approved INRMP 
for KWNAS on Boca Chica Key that includes measures that will protect 
and enhance Argythamnia blodgettii habitat, including nonnative species 
control (DOD 2014, p. 69). Furthermore, as also discussed above, DOD is 
currently preparing an INRMP for HARB and SOCSOUTH, and a 2011 Service 
biological opinion requires SOCSOUTH to protect and manage 7.4 ha (18.3 
ac)

[[Page 66854]]

of pine rocklands habitat and 70,909 individuals of Linum arenicola.
    However, certain populations of the four plants occur on State- or 
county-owned properties, and development of these areas will likely 
require no Federal permit or other authorization. Therefore, projects 
that affect the plants on State- and county-owned lands do not have 
Federal oversight, such as complying with the National Environmental 
Policy Act (NEPA; 42 U.S.C. 4321 et seq.), unless the project has a 
Federal nexus (Federal funding, permits, or other authorizations). 
Therefore, the four plants have no direct Federal regulatory protection 
in these areas.
State
    Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii are listed on 
the Regulated Plant Index (Index) as endangered under chapter 5B-40, 
Florida Administrative Code. This listing provides little or no habitat 
protection beyond the State's development of a regional impact process, 
which discloses impacts from projects, but provides only limited 
regulatory protection for State-listed plants on private lands.
    Florida Statutes 581.185 sections (3)(a) and (3)(b) prohibit any 
person from willfully destroying or harvesting any species listed as 
endangered or threatened on the Index, or growing such a plant on the 
private land of another, or on any public land, without first obtaining 
the written permission of the landowner and a permit from the Florida 
Department of Plant Industry. The statute further provides that any 
person willfully destroying or harvesting; transporting, carrying, or 
conveying on any public road or highway; or selling or offering for 
sale any plant listed in the Index as endangered must have a permit 
from the State at all times when engaged in any such activities. 
Further, Florida Statutes 581.185 section (10) provides for 
consultation similar to section 7 of the Act for listed species, by 
requiring the Department of Transportation to notify the Florida 
Department of Agriculture and Consumer Services and the Endangered 
Plant Advisory Council of planned highway construction at the time bids 
are first advertised, to facilitate evaluation of the project for 
listed plant populations, and to provide ``for the appropriate disposal 
of such plants'' (i.e., transplanting).
    However, this statute provides no substantive protection of habitat 
or protection of potentially suitable habitat at this time. Florida 
Statutes 581.185 section (8) waives State regulation for certain 
classes of activities for all species on the Index, including the 
clearing or removal of regulated plants for agricultural, forestry, 
mining, construction (residential, commercial, or infrastructure), and 
fire-control activities by a private landowner or his or her agent.
Local
    In 1984, section 24-49 of the Code of Miami-Dade County established 
regulation of County-designated NFCs. These regulations were placed on 
specific properties throughout the County by an act of the Board of 
County Commissioners in an effort to protect environmentally sensitive 
forest lands. The Miami-Dade County RER has regulatory authority over 
these County-designated NFCs and is charged with enforcing regulations 
that provide partial protection of remaining upland forested areas 
designated as NFC on the Miami Rock Ridge. NFC regulations are designed 
to prevent clearing or destruction of native vegetation within 
preserved areas. Miami-Dade County Code typically allows up to 20 
percent of pine rocklands designated as NFC to be developed, and 
requires that the remaining 80 percent be placed under a perpetual 
covenant. The code requires that no more than 10 percent of a rockland 
hammock designated as NFC may be developed for properties greater than 
5 acres and that the remaining 90 percent be placed under a perpetual 
covenant for preservation purposes (Joyner 2013a, 2014, pers. comm.; 
Lima 2014, pers. comm.). However, for properties less than 5 acres, up 
to one-half an acre may be cleared if the request is deemed a 
reasonable use of property; this allowance often may be greater than 20 
percent (for pine rocklands) or 10 percent (for rockland hammock) of 
the property (Lima 2014, pers. comm.). NFC landowners are also required 
to obtain an NFC permit for any work, including removal of nonnatives 
within the boundaries of the NFC on their property. When RER discovers 
unpermitted work, it takes appropriate enforcement action and seeks 
restoration when possible. The NFC program is responsible for ensuring 
that NFC permits are issued in accordance with the limitations and 
requirements of the county code and that appropriate NFC preserves are 
established and maintained in conjunction with the issuance of an NFC 
permit when development occurs. The NFC program currently regulates 
approximately 600 pine rocklands or pine rocklands/hammock properties, 
comprising approximately 1,200 ha (3,000 ac) of habitat (Joyner 2013, 
pers. comm.).
    Although the NFC program is designed to protect rare and important 
upland (non-wetlands) habitats in south Florida, the strategy has 
limitations. For example, in certain circumstances where landowners can 
demonstrate that limiting development to 20 percent (for pine 
rocklands) or 10 percent (for rockland hammock) does not allow for 
``reasonable use'' of the property, additional development may be 
approved. Furthermore, Miami-Dade County Code provides for up to 100 
percent of the NFC to be developed in limited circumstances for parcels 
less than 2.02 ha (5 ac) in size and only requires coordination with 
landowners if they plan to develop property or perform work within the 
NFC-designated area. Therefore, many of the existing private forested 
NFC parcels remain fragmented, without management obligations or 
preserve designation, as development has not been proposed at a level 
that would trigger the NFC regulatory requirements. Often, nonnative 
vegetation over time begins to dominate and degrade the undeveloped and 
unmanaged NFC landscape until it no longer meets the legal threshold of 
an NFC, which applies only to land dominated by native vegetation. When 
development of such degraded NFCs is proposed, Miami-Dade County Code 
requires delisting of the degraded areas as part of the development 
process. Property previously designated as NFC is removed from the list 
even before development is initiated because of the abundance of 
nonnative species, making it no longer considered to be jurisdictional 
or subject to the NFC protection requirements of Miami-Dade County Code 
(Grossenbacher 2013, pers. comm.).
Summary of Factor D
    Currently, Chamaecrista lineata var. keyensis, Chamaesyce deltoidea 
ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii are found 
on Federal, State, and county lands; however, there is no regulatory 
mechanism in place that provides substantive protection of habitat or 
protection of potentially suitable habitat at this time. NPS and 
Service Refuge regulations provide protection at ENP and the Florida 
Keys Wildlife Refuge Complex, respectively. The Act provides some 
protection for candidate species on National Wildlife Refuges and 
during intra-Service section 7 consultations. State regulations provide 
protection against trade, but allow private landowners or their agents 
to

[[Page 66855]]

clear or remove species on the Florida Regulated Plant Index. State 
Park regulations provide protection for plants within Florida State 
Parks. The NFC program in Miami is designed to protect rare and 
important upland (non-wetlands) habitats in south Florida; however, 
this regulatory strategy has several limitations (as described above) 
that reduce its ability to protect the four plants and their habitats.
    Although many populations of the four plants are afforded some 
level of protection because they are on public conservation lands, 
existing regulatory mechanisms have not led to a reduction or removal 
of threats posed to these plants by a wide array of sources (see 
discussions under Factor A, above, and Factor E, below).

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

    Other natural or manmade factors affect Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and 
Argythamnia blodgettii to varying degrees. Specific threats to these 
plants included in this factor consist of the spread of nonnative, 
invasive plants; potentially incompatible management practices (such as 
mowing and herbicide use); small population size and isolation; effects 
of pesticide spraying on pollinators; climate change and sea level rise 
(SLR); and risks from environmental stochasticity (extreme weather) on 
these small populations. Each of these threats and its specific effect 
on these plants is discussed in detail below.
Nonnative Plant Species
    Nonnative, invasive plants compete with native plants for space, 
light, water, and nutrients, and make habitat conditions unsuitable for 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii, which prefer 
open conditions. Bradley and Gann (1999, pp. 13, 71-72) indicated that 
the control of nonnative plants is one of the most important 
conservation actions for these plants and a critical part of habitat 
maintenance.
    Nonnative plants have significantly affected pine rocklands, and 
threaten all occurrences of these four species to some degree (Bradley 
2006, pp. 25-26; Bradley and Gann 1999, pp. 18-19; Bradley and Saha 
2009, p. 25; Bradley and van der Heiden 2013, pp. 12-16). As a result 
of human activities, at least 277 taxa of nonnative plants have invaded 
pine rocklands throughout south Florida (Service 1999, p. 3-175). 
Neyraudia neyraudia (Burma reed) and Schinus terebinthifolius 
(Brazilian pepper) threaten all four species (Bradley and Gann 1999, 
pp. 13, 72). S. terebinthifolius, a nonnative tree, is the most 
widespread and one of the most invasive species. It forms dense 
thickets of tangled, woody stems that completely shade out and displace 
native vegetation (Loflin 1991, p. 19; Langeland and Craddock Burks 
1998, p. 54). Acacia auriculiformis (earleaf acacia), Rhynchelytrum 
repens (natal grass), Lantana camara (shrub verbena), and Albizia 
lebbeck (tongue tree) are some of the other nonnative species in pine 
rocklands. More species of nonnative plants could become problems in 
the future, such as Lygodium microphyllum (Old World climbing fern), 
which is a serious threat throughout south Florida. Nonnative plants in 
pine rocklands can also affect the characteristics of a fire when it 
does occur. Historically, pine rocklands had an open, low understory 
where natural fires remained patchy with low temperature intensity, 
thus sparing many native plants such as Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and 
Argythamnia blodgettii. Dense infestations of Neyraudia neyraudia and 
Schinus terebinthifolius cause higher fire temperatures and longer 
burning periods. With the presence of invasive, nonnative species, it 
is uncertain how fire, even under a managed situation, will affect 
these plants.
    At least 162 nonnative plant species are known to invade rockland 
hammocks; impacts are particularly severe on the Miami Rock Ridge 
(Service 1999, pp. 3-135). Nonnative plant species have significantly 
affected rockland hammocks where Argythamnia blodgettii occurs and are 
considered one of the threats to the species (Snyder et al. 1990, p. 
273; Hodges and Bradley 2006, p. 14). In many Miami-Dade County parks, 
nonnative plant species comprise 50 percent of the flora in hammock 
fragments (Service 1999, pp. 3-135). Horvitz (et al. 1998, p. 968) 
suggests the displacement of native species by nonnative species in 
conservation and preserve areas is a complex problem with serious 
impacts to biodiversity conservation, as management in these areas 
generally does not protect native species and ecological processes, as 
intended. Problematic nonnative, invasive plants associated with 
rockland hammocks include Leucaena leucocephala (lead tree), Schinus 
terebinthifolius, Bischofia javanica (bishop wood), Syngonium 
podophyllum (American evergreen), Jasminum fluminense (Brazilian 
jasmine), Rubus niveus (mysore raspberry), Nephrolepis brownii (Asian 
swordfern), Schefflera actinophylla (octopus tree), Jasminum dichotomum 
(Gold Coast jasmine), Epipremnum pinnatum (centipede tongavine), and 
Nephrolepis cordifolia (narrow swordfern) (Possley 2013h-i, pers. 
comm.).
    Management of nonnative, invasive plants in pine rocklands and 
rockland hammocks in Miami-Dade County is further complicated because 
the vast majority of pine rocklands and rockland hammocks are small, 
fragmented areas bordered by urban development. In the Florida Keys, 
larger fragments are interspersed with development. Developed or 
unmanaged areas that contain nonnative species can act as a seed source 
for nonnatives, allowing them to continue to invade managed pine 
rocklands or rockland hammocks (Bradley and Gann 1999, p. 13).
    Nonnative plant species are also a concern on private lands, where 
often these species are not controlled due to associated costs, lack of 
interest, or lack of knowledge of detrimental impacts to the ecosystem. 
Undiscovered populations of the four plants on private lands could 
certainly be at risk. Overall, active management is necessary to 
control for nonnative species and to protect unique and rare habitats 
where the four plants occur (Snyder et al. 1990, p. 273).
Management of Roadsides and Disturbed Areas
    All four plants occur in disturbed areas such as roadsides and 
areas that formerly were pine rocklands. Linum arenicola is 
particularly vulnerable to management practices in these areas because 
nearly all populations of the species are currently found on disturbed 
sites. The large L. arenicola population at HARB and SOCSOUTH is 
located largely in areas that are regularly mowed. Similarly, the small 
population of L. arenicola at the Everglades Archery Range, which is 
owned by Miami-Dade County and managed as a part of Camp Owaissa Bauer, 
is growing along the edges of the unimproved perimeter road that is 
regularly mowed. Finally, the two populations of L. arenicola on canal 
banks are subject to mowing, herbicide treatments, and revegetation 
efforts (sodding) (Bradley and van der Heiden 2013, pp. 8-10). The 
population of Argythamnia blodgettii at Lignumvitae Key Botanical State 
Park grows around the perimeter of the large lawn around the residence. 
Maintenance activities

[[Page 66856]]

and encroachment of exotic lawn grasses are potential threats to this 
population (Hodges and Bradley 2006, p. 14). At Windley Key State Park, 
A. blodgettii grows in two quarry bottoms. In the first, larger quarry, 
to the east of the visitor center, plants apparently persist only in 
natural areas not being mowed. However, the majority of the plants are 
in the farthest quarry, which is not mowed (Hodges and Bradley 2006, p. 
15).
    While no studies have investigated the effect of mowing on the four 
plants, research has been conducted on the federally endangered Linum 
carteri var. carteri (Carter's small-flowered flax, a close relative of 
Linum arenicola that also occurs in pine rocklands and disturbed 
sites). The study found significantly higher densities of plants at the 
mown sites where competition with other plants is decreased (Maschinski 
and Walters 2007, p. 56). However, plants growing on mown sites were 
shorter, which may affect fruiting magnitude. While mowing did not 
usually kill adult plants, if mowing occurred prior to plants reaching 
reproductive status, it could delay reproduction (Maschinski and 
Walters 2007, pp. 56-57). If such mowing occurs repeatedly, 
reproduction of those plants would be entirely eliminated. If, instead, 
mowing occurs at least 3 weeks after flowering, there would be a higher 
probability of adults setting fruit prior to mowing; mowing may then 
act as a positive disturbance by both scattering seeds and reducing 
competition (Maschinski and Walters 2007, p. 57). The exact impacts of 
mowing thus depend on the timing of the mowing event, rainfall prior to 
and following mowing, and the numbers of plants in the population that 
have reached a reproductive state.
    Herbicide applications, the installation of sod, and dumping may 
affect populations of the four plants that occur on roadsides, canals 
banks, and other disturbed sites. Signs of herbicide application were 
noted at the site of the Big Torch Key roadside population of Linum 
arenicola in 2010 (Hodges 2010, p. 2). At the L-31 E canal site, plants 
of L. arenicola were lost on the levee close to Card Sound Road due to 
the installation of Bahia grass (Paspalum conjugatum) sod in recent 
years, an activity associated with the installation of new culverts. If 
similar projects are planned, other erosion control measures should be 
investigated that do not pose a threat to L. arenicola (Bradley and Van 
Der Heiden 2013, p. 10). Illegal dumping of storm-generated trash after 
Hurricane Wilma had a large impact on roadside populations of plants in 
the lower Florida Keys (Hodges and Bradley 2006, pp. 11-12, 19, 39).
    All populations of the four plants that occur on disturbed sites 
are vulnerable to regular maintenance activities such as mowing and 
herbicide applications, and dumping. This includes portions of all 
populations of Chamaecrista lineata var. keyensis and Chamaesyce 
deltoidea ssp. serpyllum, 10 of 12 Linum arenicola populations, and 5 
of 34 Argythamnia blodgettii populations. All roadside populations are 
also vulnerable to infrastructure projects such as road widening and 
installation of underground cable, sewer, and water lines.
Pesticide Effects on Pollinators
    Another potential anthropogenic threat to the four plants is 
current application of insecticides throughout these plants' ranges to 
control mosquito populations. Currently, an aerial insecticide (1,2-
dibromo-2,2-dichloroethyl dimethyl phosphate) and ground insecticide 
(Permethrin) are applied during the May through November timeframe in 
many parts of south Florida. Nontarget effects of mosquito control may 
include the loss of pollinating insects upon which certain plants 
depend.
    Koptur and Liu (2003, p. 1184) reported a decrease in Chamaecrista 
lineata var. keyensis pollinator activity following mosquito spraying 
on Big Pine Key. Mosquito spraying remains a factor on Big Pine Key, 
and its suppression of pollinator populations may have a long-term 
impact on reproduction rates. Extensive studies in the Florida Keys 
suggest that broad spectrum insecticides negatively affect nontarget 
invertebrates, including pollinators (Hennessey 1991; Eliazar and Emmel 
1991; Kevan et al. 1997; Salvato 2001; Bargar 2011; Hoang et al. 2011). 
In addition, pesticides have been shown to drift into adjacent 
undisturbed habitat that serves as a refuge for native biota (Hennessey 
1992; Pierce et al. 2005; Zhong et al. 2010; Bargar 2011). These 
pesticides can be fatal to nontarget invertebrates that move between 
urban and forest habitats, altering ecological processes within forest 
communities (Kevan and Plowright 1989, 1995; Liu and Koptur 2003).
    Pesticide spraying practices by the Monroe County Mosquito Control 
District within NKDR have changed to reduce pesticide use and limit 
insecticide drift into pine rocklands habitat as a result of agreements 
between the Service and Florida Keys Mosquito Control District (FKMCD) 
after critical habitat was designated in 2014 for the Florida leafwing 
(Anaea troglodyta floridalis) and Bartram's scrub-hairstreak (Strymon 
acis bartrami) butterflies (79 FR 47180; August 12, 2014). This 
designation includes all pine rockland within NKDR where its sole 
larval host, Croton linearis, can potentially occur.
    Since 2003, expanded larvicide treatments to surrounding islands 
have significantly reduced adulticide use on Big Pine Key, No Name Key, 
and the Torch Keys. In addition, the number of aerially applied Naled 
treatments allowed on NKDR has been limited since 2008 (Florida Key 
Mosquito Control District 2012, pp. 10-11). Designated ``No spray 
zones'' that include the core habitat used by pine rockland butterflies 
and several linear miles of pine rocklands habitat within the Refuge-
neighborhood interface are now excluded from truck spray applications 
(Anderson 2012, pers. comm.; Service 2012, p. 32). These exclusions and 
buffer zones encompass over 95 percent of extant croton distribution on 
Big Pine Key, and include the majority of known recent and historical 
Florida leafwing population centers on the island (Salvato 2012, pers. 
comm.). The area largely coincides with the range of these four plants 
in the lower Florida Keys. Therefore, the effects of mosquito control 
pesticide application on the pollinators of the four plants have been 
minimized at NKDR.
    In summary, critical habitat regulations for Bartram's scrub-
hairstreak butterfly and Florida leafwing have extended benefits to 
populations of these four plants and their pollinator guild by limiting 
mosquito insecticide activity in pine rocklands habitat in the Florida 
Keys. Nevertheless, we are proceeding cautiously and have initiated a 
multi-year research project to further investigate the level of impact 
pesticides have on these four plants and their pollinators throughout 
their ranges.
Environmental Stochasticity
    Endemic species whose populations exhibit a high degree of 
isolation and narrow geographic distribution, such as Chamaecrista 
lineata var. keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum 
arenicola, and Argythamnia blodgettii, are extremely susceptible to 
extinction from both random and nonrandom catastrophic natural or 
human-caused events. Of the four species, Argythamnia blodgettii is 
probably less vulnerable because of the larger number of sites where it 
occurs throughout Miami-Dade and Monroe Counties. Small populations of 
species,

[[Page 66857]]

without positive growth rates, are considered to have a high extinction 
risk from site-specific demographic and environmental stochasticity 
(Lande 1993, pp. 911-927).
    The climate of south Florida is driven by a combination of local, 
regional, and global weather events and oscillations. There are three 
main ``seasons'': (1) The wet season, which is hot, rainy, and humid 
from June through October; (2) the official hurricane season that 
extends one month beyond the wet season (June 1 through November 30), 
with peak season being August and September; and (3) the dry season, 
which is drier and cooler, from November through May. In the dry 
season, periodic surges of cool and dry continental air masses 
influence the weather with short-duration rain events followed by long 
periods of dry weather.
    Florida is considered the most vulnerable State in the United 
States to hurricanes and tropical storms (Florida Climate Center, 
http://coaps.fsu.edu/climate_center). Based on data gathered from 1856 
to 2008, Klotzbach and Gray (2009, p. 28) calculated the climatological 
probabilities for each State being impacted by a hurricane or major 
hurricane in all years over the 152-year timespan. Of the coastal 
States analyzed, Florida had the highest climatological probabilities, 
with a 51 percent probability of a hurricane (Category 1 or 2) and a 21 
percent probability of a major hurricane (Category 3 or higher). From 
1856 to 2008, Florida experienced 109 hurricanes, 36 of which were 
considered major hurricanes. Given the few isolated populations and 
restricted range of the four plants in locations prone to storm 
influences (i.e., Miami-Dade and Monroe Counties), they are at 
substantial risk from hurricanes, storm surges, and other extreme 
weather events.
    Hurricanes, storm surge, and extreme high tide events are natural 
events that can pose a threat to the four plants. Hurricanes and 
tropical storms can modify habitat (e.g., through storm surge) and have 
the potential to destroy entire populations. Climate change may lead to 
increased frequency and duration of severe storms (Golladay et al. 
2004, p. 504; McLaughlin et al. 2002, p. 6074; Cook et al. 2004, p. 
1015). The four plants experienced these disturbances historically, but 
had the benefit of more abundant and contiguous habitat to buffer them 
from extirpations. With most of the historical habitat having been 
destroyed or modified, the few remaining populations of these plants 
could face local extirpations due to stochastic events.
    The Florida Keys were impacted by three hurricanes in 2005: Katrina 
on August 26, Rita on September 20, and Wilma on October 24. Hurricane 
Wilma had the largest impact, with storm surges flooding much of the 
landmass of the Keys. In some places, this water impounded and sat for 
days. The vegetation in many areas was top-killed due to salt water 
inundation (Hodges and Bradley 2006, p. 9). Flooding kills plants that 
do not have adaptations to tolerate anoxic soil conditions that persist 
after flooding; the flooding and resulting high salinities might also 
impact soil seed banks of the four plants (Bradley and Saha 2009, pp. 
27-28). After hurricane Wilma, the herb layer in pine rocklands in 
close proximity to the coast was brown with few plants having live 
material above ground (Bradley 2006, p. 11). Subsequent surveys found 
no Linum arenicola and little Chamaecrista lineata var. keyensis or 
Chamaesyce deltoidea ssp. serpyllum in areas where they previously 
occurred. Not only did the storm surge kill the vegetation, but many of 
the roadside areas were heavily disturbed by dumping and removal of 
storm debris (Bradley 2006, p. 37). Estimates of the population sizes 
pre- and post-Wilma were calculated for Chamaesyce deltoidea ssp. 
serpyllum and Chamaecrista lineata var. keyensis. Each declined in the 
months following the storm, by 41.2 percent and 48.0 percent, 
respectively (Bradley and Saha 2009, p. 2). L. arenicola was not found 
at all in surveys 8 to 9 weeks after the hurricane (Bradley 2006, p. 
36). The Middle Torch Key population was extirpated after Hurricane 
Wilma, and the population on Big Torch Key declined drastically, with 
only one individual located. Both of these areas were heavily affected 
by storm surges during Hurricane Wilma (Hodges 2010, p. 2). As of 2013, 
populations of Chamaecrista lineata var. keyensis, Chamaesyce deltoidea 
ssp. serpyllum, and L. arenicola in the Florida Keys have not returned 
to pre-Hurricane Wilma levels (Bradley et al. 2015, pp. 21, 25, 29).
    Some climate change models predict increased frequency and duration 
of severe storms, including hurricanes and tropical storms (McLaughlin 
et al. 2002, p. 6074; Cook et al. 2004, p. 1015; Golladay et al. 2004, 
p. 504). Other models predict hurricane and tropical storm frequencies 
in the Atlantic are expected to decrease between 10 and 30 percent by 
2100 (Knutson et al. 2008, pp. 1-21). For those models that predict 
fewer hurricanes, predictions of hurricane wind speeds are expected to 
increase by 5 to 10 percent due to an increase in available energy for 
intense storms. Increases in hurricane winds can elevate the chances of 
damage to existing canopy and increase storm surge heights.
    All populations of the four plants are vulnerable to hurricane wind 
damage. Populations close to the coast and all populations of the four 
plants in the Florida Keys are vulnerable to inundation by storm surge. 
Historically, the four plant species may have benefitted from more 
abundant and contiguous habitat to buffer them from storm events. The 
small size of many populations of these plants makes them especially 
vulnerable, in which the loss of even a few individuals could reduce 
the viability of a single population. The destruction and modification 
of native habitat, combined with small population size, has likely 
contributed over time to the stress, decline, and, in some instances, 
extirpation of populations or local occurrences due to stochastic 
events.
    Due to the small size of some existing populations of Chamaecrista 
lineata var. keyensis, Linum arenicola, and Argythamnia blodgettii (see 
below) and the narrow geographic range of all four plant species, their 
overall resilience to these factors is likely low. These factors, 
combined with additional stress from habitat loss and modification 
(e.g., inadequate fire management) may increase the inherent risk of 
stochastic events that impact these plants. For these reasons, all four 
plants are at risk of extirpation during extreme stochastic events. Of 
the four species, Argythamnia blodgettii is probably less vulnerable 
because of the larger number of sites where it occurs throughout Miami-
Dade and Monroe Counties.
Small Population Size and Isolation
    Endemic species whose populations exhibit a high degree of 
isolation are extremely susceptible to extinction from both random and 
nonrandom catastrophic natural or human-caused events. Species that are 
restricted to geographically limited areas are inherently more 
vulnerable to extinction than widespread species because of the 
increased risk of genetic bottlenecks, random demographic fluctuations, 
climate change, and localized catastrophes such as hurricanes and 
disease outbreaks (Mangel and Tier 1994, p. 607; Pimm et al. 1998, p. 
757). These problems are further magnified when populations are few and 
restricted to a very small geographic area, and when the number of 
individuals is very small. Populations with these

[[Page 66858]]

characteristics face an increased likelihood of stochastic extinction 
due to changes in demography, the environment, genetics, or other 
factors (Gilpin and Soule 1986, pp. 24-34). Small, isolated populations 
often exhibit reduced levels of genetic variability, which diminishes 
the species' capacity to adapt and respond to environmental changes, 
thereby decreasing the probability of long-term persistence (e.g., 
Barrett and Kohn 1991, p. 4; Newman and Pilson 1997, p. 361). Very 
small plant populations may experience reduced reproductive vigor due 
to ineffective pollination or inbreeding depression. Isolated 
individuals have difficulty achieving natural pollen exchange, which 
limits the production of viable seed. The problems associated with 
small population size and vulnerability to random demographic 
fluctuations or natural catastrophes are further magnified by 
synergistic interactions with other threats, such as those discussed 
above (see Factors A and C).
    Chamaecrista lineata var. keyensis and Chamaesyce deltoidea ssp. 
serpyllum both have large populations on Big Pine Key. The other extant 
occurrence of Chamaecrista lineata var. keyensis in the Florida Keys, 
on Cudjoe Key, is small. Five out of 12 extant Linum arenicola 
populations, and 20 of 34 Argythamnia blodgettii populations, have 
fewer than 100 individuals. These small populations are at risk of 
adverse effects from reduced genetic variation, an increased risk of 
inbreeding depression, and reduced reproductive output. Many of these 
populations are small and isolated from each other, decreasing the 
likelihood that they could be naturally reestablished in the event that 
extinction from one location would occur. Argythamnia blodgettii is the 
only one of the four plants species that occurs in ENP, where a 
population of over 2,000 plants is stable and prescribed fire and other 
management activities that benefit A. blodgettii are conducted on a 
regular basis.
Climate Change and Sea Level Rise
    Climatic changes, including sea level rise (SLR), are occurring in 
the State of Florida and are impacting associated plants, animals, and 
habitats. Our analyses under the Act include consideration of ongoing 
and projected changes in climate. The term ``climate,'' as defined by 
the Intergovernmental Panel on Climate Change (IPCC), refers to the 
mean and variability of different types of weather conditions over 
time, with 30 years being a typical period for such measurements, 
although shorter or longer periods also may be used (IPCC 2013, p. 
1450). The term ``climate change'' thus refers to a change in the mean 
or variability of one or more measures of climate (e.g., temperature or 
precipitation) that persists for an extended period, typically decades 
or longer, whether the change is due to natural variability, human 
activity, or both (IPCC 2013, p. 1450). A recent compilation of climate 
change and its effects is available from IPCC reports (IPCC 2013, 
entire).
    Scientific measurements spanning several decades demonstrate that 
changes in climate are occurring, and that the rate of change has been 
faster since the 1950s. Examples include warming of the global climate 
system, and substantial increases in precipitation in some regions of 
the world and decreases in other regions. (For these and other 
examples, see IPCC 2007a, p. 30; Solomon et al. 2007, pp. 35-54, 82-
85). Results of scientific analyses presented by the IPCC show that 
most of the observed increase in global average temperature since the 
mid-20th century cannot be explained by natural variability in climate, 
and is ``very likely'' (defined by the IPCC as 90 percent or higher 
probability) due to the observed increase in greenhouse gas (GHG) 
concentrations in the atmosphere as a result of human activities, 
particularly carbon dioxide emissions from use of fossil fuels (IPCC 
2007a, pp. 5-6 and figures SPM.3 and SPM.4; Solomon et al. 2007, pp. 
21-35). Further confirmation of the role of GHGs comes from analyses by 
Huber and Knutti (2011, p. 4), who concluded it is extremely likely 
that approximately 75 percent of global warming since 1950 has been 
caused by human activities.
    Scientists use a variety of climate models, which include 
consideration of natural processes and variability, as well as various 
scenarios of potential levels and timing of GHG emissions, to evaluate 
the causes of changes already observed and to project future changes in 
temperature and other climate conditions (e.g., Meehl et al. 2007, 
entire; Ganguly et al. 2009, pp. 11555, 15558; Prinn et al. 2011, pp. 
527, 529). All combinations of models and emissions scenarios yield 
very similar projections of increases in the most common measure of 
climate change, average global surface temperature (commonly known as 
global warming), until about 2030. Although projections of the 
magnitude and rate of warming differ after about 2030, the overall 
trajectory of all the projections is one of increased global warming 
through the end of this century, even for the projections based on 
scenarios that assume that GHG emissions will stabilize or decline. 
Thus, there is strong scientific support for projections that warming 
will continue through the 21st century, and that the magnitude and rate 
of change will be influenced substantially by the extent of GHG 
emissions (IPCC 2007a, pp. 44-45; Meehl et al. 2007, pp. 760-764, 797-
811; Ganguly et al. 2009, pp. 15555-15558; Prinn et al. 2011, pp. 527, 
529). (See IPCC 2007b, p. 8, for a summary of other global projections 
of climate-related changes, such as frequency of heat waves and changes 
in precipitation. Also see IPCC 2011 (entire) for a summary of 
observations and projections of extreme climate events.)
    Various changes in climate may have direct or indirect effects on 
species. These effects may be positive, neutral, or negative, and they 
may change over time, depending on the species and other relevant 
considerations, such as interactions of climate with other variables 
(e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-19). Identifying 
likely effects often involves aspects of climate change vulnerability 
analysis. Vulnerability refers to the degree to which a species (or 
system) is susceptible to, and unable to cope with, adverse effects of 
climate change, including climate variability and extremes. 
Vulnerability is a function of the type, magnitude, and rate of climate 
change and variation to which a species is exposed, its sensitivity, 
and its adaptive capacity (IPCC 2007a, p. 89; see also Glick et al. 
2011, pp. 19-22). There is no single method for conducting such 
analyses that applies to all situations (Glick et al. 2011, p. 3). We 
use our expert judgment and appropriate analytical approaches to weigh 
relevant information, including uncertainty, in our consideration of 
various aspects of climate change.
    As is the case with all stressors that we assess, even if we 
conclude that a species is currently affected or is likely to be 
affected in a negative way by one or more climate-related impacts, it 
does not necessarily follow that the species meets the definition of an 
``endangered species'' or a ``threatened species'' under the Act. If a 
species is listed as endangered or threatened, knowledge regarding the 
vulnerability of the species to, and known or anticipated impacts from, 
climate-associated changes in environmental conditions can be used to 
help devise appropriate strategies for its recovery.
    Global climate projections are informative, and, in some cases, the 
only or the best scientific information available for us to use. 
However, projected changes in climate and related

[[Page 66859]]

impacts can vary substantially across and within different regions of 
the world (e.g., IPCC 2007a, pp. 8-12). Therefore, we use 
``downscaled'' projections when they are available and have been 
developed through appropriate scientific procedures, because such 
projections provide higher resolution information that is more relevant 
to spatial scales used for analyses of a given species (see Glick et 
al. 2011, pp. 58-61, for a discussion of downscaling).
    With regard to our analysis for Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia 
blodgettii, downscaled projections suggest that SLR is the largest 
climate-driven challenge to low-lying coastal areas in the subtropical 
ecoregion of southern Florida (U.S. Climate Change Science Program 
(USCCSP) 2008, pp. 5-31, 5-32). All populations of the four plants 
occur at elevations from 2.83-4.14 meters (m) (9.29-13.57 feet (ft)) 
above sea level, making these plants highly susceptible to increased 
storm surges and related impacts associated with SLR.
    We acknowledge that the drivers of SLR (especially contributions of 
melting glaciers) are not completely understood, and there is 
uncertainty with regard to the rate and amount of SLR. This uncertainty 
increases as projections are made further into the future. For this 
reason, we examine threats to the species within the range of 
projections found in recent climate change literature.
    The long-term record at Key West shows that sea level rose on 
average 0.229 cm (0.090 in) annually between 1913 and 2013 (National 
Oceanographic and Atmospheric Administration (NOAA) 2013, p. 1). This 
equates to approximately 22.9 cm (9.02 in) over the last 100 years. 
IPCC (2008, p. 28) emphasized it is very likely that the average rate 
of SLR during the 21st century will exceed the historical rate. The 
IPCC Special Report on Emission Scenarios (2000, entire) presented a 
range of scenarios based on the computed amount of change in the 
climate system due to various potential amounts of anthropogenic 
greenhouse gases and aerosols in 2100. Each scenario describes a future 
world with varying levels of atmospheric pollution leading to 
corresponding levels of global warming and corresponding levels of SLR. 
The IPCC Synthesis Report (2007, entire) provided an integrated view of 
climate change and presented updated projections of future climate 
change and related impacts under different scenarios.
    Subsequent to the 2007 IPCC Report, the scientific community has 
continued to model SLR. Recent peer-reviewed publications indicate a 
movement toward increased acceleration of SLR. Observed SLR rates are 
already trending along the higher end of the 2007 IPCC estimates, and 
it is now widely held that SLR will exceed the levels projected by the 
IPCC (Rahmstorf et al. 2012, p. 1; Grinsted et al. 2010, p. 470). Taken 
together, these studies support the use of higher end estimates now 
prevalent in the scientific literature. Recent studies have estimated 
global mean SLR of 1.0-2.0 m (3.3-6.6 ft) by 2100 as follows: 0.75-1.90 
m (2.50-6.20 ft; Vermeer and Rahmstorf 2009, p. 21530); 0.8-2.0 m (2.6-
6.6 ft; Pfeffer et al. 2008, p. 1342); 0.9-1.3 m (3.0-4.3 ft; Grinsted 
et al. 2010, pp. 469-470); 0.6-1.6 m (2.0-5.2 ft; Jevrejeva et al. 
2010, p. 4); and 0.5-1.4 m (1.6-4.6 ft; National Research Council 2012, 
p. 2).
    Other processes expected to be affected by projected warming 
include temperatures, rainfall (amount, seasonal timing, and 
distribution), and storms (frequency and intensity) (see 
``Environmental Stochasticity'', above). Models where sea surface 
temperatures are increasing also show a higher probability of more 
intense storms (Maschinski et al. 2011, p. 148). The Massachusetts 
Institute of Technology (MIT) modeled several scenarios combining 
various levels of SLR, temperature change, and precipitation 
differences with human population growth, policy assumptions, and 
conservation funding changes. All of the scenarios, from small climate 
change shifts to major changes, indicate significant effects on coastal 
Miami-Dade County. The Science and Technology Committee of the Miami-
Dade County Climate Change Task Force (Wanless et al. 2008, p. 1) 
recognize that significant SLR is a serious concern for Miami-Dade 
County in the near future. In a January 2008 statement, the committee 
warned that sea level is expected to rise at least 0.9-1.5 m (3.0-5.0 
ft) within this century (Wanless et al. 2008, p. 3). With a 0.9-1.2 m 
(3.0-4.0 ft) rise in sea level (above baseline) in Miami-Dade County, 
spring high tides would be at about 1.83-2.13 m (6.0-7.0 ft); 
freshwater resources would be gone; the Everglades would be inundated 
on the west side of Miami-Dade County; the barrier islands would be 
largely inundated; storm surges would be devastating to coastal habitat 
and associated species; and landfill sites would be exposed to erosion, 
contaminating marine and coastal environments. Freshwater and coastal 
mangrove wetlands will be unable to keep up with or offset SLR of 0.61 
m (2.0 ft) per century or greater. With a 1.52 m (5.0 ft) rise, Miami-
Dade County will be extremely diminished (Wanless et al. 2008, pp. 3-
4).
    SLR projections from various scenarios have been downscaled by TNC 
(2011, entire) and Zhang et al. (2011, entire) for the Florida Keys. 
Using the IPCC best-case, low-pollution scenario, a rise of 18 cm (7 
in) (a rate close to the historical average reported above) would 
result in the inundation of 23,796 ha (58,800 acres) or 38.2 percent of 
the Florida Keys upland area by the year 2100 (TNC 2011, p. 25). Under 
the IPCC worst-case, high-pollution scenario, a rise of 59 cm (23.2 in) 
would result in the inundation of 46,539 ha (115,000 acres) or 74.7 
percent of the Florida Keys upland area by the year 2100 (TNC 2011, p. 
25). Using Rahmstorf et al.'s (2007; p. 368) SLR projections of 100 to 
140 cm, 80.5 to 92.2 percent of the Florida Keys land area would be 
inundated by 2100. The Zhang et al. (2011, p. 136) study models SLR up 
to 1.8 m (5.9 ft) for the Florida Keys, which would inundate 93.6 
percent of the current land area of the Keys.
    Prior to inundations from SLR, there will likely be habitat 
transitions related to climate change, including changes to hydrology 
and increasing vulnerability to storm surge. Hydrology has a strong 
influence on plant distribution in coastal areas (IPCC 2008, p. 57). 
Such communities typically grade from salt to brackish to freshwater 
species. From the 1930s to 1950s, increased salinity contributed to the 
decline of cabbage palm forests in southwest Florida (Williams et al. 
1999, pp. 2056-2059), expansion of mangroves into adjacent marshes in 
the Everglades (Ross et al. 2000, pp. 101, 111), and loss of pine 
rocklands in the Keys (Ross et al. 1994, pp. 144, 151-155). In Florida, 
pine rocklands transition into rockland hammocks, and, as such, these 
habitat types are closely associated in the landscape. A study 
conducted in one pine rocklands location on Sugar Loaf Key (with an 
average elevation of 0.89 m (2.90 ft)) found an approximately 65 
percent reduction in an area occupied by South Florida slash pine over 
a 70-year period, with pine mortality and subsequent increased 
proportions of halophytic (salt-loving) plants occurring earlier at the 
lower elevations (Ross et al. 1994, pp. 149-152). During this same time 
span, local sea level had risen by 15 cm (6 in), and Ross et al. (1994, 
p. 152) found evidence of groundwater and soil water salinization. 
Extrapolating this situation to hardwood hammocks is

[[Page 66860]]

not straightforward, but it suggests that changes in rockland hammock 
species composition may not be an issue in the immediate future (5-10 
years); however, over the long term (within the next 10-50 years), it 
may be an issue if current projections of SLR occur and freshwater 
inputs are not sufficient to maintain high humidities and prevent 
changes in existing canopy species through salinization (Saha et al. 
2011, pp. 22-25). Ross et al. (2009, pp. 471-478) suggested that 
interactions between SLR and pulse disturbances (e.g., storm surges) 
can cause vegetation to change sooner than projected based on sea level 
alone.
    Impacts from climate change including regional SLR have been 
studied for coastal hammocks but not rockland hammock habitat. Saha (et 
al. 2011, pp. 24-25) conducted a risk assessment on rare plant species 
in ENP and found that impacts from SLR have significant effects on 
imperiled taxa. This study also predicted a decline in the extent of 
coastal hammocks with initial SLR, coupled with a reduction in 
freshwater recharge volume and an increase in pore water (water filling 
spaces between grains of sediment) salinity, which will push hardwood 
species to the edge of their drought (freshwater shortage and 
physiological) tolerance, jeopardizing critically imperiled or endemic 
species, or both, with possible extirpation. In south Florida, SLR of 
1-2 m (3.3-6.6 ft) is estimated by 2100, which is on the higher end of 
global estimates for SLR. These projected increases in sea level pose a 
threat to coastal plant communities and habitats from mangroves at sea 
level to salinity-intolerant, coastal rockland hammocks where 
elevations are generally less than 2.0 m (6.1 ft) above sea level (Saha 
et al. 2011, p. 2). Loss or degradation of these habitats can be a 
direct result of SLR or in combination of several other factors, 
including diversion of freshwater flow, hurricanes, and exotic plant 
species infestations, which can ultimately pose a threat to rare plant 
populations (Saha et al. 2011, p. 24).
    Habitats for these species are restricted to relatively immobile 
geologic features separated by large expanses of flooded, inhospitable 
wetland or ocean, leading us to conclude that these habitats will 
likely not be able to migrate as sea level rises (Saha et al. 2011, pp. 
103-104). Because of the extreme fragmentation of remaining habitat and 
isolation of remaining populations, and the accelerating rate at which 
SLR is projected to occur (Grinsted et al. 2010, p. 470), it will be 
particularly difficult for these species to disperse to suitable 
habitat once existing sites that support them are lost to SLR. Patterns 
of development will also likely be significant factors influencing 
whether natural communities can move and persist (IPCC 2008, p. 57; 
CCSP 2008, pp. 7-6). The plant species face significant risks from 
coastal squeeze that occurs when habitat is pressed between rising sea 
levels and coastal development that prevents landward migration of 
species. The ultimate effect of these impacts is likely to result in 
reductions in reproduction and survival, with corresponding decreases 
in population numbers.
    Saha (et al. 2011, p. 4) suggested that the rising water table 
accompanying SLR will shrink the vadose zone (the area which extends 
from the top of the ground surface to the water table); increase 
salinity in the bottom portion of the freshwater lens, thereby 
increasing brackishness of plant-available water; and influence tree 
species composition of coastal hardwood hammocks based upon species-
level tolerance to salinity or drought or both. Evidence of population 
declines and shifts in rare plant communities, along with multi-trophic 
effects, already have been documented on the low-elevation islands of 
the Florida Keys (Maschinski et al. 2011, p. 148).
    Direct losses to extant populations of all four plants are expected 
due to habitat loss and modification from SLR by 2100. We analyzed 
existing sites that support populations of the four plants using the 
National Oceanic and Atmospheric Administration (NOAA) Sea Level Rise 
and Coastal Impacts viewer. Below, we discuss general implications of 
sea level rise within the range of projections discussed above on the 
current distribution of these species. The NOAA tool uses 1-foot 
increments, so the analysis is based on 0.91 m (3 ft) and 1.8 m (6 ft).
    Chamaecrista lineata var. keyensis: A 0.91-m (3-ft) rise would 
inundate most areas of Big Pine Key, and all areas of Cudjoe Key, that 
support Chamaecrista lineata var. keyensis, and reduce both Keys to 
several much smaller islands. The remaining uplands on these islands 
would likely transition to buttonwoods and saltmarshes, and would be 
extremely vulnerable to storm surge. This will further reduce and 
fragment these populations. A 1.8-m (6-ft) rise would completely 
inundate all areas that support C. lineata var. keyensis and eliminate 
all pine rocklands habitat within the historic range of the species.
    Chamaesyce deltoidea var. serpyllum: A 0.91-m (3-ft) rise would 
inundate most areas of Big Pine Key that support Chamaesyce deltoidea 
var. serpyllum, and reduce the Key to three to five much smaller 
islands. The remaining uplands would likely transition to buttonwoods 
and saltmarshes, and would be extremely vulnerable to storm surge. This 
will further reduce and fragment the population. A 1.8-m (6-ft) rise 
would completely inundate all areas that support C. deltoidea var. 
serpyllum and eliminate all pine rocklands habitat within the historic 
range of the species.
    Linum arenicola: In Miami-Dade County, a 0.91-m (3-ft) rise would 
inundate the area that supports a large extant population of Linum 
arenicola along L-31E canal. While other areas that support the species 
are located in higher elevation areas along the coastal ridge, changes 
in the salinity of the water table and soils, along with additional 
vegetation shifts in the region, are likely. Remaining uplands may 
transition to wetter, more salt-tolerant plant communities. This will 
further reduce and fragment the populations. A 1.8-m (6-ft) rise would 
inundate portions of the largest known population (HARB), as well the 
population along L-31E canal. The areas that support Linum arenicola at 
the Richmond pinelands to the north would not be inundated, but pine 
rocklands in these areas may be reduced through transition to wetter, 
more salt-tolerant plant communities, as discussed above.
    In the Florida Keys, a 0.91-m (3-ft) rise would inundate most areas 
of Big Pine Key and Lower Sugarloaf Key, and all of the areas on Upper 
Sugarloaf Key and Big Torch Key, that support Linum arenicola, and 
reduce these Keys to numerous much smaller islands. The remaining 
uplands on these small islands would likely transition to buttonwoods 
and saltmarshes, and would be extremely vulnerable to further losses 
due to storm surge. This would further reduce and fragment the 
populations. A 1.8-m (6-ft) rise would completely inundate all areas 
that support Linum arenicola in the Florida Keys and eliminate all pine 
rocklands habitat within the historic range of the species in Monroe 
County.
    Argythamnia blodgettii: In Miami-Dade County, a 0.91-m (3-ft) rise 
would not inundate any extant populations of Argythamnia blodgettii 
because these habitats are located in higher elevation areas along the 
coastal ridge. However, changes in the salinity of the water table and 
soils, along with additional vegetation shifts in the region, are 
likely. Remaining uplands may likely transition to wetter, more salt-
tolerant plant communities. This will further

[[Page 66861]]

reduce and fragment the populations. A 1.8-m (6-ft) rise would inundate 
portions of Crandon Park, making it unsuitable for A. blodgettii. Other 
areas that support A. blodgettii, including the Richmond pinelands to 
the north, and Long Pine Key in ENP, would not be inundated, but 
habitats in these areas may be reduced through transition to wetter, 
more salt-tolerant plant communities, as discussed above.
    In the Florida Keys, a 0.91-m (3-ft) rise would reduce the area of 
islands in the upper Keys, but extant populations on Key Largo, Windley 
Key, and Lignumvitae Key are less vulnerable than the Middle and Lower 
Keys, which are at lower elevations. Lower Matecumbe Key, Plantation 
Key, Vaca Key, Big Pine Key, and Big Munson Island would be fragmented 
and reduced to numerous much smaller islands. The remaining uplands on 
these small islands would likely transition to buttonwoods and 
saltmarshes, and would be extremely vulnerable further losses to storm 
surge. This would further reduce and fragment the populations. A 1.8-m 
(6-ft) rise would completely inundate all areas that support 
Argythamnia blodgettii south of Lignumvitae Key. Key Largo, Windley 
Key, and Lignumvitae Key are the only existing areas supporting extant 
populations that could continue to support a population given a 1.8-m 
(6-ft) sea level rise.
Conservation Efforts To Reduce Other Natural or Manmade Factors 
Affecting Its Continued Existence
    NPS, the Service, Miami-Dade County, and the State of Florida have 
ongoing nonnative plant management programs to reduce threats on public 
lands, as funding and resources allow. In Miami-Dade County, nonnative, 
invasive plant management is very active, with a goal to treat all 
publicly owned properties at least once a year and more often in many 
cases. IRC and FTBG conduct research and monitoring in various natural 
areas within Miami-Dade County and the Florida Keys for various 
endangered plant species and nonnative, invasive species.
Summary of Factor E
    We have analyzed threats from other natural or manmade factors 
including: Nonnative, invasive plants; management practices used on 
roadsides and disturbed sites (such as mowing, sodding, and herbicide 
use); pesticide spraying and its effects on pollinators; environmental 
stochasticity; effects from small population size and isolation; and 
the effects of climate change, including SLR. The related risks from 
hurricanes and storm surge act together to impact populations of all 
four plants. Some of these threats (e.g., nonnative species) may be 
reduced on public lands due to active programs by Federal, State, and 
county land managers. Many of the remaining populations of these plants 
are small and geographically isolated, and genetic variability is 
likely low, increasing the inherent risk due to overall low resilience 
of these plants.

Cumulative Effects of Threats

    When two or more threats affect populations of the four plants, the 
effects of those threats could interact or become compounded, producing 
a cumulative adverse effect that is greater than the impact of either 
threat alone. The most obvious cases in which cumulative adverse 
effects would be significant are those in which small populations 
(Factor E) are affected by threats that result in destruction or 
modification of habitat (Factor A). The limited distributions and small 
population sizes of many populations of the four plants make them 
extremely susceptible to the detrimental effects of further habitat 
modification, degradation, and loss, as well as other anthropogenic 
threats. Mechanisms leading to the decline of the four plants, as 
discussed above, range from local (e.g., agriculture) to regional 
(e.g., development, fragmentation, nonnative species) to global (e.g., 
climate change, SLR) influences. The synergistic effects of threats, 
such as impacts from hurricanes on a species with a limited 
distribution and small populations, make it difficult to predict 
population viability. While these stressors may act in isolation, it is 
more probable that many stressors are acting simultaneously (or in 
combination) on populations of these four plants, making them more 
vulnerable.

Determination

    We have carefully assessed the best scientific and commercial data 
available regarding the past, present, and future threats to 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii. Numerous 
populations of all four plants have been extirpated from these species' 
historical ranges, and the primary threats of habitat destruction and 
modification resulting from human population growth and development, 
agricultural conversion, and inadequate fire management (Factor A); 
competition from nonnative, invasive species (Factor E); changes in 
climatic conditions, including SLR (Factor E); and natural stochastic 
events (Factor E) remain threats for existing populations. Existing 
regulatory mechanisms have not led to a reduction or removal of threats 
posed to the four plants from these factors (see Factor D discussion, 
above). These threats are ongoing, rangewide, and expected to continue 
in the future. A significant percentage of populations of Chamaecrista 
lineata var. keyensis, Linum arenicola, and Argythamnia blodgettii are 
relatively small and isolated from one another, and their ability to 
recolonize suitable habitat is unlikely without human intervention, if 
at all. The threats have had and will continue to have substantial 
adverse effects on the four plants and their habitats. Although 
attempts are ongoing to alleviate or minimize some of these threats at 
certain locations, all populations appear to be impacted by one or more 
threats.
    The Act defines an endangered species as ``any species which is in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species as ``any species which is likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range.'' As described in detail 
above, Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, and Linum arenicola are currently at risk throughout all of 
their range due to the immediacy, severity, significance, timing, and 
scope of those threats. Impacts from these threats are ongoing and 
increasing; singly or in combination, these threats place these three 
plants in danger of extinction. The risk of extinction is high because 
the populations are small, are isolated, and have limited to no 
potential for recolonization. Numerous threats are currently ongoing 
and are likely to continue in the foreseeable future, at a high 
intensity and across the entire range of these plants. Furthermore, 
natural stochastic events and changes in climatic conditions pose a 
threat to the persistence of these plants, especially in light of the 
fact these events cannot be controlled and mitigation measures have yet 
to be addressed. Individually and collectively, all these threats can 
contribute to the local extirpation and potential extinction of these 
plant species. Because these threats are placing them in danger of 
extinction throughout their ranges, we have determined that each of 
these three plants meets the definition of an endangered species 
throughout their ranges.
    Throughout its range, Argythamnia blodgettii faces threats similar 
to the

[[Page 66862]]

other three plant species that are the subjects of this rule. However, 
we find that endangered species status is not appropriate for A. 
blodgettii. While we have evidence of threats under Factors A, D, and E 
affecting the species, insufficient data are available to identify the 
trends in extant populations. Twenty populations are extant, 15 are 
extirpated, and we are uncertain of the status of 15 populations that 
have not been surveyed in 15 years or more. Additionally, data show 
that the threat of habitat loss from sea level rise is not as severe 
for this species. Also, A. blodgettii is likely less vulnerable because 
of the larger number of sites where it occurs throughout Miami-Dade and 
Monroe Counties. Further, A. blodgettii is the only one of the four 
plants species that occurs in ENP, where a population of over 2,000 
plants is stable and where prescribed fire and other management 
activities that benefit A. blodgettii are conducted on a regular basis. 
Therefore, based on the best available information,

Significant Portion of the Range (SPR)

    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. The threats to the survival of 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii occur throughout 
these species' ranges and are not restricted to any particular 
significant portion of those ranges. Accordingly, our assessment and 
determination applies to each of the four plants throughout its entire 
range. Because we have determined that Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, and Linum arenicola meet 
the definition of endangered species, and Argythamnia blodgettii meets 
the definition of a threatened species, throughout their ranges, no 
portion of their ranges can be ``significant'' for purposes of the 
definitions of ``endangered species'' and ``threatened species.'' See 
the Service's SPR Policy (79 FR 37578; July 1, 2014).
    Therefore, on the basis of the best available scientific and 
commercial information, we list Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, and Linum arenicola as endangered 
species in accordance with sections 3(6) and 4(a)(1) of the Act. We 
find that threatened species status is not appropriate for Chamaecrista 
lineata var. keyensis, Chamaesyce deltoidea ssp. serpyllum, and Linum 
arenicola because of the contracted range of each species and because 
the threats are occurring rangewide, are ongoing, and are expected to 
continue into the future. We find that A. blodgettii is likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range, and we list the species as a 
threatened species in accordance with sections 3(20) and 4(a)(1) of the 
Act.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing results in public awareness, and 
conservation by Federal, State, Tribal, and local agencies; private 
organizations; and individuals. The Act encourages cooperation with the 
States and other countries and calls for recovery actions to be carried 
out for listed species. The protection required by Federal agencies and 
the prohibitions against certain activities are discussed, in part, 
below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Subsection 4(f) of the Act calls for the Service to develop 
and implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed and preparation of a draft and final 
recovery plan. The recovery outline guides the immediate implementation 
of urgent recovery actions and describes the process to be used to 
develop a recovery plan. Revisions of the plan may be done to address 
continuing or new threats to the species, as new substantive 
information becomes available. The recovery plan also identifies 
recovery criteria for review of when a species may be ready for 
downlisting or delisting, and methods for monitoring recovery progress. 
Recovery plans also establish a framework for agencies to coordinate 
their recovery efforts and provide estimates of the cost of 
implementing recovery tasks. Recovery teams (composed of species 
experts, Federal and State agencies, nongovernmental organizations, and 
stakeholders) are often established to develop recovery plans. If these 
four plant species are listed, a recovery outline, draft recovery plan, 
and the final recovery plan will be available on our Web site (http://www.fws.gov/endangered), or from our South Florida Ecological Services 
Field Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands. 
If these four plant species are listed, funding for recovery actions 
will be available from a variety of sources, including Federal budgets, 
State programs, and cost share grants for non-Federal landowners, the 
academic community, and nongovernmental organizations. In addition, 
pursuant to section 6 of the Act, the State of Florida would be 
eligible for Federal funds to implement management actions that promote 
the protection or recovery of the four plants. Information on our grant 
programs that are available to aid species recovery can be found at: 
http://www.fws.gov/grants.
    Please let us know if you are interested in participating in 
recovery efforts for Chamaecrista lineata var. keyensis, Chamaesyce 
deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii. 
Additionally, we invite you to submit any new information on these 
plants whenever it becomes available and any information you may have 
for recovery planning purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is listed as an endangered or 
threatened species and with respect to its critical habitat, if any is 
designated. Regulations implementing this interagency cooperation 
provision of the Act are codified at 50 CFR part 402. Section

[[Page 66863]]

7(a)(2) of the Act requires Federal agencies to ensure that activities 
they authorize, fund, or carry out are not likely to jeopardize the 
continued existence of the species or destroy or adversely modify its 
critical habitat. If a Federal action may affect a listed species or 
its critical habitat, if designated, the responsible Federal agency 
must enter into consultation with the Service.
    Federal agency actions within the species' habitat that may require 
consultation as described in the preceding paragraph include management 
and any other landscape-altering activities on Federal lands 
administered by the Service, NPS, and Department of Defense; issuance 
of section 404 Clean Water Act (33 U.S.C. 1251 et seq.) permits by the 
U.S. Army Corps of Engineers; construction and management of gas 
pipeline and power line rights-of-way by the Federal Energy Regulatory 
Commission; construction and maintenance of roads or highways by the 
Federal Highway Administration; and disaster relief efforts conducted 
by the Federal Emergency Management Agency.
    With respect to endangered plants, prohibitions outlined at 50 CFR 
17.61 make it illegal for any person subject to the jurisdiction of the 
United States to import or export, transport in interstate or foreign 
commerce in the course of a commercial activity, sell or offer for sale 
in interstate or foreign commerce, or to remove and reduce to 
possession any such plant species from areas under Federal 
jurisdiction. In addition, for endangered plants, the Act prohibits 
malicious damage or destruction of any such species on any area under 
Federal jurisdiction, and the removal, cutting, digging up, or damaging 
or destroying of any such species on any other area in knowing 
violation of any State law or regulation, or in the course of any 
violation of a State criminal trespass law. Exceptions to these 
prohibitions are outlined at 50 CFR 17.62. With respect to threatened 
plants, 50 CFR 17.71 provides that, with certain exceptions, all of the 
prohibitions outlined at 50 CFR 17.61 for endangered plants also apply 
to threatened plants. Permit exceptions to the prohibitions for 
threatened plants are outlined at 50 CFR 17.72.
    Preservation of native flora of Florida through Florida Statutes 
581.185, sections (3)(a) and (3)(b), provide limited protection to 
species listed in the State of Florida Regulated Plant Index including 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii, as described 
under the Factor D discussion, above. Federal listing will increase 
protection for these plants by making violations of section 3 of the 
Florida Statute punishable as a Federal offense under section 9 of the 
Act. This would provide increased protection from unauthorized 
collecting and vandalism for the plants on State and private lands, 
where they might not otherwise be protected by the Act, and would 
increase the severity of the penalty for unauthorized collection, 
vandalism, or trade in these plants.
    The Service acknowledges that it cannot fully address some of the 
natural threats facing Chamaecrista lineata var. keyensis, Chamaesyce 
deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia blodgettii, 
(e.g., hurricanes, storm surge) or even some of the other significant, 
long-term threats (e.g., climatic changes, SLR). However, through 
listing, we can provide protection to the known populations and any new 
population of these plants that may be discovered (see discussion 
below). With listing, we can also influence Federal actions that may 
potentially impact these plants (see discussion below); this is 
especially valuable if these plants are found at additional locations. 
With listing, we will also be better able to deter illicit collection 
and trade.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered or threatened plants under certain circumstances. 
Regulations governing permits for endangered plants are codified at 50 
CFR 17.62, and for threatened plants at 50 CFR 17.72. With regard to 
endangered plants, the Service may issue a permit authorizing any 
activity otherwise prohibited by 50 CFR 17.61 for scientific purposes 
or for enhancing the propagation or survival of endangered plants.
    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is proposed for listing or listed, those activities 
that would or would not constitute a violation of section 9 of the Act. 
The intent of this policy is to increase public awareness of the effect 
of a final listing on proposed and ongoing activities within the range 
of the species. Based on the best available information, the following 
actions may potentially result in a violation of section 9, of the Act; 
this list is not comprehensive:
    (1) Import any such species into, or export any of the four plant 
species from, the United States.
    (2) Remove and reduce to possession any of the four plant species 
from areas under Federal jurisdiction; maliciously damage or destroy 
any of the four plant species on any such area; or remove, cut, dig up, 
or damage or destroy any of the four plant species on any other area in 
knowing violation of any law or regulation of any State or in the 
course of any violation of a State criminal trespass law.
    (3) Deliver, receive, carry, transport, or ship in interstate or 
foreign commerce, by any means whatsoever and in the course of a 
commercial activity, any of the four plant species.
    (4) Sell or offer for sale in interstate or foreign commerce any of 
the four plant species.
    (5) Introduce any nonnative wildlife or plant species to the State 
of Florida that compete with or prey upon Chamaecrista lineata var. 
keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, or 
Argythamnia blodgettii.
    (6) Release any unauthorized biological control agents that attack 
any life stage of Chamaecrista lineata var. keyensis, Chamaesyce 
deltoidea ssp. serpyllum, Linum arenicola, or Argythamnia blodgettii.
    (7) Manipulate or modify, without authorization, the habitat of 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, or Argythamnia blodgettii on Federal lands.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the Field 
Supervisor of the Service's South Florida Ecological Services Field 
Office (see FOR FURTHER INFORMATION CONTACT). Requests for copies of 
regulations regarding listed species and inquiries about prohibitions 
and permits should be addressed to the U.S. Fish and Wildlife Service, 
Ecological Services Division, Endangered Species Permits, 1875 Century 
Boulevard, Atlanta, GA 30345 (phone 404-679-7140; fax 404-679-7081).
    When Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii are listed under 
the Act, the State of Florida's Endangered Species Act (Florida 
Statutes 581.185) is automatically invoked, which also prohibits take 
of these plants and encourages conservation by State government 
agencies. Further, the State may enter into agreements with Federal 
agencies to administer and manage any area required for the 
conservation, management, enhancement, or protection of endangered 
species (Florida Statutes 581.185). Funds for these activities can be 
made available

[[Page 66864]]

under section 6 of the Act (Cooperation with the States). Thus, the 
Federal protection afforded to these plants by listing them as 
endangered species will be reinforced and supplemented by protection 
under State law.
    Activities that the Service believes could potentially harm these 
four plants include, but are not limited to:
    (1) Actions that would significantly alter the hydrology or 
substrate, such as ditching or filling. Such activities may include, 
but are not limited to, road construction or maintenance, and 
residential, commercial, or recreational development.
    (2) Actions that would significantly alter vegetation structure or 
composition, such as clearing vegetation for construction of 
residences, facilities, trails, and roads.
    (3) Actions that would introduce nonnative species that would 
significantly alter vegetation structure or composition. Such 
activities may include, but are not limited to, residential and 
commercial development, and road construction.
    (4) Application of herbicides, or release of contaminants, in areas 
where these plants occur. Such activities may include, but are not 
limited to, natural resource management, management of rights-of-way, 
residential and commercial development, and road construction.

Critical Habitat

    Section 3(5)(A) of the Act defines critical habitat as (i) the 
specific areas within the geographical area occupied by the species, at 
the time it is listed on which are found those physical or biological 
features (I) essential to the conservation of the species and (II) 
which may require special management considerations or protection; and 
(ii) specific areas outside the geographical area occupied by the 
species at the time it is listed upon a determination by the Secretary 
of the Interior that such areas are essential for the conservation of 
the species. Section 3(3) of the Act defines conservation as to use and 
the use of all methods and procedures which are necessary to bring any 
endangered species or threatened species to the point at which the 
measures provided pursuant to the Act are no longer necessary.
    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12), require that, to the maximum extent 
prudent and determinable, the Secretary will designate critical habitat 
at the time the species is determined to be an endangered or threatened 
species. Our regulations (50 CFR 424.12(a)(1)) state that the 
designation of critical habitat is not prudent when one or both of the 
following situations exist:
    (1) The species is threatened by taking or other human activity, 
and identification of critical habitat can be expected to increase the 
degree of threat to the species, or
    (2) Such designation of critical habitat would not be beneficial to 
the species.
    In our proposed listing rule, we determined that because the 
designation of critical habitat will not likely increase the degree of 
threat to the species and may provide some measure of benefit, the 
designation of critical habitat is prudent for Chamaecrista lineata 
var. keyensis, Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, 
and Argythamnia blodgettii.
    Our regulations (50 CFR 424.12(a)(2)) further state that critical 
habitat is not determinable when one or both of the following 
situations exists: (1) Information sufficient to perform required 
analysis of the impacts of the designation is lacking; or (2) the 
biological needs of the species are not sufficiently well known to 
permit identification of an area as critical habitat. On the basis of a 
review of available information, we find that critical habitat for 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, Linum arenicola, and Argythamnia blodgettii is not 
determinable because the specific mapping and economic information 
sufficient to perform the required analysis of the impacts of the 
designation is currently lacking. We are still in the process of 
obtaining more information needed to properly evaluate the economic 
impacts of designation. We intend to publish a proposed rule 
designating critical habitat for Chamaecrista lineata var. keyensis, 
Chamaesyce deltoidea ssp. serpyllum, Linum arenicola, and Argythamnia 
blodgettii by the end of fiscal year 2017.

Required Determinations

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act need not be prepared in connection with 
listing a species as an endangered or threatened species under the 
Endangered Species Act. We published a notice outlining our reasons for 
this determination in the Federal Register on October 25, 1983 (48 FR 
49244).

References Cited

    A complete list of references cited in this rulemaking is available 
on the Internet at http://www.regulations.gov and upon request from the 
South Florida Ecological Services Field Office (see FOR FURTHER 
INFORMATION CONTACT).

Authors

    The primary authors of this final rule are the staff members of the 
South Florida Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Regulation Promulgation

    Accordingly, we amend part 17, subchapter B of chapter I, title 50 
of the Code of Federal Regulations, as follows:

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

0
1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless 
otherwise noted.


0
2. Amend Sec.  17.12(h) by adding entries for Argythamnia blodgettii, 
Chamaecrista lineata var. keyensis, Chamaesyce deltoidea ssp. 
serpyllum, and Linum arenicola, in alphabetical order under FLOWERING 
PLANTS, to the List of Endangered and Threatened Plants to read as 
follows:


Sec.  17.12  Endangered and threatened plants.

* * * * *
    (h) * * *

[[Page 66865]]



----------------------------------------------------------------------------------------------------------------
                                                                                              Listing citations
         Scientific name               Common name          Where listed         Status        and  applicable
                                                                                                    rules
----------------------------------------------------------------------------------------------------------------
Flowering Plants
 
                                                  * * * * * * *
Argythamnia blodgettii...........  Blodgett's           Wherever found.....  T               [Insert Federal
                                    silverbush.                                               Register
                                                                                              citation];
                                                                                              September 29,
                                                                                              2016.
 
                                                  * * * * * * *
Chamaecrista lineata var.          Big Pine partridge   Wherever found.....  E               [Insert Federal
 keyensis.                          pea.                                                      Register
                                                                                              citation];
                                                                                              September 29,
                                                                                              2016.
 
                                                  * * * * * * *
Chamaesyce deltoidea ssp.          Wedge spurge.......  Wherever found.....  E               [Insert Federal
 serpyllum.                                                                                   Register
                                                                                              citation];
                                                                                              September 29,
                                                                                              2016.
 
                                                  * * * * * * *
Linum arenicola..................  Sand flax..........  Wherever found.....  E               [Insert Federal
                                                                                              Register
                                                                                              citation];
                                                                                              September 29,
                                                                                              2016.
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------


    Dated: September 21, 2016.
Stephen Guertin,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2016-23546 Filed 9-28-16; 8:45 am]
 BILLING CODE 4333-15-P