[Federal Register Volume 80, Number 193 (Tuesday, October 6, 2015)]
[Rules and Regulations]
[Pages 60440-60465]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-25299]



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Vol. 80

Tuesday,

No. 193

October 6, 2015

Part II





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





Endangered and Threatened Wildlife and Plants; Endangered Species 
Status for Trichomanes punctatum ssp. floridanum (Florida Bristle 
Fern); Final Rule

  Federal Register / Vol. 80 , No. 193 / Tuesday, October 6, 2015 / 
Rules and Regulations  

[[Page 60440]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2014-0044; 4500030113]
RIN 1018-AY97


Endangered and Threatened Wildlife and Plants; Endangered Species 
Status for Trichomanes punctatum ssp. floridanum (Florida Bristle Fern)

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 Trichomanes punctatum ssp. floridanum (Florida 
bristle fern), a plant subspecies from Miami-Dade and Sumter Counties, 
Florida. The effect of this regulation will be to add this subspecies 
to the Federal List of Endangered and Threatened Plants and extend the 
Act's protections to this subspecies.

DATES: This rule becomes effective on November 5, 2015.

ADDRESSES: This final rule is available on the internet at http://www.regulations.gov and http://www.fws.gov/verobeach/. 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. All of the comments, materials, and documentation 
that we considered in this rulemaking are available by appointment, 
during normal business hours at: U.S. Fish and Wildlife Service, South 
Florida Ecological Services Office, 1339 20th Street, Vero Beach, FL 
32960; telephone 772-562-3909.

FOR FURTHER INFORMATION CONTACT: Roxanna Hinzman, Field Supervisor, 
U.S. Fish and Wildlife Service, South Florida Ecological Services 
Office, 1339 20th Street, Vero Beach, FL 32960, by telephone 772-562-
3909 or by 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 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. This rule will finalize the listing of the Trichomanes punctatum 
ssp. floridanum (Florida bristle fern) as an endangered species.
    The basis for our action. Under the Act, we can 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 Trichomanes 
punctatum ssp. floridanum consist primarily of destruction and 
modification of habitat (Factor A), proliferation of nonnative invasive 
species, natural stochastic events including hurricanes and tropical 
storms, and impacts from climate change including temperature shifts 
and sea level rise (Factor E), and that existing regulatory mechanisms 
have not reduced or removed such threats (Factor D).
    Peer review and public comment. We sought comments from independent 
specialists to ensure that our designation is based on scientifically 
sound data, assumptions, and analyses. We invited these peer reviewers 
to comment on our listing proposal. We also considered all comments and 
information received during the comment period.

Previous Federal Actions

    Please refer to the proposed listing rule for Trichomanes punctatum 
ssp. floridanum (79 FR 61136), published on October 9, 2014, for a 
detailed description of previous Federal actions concerning this 
subspecies.
    Our proposed listing rule included a finding that designation of 
critical habitat was prudent, but that critical habitat was not 
determinable. In this final listing rule, we find that critical habitat 
is still not determinable (see Critical Habitat discussion below).

Background

    Below we present updated and revised information, based on peer 
review and public comment received during the comment period on the 
proposed rule, as well as new information, related to the subspecies' 
life history, historical and current ranges, and habitat requirements.

Species Description

    Trichomanes punctatum ssp. floridanum, commonly referred to as the 
Florida bristle fern, is mat-forming, has root-like structures, and 
contains trichomes (hairlike/bristlelike outgrowths), which extend from 
soral involucres (tubes containing sporangia (an enclosure in which 
spores, or reproductive cells, are formed)) on the tips of some fronds 
(leaves of ferns) when the plant is fertile (Wunderlin and Hansen 2000, 
pp. 153-154). This subspecies is very small in size and superficially 
resembles bryophytes, such as mosses and liverworts, making it 
difficult to observe in its natural habitat.
    Wunderlin and Hansen (2000, pp. 153-154) described Trichomanes 
punctatum ssp. floridanum as having leaves, with the petiole (stalk by 
which a leaf is attached to a plant) 0.1-2.0 centimeters (cm) (0.04-
0.79 inches (in)) long and typically shorter than the blade. The blade 
is fan-shaped, round, entire or irregularly lobed at the apex, and 0.5-
2.0 cm (0.20-0.79 in) long and 0.2-1.1 cm (0.08-0.43 in) wide. T. p. 
ssp. floridanum has thin veinlets (small veins) that are not enlarged 
towards the margin while true veins are uniform in width to their 
apices (tips) (Nauman 1986, p. 179). This subspecies has few false 
veins, and fronds are considered simple (Morton 1963, p. 89).
    One unusual characteristic of this plant is that it lacks cuticles 
(the protective layer that covers the epidermis, which is the outermost 
layer of cells that cover the leaves) or has highly reduced cuticles. 
The fern has differentiated epidermises and stomata (small openings in 
leaves and stems through which gases are exchanged), causing it to be 
dependent on elevated moisture conditions because a barrier is not 
present to prevent unregulated loss of water (Kr[ouml]mer and Kessler 
2006, p. 57). This dependence restricts most Trichomanes ssp. to shaded 
areas within forested environments with high humidity, making them more 
vulnerable to changes in localized climatic conditions (Schuster 1971, 
p. 91; Nauman 1986, pp. 181-182; van der Heiden 2014, p. 5).

Taxonomy

    The genus Trichomanes contains approximately 320 species of ferns 
that occur primarily in the tropics and for which we generally lack 
ecological information (Nauman 1986, p. 179; Nelson 2000, p. 77). The 
genus belongs to the family Hymenophyllaceae and the hymenophylloid 
clade, where ferns are also referred to as filmy ferns, which

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describes the thin, filmy leaves of the species (Nelson 2000, p. 77). 
The common name, bristle fern, is used to reference the bristlelike 
structure that singularly protrudes from each soral involucre (a 
structure that holds and produces spores) (Nelson 2000, p. 77).
    Five species commonly known as bristle ferns (Trichomanes ssp.) 
have been found in Florida (Kr[ouml]mer and Kessler 2006, p. 57). 
Trichomanes punctatum ssp. floridanum is a subspecies of Trichomanes 
punctatum, the current taxonomy of which is the result of monographic 
revision of Trichomanes sections (a taxonomic rank or position below 
the genus but above the species) Didymoglossum and Microgonium by 
Wessels Boer (1962, pp. 300-301). All U.S. species of Trichomanes now 
belong to the section Didymoglossum, except T. boschianum (Morton 
1963). Wessels Boer, in reviewing specimens from throughout the 
American tropics, determined that all Trichomanes punctatum plants in 
Florida represented the same taxon, not two separate species, and that 
T. sphenoides (which he described as T. punctatum ssp. sphenoides) does 
not occur in Florida. He further determined that Trichomanes punctatum 
plants in Florida were different from those in the tropics and 
described them as a new subspecies, Trichomanes punctatum ssp. 
floridanum (Boer 1962, pp. 300-301). This treatment has been followed 
by almost all subsequent authors (Lakela and Long 1976, p. 53; 
Wunderlin 1982, p. 32; Lellinger 1985, p. 205; Nauman 1986, p. 181; 
Flora of North America Editorial Committee 1993, p. 196; Wunderlin 
1998, p. 44; Nelson 2000, p. 81; Wunderlin and Hansen 2000, p. 153; 
Wunderlin and Hansen 2003, p. 44). The only exception is Long and 
Lakela (1971, p. 73), who treated the subspecies as T. punctatum 
without further explanation. Additionally, the following entities use 
the name T. p. ssp. floridanum and indicate that this subspecies' 
taxonomic standing is accepted:
     Florida Department of Agriculture and Consumer Services 
(2013, https://www.flrules.org/gateway/RuleNo.asp?title=PRESERVATION%20OF%20NATIVE%20FLORA%20OF%20FLORIDA&ID=5B-40.0055),
     The Integrated Taxonomic Information System (2011, p. 1),
     NatureServe (2013, http://explorer.natureserve.org/servlet/NatureServe?loadTemplate=tabular_report.wmt&paging=home&save=all&sourceTemplate=reviewMiddle.wmt),
     The online Atlas of Florida Vascular Plants (Wunderlin and 
Hansen 2008, (http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1122),
     The Flora of North America (http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501316), and
     The Florida Natural Areas Inventory (FNAI) (FNAI, 2013, 
http://fnai.org/trackinglist.cfm).
    In summary, there is consensus that Trichomanes punctatum ssp. 
floridanum is a distinct taxon.
    Currently there are two extant metapopulations (groups of spatially 
separated populations) of this subspecies (Gann et al. 2002, pp. 552-
554), comprising four populations in Miami-Dade County and two in 
Sumter County, separated by a distance of approximately 400 kilometers 
(km) (249 miles (mi)). As noted by Small (1938, p. 50), the Sumter 
metapopulation is a considerable distance from where T. p. ssp. 
floridanum was first discovered (i.e., south Florida) and resides in a 
climate and habitat unlike the Miami-Dade County metapopulation. These 
differences are likely why Morton (1963, p. 90) suggested that the 
previous determination of these two metapopulations be reviewed. In 
March 2014, the Service contracted researchers from Florida Atlantic 
University to determine if the two metapopulations were the same 
subspecies. Samples were collected from both metapopulations for 
genetic analysis. DNA was isolated from the samples, and sequencing was 
completed on five samples from each metapopulation. Researchers found 
no observable differences in the sequence between the five samples 
collected from Miami-Dade County and the five samples from Sumter 
County, indicating that both metapopulations are the same subspecies 
(Hughes 2014, pp. 1-4).

Life History

    The life cycle of ferns is not commonly understood (Possley 2014c, 
pers. comm.). Information about the specific life cycle of T. p. ssp. 
floridanum is also lacking. Like all ferns, this taxon has two life-
history stages, a gametophyte stage and a sporophyte stage, and only 
the sporophyte form is recognizable in the wild, while the gametophyte 
form is very cryptic (Possley 2013a, pers. comm.; van der Heiden 2013b, 
pers. comm.). Therefore, all reported populations of Trichomanes 
punctatum ssp. floridanum have been in the sporophyte stage.
    Mature plants can reproduce sexually or asexually. The initial 
stage, when a spore germinates, is referred to as the gametophyte 
stage. The gametophyte contains separate sperm and egg-producing 
structures. In the presence of water or moisture, sperm reach the eggs 
for fertilization. Fertilized eggs, under the proper conditions, 
develop into sporophytes. The sporophytes produce spores, which in turn 
can germinate to produce new gametophytes (Nelson 2000, pp. 17-19). 
Reproduction may also occur in one other way: By division, when 
rhizomes (horizontal, underground plant stems capable of producing the 
shoot and root-like structures of a new plant) break, forming clones of 
the parent plant.
    Although it has been suggested that plants sporulate (produce 
spores) mostly in the spring and summer (Nauman 1986, p. 182), field 
observations in Miami-Dade County have observed sporangia in the months 
of February, March, May, August, October, and December. The plants are 
likely fertile any time of year; however, during the dry season, 
sporophytes have been observed to desiccate and probably do not produce 
spores (Possley 2013d, pers. comm.). In Sumter County, sporangia have 
been observed from April through September; however, researchers 
suggest they are likely producing all year, with peaks in the wet 
season (van der Heiden 2013c, pers. comm.). For Trichomanes punctatum 
ssp. floridanum, specific reproductive and growth requirements, such as 
moisture levels needed for each stage of its life history, plant 
longevity, growth rates, recruitment rates, dispersal methods, and 
genetic variation, are currently unknown.
    Organizations such as the Institute for Regional Conservation (IRC) 
and Fairchild Tropical Botanic Garden (Fairchild) are working together 
to understand the biology and life history of Trichomanes punctatum 
ssp. floridanum. In 2002, IRC and Fairchild collaborated with fern 
culture experts from Marie Selby Botanical Gardens (MSBG) in Sarasota, 
Florida, and tissue culture experts at the Lindner Center for 
Conservation and Research on Endangered Wildlife (CREW) in Cincinnati, 
Ohio (Gann et al. 2009, pp. 35-36). Currently, Fairchild maintains 
fewer than five healthy clusters of T. p. ssp. floridanum from plants 
obtained in local hammocks (tropical hardwood forests) that are 
monitored by their organization. The success of this effort to grow 
healthy T. p. ssp. floridanum has yet to be determined due to several 
factors, including: Slow growth rates, the formation of unusual linear 
fronds, the susceptibility to mold, and the lack of sporulation 
(Possley et al. 2013, pp. 43-45). However, researchers at CREW

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have recently developed a successful method to culture T. p. ssp. 
floridanum in-vitro and cryopreserve (to preserve by freezing at low 
temperatures) sporophytes (V. Pence, submitted; Pence and Charls 2006, 
pp. 29-34). The new plants from CREW have recently been transferred to 
MSBG, and plans are under way to establish T. p. ssp. floridanum onto 
limestone rock, which could potentially be transferred to solution hole 
(see description under ``Habitat'' section, below) walls for eventual 
reintroduction to the wild (Holst 2014, pers. comm.).
    It is important to note that the numerous efforts to cultivate 
Trichomanes punctatum ssp. floridanum ex-situ for possible future 
reintroduction have been only partially successful. Researchers have 
not been able to propagate T. p. ssp. floridanum via sexual 
reproduction. Although they have been able to maintain the subspecies 
in cultivation in the greenhouse for several months at a time, and 
temporarily establish rhizome growth onto limestone rock, the 
propagated fern eventually declines or becomes overrun with mosses. 
Even when there is vegetative growth, there is no sign of spore 
production (Holst 2014, pers. comm.).

Habitat

    In southeastern North America, Trichomanes ssp. are considered rare 
because of their delicate nature and requirements for deeply sheltered 
habitats with almost continuous high moisture and humidity (Farrar 
1993, pp. 190-197; Zots and Buche 2000, p. 203), restricting them from 
a more widespread pre-glaciation distribution. Trichomanes punctatum 
ssp. floridanum is considered strongly hygrophilous (growing or adapted 
to damp or wet conditions) and generally perceived as restricted to 
constantly humid microhabitat (Kr[ouml]mer and Kessler 2006, p. 57). T. 
p. ssp. floridanum occurs only in the United States in the State of 
Florida. In Florida, T. p. ssp. floridanum is known to occur only in 
Miami-Dade and Sumter Counties.
    Both extant metapopulations occur in dense canopy habitats, with 
shady conditions that may be obligatory due to the poikilohydric (i.e., 
possessing no mechanism to prevent desiccation) nature of some fern 
species (Kr[ouml]mer and Kessler 2006, p. 57). The canopy directly 
contributes to the surrounding humidity of an area. Dense canopies 
found in rockland habitats can minimize temperature fluctuations by 
reducing soil warming during the day and heat loss at night. In areas 
with greater temperature variations, as in Sumter County, this 
temperature minimization effect can help prevent frost damage to the 
interior of the hammock (FNAI 2010, p. 25). Mesic conditions are 
further maintained by the hammock's rounded canopy profile, which 
deflects winds, limiting desiccation during dry periods and reducing 
interior storm damage (FNAI 2010, p. 25). Changes in the canopy can 
impact humidity and evaporation rates, as well as the amount of light 
available to the understory.
    In Miami-Dade County, Trichomanes punctatum ssp. floridanum is 
generally epipetric (a plant that grows on rocks) or epiphytic (a plant 
that grows non-parasitically upon another plant), typically growing in 
rocky outcrops of rockland hammocks, in oolitic (composed of minute 
rounded concretions resembling fish eggs) limestone solution holes (see 
description below), and, occasionally, on tree roots in limestone-
surrounded areas (Phillips 1940, p. 166; Nauman 1986, p. 180; Whitney 
et al. 2004, pp. 105-106; Possley 2013e, pers. comm.; van der Heiden 
2014b, pers. comm.). These rockland habitats are outcrops primarily 
comprising marine limestone representing the distinct geological 
formation of the Miami Rock Ridge, a feature that encompasses a broad 
area from Miami to Homestead, Florida, and narrows westward through the 
Long Pine Key area of Everglades National Park (ENP) (Snyder et al. 
1990, pp. 233-234). Several endemic plant species have been identified 
to be closely associated with the rocklands of southern Florida; these 
plants are believed to have no adaptation for long-distance dispersal, 
suggesting a lengthy period of evolution on rocky substrate in southern 
Florida (Snyder et al. 1990, p. 236).
    Rockland hammocks are a type of rich tropical hardwood forest on 
upland sites in areas where limestone is very near the surface and 
often exposed. Once numerous throughout South Florida, these rockland 
hammocks have a diverse closed canopy and shrub layer, where more than 
120 native tree and shrub species are known to occur, including a 
number of rare plant and animal species, federally listed and candidate 
species, South Florida endemics, and tropical species at or near the 
northern limit of their ranges (Phillips 1940, p. 166; Snyder et al. 
1990, p. 16; Gann et al. 2009, p. 3). The forest floor is characterized 
by leaf litter with varying amounts of exposed limestone and has few 
herbaceous species. Rockland hammocks generally consist of larger, 
mature trees in the interior, while the margins can be almost 
impenetrable due to dense growth of smaller shrubs, trees, and vines 
(FNAI 2010, pp. 24-27). The canopy cover is typically very dense where 
Trichomanes punctatum ssp. floridanum occurs. In Miami-Dade County, the 
hammocks consist of a mix of temperate and tropical hardwood trees, 
both canopy and understory, including Ocotea coriacea (lancewood), 
Coccoloba diversifolia (pigeon plum), Quercus virginiana (live oak), 
Simarouba glauca (paradise tree), Ficus aurea (strangler fig), and 
Sideroxylon foetidissimum (mastic) (see Snyder et al. 1990, p. 241, for 
complete list). Soils where T. p. ssp. floridanum is extant in Miami-
Dade County generally consist of an uneven layer of highly organic soil 
overlying rock (Snyder et al. 1990, p. 238); soils are classified as 
Matecumbe Muck (moderately well-drained soils that are very shallow) 
(Florida Geographic Data Library 2013, http://www.fgdl.org/). Soils 
from historical and extant records consist of the following soil types: 
Krome Very Gravelly Loam, Cardsound Silty Clay Loam-Rock Outcrop 
Complex, Opalocka Sand-Rock Outcrop Complex, and Dania Muck.
    The limestone solution holes are considered specialized habitat 
within these hammock areas that host Trichomanes punctatum ssp. 
floridanum, as well as several other fern species (Snyder et al. 1990, 
p. 247). The solution hole features that dominate the rock surface in 
the Miami Rock Ridge are steep-sided pits, varying in size, formed by 
dissolution of subsurface limestone followed by a collapse above 
(Snyder et al. 1990, p. 236). Limestone solution holes vary in size, 
from shallow holes less than 0.5 meter (m) (1.6 feet (ft)) deep to 
those that cover over 100 m\2\ (1,076 ft\2\) and are several meters 
deep (Snyder et al. 1990, p. 238). The bottoms of most solution holes 
are filled with organic soils, while deeper solution holes penetrate 
the water table and have (at least historically) standing water for 
part of the year (Snyder et al. 1990, pp. 236-238). Humidity levels are 
higher in and around the solution holes because of standing water and 
moisture retained in the organic soils. Many tropical, epipetric plant 
species are associated with the sinkholes and solution holes in 
rockland hammocks.
    In Sumter County, Trichomanes punctatum ssp. floridanum is known to 
be epipetric, residing on limestone boulders in high atmospheric 
humidity hammocks (van der Heiden 2013a, pers. comm). The extant 
populations are located in mesic hammocks on limestone boulders 0.1-1.5 
m (0.3-4.9 ft) tall (see ``Current Range'' section,

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below). Mesic hammock is a developed evergreen hardwood and/or palm 
forest on soils that are rarely inundated (FNAI 2010, pp. 19-23) and 
commonly associated with hydric hammock and mixed wetland hardwoods. 
The difference between mesic hammocks and surrounding habitats is a 
slight difference in elevation. Mesic hammocks occur on higher ground 
within basin or floodplain wetlands; as patches of oak/palm forest in 
dry prairie or flatwoods communities; on river levees; in ecotones 
(transition area between two biomes or areas of distinct plant and 
animal groups) between wetlands and upland communities; and at the 
edges of lakes, sinkholes, other depressional or basin wetlands, and 
river floodplains where natural fires do not occur (FNAI 2010, pp. 19-
23).
    Recent field surveys (van der Heiden 2015a, p. 6; van der Heiden 
2015b, unpublished data; van der Heiden 2015c, unpublished data) have 
provided additional information regarding potential suitable habitat in 
Sumter County. These surveys, conducted by IRC and funded by the 
Service, delineated suitable habitat within and around the Jumper Creek 
Tract of the Withlacoochee State Forest. Within surveyed areas, IRC 
mapped all suitable substrate found in areas having suitable canopy and 
hydrology to support growth of Trichomanes punctatum ssp. floridanum. 
The resulting map included limestone rocks and boulders in not only 
mesic hammock, but also hydric hammock, elevated hydric hammock, and 
(in a small number of instances) adjacent wetland (but non-hammock) 
habitats. The Service is still evaluating this information and working 
with IRC to further refine suitable habitat parameters for the fern in 
Sumter County. Despite extensive surveys through approximately 1,904 ha 
(4,705 ac) in and around the Jumper Creek Tract, van der Heiden (2015a, 
p. 9) did not find any new populations of T. p. ssp. floridanum.
    Although there are several occurrences of Trichomanes punctatum 
ssp. floridanum in Sumter County where sunlight can be observed through 
the canopy, generally the habitat is shaded throughout the year, with 
the lowest amount of canopy cover recorded at approximately 65 percent 
(van der Heiden and Johnson 2014, p. 20; in Rocky Hammock). T. p. ssp. 
floridanum has been observed growing on small limestone rocks, as well 
as boulders with tall, horizontal faces with numerous other species, 
including rare State-listed species (e.g., Asplenium cristatum (hemlock 
spleenwort)) and widespread Pecluma dispersa (widespread polypody) (van 
der Heiden 2013b, pers. comm.; van der Heiden and Johnson 2014, pp. 15-
16).
    Within one occupied Sumter County hammock (Rocky Hammock), the 
majority of Trichomanes punctatum ssp. floridanum occur on the northern 
face of limestone boulders; however, those clusters found on non-north-
facing limestone generally occur in close proximity to other boulders, 
trees, or within protected crevices (van der Heiden and Johnson 2014, 
p. 7). Van der Heiden and Johnson (2014, pp. 9-10) suggested that the 
northern aspect of limestone boulders is more often inhabited by this 
taxon because of the reduced exposure to sunlight, promoting cooler 
temperatures and higher moisture as compared to other sun-exposed 
sections of rock. This may also be the case for those clusters shielded 
by other boulders, by trees, or in crevices, allowing the plant to grow 
on any portion of the shielded rock as long as moisture levels remain 
high enough to prevent desiccation (van der Heiden and Johnson 2014, 
pp. 9-10). Additionally, both populations of T. p. ssp. floridanum in 
Sumter County grow within the northern quadrant of each hammock.
    Soils of mesic hammock are sands mixed with organic matter, often 
containing a thick layer of leaf litter and generally well-drained. 
Although some areas maintain high-moisture soils due to the 
accumulation of leaf litter and extensive canopy cover, in general, 
mesic hammocks can occur across a broad gradient of soil moisture 
conditions, from somewhat xeric to almost hydric soils. Rock outcrops 
may also occur in mesic hammocks, especially where limestone is near 
the surface (FNAI 2010, pp. 19-23). Soil types for the extant 
metapopulation of Trichomanes punctatum ssp. floridanum in Sumter 
County include Okeelanta Muck, Frequently Flooded, and Mabel Fine Sand 
(i.e., deep and very deep, somewhat poorly drained, slowly permeable 
soils that formed in sandy to clayey marine deposits, with a bouldery 
(abounding in rocks or stones) subsurface and 0-5 percent slopes 
(Florida Geographic Data Library 2013, http://www.fgdl.org/)). 
Additionally, one historical record has Adamsville Fine Sand, Bouldery 
Subsurface, while another population containing a questionable record 
from an extirpated population has what is classified as Malabar Fine 
Sand, Frequently Flooded.
    Plant communities associated with mesic hammocks vary depending on 
the latitude; tropical species gradually increase in frequency from the 
central to southern peninsular Florida. In south Florida, some high-
elevation areas dry enough to support a semi-tropical mesic hammock do 
exist; however, most ``high hammocks'' are rockland hammocks occurring 
on limestone (FNAI 2010, pp. 19-23). Q. virginiana is common in mesic 
hammock communities. Oak species found in these hammocks tend to 
possess a broader tolerance of a range of conditions than do oaks in 
other habitats (FNAI 2010, pp. 19-23). Mesic hammocks do not contain 
wetland trees, as found in hydric hammocks; however, these two hammock 
types often occur as intermixed stands. Because mesic hammocks are 
often associated with hydric hammocks, with wetlands, or as a 
transition to uplands, they are sensitive to hydrologic alteration in 
the landscape. For example, changes in flooding frequency and/or 
duration can kill most mesic hammock tree species, while lowered water 
tables can shift vegetation towards xeric species or promote wildfires, 
destroying the hammock (FNAI 2010, pp. 19-23). Mesic hammocks may be 
distinguished from rockland hammocks by the dominance of temperate 
species in the canopy, whereas rockland hammocks are composed of 
predominantly tropical woody species.
    Trichomanes punctatum ssp. floridanum in Sumter County can be found 
under a dense canopy including Q. virginiana, Sabal palmetto (cabbage 
palm), Carpinus caroliniana (American hornbeam), Celtis laevigata 
(sugarberry), Acer negundo (boxelder), Liquidambar styraciflua 
(sweetgum), and Sapindus saponaria (wingleaf soapberry) (van der Heiden 
2013c, pers. comm.; van der Heiden and Johnson 2014, p. 19). The 
hammocks where T. p. ssp. floridanum has been found are also surrounded 
by a mosaic of wetlands dominated by Taxodium distichum (cypress 
trees). Field surveys of Sumter County populations recorded 18 canopy 
species in Rocky Hammock and 12 in Tree Frog Hammock (van der Heiden 
and Johnson 2014, p. 19). The average canopy closure for both 
populations in Sumter County has been estimated to be more than 75 
percent, where it is heavily shaded, maintaining high humidity to 
reduce chances of desiccation (van der Heiden and Johnson 2014, p. 9). 
Van der Heiden and Johnson (2014, p. 9) speculate this dense, closed 
canopy can serve as a shield for T. p. ssp. floridanum to inhibit the 
growth of other plant species on the same part of an inhabited rock 
area.
    Although it is believed this subspecies needs high temperatures 
(although likely not above 100 degrees Fahrenheit ([deg]F); Possley 
2014c, pers. comm.) and humidity, along with dense

[[Page 60444]]

canopy, there is limited information on optimal temperature and 
humidity ranges or thresholds for Trichomanes punctatum ssp. floridanum 
growth and survival. In Miami-Dade County where T. p. ssp. floridanum 
currently is found, the mean maximum temperature from 2004 to 2013 was 
29.0 degrees Celsius ([deg]C) (84.3[emsp14][deg]F), and the mean 
minimum temperature for the same time period was 21.4 [deg]C 
(70.5[emsp14][deg]F) (http://www1.ncdc.noaa.gov). In contrast, yearly 
mean temperatures were lower for Sumter County with 23.4 [deg]C 
(74.2[emsp14][deg]F) recorded as the mean maximum temperature from 2004 
to 2013, and 11.8 [deg]C (53.2[emsp14][deg]F) as the mean minimum 
temperature for the same time period (National Oceanic and Atmospheric 
Administration 2014, http://www1.ncdc.noaa.gov).
    Recent field studies have provided some data on microhabitat 
conditions (e.g., temperature and humidity) for Trichomanes punctatum 
ssp. floridanum populations in Sumter County. Van der Heiden and 
Johnson (2014, pp. 8, 21) found average relative humidity to be around 
95 percent in both Rocky Hammock and Tree Frog Hammock, while average 
ambient temperature in both hammocks was approximately 21 [deg]C 
(70[emsp14][deg]F) from September 2013 to November 2013. However, 
during cooler periods (19-21 [deg]C; 66-70[emsp14][deg]F) when humidity 
levels dropped slightly (by approximately 2 percent), observed plant 
health declined, demonstrating the fragile nature of this taxon and its 
dependence on high-humidity conditions (van der Heiden and Johnson 
2014, pp. 9, 21). Collection of humidity and temperature data within 
these same areas was subsequently continued through March 2015. From 
September 2013 to March 2015, average monthly temperatures in both 
hammocks were very similar and ranged from approximately 12 [deg]C 
(53[emsp14][deg]F; in January 2014) to 25 [deg]C (78[emsp14][deg]F; in 
August 2014) (van der Heiden 2015a, p. 17). The average relative 
humidity in both hammocks was 94.8 percent throughout the study (van 
der Heiden 2015a, p. 5). This type of information needs to be further 
explored to determine habitat requirements (i.e., thresholds for 
humidity and temperature) for both metapopulations of this taxon.

Historical Range/Distribution

    The historical range of Trichomanes punctatum ssp. floridanum 
included southern (Miami-Dade County; see Table 1, below) and central 
(Sumter County; see Table 2, below) Florida.
Miami-Dade County
    In Miami-Dade County, the historical range of this subspecies 
extended from its southern limit in Royal Palm Hammock (now part of 
ENP) northeast to Deering-Snapper Creek Hammock, which includes the 
modern-day site of Smather's Four Fillies Farm residential area, near 
R. Hardy Matheson Preserve (derived from Gann et al. 2002, pp. 552-
554), a range of at least 45 square kilometers (km\2\) (17 square miles 
(mi\2\)). Plants in Miami-Dade were known to historically occur in at 
least 11 hammocks: Deering-Snapper Creek Hammock, Castellow Hammock, 
Silver Palm Hammock (also known as Caldwell), Ross Hammock, Royal Palm 
Hammock (in ENP), Hattie Bauer Hammock, Shields Hammock, Nixon-Lewis 
Hammock, Fuchs Hammock, Addison Hammock (in the Deering Estate at 
Cutler), and Matheson Hammock. In the 1980s, T. p. ssp. floridanum was 
also documented in Meissner Hammock and Cox Hammock (now part of the 
tourist attraction ``Monkey Jungle'') (Small 1918, p. 6; Small 1921, p. 
211; Morton 1963 p. 90; Fairchild Tropical Garden 1968, p. 1; Nauman 
1986 p. 182; Gann et al. 2002, pp. 552-554; Gann 2013, http://regionalconservation.org/ircs/database/plants/IRCSpAccount.asp?TXCODE=Tricpuncflor&GENUS=Trichomanes&SPECIES=punctatum&Author=Poir.&INFRA1=subsp.&INFRA1NAME= ssp. 
floridanum&INFRA1AUTHOR=Wess.%20Boer&CommonNames=Florida%20bristle%20fer
n).
    J.K. Small documented Trichomanes punctatum ssp. floridanum in 1901 
at Deering-Snapper Creek. J.K. Small made subsequent collections of the 
subspecies in and around Miami-Dade County including one in 1903, 
probably located in or near present-day Castellow Hammock (Gann 2014d, 
pers. comm.). A.A. Eaton collected additional specimens from Castellow 
Hammock in 1903. More recent observations of T. p. ssp. floridanum in 
Castellow Hammock include documentation by G. Gann and K. Bradley in 
the late 1990s (Bradley and Gann 1999), and subsequent observations by 
J. Possley and others (Gann et al. 2002, pp. 552-554; Possley et al. 
2013, pp. 43-45). T. p. ssp. floridanum was collected by A.A. Eaton in 
Silver Palm Hammock in 1903 and reported again in 1980; however, the 
1980 report was not confirmed. The fern was collected from Ross Hammock 
by J.K. Small and colleagues in 1906. Since then, part of this hammock 
has been damaged, and what remains is currently protected as a Miami-
Dade County Environmentally Endangered Lands (EEL) Preserve. In 1909, 
the subspecies was collected in Royal Palm Hammock (also known as 
Paradise Key), now within ENP, and later reported by W.E. Stafford in 
1917 (Stafford 1919, p. 386; Gann et al. 2002, pp. 552-554).
    Several collections of Trichomanes punctatum ssp. floridanum were 
made in Miami-Dade in 1915, including: Hattie Bauer Hammock, Shields 
Hammock, Nixon-Lewis Hammock, Fuchs Hammock, and Deering-Snapper Creek 
Hammock. Hattie Bauer Hammock, now a Miami-Dade County conservation 
area, has numerous subsequent collection records by Small (1915, 1916), 
Correll (1936), and McFarlin (1934, 1940) as cited by Gann 2013, http://regionalconservation.org/ircs/database/plants/IRCSpAccount.asp?TXCODE=Tricpuncflor&GENUS=Trichomanes&SPECIES=punctatum&Author=Poir.&INFRA1=subsp.&INFRA1NAME= ssp. 
floridanum&INFRA1AUTHOR=Wess.%20Boer&CommonNames=Florida%20bristle%20fer
n. The last known collection in Hattie Bauer Hammock was recorded in 
1960, by T. Darling, Jr. It was subsequently reported as extirpated by 
Gann et al. (2002, pp. 552-554), until it was rediscovered in this 
hammock in 2011 by Possley (Possley et al. 2013, pp. 1-2). Shields 
Hammock was destroyed prior to 1991 (Cressler 1991, Handwritten Notes). 
Fuchs Hammock is now part of the Fuchs Hammock Preserve (Gann et al. 
2002, pp. 552-554), and the subspecies was vouchered (pressed plant 
samples taken for future reference) again in 1954, by L. J. Brass; in 
1959, by T. Darling Jr.; and in 1969, by F.C. Craighead (The Institute 
for Regional Conservation, Herbarium Specimens, Floristic Inventory of 
South Florida Database, September 12, 2007). T. p. ssp. floridanum was 
also vouchered in Fuchs Hammock in 1993, following Hurricane Andrew 
(1992) by A. Cressler (Cressler 12 February 1993, handwritten notes), 
and it has been more recently observed by Possley and others over the 
years (Gann et al. 2002, pp. 552-554; Possley et al. 2013, pp. 43-45). 
T. p. ssp. floridanum was observed by G. N. Avery in 1983 in Meissner 
Hammock (immediately adjacent to Fuchs Hammock) and was since vouchered 
by K. Bradley in 1997 and 2002 and also observed by others (Gann et al. 
2002, pp. 552-554; Possley et al. 2013, pp. 43-45).
    In 1916, J.K. Small reported Trichomanes punctatum ssp. floridanum 
in Addison Hammock, now located within Deering Estate at Cutler,

[[Page 60445]]

currently Miami-Dade County Park; however, these reports were never 
vouchered (J.K. Small 1916; Gann et al. 2002, pp. 552-554). Surveys in 
recent years have yet to find any populations of T. p. ssp. floridanum 
in Deering Estate at Cutler, Matheson Hammock, or Silver Palm Hammock 
(Possley 2013i, pers. comm.). The subspecies was last reported from Cox 
Hammock in 1989, by A. Cressler, where plants were observed in a 
sinkhole in the tourist attraction ``Monkey Jungle'' (Cressler 1991, 
handwritten notes); it is not known if these plants still exist. Cox 
Hammock is located about 1.6 km (1.0 mi) northeast of Castellow Hammock 
Park. Additional hammocks existing today where the taxon formerly 
occurred include Ross and Royal Palm Hammock (in ENP) and Deering-
Snapper Creek Hammock. A section of Deering-Snapper Creek Hammock was 
destroyed in 1912-1913, when the Snapper Creek Canal was constructed. 
Dredging of this canal drastically altered the water table in the area, 
depleting the freshwater springs, while a large spoil berm from 
excavation of the canal destroyed habitat (Metro-Dade County Park and 
Recreation Department 1991, p. 10). Other hammocks in the historical 
range that are presumed destroyed include Nixon Lewis Hammock, which is 
partially destroyed (Gann 2013, http://regionalconservation.org/ircs/database/plants/IRCSpAccount.asp?TXCODE=Tricpuncflor&GENUS=Trichomanes&SPECIES=punctatum&Author=Poir.&INFRA1=subsp.&INFRA1NAME= ssp. 
floridanum&INFRA1AUTHOR=Wess.%20Boer&CommonNames=Florida%20bristle%20fer
n) and a station presumably near the Matheson Hammock Park vouchered by 
G. Peterson in 1940.

  Table 1--Summary of Historical Reports and Current Population and Hammock Status of Each Trichomanes Punctatum ssp. Floridanum Location in Miami-Dade
                                                                         County
   [Gann et al. 2002; The Institute for Regional Conservation, Herbarium Specimens, Floristic Inventory of South Florida Database, September 12, 2007;
Florida Natural Areas Inventory element occurrences 9/12/2013; Possley 2013c, i-j, 2014a-c; Possley 2013, 2014a pers. comm.; Gann 2013, pers. comm.; van
der Heiden 2013e, pers. comm.; Gann 2014a-f, pers. comm.; Gann et al. 2001-2014). Population locations (hammocks) are numbered in chronological order by
                                                     T. p. ssp. floridanum initial discovery date.]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Year(s) of                               Number of
           No.              Population location       initial            Observer            specimens      Current population    Current hammock status
                                                     report(s)                               collected            status
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.......................  Deering-Snapper Creek             1901  J.K. Small, G.V. Nash.               3  Extirpated............  Protected Area,
                           Hammock-Smather's                                                                                       Partially Destroyed.
                           Four Fillies Farm (R.
                           Hardy Matheson
                           Preserve).
                                                            1915  J.K. Small, C.A.                     1
                                                                   Mosier.
2.......................  Castellow Hammock.....            1903  J.K. Small, J.J.                     2  Extant................  Protected Area.
                                                                   Carter.
                                                            1903  A.A. Eaton............               4
3.......................  Silver Palm Hammock...            1903  A.A. Eaton............               1  Extirpated............  Protected Area.
4.......................  Ross Hammock..........            1906  J.K. Small, J.J.                     2  Extirpated............  Protected Area,
                                                                   Carter.                                                         Partially Destroyed.
5.......................  Royal Palm Hammock                1909  J.K. Small, J.J.                     2  Extirpated............  Protected Area.
                           (ENP); aka Paradise                     Carter.
                           Key.
                                                            1917  W.E. Stafford.........            None
                                                            1915  J.K. Small, C.A.                     2
                                                                   Mosier.
                                                            1915  J.K. Small............               3
                                                            1915  J.K. Small, C.A.                     5
                                                                   Mosier, G.K. Small.
6.......................  Hattie Bauer Hammock              1916  J.K. Small............               1  Extant................  Protected Area.
                           (Orchid Jungle).
                                                            1934  J.B. McFarlin.........               2
                                                            1936  D.S. Correll..........               2
                                                            1940  J.B. McFarlin.........               1
                                                            1960  T. Darling Jr.........               1
7.......................  Shields Hammock.......            1915  J.K. Small, C.A.                     1  Extirpated............  Destroyed.
                                                                   Mosier, G.K. Small.
8.......................  Nixon-Lewis Hammock...            1915  J.K. Small, C.A.                     1  Extirpated............  Protected Area,
                                                                   Mosier.                                                         Partially Destroyed.
9.......................  Fuchs Hammock (Sykes              1915  J.K. Small, C.A.                     1  Extant................  Protected Area.
                           Hammock).                               Mosier.
                                                            1954  L.J. Brass............               1
                                                            1959  T. Darling Jr.........               1
                                                            1969  A.F. Clewell, F.C.                   1
                                                                   Craighead.
10......................  Deering Estate at                 1916  J.K. Small............            None  Unconfirmed \1\.......  Protected Area.
                           Cutler (Addison
                           Hammock).
11......................  Matheson Hammock Park.            1940  G. Peterson...........               2  Unconfirmed \2\.......  Protected Area.
12......................  Meissner Hammock......            1983  G.N. Avery............            None  Extant................  Protected Area.
13......................  Monkey Jungle (Cox                1989  A. Cressler...........            None  Unknown \3\...........  Privately Owned,
                           Hammock).                                                                                               Partially Destroyed.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Initial report is questionable.
\2\ Precise location of sample and associated report is questionable.
\3\ It is not known whether the subspecies still occurs here.


[[Page 60446]]

Sumter County
    In Sumter County, early collections and herbarium label data for 
Trichomanes punctatum ssp. floridanum are not accurate or precise in 
their location descriptions. The first documented collection in 1936, 
by R.P. St. John, simply states that T. p. ssp. floridanum was found 
11.26 km (7.0 mi) east of Floral City. This collection is close to the 
extant populations in Sumter (in Rocky Hammock within Withlacoochee 
State Forest), which is east-southeast of Floral City, and is thought 
to be the location where T. p. ssp. floridanum existed on private land 
until it was cleared for cattle sometime after 1983. A specimen found 3 
years later, by J.B. McFarlin in 1939, was originally thought to be T. 
sphenoides; the herbarium label data described this collection as 
``South of Floral City, Florida. T. sphenoides is a misapplied synonym 
for T. p. ssp. floridanum according to FNAI. This is the only known 
station in the United States.'' It is believed that these label data 
may have been incorrectly recorded, indicating a direction of south 
from Floral City, when it should have been east. In all likelihood, 
McFarlin's collection probably referred to the population in the Wahoo 
area, where St. John previously collected because he states his 
collection was from the same locality where it was originally found in 
1936. The specimen found by McFarlin eventually led to reports of the 
taxon in Citrus County (Wherry 1964, p. 232; Nelson 2000, p. 81); 
however, this was never confirmed beyond the initial report. Systematic 
surveys have not been conducted in Citrus County; therefore, the only 
documented occurrences of T. p. ssp. floridanum in this region of 
Florida have been in Sumter County, just north of Wahoo and east of the 
Withlacoochee River.
    Several years later, in 1954, R. Garrett collected Trichomanes 
punctatum ssp. floridanum southeast of Floral City. It is thought to be 
the same location where St. John and McFarlin made their previous 
collections; however, label data were again minimal and the exact 
location is uncertain. In 1959, T. Darling Jr. found this subspecies 
near Floral City, 11.26 km (7.0 mi) south near a location called Battle 
Slough. This record has never been confirmed because it is located on 
private property. Another specimen was found in 1963, by O. Lakela in 
an area known as Indian Field Ledges. Lakela recorded his location and 
collection to be west of Withlacoochee River off State Road #48. This 
information is believed to be incorrect based on a site visit by 
Darling (1961, p. 7), stating that the Indian Field Ledges is north of 
Wahoo, a locality east of the Withlacoochee River. T. p. ssp. 
floridanum was not found again in Sumter County until 1983, when SW. 
Leonard made a collection on private property known as Rocky Point, 
north of Wahoo. This is presumed to be the same location where St. 
John, McFarlin, and Garrett collected their specimens. This population 
is now extirpated.

         Table 2--Summary of Presumed Extirpated, Extirpated, and Unconfirmed Trichomanes Punctatum ssp. Floridanum Populations in Sumter County
   [Gann et al. 2002; The Institute for Regional Conservation, Herbarium Specimens, Floristic Inventory of South Florida Database, September 12, 2007;
  Florida Natural Areas Inventory Element Occurrences 9/12/2013; van der Heiden 2013d, 2014a, pers. comm.; Gann et al. 2001-2014). Population locations
                            (hammocks) are numbered in chronological order by T. p. ssp. floridanum initial discovery date.]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  Number of
                No.                  Population location       Year of           Observer         specimens    Current population      Current hammock
                                                           initial report                         collected          status                status
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.................................  11.26 km (7 mi) East             1936  R.P. St. John.......            1  Presumed Extirpated.  Privately Owned,
                                     of Floral City \1\.                                                                             Presumed Destroyed.
2.................................  Floral City Area \1\.            1939  J.B. McFarlin.......            1  Unconfirmed \2\.....  Unknown.
3.................................  Southeast of Floral              1954  R. Garret...........            1  Presumed Extirpated.  Privately Owned,
                                     City \1\.                                                                                       Presumed Destroyed.
4.................................  Floral City, 11.26 km            1959  T. Darling Jr.......            1  Unconfirmed \2\.....  Privately Owned,
                                     (7 mi) south (Battle                                                                            Unknown.
                                     Slough) \1\.
5.................................  East of Withlacoochee            1963  O. Lakela...........            1  Extirpated..........  Protected Area.
                                     River, off State
                                     Road #48 (Indian
                                     Field Ledges) \1\.
6.................................  Rocky Point, (north              1983  S.W. Leonard........            1  Extirpated..........  Privately Owned,
                                     of Wahoo).                                                                                      Destroyed.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Sumter County collections and herbarium label data for Trichomanes punctatum ssp. floridanum are inaccurate in location descriptions.
\2\ Initial report is questionable.

Current Range

    The extant metapopulation of Trichomanes punctatum ssp. floridanum 
in Miami-Dade County is approximately 400 km (249 mi) south of the 
extant metapopulation in Sumter County. Both metapopulations of T. p. 
ssp. floridanum are located entirely on public lands (see Table 3, 
below). In general, Trichomanes punctatum ssp. floridanum occurs in 
small areas within each hammock.

             Table 3--Summary of Known Extant Occurrences of Trichomanes punctatum ssp. floridanum.
          [Possley 2013, pp. 1-2; Dozier 2014, Pers. Comm.; van der Heiden and Johnson 2014, pp. 5, 26]
----------------------------------------------------------------------------------------------------------------
                                                                                   Number of
Metapopulation location (county)    Population location      Land ownership     subpopulations        Status
----------------------------------------------------------------------------------------------------------------
Miami-Dade......................  Meissner Hammock.......  State.............                 2  Extant.
Miami-Dade......................  Fuchs Hammock Preserve.  County............                 4  Extant.
Miami-Dade......................  Castellow Hammock Park.  County............                 3  Extant.

[[Page 60447]]

 
Miami-Dade......................  Hattie Bauer Hammock...  County............                 1  Extant.
Sumter..........................  Rocky Hammock,           State.............                 1  Extant.
                                   Withlacoochee State
                                   Forest's Jumper Creek
                                   Tract.
Sumter..........................  Tree Frog Hammock,       State.............                 1  Extant.
                                   Withlacoochee State
                                   Forest's Jumper Creek
                                   Tract.
----------------------------------------------------------------------------------------------------------------

Miami-Dade County
    The four populations that constitute the Miami-Dade County 
metapopulation are located in urban preserves managed by the County's 
EEL Program and the Natural Areas Management (NAM) Division of Miami-
Dade County's Parks, Recreation and Open Spaces (PROS) Department (see 
Factor A, Conservation Efforts to Reduce Habitat Destruction, 
Modification, or Curtailment of Its Range, below). These EEL Preserves 
include: Castellow Hammock Park (39.5 hectares (ha)) (97.6 acres (ac)), 
Hattie Bauer Hammock (5.7 ha (14.0 ac)), Fuchs Hammock Preserve (15.7 
ha (38.8 ac)), and Meissner Hammock (4.1 ha (10.1 ac)). Three of these 
preserves (76 percent of the land area) are owned by the County; the 
fourth, Meissner Hammock (24 percent), is owned by the State and leased 
to the County (Dozier 2014, pers. comm.). The population in Fuchs 
Hammock Preserve includes a new subpopulation that was found in July 
2013 (Possley et al. 2013, pp. 43-45). Fuchs and Meissner Hammocks are 
immediately adjacent to each other, and Castellow Hammock Park is 10.5 
km (6.5 mi) to the northeast. Although the fern was thought to be 
extirpated from Hattie Bauer Hammock in 1960, another population was 
re-discovered there in 2011 (8 ha (20 ac)) (Possley et al. 2013, pp. 
43-45). Hattie Bauer Hammock is 4.02 km (2.5 mi) south of Castellow 
Hammock and approximately 8.05 km (5 mi) northeast of Fuchs and 
Meissner Hammocks.
    No comprehensive survey has been conducted in rockland hammocks in 
Miami-Dade County where suitable Trichomanes punctatum ssp. floridanum 
habitat has been identified. Although these areas have been extensively 
explored by numerous botanists and plant enthusiasts, including sites 
where the subspecies was formerly found, due to the cryptic nature of 
this plant it may have been overlooked and new occurrences may yet be 
discovered (Possley 2013e, pers. comm.; van der Heiden 2013c, pers. 
comm.). Surveys conducted in the late 1990s, and as late as 2010, did 
not find T. p. ssp. floridanum in Silver Palm Hammock (Gann et al. 
2002, pp. 552-554; Possley 2013f, pers. comm.). A sporophyte sample was 
collected in Nixon-Lewis Hammock by Small and Mosier in 1915; however, 
due to extensive disturbance of this hammock, subsequent surveys 
conducted in 2006, by IRC, could not find the taxon (Bradley and Gann 
2005, unpublished data). Over the years, IRC has completed systematic 
surveys in ENP in Royal Palm Hammock and other hammocks on Long Pine 
Key (also in ENP); however, sporophytes have not been found there (Gann 
et al. 2009; pp. 1-66). In 2003, based on historical records, staff 
from ENP and IRC surveyed Royal Palm Hammock for T. p. ssp. floridanum 
without success; subsequent surveys conducted in rockland hammocks 
throughout Long Pine Key for other rare plants also were not successful 
in finding T. p. ssp. floridanum (Sadle 2013, pers. comm.).
Sumter County
    The Sumter County metapopulation consists of two extant populations 
of Trichomanes punctatum ssp. floridanum that have been reported north 
of Wahoo, in the Withlacoochee State Forest's Jumper Creek Tract; these 
populations are located in Rocky Hammock (located on 44 boulders) and 
Tree Frog Hammock (located on 4 boulders) (van der Heiden and Johnson 
2014, p. 7). The population in Tree Frog Hammock was discovered as 
recently as April 2013, during regional surveys (van der Heiden 2013c, 
pers. comm.). Two additional populations were known from private land 
just south of the State Forest; however, these populations were 
subsequently extirpated due to the clearing of land for agriculture by 
the property owner (van der Heiden 2013c, pers. comm.).
    Recent GIS analyses show the soil type associated with known extant 
occurrences of Trichomanes punctatum ssp. floridanum in the northern 
metapopulation to be Okeelanta Muck, Frequently Flooded; this soil 
covers approximately 1,478 ha (3,652 ac) in Sumter County. However, not 
all of these areas have been systematically surveyed. Surveys were 
conducted of a boulder field within Withlacoochee State Forest's Jumper 
Creek Tract (called the Indian Field Ledges) in August 2007 and April 
2013 and were unsuccessful (van der Heiden 2013c, pers. comm.). The 
discovery of new populations may be possible in the area. Indeed, the 
population of this subspecies in Jumper Creek's Tree Frog Hammock is a 
new population that was discovered in April 2013, during additional 
hammock surveys within Withlacoochee State Forest and the surrounding 
area (van der Heiden 2013c, pers. comm.). However, IRC recently 
conducted extensive surveys through approximately 1,904 ha (4,705 ac) 
in and around the Jumper Creek Tract, and no additional populations of 
T. p. ssp. floridanum were located (van der Heiden 2015a, p. 9).
    It is also possible that other subpopulations may exist in Sumter 
County. Indian Ledges, a hammock located on private land near Jumper 
Creek (not to be confused with Indian Field Ledges), just north of 
Wahoo, is believed to be suitable for Trichomanes punctatum ssp. 
floridanum, including a dense canopy and appropriate soil (Deangelis 
2014a-b, pers. comm.). Over the years, many rare ferns and orchids have 
been observed in the Indian Ledges Hammock; unfortunately, this hammock 
was heavily damaged by hurricanes in 2004 (Deangelis 2014a, pers. 
comm.).
    Portions of the Southwest Florida Water Management District 
(SWFWMD) property within the Green Swamp, more than 40.23 km (25 miles) 
southeast of the Jumper Creek Tract in Withlacoochee State Forest, may 
also contain appropriate habitat for Trichomanes punctatum ssp. 
floridanum based on existing habitat features such as dense canopy, 
high humidity microclimates, mesic hammock, and limestone outcroppings 
(Elliott 2014, pers. comm.). The SWFWMD property within the Green Swamp 
is the only area where land alteration has not occurred in Sumter

[[Page 60448]]

County (11,343 ha (28,030 ac)). Portions of Green Swamp owned by the 
SWFWMD also extend into three other counties: Lake, Polk, and Pasco. 
Future survey efforts, coordinating with local land owners and 
conservation organizations in this area, may prove successful in 
finding new populations of T. p. ssp. floridanum.

Population Estimates and Status

    Trichomanes punctatum ssp. floridanum grows in dense mats and is 
rhizomatous (a horizontal stem that often sends out root-like 
structures from its nodes). Fronds are scattered in matted clusters 
along the stems, making it difficult to count clusters, or groups of 
plants in the same location, and nearly impossible to accurately count 
individual plants (Nelson 2000, p. 79). This issue has been encountered 
in other Trichomanes species, such as Trichomanes boschianum 
(Appalachian bristle fern) (Hill 2003, p. 11). As such, populations are 
typically described by the number of clusters (i.e., groups of plants 
in various sinkholes, on tree roots, on boulders) and the total area 
covered by the cluster.
Miami-Dade County
    In Miami-Dade County, there are four populations of the fern with a 
total of 10 subpopulations (i.e., nine solution holes and one rocky 
outcropping on a tree root). Overall, this taxon occurs in small areas 
(i.e., less than 0.5 ha (1.2 ac)) at each site, with 88 percent of the 
total area in three subpopulations in Castellow Hammock. Recent surveys 
(see Table 4, below) in Miami-Dade by Fairchild (Possley 2013, pp. 1-2) 
found the fern covering a total area of approximately 9.92 m\2\ (106.56 
ft\2\) (Possley 2013, pp. 1-2).

 Table 4--Area Covered by Each of 10 Known Subpopulations of Trichomanes punctatum ssp. floridanum in Miami-Dade
                                        County, October and November 2013
   [(Possley 2013, pp. 1-2) and in Sumter County, December 2013 (van der Heiden and Johnson 2014, pp. 7, 14)]
----------------------------------------------------------------------------------------------------------------
                                                                                Estimated area       Number of
          Metapopulation                Population          Subpopulation       covered  (m\2\)      clusters
----------------------------------------------------------------------------------------------------------------
Miami-Dade.......................  Hattie Bauer Hammock  Hole (no tag)......               0.078            2-10
Miami-Dade.......................  Fuchs Hammock.......  Hole 532...........               0.017            2-10
Miami-Dade.......................  Fuchs Hammock.......  Hole 533...........               0.038            2-10
Miami-Dade.......................  Fuchs Hammock.......  Hole 1431..........               0.128            2-10
Miami-Dade.......................  Fuchs Hammock.......  Root 1430..........               0.047               1
Miami-Dade.......................  Meissner Hammock....  Hole 2319..........               0.145            2-10
Miami-Dade.......................  Meissner Hammock....  Hole 3337..........               0.713            2-10
Miami-Dade.......................  Castellow Hammock...  Hole 2332..........               4.688          11-100
Miami-Dade.......................  Castellow Hammock...  Hole 2331..........               3.925          11-100
Miami-Dade.......................  Castellow Hammock...  Hole 944...........               0.141            2-10
                                                                             -----------------------------------
    Miami-Dade County Total......  ....................  ...................               9.920  ..............
Sumter...........................  Rocky Hammock.......  N/A................               4.355              44
Sumter...........................  Tree Frog Hammock...  N/A................               0.132               4
                                                                             -----------------------------------
    Sumter County Total..........  ....................  ...................               4.487  ..............
                                  ------------------------------------------------------------------------------
    TOTAL Area Covered...........  ....................  ...................              14.407  ..............
----------------------------------------------------------------------------------------------------------------

    The largest known population of Trichomanes punctatum ssp. 
floridanum in Miami-Dade County is located at Castellow Hammock 
(Possley et al. 2013, p. 43), where it occurs in three of the larger 
subpopulations. In October of 2011, field surveys revealed extensive 
desiccation of this population after intensive nonnative vegetation 
removal (Possley 2013g, pers. comm.); however, by November 2013, these 
plants had recovered, and the total area covered by all clusters (i.e., 
two or more plants next to each other) was estimated at 8.754 m\2\ 
(94.227 ft\2\). Meissner Hammock has two subpopulations; the clusters 
in this hammock cover an area of 0.858 m\2\ (9.235 ft\2\) and are 
considered healthy, with no signs of desiccation (Possley et al. 2013, 
pp. 43-45). There is one subpopulation in Hattie Bauer Hammock covering 
approximately 0.78 m\2\ (8.4 ft\2\), and three subpopulations of T. p. 
ssp. floridanum at Fuchs Hammock, with an additional one that was 
discovered in July 2013, totaling an area of 0.230 m\2\ (2.476 ft\2\) 
(Possley 2013, pp. 1-2; Possley et al. 2013, pp. 43-45).
Sumter County
    In Sumter County, the Rocky Hammock subpopulation contains 44 
clusters, while the newly discovered subpopulation (Tree Frog Hammock) 
is much smaller with only 4 clusters observed (van der Heiden and 
Johnson 2014, p. 7). Average cluster size for Rocky Hammock is 
estimated at 4.355 m\2\ (46.877 ft\2\) and 0.132 m\2\ (1.421 ft\2\) for 
Tree Frog Hammock.

Summary of Comments and Recommendations

    In the proposed rule published on October 9, 2014, we requested 
that all interested parties submit written comments on the proposal by 
December 8, 2014. 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. We 
did not receive any requests for a public hearing. All substantive 
information provided during comment periods has either been 
incorporated directly into this final determination or 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 five knowledgeable 
individuals with scientific expertise that included familiarity with 
Trichomanes punctatum ssp. floridanum and its habitat, biological 
needs, and threats. We received responses from all five of the peer 
reviewers.
    We reviewed all comments received from the peer reviewers for 
substantive issues and new information regarding the listing of 
Trichomanes punctatum ssp. floridanum. The peer reviewers

[[Page 60449]]

generally concurred with our methods and conclusions and provided 
additional information, clarifications, and suggestions to improve the 
final rule.
    (1) Comment: One peer reviewer noted that he was unaware of any 
documentation that Trichomanes punctatum ssp. floridanum formed gemmae, 
as stated in the proposed rule. He commented that the works cited were 
in reference to other species of Trichomanes and Hymenophyllaceae, in 
general. Also, the peer reviewer pointed out a reference (Hughes 2014) 
in the proposal that the two metapopulations have no observable genetic 
differences. The peer reviewer noted that, in the Life History section, 
the proposal states many traits of the subspecies, such as ``genetic 
variation,'' are unknown, which contradicts the data from Hughes.
    Our Response: We appreciate this information and have corrected and 
updated the rule as follows: (1) We removed the phrase that stated 
Trichomanes punctatum ssp. floridanum produces gemmae; and (2) the term 
genetic variation has been removed from a sentence discussing specific 
reproductive and growth requirements that are unknown for the 
subspecies, as it conflicted with previous information within the 
proposed rule.
    (2) Comment: Two peer reviewers noted that, under the Species 
Description section, the proposed rule incorrectly compares physical 
characteristics of Trichomanes punctatum ssp. floridanum with ``other 
bryophytes.'' The phrase should only read ``bryophytes,'' not ``other 
bryophytes.''
    Our Response: The word ``other'' has been deleted from the text 
within the Species Description section because Trichomanes punctatum 
ssp. floridanum is a fern and not a bryophyte.
    (3) Comment: One peer reviewer noted, under the Life History 
section, that although it is true that the sporophyte form is 
recognizable and spores are invisible to the naked eye, that sentence 
does not align with the previous thought in the paragraph that there 
are two stages, a sporophyte and a gametophyte stage.
    Our Response: We have restructured the sentence and noted that the 
gametophyte form is cryptic and invisible to the naked eye.
    (4) Comment: One peer reviewer questioned why the two extant 
populations in Sumter County (that are listed in Table 3) are not 
listed in Table 2.
    Our Response: Table 2 is a composite of populations that are 
presumed extirpated, extirpated, or unconfirmed (where the report was 
questionable). Table 3 is a summary of the known extant occurrences of 
Trichomanes punctatum ssp. floridanum. The title of Table 2 has been 
modified for clarity in the final rule.
    (5) Comment: One peer reviewer noted that numerous efforts to 
cultivate Trichomanes punctatum ssp. floridanum ex-situ for possible 
future reintroduction have only been partially successful and provided 
information on ex-situ reproduction efforts. The reviewer noted that, 
given the problems with ex-situ reproduction, it is critical the extant 
wild populations be protected to the greatest extent possible.
    Our Response: We have added text explaining propagation challenges 
and the importance of protecting extant populations in the wild.
Comments From the State
    We received one comment from the Florida Natural Areas Inventory 
regarding a discrepancy between Table 2 and Table 3. That comment is 
addressed above under Peer Reviewer Comments in our response to Comment 
(4).
Public Comments
    We received eight public comments, three of which were from the 
same individual, directly addressing the proposed listing. Most 
commenters suggested technical corrections pertaining to the Background 
and Summary of Factors Affecting the Species sections of the proposed 
rule, scientific names, species biology, and citations. Some commenters 
suggested we include additional information and correct minor errors. 
We did not receive any requests for a public hearing. The comments are 
appreciated, and most have been incorporated into the appropriate 
sections of the final rule.
    (6) Comment: Two commenters noted an inaccurate statement in the 
proposed listing rule that states ``The life cycle of ferns is not well 
known'' (Woodmansee, 2013, pers. comm.). One of these commenters also 
noted that the second part of the same sentence mentions the life 
history of Trichomanes punctatum ssp. floridanum and then includes 
other members of the genus, which is inconsistent. One of these 
commenters also noted that the next sentence in this paragraph is 
incorrect and provided edits to describe the gametophyte form and the 
sporophyte form.
    Our Response: We revised the language regarding the life cycle of 
the Trichomanes punctatum ssp. floridanum in the Life History section 
from not well known to not commonly understood, as suggested by one of 
the commenters. The second part of the sentence, which includes 
information on other members of the genus Trichomanes, is unnecessary 
and has been removed. We have also revised the last sentence in that 
paragraph to best describe the gametophyte and sporophyte forms.
    (7) Comment: One commenter noted that Trichomanes punctatum ssp. 
floridanum bristles do not protrude from the sporangia, but rather one 
bristle protrudes from each soral involucre, which is the tube that 
also houses the sporangia.
    Response: We have corrected this information in the Background 
section of this final rule.
    (8) Comment: Two commenters noted that the four populations of 
Trichomanes punctatum ssp. floridanum within the urban preserves of 
Miami-Dade County are cooperatively managed by Miami-Dade County's EEL 
Program as well as the NAM Division of Miami-Dade County. One of these 
commenters suggested specific edits to sections about the EEL Program 
and the EEL Covenant Program. Both commenters provided additional 
information and clarification about the impacts of Hurricane Andrew on 
Hattie Bauer Hammock and the recovery of the hammock.
    Our Response: We agree that the NAM Division of the Miami-Dade 
County PROS Department and the EEL Program are significant local 
partners in the conservation of Trichomanes punctatum ssp. floridanum. 
As such, their efforts have been acknowledged in the final rule. We 
have incorporated suggested edits about the EEL Program, the EEL 
Covenant Program, and Hattie Bauer Hammock.
    (9) Comment: A commenter provided information clarifying the 
historical range of the subspecies. The text in the proposed rule reads 
``In Miami-Dade, the range of this subspecies extended from Royal Palm 
Hammock (now in Everglades National Park (ENP)) at its southern limit, 
northeast to Snapper Creek Hammock, which is located in R. Hardy 
Matheson Preserve.'' The reviewer noted that portions of historical 
Snapper Creek are now developed and are a residential community called 
Smather's Four Fillies Farm, owned by the University of Miami. 
Smather's Four Fillies Farm is located in the northwestern 6.5 acres of 
what was historical Snapper Creek Hammock.
    Our Response: We modified the historical range of the subspecies to

[[Page 60450]]

include the additional description of the Smather's Four Fillies Farm 
residential development within the Background section of the final 
rule.
    (10) Comment: One commenter noted the proposed listing rule states, 
in the Species Description section, that the subspecies does not have 
roots and then later states, in the Life History section, that the 
subspecies sends out roots and shoots. The commenter requested 
clarification on this issue.
    Response: The first paragraph in the Species Description section 
has been modified to state that Trichomanes punctatum ssp. floridanum 
is mat-forming, has root-like structures, and contains trichomes. The 
Life History section has been modified to reflect that T. punctatum 
ssp. floridanum is rhizomatous (having a horizontal stem and scale 
leaves, bearing aerial shoots from its tips, and producing root-like 
structures from its undersurface).
    (11) Comment: One commenter noted that the proposed listing states 
the subspecies needs high temperatures and humidity for optimum growth. 
The commenter remarked that this information is vague and temperatures 
above 100 [deg]F may be harmful to the subspecies.
    Response: We have modified our statements regarding suitable 
temperatures for Trichomanes punctatum ssp. floridanum. In addition, we 
have included new humidity and temperature data recorded in two Sumter 
County hammocks where Trichomanes punctatum ssp. floridanum is found.
    (12) Comment: One commenter reported that Ross Hammock continues to 
exist and was not destroyed by a hurricane in 1935. The same commenter 
reported the canopy of Hattie Bauer has also recovered after Hurricane 
Andrew.
    Response: We have corrected these statements in the Background 
section of this final rule.
    (13) Comment: One commenter noted that we cannot definitively state 
that Trichomanes punctatum ssp. floridanum is extirpated outside of the 
four known populations in Miami-Dade County. It is possible that 
gametophytes or undiscovered sporophytes exist outside the known extant 
range, particularly in the ``Monkey Jungle'' (Cox Hammock) area.
    Response: We have revised this statement in the Summary of Factors 
Affecting the Species section in this final rule.

Summary of Changes From the Proposed Rule

    Based on the information we received from peer reviewers and public 
commenters, we made the changes listed below. Additional minor 
corrections and edits were made in the text of the rule. We also 
incorporated new temperature, humidity, and survey information from a 
recent study conducted by the IRC in Sumter County and added 
information about the Clean Water Act (CWA; 33 U.S.C. 1251 et seq.) 
under Factor D. The Inadequacy of Existing Regulatory Mechanisms.

Background Section

    (1) We modified the information in the rule regarding the 
relationship between the bristles and the sporangia of Trichomanes 
punctatum ssp. floridanum and their functions.
    (2) We clarified the sentence regarding the visibility of the 
sporophyte and the gametophyte of Trichomanes punctatum ssp. 
floridanum.
    (3) We clarified information regarding the historical extent of the 
subspecies to include the addition of the current-day residential 
community, Smather's Four Fillies Farm, to the description of the 
Snapper Creek Hammock historical area.
    (4) We added the NAM Division of Miami-Dade County's PROS 
Department as cooperative managers of EEL's preserves and clarified the 
difference between the EEL Program and the EEL Covenant Program.
    (5) We clarified that Trichomanes punctatum ssp. floridanum does 
not have roots and that the subspecies is rhizomatous.
    (6) We added information regarding challenges to propagation and 
the importance of protecting extant populations in the wild.

Summary of Factors Affecting the Species Section

    (1) We revised the information about the impacts of the hurricane 
of 1935 on the habitat at Ross Hammock and the impacts of Hurricane 
Andrew on Hattie Bauer Hammock and Trichomanes punctatum ssp. 
floridanum. We also included additional information about the recovery 
and restoration of that habitat in Hattie Bauer Hammock after Hurricane 
Andrew.
    (2) We added information regarding the potential existence of 
Trichomanes punctatum ssp. floridanum in Miami-Dade County outside of 
the four known populations, particularly in ``Monkey Jungle'' (Cox 
Hammock).

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations at 50 CFR part 424, set forth the procedures for adding 
species to the Federal Lists of Endangered and Threatened Wildlife and 
Plants. Under section 4(a)(1) of the Act, we may list a species based 
on one or more of the following 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. Listing actions may be warranted 
based on any of the above threat factors, singly or in combination.
    Information pertaining to Trichomanes punctatum ssp. floridanum in 
relation to the five factors provided in section 4(a)(1) of the Act is 
discussed below. In considering what factors might constitute threats, 
we must look beyond the mere exposure of the species to the factor to 
determine whether the species responds to the factor in a way that 
causes actual impacts to the species. If there is exposure to a factor, 
but no response, or only a positive response, that factor is not a 
threat. If there is exposure and a negative response, the factor may be 
a threat, meaning that it may drive or contribute to the risk of 
extinction of the species such that the species warrants listing as an 
endangered or threatened species as those terms are defined by the Act. 
This does not necessarily require empirical proof of a threat. The 
combination of exposure and some corroborating evidence of how the 
species is likely impacted could suffice. The mere identification of 
factors that could impact a species negatively is not sufficient to 
compel a finding that listing is appropriate; we require evidence that 
these factors are operative threats that act on the species to the 
point that the species meets the definition of an endangered or 
threatened species under the Act.

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

    Habitat modification and destruction, caused by human population 
growth and development, agricultural conversion, regional drainage, and 
canal installation, have impacted the range and abundance of 
Trichomanes punctatum ssp. floridanum. Secondary effects from hydrology 
and canopy changes have resulted in changes in humidity, temperature, 
and existing water levels; loss of natural vegetation; and habitat 
fragmentation. The modification and destruction of habitat where T.p. 
ssp. floridanum was once

[[Page 60451]]

found has been extreme in most areas of Miami-Dade County; while they 
have been less dramatic in Sumter County, clearing of land for 
agricultural conversion and historical logging has resulted in very few 
areas where the habitat has not been modified. These threats are 
discussed in detail below.
Human Population Growth, Development, and Agricultural Conversion
    Miami-Dade County--Rockland hammocks are considered imperiled both 
locally and globally, with a limited distribution and an FNAI ranking 
of G2 (imperiled globally because of rarity (6 to 20 occurrences or 
fewer than 3,000 individuals) or because of vulnerability to extinction 
due to some natural or manmade factor)/S2 (either very rare and local 
in Florida (21-100 occurrences or fewer than 10,000 individuals) or 
found locally in a restricted range or vulnerable to extinction from 
other factors)) (FNAI 2010, pp. 24-26, FNAI 2013). The tremendous 
development and agricultural pressures in the rapidly urbanizing 
rockland hammock areas in south Florida have resulted in significant 
reductions of this habitat type, which is also susceptible to fire, 
frost, canopy disruption, and groundwater reduction (FNAI 2010, pp. 24-
26).
    Extensive land clearing for human population growth and development 
in Miami-Dade County has altered, degraded, or destroyed hundreds of 
acres of this once abundant rockland hammock ecosystem. Rockland 
hammocks once occurred across the Miami-Rock Ridge, usually in 
association with pine rocklands, or the edges of marl prairies (areas 
of thin, calcitic soil that has accumulated over limestone bedrock) or 
tidal swamps (Service 1999, p. 122). Destruction of rocklands, 
including rockland hammocks, has occurred since the beginning of the 
1900s. Historical impacts to the environment were addressed by Small 
(1938, p. 50), who called attention to the demise of Trichomanes 
punctatum ssp. floridanum from habitat destruction, and Phillips (1940, 
p. 167) who expressed his concern for south Florida hammocks due to the 
obvious and vast amount of destruction of land in the region. Early 
settlers in Florida cleared hammocks for residential development, 
farming, and range for livestock, while industrial logging also 
occurred in the region (Snyder et al. 1990, pp. 271-272). Consistent 
burning of pinelands in Miami-Dade also encroached upon adjacent 
hammocks, as in the case of Castellow Hammock (Phillips 1940, p. 167). 
Habitat impacts were further exacerbated by natural stochastic events, 
such as the hurricane in 1935 that impacted Ross Hammock (Phillips 
1940, p. 167).
    Public conservation lands play a significant role in the recovery 
of rockland hammock habitat where future development and habitat 
alteration are less likely than on private lands. However, these lands 
could be sold off in the future and become more likely to be developed 
or altered in a way that negatively impacts the subspecies and its 
habitat. Additionally, rockland hammock may be found on private lands; 
however, the fate of this existing habitat is unknown, as it is 
dependent upon actions of individual property owners (see discussion 
under Factor D). Therefore, we find that habitat loss due to population 
growth, development, and agricultural conversion poses a threat to this 
subspecies in Miami-Dade County.
    Sumter County--In Sumter County, human population growth and 
development has occurred, but to a lesser degree than in Miami-Dade 
County. However, Sumter County has a long history of agriculture dating 
back to the early 1860s. Generally speaking, all land that was feasible 
for agriculture was cleared at some point. In particular, mesic 
hammocks where Trichomanes punctatum ssp. floridanum occurs have 
experienced disturbances from human activities such as logging, 
understory clearing, cattle grazing, and introduction of feral hogs. 
These natural mesic canopies and soils have largely been destroyed due 
to their desirable locations for living, camping, and recreating. The 
global and State rank for mesic hammock habitat (G3/S3) signifies it is 
considered to have a restricted range or be vulnerable to extinction 
from other factors (FNAI 2010, p. 22).
    Concerns exist regarding future population growth and development 
in those communities remaining in Sumter County and on lands where 
urbanization and agriculture have not yet been established. According 
to the Sumter County Comprehensive Plan, a growth management paradigm 
has been developed that focuses public resources on urban areas to 
protect existing undeveloped land for agricultural use (Sumter County 
2012, Data and Analysis section). Currently, the threat with greatest 
impact to T.p. ssp. floridanum habitat in Sumter County is the 
potential for agricultural and residential clearing of mesic hammocks 
on small, fragmented private parcels.
    Privately owned land in the area around Wahoo where Trichomanes 
punctatum ssp. floridanum is found has been zoned as ``agricultural'' 
on the Sumter County Future Land Use Map (Sumter County 2012, p. 42). 
The County exempts single-site residential development and agriculture 
from environmental review and does not regulate land clearing for a 
single residence. Therefore, any undocumented populations and suitable 
habitat on private lands are at risk due to land-clearing activities, 
agricultural conversions, and development. For example, one Sumter 
County subpopulation observed in 1999 on private land was extirpated 
due to pasture clearing on the property for livestock (van der Heiden 
2013c, pers. comm.). A full survey for T.p. ssp. floridanum and 
associated suitable habitat is needed in Sumter County to determine the 
severity of potential habitat loss on this subspecies regionally, 
including the potential impact from future human population growth and 
development.
    Due to existing agricultural and residential clearing of mesic 
hammocks and potential future clearing on private lands, habitat loss 
due to human population growth, development, and agricultural 
conversion poses a threat to T.p. ssp. floridanum in Sumter County.
Regional Drainage and Consumptive Use
    Miami-Dade County--Landscape-level drainage has been extensive in 
Miami-Dade County. In the early 1900s, drainage initiatives were 
undertaken to modify land for agriculture and development. Impacts 
resulted in a region-wide drop in the water table (Nauman 1986, p. 182; 
Lodge 2005, p. 222), disturbing rockland hammocks and their flora 
(Service 1999, pp. 3-138), including Trichomanes punctatum ssp. 
floridanum. Additional stress from regional drainage for canal 
construction has also contributed to the decline of this metapopulation 
(Nauman 1986, p. 182; see also ``Historical Range/Distribution,'' 
Miami-Dade County section, above). As a consequence of the pervasive 
drainage throughout Miami-Dade County, solution holes, which often 
contained standing water during the rainy season, now hold much less, 
if any, water during much of the year, resulting in decreased ambient 
humidity levels (Phillips 1940, p. 171; Nauman 1986, p. 182; Adimey 
2013a, field notes). Even though regional changes in hydrology have not 
caused extirpation of T.p. ssp. floridanum at most locations, they may 
have already induced stress by promoting vulnerability to other 
stressors, such as periodic long-term droughts, cold

[[Page 60452]]

weather exposure, and other stochastic events. Furthermore, groundwater 
levels in the vicinity of T.p ssp. floridanum are not targeted as part 
of the Comprehensive Everglades Restoration Plan (CERP) (a framework 
and guide to restore, protect, and preserve the water resources of 
central and southern Florida, including the Everglades), and, 
therefore, impacts from regional drainage are not expected to be 
ameliorated by CERP. Rockland hammocks in Miami-Dade County have been 
modified as a result of hydrology changes, reducing the amount of water 
available to these habitats. This is an ongoing threat to T.p. ssp. 
floridanum, as hammocks on limestone substrates are dependent on the 
underlying water table to keep humidity levels high, especially in 
limestone sinkholes (Service 1999, pp. 3-127).
    Currently, the human population in Miami-Dade County 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). Although water demands will 
continue to rise with population increases, the extent of future 
impacts on existing habitat and the metapopulation of Trichomanes 
punctatum ssp. floridanum in Miami-Dade County is unknown at this time.
    Sumter County--In Sumter County, water drawdowns have historically 
been minimal. Regional modeling conducted by SWFWMD indicates less than 
a 0.06-m (0.2-ft) current use of water in the Upper Floridan Aquifer 
(Deangelis 2014a, 2014c, pers. comm.). No surface water withdrawals are 
currently occurring in Sumter County; however, they are possible in the 
future. Minimum flows and levels (MFLs), which are water withdrawal 
standards to limit water use set by the regional water management 
districts, are already established for the Withlacoochee River portion 
of the Withlacoochee River watershed in Sumter County. Although 
increases in human population and development in Sumter County may 
increase water use, it is believed that changes due to drought 
conditions (e.g., on the order of several feet) will have a far greater 
impact on the hydrology (Deangelis 2013a, pers. comm.).
Hydrology Changes
    Hydrology is a key ecosystem property that affects distribution and 
viability of rare plants (Gann et al. 2009, p. 6). Hydrology changes 
have extensively modified and, in some cases, destroyed habitat in 
south Florida. As a result of human population growth, development, 
agricultural conversion, and regional drainage, the hydrology of 
Trichomanes punctatum ssp. floridanum habitat has changed drastically 
and has contributed to the alteration in ambient humidity and 
temperature.
    For a hygrophilous (living or growing in damp places) subspecies 
thought to be restricted to a consistently humid microhabitat 
(Kr[ouml]mer and Kessler 2006, p. 57), high humidity is a critical 
factor to its survival, so any habitat modification or destruction that 
changes ambient humidity levels poses a threat to this subspecies 
(Nauman 1986, p. 182). As noted above, drainage efforts implemented in 
south Florida have significantly reduced historical water table levels, 
altering ambient humidity in the area. It is speculated that this 
subspecies may be living in discrete areas where humidity may be at the 
threshold for T.p. ssp. floridanum to survive. Minor drops in ambient 
humidity may limit reproduction and can negatively impact overall 
health of existing metapopulations, as well as inhibit the growth of 
new plants, impacting long-term viability (van der Heiden, 2013c, pers. 
comm.; Possley 2013e, pers. comm.). Van der Heiden and Johnson (2014, 
p. 9) recently observed this in Sumter County, where small drops in 
ambient temperature and humidity resulted in observed declines in the 
health of some clusters of T.p. ssp. floridanum within the local 
population.
Canopy Changes
    Canopy also is an important habitat feature for Trichomanes 
punctatum ssp. floridanum, and, in most cases, is the primary factor 
controlling surrounding temperature and humidity levels that are 
critical to the survival of this subspecies. The proper amount of high 
shade and low light is critical for the persistence of this subspecies. 
These features help to maintain humidity and prevent desiccation from 
excessive light exposure (van der Heiden 2013c, pers. comm.; Possley 
2013e, pers. comm.; Adimey 2013a-b, field notes). Currently, in both 
metapopulations, dense canopy cover is a necessity; however, the amount 
of canopy density needed to ensure survival is not yet known. Changes 
to existing canopies can result from land clearing and conversion, 
natural stochastic events, competition with nonnative species, and 
nonnative species control (see discussion under Factor E).
    Historically, as land was developed, natural features of the 
landscape changed, directly eliminating Trichomanes punctatum ssp. 
floridanum and also eliminating surrounding vegetation and habitat 
features essential to this subspecies. Field observations in Miami-Dade 
County have found clusters of T.p. ssp. floridanum desiccated when the 
immediate canopy above the ferns was destroyed or substantially 
reduced, allowing high amounts of light into the understory (Possley 
2013g, pers. comm.); however, over the course of many months, these 
clusters eventually recovered.
    The loss of canopy can result in plant desiccation via increased 
sun and wind exposure, increased ambient temperatures, changes in 
ambient humidity, and the proliferation of exotic species (see Factor E 
discussion, below). Destruction or changes in canopy of any existing 
populations could result in elimination of an entire population. 
Therefore, we find the loss of canopy through habitat loss and 
modification to be a threat to T.p. ssp. floridanum.
Habitat Fragmentation
    Habitat fragmentation limits dispersal and population size, and 
promotes vulnerability among existing populations. In Miami-Dade 
County, most remaining Trichomanes punctatum ssp. floridanum habitat 
(i.e., Fuchs, Meissner, Castellow, Hattie Bauer hammocks) is surrounded 
by housing development and agricultural land, resulting in scattered 
and small natural areas. Regional drainage and hydrology changes may 
also have contributed to the fragmented habitat in Miami-Dade County. 
In Sumter County, the impacts of habitat fragmentation are not as 
severe, as conservation lands are on large, adjacent tracts. Future 
development in Sumter County could result in an increase in fragmented 
habitat and pose a threat for this northern metapopulation (van der 
Heiden 2013c, pers. comm.). However, data regarding the impacts and 
subsequent consequences from habitat fragmentation are incomplete for 
both metapopulations of Trichomanes punctatum ssp. floridanum. 
Information and understanding of dispersal mechanisms for this 
subspecies are also currently lacking. The best available data for 
other plant species regarding the impacts of habitat fragmentation 
suggest that habitat fragmentation is likely a stressor impacting this 
subspecies but does not indicate that it rises to the level of a 
threat.
Conservation Efforts To Reduce Habitat Destruction, Modification, or 
Curtailment of Its Range
    Conservation efforts to reduce habitat destruction are generally 
focused on the conservation of land on which both metapopulations 
occur. All known

[[Page 60453]]

extant populations occur on State- or County-owned land that is 
currently protected from future development. In Miami-Dade County, 
extant occurrences of Trichomanes punctatum ssp. floridanum have been 
protected through acquisition within the County's EEL Program.

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 (acquisition) 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 95 ha (236 ac) of 
tropical hardwood and rockland hammocks (Gil 2013b, pers. comm.). The 
EEL Program also manages approximately 639 ha (1,578 ac) of tropical 
hardwood and rockland hammocks known as EEL Preserves and owned by the 
Miami-Dade County PROS Department, including some of the largest 
remaining areas of tropical hardwood and rockland hammocks (e.g., 
Matheson Hammock Park, Castellow Hammock Park, and Deering Estate Park 
and Preserves). The EEL Program may acquire lands that were once under 
an EEL Covenant (see description below). However, the existence of an 
EEL Covenant is not a requirement or precursor for acquisition of lands 
under the EEL Program.

EEL Covenant Program

    In 1979, Miami-Dade County established the EEL Covenant Program to 
reduce taxes for private landowners who own natural forest communities 
(NFC), such as pine rocklands and rockland hammocks. Under the EEL 
Covenant Program, landowners agree not to develop their property and to 
manage it for a period of 10 years, with the option to renew for 
additional 10-year periods (Service 1999, pp. 3-177). The EEL Covenant 
Program currently protects approximately 119 rockland hammock 
properties, comprising approximately 315.65 ha (780 ac) of habitat 
(Joyner 2013b, pers. comm.).
    Although these temporary conservation easements provide valuable 
protection for their duration, they are not considered under Factor D, 
below, because they are voluntary agreements and not regulatory in 
nature. Miami-Dade County currently has approximately 21 rockland 
hammock 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 removal of nonnative, invasive plants. Although the 
EEL Covenant Program has the potential to provide valuable habitat for 
unknown or future populations of Trichomanes punctatum ssp. floridanum, 
the actual contribution of these designated conservation lands is 
largely determined by whether individual landowners follow prescribed 
EEL management plans and NFC regulations (see ``Local'' under Factor D 
below).
    The County- and State-owned land areas that are protected by the 
EEL Program are critical to providing habitat for Trichomanes punctatum 
ssp. floridanum, as well as other native flora in Florida. Conservation 
efforts to prevent the future extirpation of T. p. ssp. floridanum and 
other fern species in Miami's EEL Preserves have been under way for 
many years. In Miami-Dade County, conservation lands are and have been 
monitored by Fairchild and IRC, in coordination with the EEL Program 
and the NAM Division of Miami-Dade County's PROS Department, to assess 
habitat status and determine any changes that may pose a threat to or 
alter the abundance of T. p. ssp. floridanum (Possley 2013k, pers. 
comm.; van der Heiden 2013f-h, pers. comm.). 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.

Other Efforts

    To date, only one reintroduction of filmy ferns (no specific 
species was indicated) was attempted by F.C. Craighead in the early 
1960s, in several hammocks within ENP within the Long Pine Key area. 
These efforts were unsuccessful, but no explanation was provided as to 
why they were unsuccessful (Gann 2013). Within-range reintroductions 
into unoccupied habitat have historically resulted in low success rates 
for plants (Maschinski et al. 2011, p. 159). Future reintroduction 
efforts will likely be attempted by MSBG from Trichomanes punctatum 
ssp. floridanum plants grown in-vitro from CREW.
    In Sumter County, monitoring and management in Withlacoochee State 
Forest is provided through the Florida Forest Service (Werner 2013e, 
pers. comm.). Habitat is assessed annually for canopy changes that may 
alter ambient humidity levels and for impacts from nonnative plant 
species and feral pigs. Additionally, surveys on SWFWMD property are 
conducted periodically to assess habitat and search for rare plant 
species in the area (Deangelis 2013b, pers. comm.).
Summary of Factor A
    Past human actions have destroyed, modified, and curtailed the 
range and habitat available for Trichomanes punctatum ssp. floridanum. 
Human population growth and development, agricultural conversion, and 
regional drainage have modified, or in most cases, destroyed, habitat 
where T. p. ssp. floridanum once occurred, thereby limiting the 
subspecies' current range and abundance in Florida.
    In Miami-Dade County, habitat modification and destruction have 
severely impacted rockland hammocks that were once abundant. The 
Trichomanes punctatum ssp. floridanum metapopulation in Miami-Dade 
County is currently composed of four known populations, all on County-
managed conservation lands. Historically, T. p. ssp. floridanum was 
found in an additional nine hammocks in Miami-Dade County. Most of 
these populations have been extirpated, and the historical range of the 
southern metapopulation has been reduced by nearly 80 percent. However, 
the subspecies was observed in ``Monkey Jungle'' (historically referred 
to as Cox Hammock) in 1989, and no thorough surveys have been conducted 
there since then. Upon recent visitation to the site (Adimey 2013a, 
field notes), the habitat features appeared to be similar to other 
hammocks where T. p. ssp. floridanum is currently known to occur (large 
solution holes, high humidity, dense canopy, standing water). Thus, 
much of the habitat has been destroyed, and while those fragments 
suitable for the plant remain protected in Miami-Dade County, habitat 
loss and modification from future development or conversion on private 
and conservation lands in Miami-Dade County poses a threat. In 
addition, the areas where T. p. ssp. floridanum currently exists are 
still vulnerable to activities in the surrounding areas, including 
agricultural clearing and hydrologic alterations.
    The Sumter County metapopulation of Trichomanes punctatum ssp. 
floridanum is composed of two known

[[Page 60454]]

populations, both on State-owned land in the Jumper Creek Tract of the 
WSF. In central Florida, the subspecies was historically found in as 
many as seven additional locations. All of these historical populations 
have since been extirpated, primarily due to land conversion and 
clearing (including for cattle grazing) and the impacts of local and 
regional drainage. Land clearing and hydrological alterations on 
private lands adjacent to the Jumper Creek Tract continue to be threats 
to T. p. ssp. floridanum populations and habitat.
    The destruction and modification of habitat have resulted in 
changes in canopy, humidity, hydrology, and fragmentation that have 
contributed to the declines of this taxon. High humidity and dense 
canopy cover are critical for Trichomanes punctatum ssp. floridanum's 
survival. Therefore, any habitat modification or destruction that 
changes ambient humidity levels or canopy cover poses a threat to this 
subspecies. Data regarding the impacts of habitat fragmentation are 
incomplete for both metapopulations of T. p. ssp. floridanum because 
information on dispersal mechanisms of this subspecies is currently 
lacking. Habitat fragmentation is likely a stressor impacting this 
subspecies, but the best available data do not indicate that it rises 
to the level of a threat.
    Conservation efforts are currently providing some benefits to this 
subspecies but are not sufficient to ameliorate the habitat threats. 
Therefore, based on the best information available, we have determined 
that the threats to Trichomanes punctatum ssp. floridanum 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 
occurring and, therefore, we find that overutilization is not a threat 
to Trichomanes punctatum ssp. floridanum.

Factor C. Disease or Predation

    No diseases or incidences of predation have been reported for 
Trichomanes punctatum ssp. floridanum. Therefore, the best available 
data do not indicate that disease or predation is a threat to the 
subspecies.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    Under this factor, we examine whether threats to the subspecies 
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. An 
example would be State governmental actions enforced under a State 
statute or constitution or Federal action under 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 designed to address threats to Trichomanes punctatum ssp. 
floridanum to determine whether they effectively reduce or remove 
threats to the subspecies.
Federal
    The only known extant populations of Trichomanes punctatum ssp. 
floridanum occur on State- or County-owned properties, and development 
of most of these areas is not likely to require a Federal permit or 
other authorization.
    Section 404 of the Clean Water Act (CWA; 33 U.S.C. 1251 et seq.) 
establishes a Federal program for regulating the discharge of dredged 
or fill material into waters of the United States, including wetlands. 
Additionally, section 401 of the CWA forbids Federal agencies from 
issuing a permit or license for activities that may result in a 
discharge to waters of the United States until the State or Tribe where 
the discharge would originate has granted or waived certification. The 
State of Florida maintains regulatory programs providing a framework 
for issuance of section 401 certifications related to applications for 
section 404 permits. This legislation does not prohibit the discharge 
of these materials into wetlands; rather, it provides a regulatory 
framework that requires permits prior to such action being taken. The 
U.S. Army Corps of Engineers (Corps) reviews individual permits for 
potentially significant impacts; however, most discharges are 
considered to have minimal impacts and may be covered by a general 
permit that does not require individual review.
    On June 29, 2015, the Environmental Protection Agency and Corps 
published a final rule (80 FR 37054), effective August 28, 2015, that 
revises the definition of ``waters of the United States.'' Specific 
guidance on implementation of this revised definition is currently 
lacking, but it appears that the revised definition is likely to 
include hydric hammocks in areas where Trichomanes punctatum ssp. 
floridanum occurs in Sumter County among waters of the United States. 
However, as noted above, section 404 of the CWA does not necessarily 
prevent degradation to such habitats from the discharge of dredge or 
fill material. It simply provides a regulatory program for permitting 
activities that would result in such a discharge. Further, discharges 
associated with normal farming, ranching, and forestry activities, such 
as plowing, cultivating, minor drainage, and harvesting for the 
production of food, fiber, and forest products are exempt from the 
requirement to obtain a permit.
State
    FNAI considers the State status of Trichomanes punctatum ssp. 
floridanum to be S1, ``critically imperiled in Florida because of 
extreme rarity (five or fewer occurrences or less than 1,000 
individuals) or because of extreme vulnerability to extinction due to 
some natural or man-made factor'' (FNAI, 2013; Element Tracking 
Summary). The IRC considers its status as ``critically imperiled'' 
(Gann et al. 2002, pp. 552-554).
    The Florida Department of Agriculture and Consumer Services has 
listed Trichomanes punctatum ssp. floridanum on the Regulated Plant 
Index (Index) as endangered under Chapter 5B-40, Florida Administrative 
Code (State of Florida 2013, Florida Statutes). This listing provides 
little or no habitat protection beyond the State's Development of 
Regional Impact process, which discloses impacts from projects, but 
provides no regulatory

[[Page 60455]]

protection for State-listed plants on private lands.
    Florida Statutes chapter 581.185, sections (3)(a) and (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, section (10) of the statute provides for consultation similar 
to section 7 of the Act for listed species, by requiring the Department 
of Transportation to notify the FDACS 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. Sections (8)(a) and (b) of the statute waive 
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.
    The Florida Forest Service (FFS) is the lead managing agency for 
State forests, as outlined in the Management Lease from the landowner 
(Board of Trustees of the Internal Improvement Trust Fund of the State 
of Florida) with guidance provided in chapters 253, 259, and 589 of the 
Florida Statutes (State of Florida, 2013 Florida Statutes, Preservation 
of Native Flora and Fauna). FFS is responsible for the management and 
supervision of the multiple-use guidelines of Withlacoochee State 
Forest. For research on State forest lands, prior approval is required. 
Research deemed legitimate will be issued a State Forest Use Permit 
(FDACS-11228) or letter of authorization (The Florida Forest Service 
2013, State Forest Handbook).
    Although the MFLs established by the South Florida Water Management 
District (SFWMD) in southeast Florida (a separate entity from the 
SWFWMD described earlier) are not directly applicable in the area of 
Miami Rock Ridge where Trichomanes punctatum ssp. floridanum occurs, 
they do indirectly limit ground water withdrawals in other areas of 
south Florida, including other areas of the Miami Rock Ridge. 
Unfortunately, MFL thresholds in place that establish water withdrawal 
standards are set so low that protection measures are rarely triggered. 
These low water level standards may be further exacerbated during times 
of drought, resulting in even greater impacts to the water table and 
the overall regional hydrology. Furthermore, MFL standards also do not 
apply to wells on private property or for consumptive use. The lowering 
of ground water and associated changes in local ambient humidity have 
already occurred throughout south Florida and have likely contributed 
to the decline of T. p. ssp. floridanum and possibly limited 
distribution and resilience (i.e., ability to withstand stochastic 
(random) events and recover from disturbances) of the subspecies 
(Grossenbacher 2013, pers. comm.). Plants are likely to be further 
stressed by the continued lowering of ground water if additional large 
wells are created on private property for such activities as 
agriculture or during extended periods of drought because these types 
of circumstances are not regulated by the water withdrawal standards 
established by the SFWMD. In general, this regulatory mechanism has not 
been sufficient to reduce or remove the threat to T. p. ssp. floridanum 
posed by changes in hydrology discussed under Factor A by ensuring that 
current water levels will persist into the future.
    Sumter County MFLs identified and adopted by the SWFWMD protect the 
Withlacoochee River and the Tsala Apopka lake chain, which connects to 
the Withlacoochee in the vicinity of Jumper Creek Tract where 
Trichomanes punctatum ssp. floridanum occurs. Maintaining designated 
MFLs will have a direct bearing on the design of future water supply 
development projects, of which there are several already proposed in 
Sumter County (Deangelis 2014c, pers. comm.). However, it is uncertain 
how these future projects would impact extant occurrences of T. p. ssp. 
floridanum or suitable habitat for the subspecies.
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 Department of Regulatory and 
Economic Resources (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 10 percent of a rockland 
hammock designated as NFC to be developed for properties greater than 5 
acres and requires 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 can be cleared if the request is deemed a 
reasonable use of property; this allowance often can be greater than 10 
percent 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 
discovered, unpermitted work is pursued by RER through appropriate 
enforcement action, and restoration is sought 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.
    Although the NFC program is designed to protect rare and important 
upland (non-wetlands) habitats in south Florida, it is a regulatory 
strategy with limitations. For example, in certain circumstances where 
landowners can demonstrate that limiting development to 10 percent 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 requires 
coordination with the landowners only if they plan to develop property 
or perform work within the NFC designated area. As such, 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

[[Page 60456]]

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 requires the land to be 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 the Miami-Dade County 
Code (Grossenbacher 2013, pers. comm.).
    Although Trichomanes punctatum ssp. floridanum is currently 
afforded some protection from outright destruction on public 
conservation land, changes in the surrounding landscape that affect the 
subspecies are not regulated. For example, the private property known 
as ``Monkey Jungle'' (historically referred to as Cox Hammock) is a 
public attraction and is home to a considerable number of primate 
species. Upon recent visitation to this site (Adimey 2013a, field 
notes), the habitat features appeared to be similar to other hammocks 
where T. p. ssp. floridanum currently is known to live (i.e., large 
solution holes, high humidity, dense canopy, standing water). Although 
much of the hammock has been altered to accommodate captive animals and 
visitors, a significant portion of the hammock still remains untouched 
and overgrown with extensive nonnative, invasive plant species. 
``Monkey Jungle'' receives limited protection under the Miami-Dade 
County Environmental Protection Ordinance as an NFC, where only 
portions of NFCs can be cleared once a permit is obtained from the 
County.
    Additionally, Miami-Dade County has oversight of any work or 
research completed within the local preserve areas; permits are 
required for any outside work or research on County-owned lands in 
order to further protect the habitat from potential direct or indirect 
impacts (Gil 2013a, pers. comm.).
    Under section 13-644(a)(1) of the Sumter County code, ``[m]ajor 
developments shall identify and protect habitats of protected wildlife 
and vegetation species,'' and in section 13-644(a)(1)2.b.2, ``[n]o 
permit will be issued for development which results in unmitigated 
destruction of specimens of endangered, threatened or rare species.'' 
Therefore, the County code prevents unmitigated destruction of 
endangered, threatened, or rare species only when associated with 
``major developments.'' Current zoning in the Wahoo area limits 
development to one unit per 4 ha (10 ac); therefore, ``major 
developments'' do not seem to be likely in that area. In general, 
existing county ordinances do not prevent the conversion of habitat to 
agricultural use or building on sites with endangered, threatened, or 
rare plant species. Without complete survey information for Sumter 
County, it is difficult to assess the extent to which unknown 
occurrences and suitable habitat on private lands are at risk. 
Agriculture and development are ongoing and promoted in this County, 
and no regulatory mechanisms exist that protect T. p. ssp. floridanum 
and its habitat on private lands.
Summary of Factor D
    Currently, Trichomanes punctatum ssp. floridanum is only known to 
occur on State and County lands; however, there are no regulatory 
mechanisms in place that provide substantive protection of habitat or 
protection of potentially suitable habitat at this time. In addition, 
subsections of applicable statutes waive State regulation for private 
landowners or their agents, allowing certain activities to clear or 
remove species on the Index. Little, if any, protection is afforded to 
T. p. ssp. floridanum by the established MFLs in south Florida, as they 
are set very low, are rarely triggered, and are not applicable in the 
portion of the Miami Rock Ridge where the subspecies currently lives. 
Established MFLs in Sumter County can positively impact areas where T. 
p. ssp. floridanum occurs, provided that these designated MFLs are 
maintained when future water supply development projects are 
undertaken. The NFC program in Miami is designed to protect rare and 
important upland (non-wetland) habitats in south Florida. However, this 
regulatory strategy has several limitations that can negatively affect 
T. p. ssp. floridanum. Sumter County code prevents unmitigated 
destruction of endangered, threatened, or rare species only when 
associated with ``major developments'' and does not prevent conversion 
of habitat to agricultural use or building on private property.
    Although all known extant populations of Trichomanes punctatum ssp. 
floridanum 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 the subspecies by a wide 
array of sources (see discussions under Factors A and E).

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

    Other natural or manmade factors affect Trichomanes punctatum ssp. 
floridanum to varying degrees. Specific threats include the spread of 
nonnative, invasive species; potentially incompatible management 
practices (e.g., inadvertent spraying of T. p. ssp. floridanum while 
controlling for nonnatives); direct impacts to plants from recreation 
and other human activities; small population size and isolation; 
climate change; and the related risks from environmental stochasticity 
(extreme weather). Each of these threats and its specific effect on T. 
p. ssp. floridanum is discussed in detail below.
Nonnative Species
    Nonnative species can stress, alter, or even destroy native species 
and their habitats. The threat of nonnative plant species is ongoing 
due to their: (1) Number and extent, (2) ability to out-compete native 
species, (3) abundant seed sources, and (4) extensive disturbance 
within habitats. Further challenges exist due to limitation of 
resources to combat this threat, as well as the difficulty in managing 
fragmented hammocks bordered by urban development, which often can 
serve as seed sources for nonnative species (Bradley and Gann 1999, p. 
13). Nonnative, invasive plants compete with native plants for space, 
light, water, and nutrients, and they limit growth and abundance of 
natural vegetation and can make habitat conditions unsuitable for 
native plants.
    In south Florida, 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 hammock and mesic hammock habitats 
where Trichomanes punctatum ssp. floridanum occurs and are considered 
one of the threats with greatest impact to the subspecies (Snyder et 
al. 1990, p. 273; Gann et al. 2002, pp. 552-554; FNAI 2010, pp. 22, 
26). Nonnative plants outcompete and displace T. p. ssp. floridanum in 
solution holes, and may form dense strata (layers) in the hammock, 
where it is possible that the fern may be blanketed and smothered 
(Possley 2014c, pers. comm.). It has also been suggested that the 
insular nature of south Florida, as well as the hammocks themselves, 
predispose this habitat to

[[Page 60457]]

invasion by nonnative plants (e.g., the proximity of seed sources, 
which increases the volume of nonnatives and accelerates the time it 
takes for the arrival and establishment of nonnatives) (Horvitz et al. 
1998, p. 961).
    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. 
Problematic nonnative invasive plants in Miami-Dade County associated 
with Trichomanes punctatum ssp. floridanum include Schinus 
terebinthifolia (Brazilian pepper), Bischofia javanica (bishop wood), 
Syngonium podophyllum (American evergreen), Jasminum fluminense 
(Brazilian jasmine), Rubus niveus (mysore raspberry), Thelypteris 
opulenta (jeweled maiden fern), Nephrolepis multiflora (Asian 
swordfern), Schefflera actinophylla (octopus tree), Jasminum dichotomum 
(Gold Coast jasmine), Epipremnum pinnatum (centipede tongavine), and 
Nephrolepis cordifolia (narrow swordfern) (Possley 2013g-h, pers. 
comm.).
    In Sumter County, the most problematic nonnative invasive species 
occurring in Trichomanes punctatum ssp. floridanum habitat are 
Tradescantia fluminensis (small leaf spiderwort) and Paederia foetida 
(skunkvine) (Werner 2013d, pers. comm.). Furthermore, Citrus aurantium 
(bitter orange) is found in this locale and is considered problematic 
due to its tendency to attract feral hogs, another nonnative species 
associated with extensive habitat destruction (see below). Agricultural 
fields in proximity to the Sumter metapopulation are a nonnative seed 
source, increasing potential encroachment of nonnative plants to the 
area (Werner 2013b-c, pers. comm.).
    In some instances, management of nonnative vegetation may also be 
detrimental, in that nonnative species may actually provide the 
necessary canopy to limit sunlight exposure and control humidity, so 
that removing the nonnative species exposes the fern. In Castellow 
Hammock, the majority of the shade near two of the large solution holes 
containing Trichomanes punctatum ssp. floridanum is provided by giant 
Schinus terebinthifolia trees; eliminating these trees could likely 
result in detrimental effects to T. p. ssp. floridanum residing in the 
underlying solution holes. In hammocks such as Castellow, desiccation 
from excessive sun exposure due to the removal of S. terebinthifolia 
canopy has already occurred. In this case, the subpopulation of T. p. 
ssp. floridanum below the S. terebinthifolia tree turned brown; 
however, T. p. ssp. floridanum could eventually revitalize if 
sufficient canopy is reestablished to limit sunlight exposure (Possley 
2013d, pers. comm.). Additionally, nonnative plant control may also 
become a threat when T. p. ssp. floridanum is inadvertently sprayed 
while authorities conduct local nonnative removal efforts (Possley 
2013d, pers. comm.).
    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. 
Overall, active management is necessary to control for nonnative 
species and to protect unique and rare habitat where T.p. ssp. 
floridanum occurs (Snyder et al. 1990, p. 273). Treatment of nonnative 
plant species should consider canopy and humidity needs of T.p. ssp. 
floridanum.
    Nonnative feral hogs living in the Withlacoochee State Forest are 
also considered a threat to this plant. Surveys in Sumter County have 
revealed evidence of hogs lying against or rubbing their bodies against 
large rocks, removing existing vegetation in the process. Recently, van 
der Heiden and Johnson (2014, p. 11) found one small rock where 
Trichomanes punctatum ssp. floridanum had been scraped off when a hog 
rubbed itself on the rock after wallowing in the mud. Furthermore, 
rooting from hogs can destroy existing habitat by displacing smaller 
rocks where T.p. ssp. floridanum is found to grow and potentially 
damaging or eliminating a cluster (Werner 2013d, pers. comm.). In 
Withlacoochee State Forest, damaged areas from feral hogs are also more 
susceptible to invasion from nonnative plant species, such as Urena 
lobata (Caesarweed) and Tradescantia fluminensis (small-leaf 
spiderwort) (Werner 2013a, pers. comm.). If feral hogs continue to 
forage in areas where T.p. ssp. floridanum lives, it is possible that 
entire clusters inhabiting one rock/boulder could be eliminated.
    In recent years, scientists in south Florida have noticed an 
increase in sightings of the nonnative genus Zachrysia (Cuban tree 
snails). Although snail grazing has not been observed on Trichomanes 
punctatum ssp. floridanum, it has been documented on other rare ferns 
living in the same habitat and could possibly become a threat in the 
future, either by this snail or another introduced species (Possley 
2013b, c, pers. comm.).
Climate Change
    Climatic changes, including sea level rise (SLR), are occurring in 
the State of Florida and are impacting associated plants, animals, and 
habitats. 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 reports of the IPCC (IPCC 2013, entire).
    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). Projected 
changes in climate and related impacts can vary substantially across 
and within different regions of the world (e.g., IPCC 2007, p. 8-12). 
Therefore, we use ``downscaled'' projections when they are available 
and have been developed through appropriate scientific procedures (see 
Glick et al. 2011, pp. 58-61, for a discussion of downscaling). As to 
Trichomanes punctatum ssp. floridanum, 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 Miami-Dade 
County populations of T.p. ssp. floridanum occur at elevations 2.83-
4.14 m (9.29-13.57 ft) above sea level, making the subspecies highly 
susceptible to increased storm surges and related impacts associated 
with SLR, whereas the Sumter County populations are at approximately 
10.40 m (34.12 ft) above sea level and significantly farther from the 
coast.
    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

[[Page 60458]]

(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,'' below). Models where sea level 
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 (see ``Alternative Future Landscape 
Models,'' below). 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) recognizes 
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).
    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 of coastal waters 
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 rockland 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 rockland location in the 
Florida Keys (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 ground water and soil 
water salinization.
    Extrapolating this situation to hardwood hammocks is 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. Patterns of human development will also likely be significant 
factors influencing whether natural communities can move and persist 
(IPCC 2008, p. 57; USCCSP 2008, p. 7-6).
    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 and/or 
endemic species with possible extirpation. In south Florida, SLR of 1-2 
m (0.30-0.61 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 2.00 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 a 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).
    Saha (et al. 2011, p. 4) suggested that the rising water table 
accompanying SLR will shrink the vadose zone (the area that extends 
from the top of the ground surface to the water table); increase 
salinity in the bottom portion of the freshwater lens (a convex layer 
of fresh ground water that floats on top of denser saltwater), thereby 
increasing brackishness of plant-available water; and influence tree 
species composition

[[Page 60459]]

of hardwood hammocks based upon species-level tolerance to salinity 
and/or drought. 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). Altered freshwater inputs can lead to the 
disappearance or decline of critically imperiled coastal plant species. 
Shifts in freshwater flows, annual precipitation, and variability in 
SLR can impact salinity regimes. Although it is unknown if salinity 
changes will impact existing habitat where T. p. ssp. floridanum 
currently lives, it should be noted that salinity-intolerant plants can 
become stressed within a few weeks from exposure to saline conditions, 
and persistent conditions can promote colonization by more salinity-
tolerant species, thereby leading to an irreversible composition 
change, even if the salinity is lower over subsequent years (Saha et 
al. 2011, p. 23).
    In some areas of south Florida, precipitation is the main source of 
fresh water. Predictive climate change models demonstrate periods of 
drought will pose a threat to existing populations of Trichomanes 
punctatum ssp. floridanum. Saha (et al. 2011, pp. 19-21) found that 
during times of drought and resultant salinity stress, coastal hardwood 
tree density from the canopy was lost, while other species showed an 
increase. Areas with a deeper freshwater lens, such as rockland 
hammocks, may be able to sustain vegetation during periods of drought; 
however, whether this theory is true is currently unknown. Some tree 
species in coastal hammocks have the ability to access pockets of fresh 
water and tolerate mild salinities. These initial responses to salinity 
increases may trigger responses similar to drought, while prolonged 
exposure may cause irreversible toxicity caused by accumulation of 
salts (Munns 2002, p. 248), causing a reduction in canopy or mortality 
(Maschinski et al. 2009, entire paper). Impacts from climate change 
causing shifts in local plant communities and invasion of additional 
nonnative plant species may be lessened by the ability of hardwood 
hammocks (such as rockland hammocks) to harvest rainfall water and 
retain it in the highly organic soil and lower their transpiration 
(i.e., the process of water movement through a plant and its 
evaporation from leaves and stems) during the dry season (Saha et al. 
2011, p. 24).
    Drier conditions and increased variability in precipitation 
associated with climate change are expected to hamper successful 
regeneration of forests and cause shifts in vegetation types through 
time (Wear and Greis 2012, p. 39). With regard to Trichomanes punctatum 
ssp. floridanum, any weather shifts causing less precipitation would 
likely impact the viability of existing populations and could 
potentially limit future reproduction if droughts were to become a 
common occurrence. Ecosystem shifts would result in rockland and mesic 
hammocks having drier conditions, regular droughts, and changes in 
humidity, temperature, and canopy. Increases in the scale, frequency, 
or severity of droughts and wildfires (see ``Fires'' section, below) 
could have negative effects on this taxon considering its general 
vulnerability due to small population size, restricted range, few 
populations, and relative isolation.
    Climate change impacts specifically for Trichomanes punctatum ssp. 
floridanum may be numerous and vary depending on factors such as 
severity, the speed at which climate changes occur, timing, health of 
the species, and habitat and tolerance of species. Overall, management 
of healthy ecosystems can support greater biodiversity, which is 
considered one of the best strategies to combat impacts of climate 
change. Removing nonnative plants and minimizing natural disturbance 
impacts and other external stresses can improve the subspecies' 
response to climate change impacts (Maschinski et al. 2011, p. 159). In 
general, the best ways to prepare and protect rare species, such as T. 
p. ssp. floridanum, from impacts of climate change include actively 
managing habitats to improve population growth and potential for 
natural dispersal, and controlling for nonnative species. Efforts to 
actively manage for T. p. ssp. floridanum are currently limited for 
both metapopulations due to logistical feasibility (e.g., dense forest, 
difficulty locating populations), insufficient funding and research, 
small and fragmented existing populations, and lack of successful 
reintroduction efforts into the wild.
Alternative Future Landscape Models
    To accommodate the high uncertainty in SLR projections, researchers 
must estimate effects from a range of scenarios. Various model 
scenarios developed at MIT and GeoAdaptive Inc. have projected possible 
trajectories of future transformation of the peninsular Florida 
landscape by 2060 based upon four main drivers: Climate change, shifts 
in planning approaches and regulations, human population change, and 
variations in financial resources for conservation (Vargas-Moreno and 
Flaxman 2010, pp. 1-6). The scenarios do not account for temperature, 
precipitation, or species habitat shifts due to climate change, and no 
storm surge effects are considered. The current MIT scenarios in 
Florida range from an increase in sea level of 0.09-1.0 m (0.3-3.3 ft) 
by 2060.
    Based on the most recent estimates of SLR and the best available 
data at this time, we evaluated potential effects of SLR using the 
current ``worst case'' (e.g., the highest range for SLR) MIT scenario, 
as well as comparing elevations of remaining rockland hammock fragments 
in Miami-Dade County and mesic hammocks in Sumter County with extant 
populations of Trichomanes punctatum ssp. floridanum. The ``worst 
case'' MIT scenario assumes SLR of 1.0 m (3.3 ft) by 2060, low 
financial resources, a `business as usual' approach to planning, and a 
doubling of human population.
    Based on the 1.0-m (3.3-ft) scenario, none of the rockland hammocks 
in Miami-Dade County where extant populations of Trichomanes punctatum 
ssp. floridanum occur would be inundated. However, all four populations 
would be within 9.66 km (6.0 mi) of saltwater, increasing the 
likelihood of localized vegetation shifts within the rockland hammocks 
and vulnerability to natural stochastic events such as hurricanes and 
tropical storms. The 1.0-m SLR scenario shows existing rockland 
hammocks in Miami-Dade County (that do not contain T.p. ssp. 
floridanum) directly adjacent to saltwater. Although these existing 
hammocks 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. A few remaining 
rockland hammocks further inland (e.g., Big and Little George Hammocks) 
are located in highly urbanized areas; these hammocks are small and 
fragmented, reducing the chances of further development due to SLR in 
the area. Actual impacts may be greater or less than anticipated based 
upon the high variability of factors involved (e.g., SLR, human 
population growth) and the assumptions made in this model.
    A projected SLR (using elevation data) of 2.0 m (6.6 ft) appears to 
inundate much larger portions of urban Miami-Dade County. This 
evaluation was not based on any modeling, as opposed to the previous 
1.0-m scenario; rather, this scenario examines current elevation based 
on LiDAR (remote sensing technology that measures distance by

[[Page 60460]]

illuminating a target with a laser and analyzing the reflected light) 
data. Under this 2.0-m (6.6-ft) SLR scenario, none of the four hammocks 
where Trichomanes punctatum ssp. floridanum is known to occur will be 
inundated, but all will be within approximately 2.41 km (1.5 mi) of 
saltwater in the inundated transverse glades joining the enlarged 
Biscayne Bay. Castellow Hammock will be the least impacted at 
approximately 2.41 km (1.5 mi) from saltwater, while Hattie Bauer will 
be adjacent to saltwater. Fuchs and Meissner hammocks will be 1.61 km 
(1.0 mi) from saltwater and will be surrounded by more wetlands. This 
scenario will leave all these locations extremely vulnerable to 
vegetation shifts, natural stochastic events, and loss of existing 
habitat and land protection. Of the remaining rockland hammocks not 
containing T.p. ssp. floridanum in south Florida, most would be fully 
or partially inundated after a 2.0-m (6.6-ft) SLR, except for the 
hammocks located on the higher elevated coastal ridge, which would 
still be adjacent to saltwater.
    Due to the higher elevation and inland location of Sumter County in 
north Florida, existing populations of Trichomanes punctatum ssp. 
floridanum and associated habitat will not be impacted by 1.0- and 2.0-
m (3.3- and 6.6-ft) rises in sea level. The 2.0-m (6.6-ft) SLR scenario 
would still leave the Sumter occurrences approximately 37.0 km (23.0 
mi) from saltwater. Regional shifts in water table salinity, soils, or 
vegetation are not expected.
Environmental Stochasticity
    Endemic species whose populations exhibit a high degree of 
isolation, such as Trichomanes punctatum ssp. floridanum, are extremely 
vulnerable to extinction from both random and nonrandom catastrophic 
natural or human-caused events. Small populations of species, without 
positive growth rates, are considered to have a high extinction risk 
from site-specific demographic (variability in population growth rates 
arising from random differences among individuals in survival and 
reproduction within a season) and environmental (unpredictable changes 
in environmental conditions such as weather, food supply, or predators) 
stochasticity (Lande 1993, pp. 911-927). Populations at the edge of a 
species' range, as may be the case with T.p. ssp. floridanum in Sumter 
County, may be particularly vulnerable to environmental stochasticity, 
as they may also be at the edge of their physiological and adaptive 
limits (Baguette 2004, p. 216).
    The climate in Florida is driven by a combination of local, 
regional, and global events, regimes, and oscillations (e.g., El 
Ni[ntilde]o Southern Oscillation with a frequency of every 4 to 7 
years, solar cycle every 11 years, and the Atlantic Multi-decadal 
Oscillation); however, the exact magnitude, direction, and distribution 
of these climatic influences on a regional level are difficult to 
project. There are three main ``seasons'' in Florida: (1) The wet 
season, which is hot, rainy, and humid from June through October; (2) 
the official hurricane season that extends 1 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 (Miller 2013, pers. comm.). 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 and 36 major 
hurricanes. Given the few isolated populations and restricted range of 
Trichomanes punctatum ssp. floridanum in locations prone to storm 
influences (i.e., Miami-Dade County), this subspecies is at substantial 
risk from hurricanes, storm surges, and other extreme weather events.
    Natural stochastic events can pose a threat to the persistence of 
Trichomanes punctatum ssp. floridanum through the destruction of 
existing habitat. 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 that 
hurricane and tropical storm frequencies in the Atlantic will decrease 
between 10-30 percent by 2100 (Knutson et al. 2008, pp. 1-21). For 
those models that predict fewer hurricanes, hurricane wind speeds are 
expected to increase by 5-10 percent due to an increase in available 
energy for intense storms. Increases in hurricane winds can elevate the 
chances of damage to existing canopy.
    In south Florida, tropical hardwood hammock forests are known to 
experience frequent disturbances from hurricanes (Horvitz et al. 1998, 
p. 947). Hurricanes and tropical storms can damage existing canopy, 
which provides shade and cover from wind. Canopy loss of any kind is 
determined to be the threat with greatest impact to existing 
metapopulations of Trichomanes punctatum ssp. floridanum (Adimey 2013b, 
field notes; Possley 2013l, pers. comm.). For example, impacts from 
Hurricane Andrew in 1992 may have been responsible for the temporary 
loss of the subspecies from Hattie Bauer Hammock, where it had been 
observed for many years. Following this hurricane, the canopy was 
damaged, allowing increased exposure to sunlight for several years. 
T.p. ssp. floridanum was not seen again in Hattie Bauer Hammock until 
2011 (Possley 2013l, pers. comm.). Through natural recovery, assisted 
by active management activities by the EEL Program and PROS-NAM, a 
large portion of the Hattie Bauer Hammock canopy has been restored to 
pre-hurricane Andrew conditions (Guerra 2014, pers. comm.). Destruction 
of habitat due to hurricanes has also been documented in Sumter County 
in the Indian Ledges Hammock located near the town of Wahoo. This 
hammock, known to host a variety of rare ferns, orchids, and large 
trees, sustained severe damage from several hurricanes in 2004; very 
few native plant species once found in Indian Ledges Hammock exist in 
this location today (Deangelis 2014a, pers. comm.).
    Historically, Trichomanes punctatum ssp. floridanum may have 
benefitted from more abundant and contiguous habitat to buffer it from 
storm events. The destruction and modification of native habitat, 
combined with the subspecies' small population sizes, has likely 
contributed over time to the stress, decline, and, in some instances, 
extirpation of populations or local occurrences due to stochastic 
events.
    A study conducted by Horvitz et al. (1998, p. 947) found that the 
regeneration of forest species after stochastic events depended on the 
amount of canopy disturbance, the time since disturbance, and the 
biological relationship between the individual species and its 
environment. Following Hurricane Andrew, the relative abundance and 
life stage changed for

[[Page 60461]]

many nonnative plant species within Miami-Dade County. These shifts 
continued to occur as a result of subsequent stochastic events, 
suggesting hurricanes can alter long-term hammock structure and the 
ongoing changes in species composition (Horvitz et al. 1998, pp. 961, 
966).
    Stochastic events resulting in changes in normal precipitation 
(amount, seasonal timing, and distribution) and extreme temperature 
fluctuations may also impact Trichomanes punctatum ssp. floridanum. 
During the winter dry season, T.p. ssp. floridanum can become 
desiccated without periodic rainfall and then recover during the wet 
season. Multiyear droughts may negatively impact populations. While 
droughts are natural events, they are a threat because there are so few 
populations of this subspecies. Specific parameters regarding humidity, 
temperature, and precipitation requirements are not known at this time 
for T.p. ssp. floridanum, making it difficult to accurately determine 
what impacts will occur from modifications in current environmental 
conditions where extant metapopulations occur. Extreme temperature 
changes such as cold events in south Florida or freezing temperatures 
in central Florida could have devastating impacts on this subspecies. 
The small size of each population makes this plant especially 
vulnerable, in which the loss of even a few individuals could reduce 
the viability of a single population.
    Due to the small size of existing populations of Trichomanes 
punctatum ssp. floridanum and its limited genetic variability, the 
subspecies' overall ability to respond and adapt to threats is likely 
low. These factors, combined with additional stress from habitat 
modifications (e.g., hydrological changes) may increase the inherent 
risk posed by stochastic events that impact this subspecies (Matthies 
et al. 2004, pp. 481-488). Additionally, stochastic events are expected 
to exacerbate the impacts of regional drainage and subsequent drops in 
humidity. For these reasons, T.p. ssp. floridanum is at risk of 
extirpation during extreme stochastic events. We have determined that 
these natural stochastic events coupled with existing small population 
sizes, as addressed above, are a threat to the subspecies (Adimey 
2013b, field notes; Possley 2013l, pers. comm.).
Fires
    Although fires are not a current concern for existing populations 
of Trichomanes punctatum ssp. floridanum, they have been known to 
impact populations in the past. Craighead (1963, p. 39) noted that 
extensive fires in hammocks eliminated ferns in much of their former 
range. Drainage efforts in the early 1900s also increased the 
occurrence of fire, as lands became drier. Phillips (1940, p. 166) 
noted that the frequent occurrence of fires in the late 1930s in 
southern Florida resulted in widespread destruction of flora. Fires may 
have been a factor in the disappearance of this taxon in Royal Palm 
Hammock, which suffered multiple fires in the first half of the 1900s 
according to photographs from J.K. Small (1917; Florida Memory, State 
Library and Archives of Florida; Tallahassee, Florida). In recent 
decades, wildfires have been controlled in most rockland hammocks due 
to the extensive urbanization in Miami-Dade County. However, fires do 
have the potential to impact T.p. ssp. floridanum during periods of 
prolonged drought. While fires are a natural component of some 
ecosystems in south Florida, fires in hammocks can set back succession 
to pine rockland or other communities and will directly kill many plant 
species that are not adapted to fires, such as T.p. ssp. floridanum.
    Generally, hammock environments are considered less susceptible to 
wildfires because their shaded, humid microclimate is not conducive to 
fire spread (Snyder et al. 1990, p. 258). Additionally, rockland 
hammocks occupy elevated, rarely inundated, and fire-free sites in all 
three of the major rockland areas in south Florida (Snyder et al. 1990, 
p. 239). Mesic hammocks are also considered fire resistant in that many 
occur as ``islands'' on high ground within basin or floodplain 
wetlands, as patches of oak/palm forest in dry prairie or flatwoods 
communities, on river levees, or in ecotones between wetlands and 
upland communities, and possess high-moisture soils due to heavy 
shading of the ground layer and accumulation of litter (FNAI 2010, p. 
20). Additionally, wildfires are now considered a minor stressor in 
mesic hammocks because of the use of prescribed burns within the last 
15 years (Werner 2013d, pers. comm.).
    Snyder (et al. 1990, p. 238) points out that the high organic 
content of hammock soils in south Florida can enable the soil to burn; 
however, soil fires typically only burn in hammocks in times of drought 
or when fires are intentionally set (Snyder et al. 1990, pp. 258-260). 
This stressor is considered minimal in that fires typically will go out 
when they reach hammock margins, whether entering from pineland or some 
other community due to the presence of hardwood leaf litter lying 
directly on moist organic soil with minimal herbaceous fuel.
    Although wildfires are known to occur in Miami-Dade and Sumter 
Counties, they are not currently considered a threat at this time due 
to regional prescribed burn efforts that help minimize the occurrence 
of wildfires, the natural fire-resistant features of these two 
habitats, and, in Sumter County, hydric hammock (less likely to burn) 
surrounding Trichomanes punctatum ssp. floridanum populations.
Public Use/Encroachment
    In Miami-Dade County, two of the four hammocks containing 
Trichomanes punctatum ssp. floridanum (Castellow and Hattie Bauer) are 
accessible to the public. However, in both cases, T.p. ssp. floridanum 
is not accessible from the nature trail (Possley 2013g, pers. comm.). 
If public use were to increase significantly at any of the Miami-Dade 
hammocks, populations of T.p. ssp. floridanum could become at risk. For 
example, because the taxon grows along the rim and walls of solution 
holes, people climbing into these holes could damage existing 
populations; increased use could also introduce additional nonnative 
seed sources into the habitat. Similarly, climbing on boulders where 
the fern occurs in Sumter County could also cause damage. However, due 
to the low amount of visitation at the Withlacoochee State Forest 
(Werner 2013b-c, pers. comm.), public use and encroachment do not 
appear to be occurring at this time, and we have determined they do not 
pose a threat to T.p. ssp. floridanum.
Small Population Size Effects and Isolation
    Small, isolated populations are more susceptible to impacts 
overall, and relatively more vulnerable to extinction due to genetic 
problems, demographic and environmental fluctuations, and natural 
catastrophes (Primack 1993, p. 255). That is, the smaller a population 
becomes, the more likely it is that one or more stressors could impact 
a population, potentially reducing its size such that it is at 
increased risk of extinction. Although robust population viability 
analyses (including minimum viable population calculations) have not 
been conducted for this subspecies, indications are that most existing 
populations are minimal in terms of abundance and size. Lack of 
dispersal between occurrences also contributes to the low resilience 
for this subspecies (see ``Habitat Fragmentation'' under Factor A).

[[Page 60462]]

    Limited genetic variability will also impact Trichomanes punctatum 
ssp. floridanum populations. The ability of a species to adapt to 
environmental change is dependent upon genetic variation, a property of 
populations that derives from its members possessing different forms 
(i.e., alleles) of the same gene (Primack 1998, p. 283). High genetic 
diversity can enhance a species' persistence in a changing environment 
(Lynch and Lande 1993, pp. 246-247). Although Trichomanes punctatum 
ssp. floridanum can grow in clusters, separate clusters are not 
necessarily different individuals, as they may have been connected by 
one or more stems in the past (Possley 2014b, pers. comm.). Thus, a 
population of T.p. ssp. floridanum containing many clusters may not 
have greater genetic diversity than a population with few clusters. 
Because there are only six extant populations of T.p. ssp. floridanum, 
each with few plants, the genetic variability is considered low, and 
the subspecies is inherently at greater risk from stochastic events and 
changes in environmental conditions (Matthies et al. 2004, pp. 481-
488).
    In summary, Trichomanes punctatum ssp. floridanum is impacted by 
factors such as small population size, vulnerability to random 
demographic fluctuations or natural catastrophes, and low genetic 
diversity, which is further magnified by synergistic (interaction of 
two or more components) effects with other threats, such as those 
discussed above. In evaluating the stressor of small population size 
effects on Trichomanes punctatum ssp. floridanum, we reviewed the 
limited data available concerning abundance at each of the occurrences 
across the subspecies' range. This represents a conservative 
classification of small population size, as available data do not 
discriminate among individual plants and life-history stages. 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 extirpation from one location occurs.
Conservation Efforts To Reduce Other Natural or Manmade Factors 
Affecting Its Continued Existence
    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 publically owned 
properties at least once a year and more often in many cases. Annual 
monitoring of Trichomanes punctatum ssp. floridanum is conducted by 
Fairchild, which records health and size of individual clusters of the 
subspecies along with potential new stressors, including nonnative, 
invasive species or habitat destruction; reports are forwarded to the 
County preserve managers for further attention (Possley 2013l, pers. 
comm.). IRC also conducts research and monitoring in multiple hammocks 
within Miami-Dade County for various rare and endangered plant species. 
Nonnative, invasive species are documented, along with any occurrence 
of human disturbance (van der Heiden 2013i, pers. comm.). In Sumter 
County, the Florida Park Service surveys each State-owned property at 
least once a year to manage for nonnative plants (Werner 2013a-b, pers. 
comm.). Furthermore, Withlacoochee State Forest conducts prescribed 
burning on an annual basis, controlling regional wildfires in dry 
swamps and mesic hammocks.
    Continuing efforts to propagate Trichomanes punctatum ssp. 
floridanum in-vitro may eventually lead to the establishment of healthy 
populations that can be reintroduced in locations where the taxon once 
occurred or introduced to new areas deemed appropriate. These efforts 
can assist with combating potential or realized impacts from natural 
stochastic events that may harm or destroy existing populations.
Summary of Factor E
    Stochastic events resulting in changes in canopy structure and 
environmental conditions within the taxon's current habitat are 
considered threats to existing and future populations of T.p. ssp. 
floridanum. Droughts, tropical storms, and hurricanes are common 
occurrences in Florida, and changes associated with these events have 
the potential to limit reproduction and compromise overall health in 
the long term, making plants more vulnerable to other stressors (e.g., 
periodic, long-term droughts, hurricanes) or causing extirpations. As 
few populations remain, the entire taxon is at risk of extinction 
during these events. Climatic changes, including SLR, are longer term 
concerns expected to exacerbate existing impacts and ultimately reduce 
the extent of available habitat for T.p. ssp. floridanum.
    The presence of nonnative species, including other plants and feral 
hogs, is also a threat, but may be reduced on public lands due to 
active programs by Miami-Dade County and the State. The majority of the 
remaining populations of this plant are small and geographically 
isolated, and genetic variability is likely low, increasing the 
inherent risk due to overall low resilience of this subspecies. 
Furthermore, the isolated existence of Trichomanes punctatum ssp. 
floridanum makes natural recolonization of extirpated populations 
virtually impossible without human intervention. Although considered 
stressors, wildfires and public use at extant sites are minimal and do 
not rise to the level of a threat.

Cumulative Effects of Threats

    When two or more threats affect Trichomanes punctatum ssp. 
floridanum occurrences, 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 T.p. ssp. floridanum make 
it 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 this taxon, as discussed 
above, range from local (e.g., hydrology changes, agriculture) to 
regional (e.g., development, fragmentation, nonnative species) to 
global influences (e.g., climate change, SLR). 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 T.p. ssp. floridanum, making this 
subspecies more vulnerable.

Determination

    We have carefully assessed the best scientific and commercial data 
available regarding the past, present, and future threats to 
Trichomanes punctatum ssp. floridanum. T.p. ssp. floridanum has been 
extirpated from the majority of its historical range, and the primary 
threats of habitat destruction and modification resulting from human 
population growth and development, agricultural conversion, regional 
drainage, and resulting changes in canopy and hydrology (Factor A); 
competition from

[[Page 60463]]

nonnative, invasive species (Factor E); changes in climatic conditions, 
including sea level rise (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 subspecies from these factors (see Factor D discussion). These 
threats are ongoing, rangewide, and expected to continue in the future. 
Populations of T.p. ssp. floridanum are relatively small and isolated 
from one another, and their ability to recolonize suitable habitat is 
unlikely without human intervention. Because of the current condition 
of the extant populations and life-history traits of the subspecies, it 
is vulnerable to natural or human-caused changes in its currently 
occupied habitats. The threats have had and will continue to have 
substantial adverse effects on T.p. ssp. floridanum and its habitat. 
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, this plant is currently at risk throughout all of its 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 the subspecies in danger of 
extinction. The risk of extinction is high because the populations are 
small, isolated, and have limited to no capacity 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 this subspecies. Furthermore, natural stochastic events and changes 
in climatic conditions pose a threat to the persistence of the 
subspecies, especially because mitigation measures have yet to be 
developed. Individually and collectively, all of these threats can 
contribute to the local extirpation and potential extinction of this 
subspecies. Because these threats are placing this subspecies in danger 
of extinction throughout its range, we have determined this plant meets 
the definition of an endangered species. Therefore, on the basis of the 
best available scientific and commercial information, we are listing 
Trichomanes punctatum ssp. floridanum as an endangered species in 
accordance with sections 3(6) and 4(a)(1) of the Act. We find that a 
threatened species status is not appropriate for T.p. ssp. floridanum 
because of the contracted range of the subspecies and because the 
threats are occurring rangewide, are currently acting on the subspecies 
at a high intensity, and are expected to continue into the future.

Significant Portion of the Range

    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. Because we have determined that 
Trichomanes punctatum ssp. floridanum is an endangered species 
throughout all of its range, no portion of its range can be 
``significant'' for purposes of the definitions of ``endangered 
species'' and ``threatened species.'' See the Final Policy on 
Interpretation of the Phrase ``Significant Portion of Its Range'' in 
the Endangered Species Act's Definitions of ``Endangered Species'' and 
``Threatened Species'' (79 FR 37578, July 1, 2014).

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened species 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 requires that recovery actions be carried out for all 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 requires 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 develop a 
recovery plan. The plan may be revised to address continuing or new 
threats to the species, as new substantive information becomes 
available. The recovery plan identifies recovery criteria for review of 
when a species may be ready for downlisting (from endangered species to 
threatened species) 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. When 
completed, the draft and final recovery plans 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.
    Following publication of this final listing rule, 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 
will be eligible for Federal funds to implement management actions that 
promote the protection or recovery of Trichomanes punctatum ssp. 
floridanum. Information on our grant programs that are available to aid 
species recovery can be found at: http://www.fws.gov/grants.

[[Page 60464]]

    Please let us know if you are interested in participating in 
recovery efforts for Trichomanes punctatum ssp. floridanum. 
Additionally, we invite you to submit any new information on this 
subspecies 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 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 any endangered or threatened species or destroy 
or adversely modify its critical habitat. If a Federal action may 
affect a listed species or its critical habitat, the responsible 
Federal agency must enter into consultation with the Service.
    Federal agency actions within the species' habitat that may require 
conference or consultation, or both, as described in the preceding 
paragraph, include, but are not limited to, federally funded or 
authorized actions such as habitat restoration and control of 
nonnatives management and any other landscape-altering activities on 
Federal lands administered by the U.S. Fish and Wildlife Service; 
issuance of section 404 Clean Water Act permits by the Army Corps of 
Engineers; and construction and maintenance of roads or highways by the 
Federal Highway Administration.
    With respect to endangered plants, 50 CFR 17.61 makes 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 contained in 50 CFR 
17.62.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered plants under certain circumstances. Regulations 
governing permits are codified at 50 CFR 17.62. 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 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 listing on 
proposed and ongoing activities within the range of a listed species. 
The following activities could potentially result in a violation of 
section 9 of the Act. This list is not comprehensive:
    (1) Import the subspecies into, or export the subspecies from, the 
United States without authorization;
    (2) Remove and reduce to possession the subspecies from areas under 
Federal jurisdiction; maliciously damage or destroy the subspecies on 
any such area; or remove, cut, dig up, or damage or destroy the 
subspecies 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) Sell or offer for sale in interstate or foreign commerce the 
subspecies; except for properly documented antique specimens of the 
taxon at least 100 years old, as defined by section 10(h)(1) of the 
Act;
    (4) Unauthorized delivering, carrying, or transporting of the 
subspecies, including import or export across State lines and 
international boundaries;
    (5) Introduction of nonnative species that compete with or prey 
upon Trichomanes punctatum ssp. floridanum;
    (6) Unauthorized release of biological control agents that attack 
any life stage of this subspecies; and
    (7) Unauthorized manipulation or modification of the habitat where 
Trichomanes punctatum ssp. floridanum is present on Federal lands 
including, but not limited to, unauthorized water withdrawal from 
solution holes and unauthorized removal of canopy.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the South 
Florida Ecological Services Field Office (see FOR FURTHER INFORMATION 
CONTACT).

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 that such areas are essential for the 
conservation of the species.'' Section 3(3) of the Act (16 U.S.C. 
1532(3)) also defines the terms ``conserve,'' ``conserving,'' and 
``conservation'' to mean ``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 this chapter are no longer necessary.''

Prudency Determination

    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 shall 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, because we determined that the 
designation of critical habitat will not likely increase the degree of 
threat to the species and may provide some measure of benefit, we 
determined that designation of critical habitat is prudent for 
Trichomanes punctatum ssp. floridanum.

Critical Habitat Determinability

    Having determined that designation is prudent under section 4(a)(3) 
of the Act, we must find whether critical habitat for Trichomanes 
punctatum ssp. floridanum is determinable. 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

[[Page 60465]]

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.
    In our proposed listing rule, we found that critical habitat was 
not determinable because a careful assessment of the economic impacts 
that may occur due to a critical habitat designation was still ongoing, 
and we were still in the process of acquiring the information needed to 
perform that assessment. We have recently received new data on suitable 
habitat for T. p. ssp. floridanum in Sumter County, which has caused us 
to begin reassessing which specific features and areas are essential 
for the conservation of the species and, therefore, meet the definition 
of critical habitat. Consequently, a careful assessment of the new 
biological information is still ongoing, and we are still in the 
process of acquiring the information needed to perform that assessment. 
The information sufficient to perform a required analysis of the 
impacts of the designation is lacking, and therefore, we find 
designation of critical habitat to be not determinable at this time. 
Accordingly, we will publish a proposed critical habitat rule when we 
finish our assessment of the new biological information.

Required Determinations

National Environmental Policy Act

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act (42 U.S.C. 4321 et seq.), 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).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination with Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
tribes in developing programs for healthy ecosystems, to acknowledge 
that tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to tribes. We are not aware of any Trichomanes 
punctatum ssp. floridanum populations on tribal lands.

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--[AMENDED]

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

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


0
2. Amend Sec.  17.12(h) by adding an entry for ``Trichomanes punctatum 
ssp. floridanum'' to the List of Endangered and Threatened Plants in 
alphabetical order under Ferns and Allies to read as follows:


Sec.  17.12  Endangered and threatened plants.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                          Species
------------------------------------------------------------     Historic range              Family          Status      When      Critical     Special
          Scientific name                  Common name                                                                  listed      habitat      rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
          Ferns and Allies
 
                                                                      * * * * * * *
Trichomanes punctatum ssp.           Florida bristle fern..  U.S.A. (FL)...........  Hymenophyllaceae.....        E         859          NA          NA
 floridanum.
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *

    Dated: September 28, 2015.
Stephen Guertin,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-25299 Filed 10-5-15; 8:45 am]
BILLING CODE 4333-15-P