Rule2025-12196
Endangered and Threatened Wildlife and Plants; Removal of the Dwarf-flowered Heartleaf From the List of Endangered and Threatened Plants
Primary source
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Published
July 8, 2025
Effective
August 7, 2025
Issuing agencies
Interior DepartmentFish and Wildlife Service
Abstract
We, the U.S. Fish and Wildlife Service (Service), are removing the dwarf-flowered heartleaf (Hexastylis naniflora) from the Federal List of Endangered and Threatened Plants. After a review of the best available scientific and commercial information, we find that delisting the species is warranted. Our review indicates that the threats to the dwarf-flowered heartleaf have been eliminated or reduced to the point that the species no longer meets the definition of an endangered or threatened species under the Endangered Species Act of 1973, as amended (Act). Accordingly, the prohibitions and conservation measures provided by the Act, particularly through sections 4 and 7, will no longer apply to the dwarf-flowered heartleaf.
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[Federal Register Volume 90, Number 128 (Tuesday, July 8, 2025)]
[Rules and Regulations]
[Pages 30004-30018]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-12196]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2019-0081; FXES11130900000-234-FF09E22000]RIN
1018-BD95
Endangered and Threatened Wildlife and Plants; Removal of the
Dwarf-flowered Heartleaf From the List of Endangered and Threatened
Plants
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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[[Page 30005]]
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are removing
the dwarf-flowered heartleaf (Hexastylis naniflora) from the Federal
List of Endangered and Threatened Plants. After a review of the best
available scientific and commercial information, we find that delisting
the species is warranted. Our review indicates that the threats to the
dwarf-flowered heartleaf have been eliminated or reduced to the point
that the species no longer meets the definition of an endangered or
threatened species under the Endangered Species Act of 1973, as amended
(Act). Accordingly, the prohibitions and conservation measures provided
by the Act, particularly through sections 4 and 7, will no longer apply
to the dwarf-flowered heartleaf.
DATES: This rule is effective August 7, 2025.
ADDRESSES: This final rule is available on the internet at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Comments and materials we received are available
for public inspection at <a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No.
FWS-R4-ES-2019-0081.
Availability of supporting materials: This rule and supporting
documents, including the proposed rule, post-delisting monitoring plan,
and the species status assessment (SSA) report, are available at
<a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No. FWS-R4-ES-2019-0081.
FOR FURTHER INFORMATION CONTACT: Janet Mizzi, Field Supervisor, U.S.
Fish and Wildlife Service, Asheville Ecological Services Field Office;
<a href="/cdn-cgi/l/email-protection#98f2f9f6fdecc7f5f1e2e2f1d8feefebb6fff7ee"><span class="__cf_email__" data-cfemail="4a202b242f3e1527233030230a2c3d39642d253c">[email protected]</span></a>; telephone 828-258-3939. Individuals in the United
States who are deaf, deafblind, hard of hearing, or have a speech
disability may dial 711 (TTY, TDD, or TeleBraille) to access
telecommunications relay services. Individuals outside the United
States should use the relay services offered within their country to
make international calls to the point-of contact in the United States.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Act, a species warrants
removal from the Federal Lists of Endangered and Threatened Wildlife
and Plants if it no longer meets the definition of an endangered
species (in danger of extinction throughout all or a significant
portion of its range) or a threatened species (likely to become an
endangered species within the foreseeable future throughout all or a
significant portion of its range). The dwarf-flowered heartleaf is
listed as threatened, and we are delisting it because we have
determined it does not meet the Act's definition of an endangered or
threatened species. Delisting a species can be completed only by
issuing a rule through the Administrative Procedure Act rulemaking
process (5 U.S.C. 551 et seq.).
What this document does. This rule removes the dwarf-flowered
heartleaf from the Federal List of Endangered and Threatened Plants
based on the species' recovery.
The basis for our action. Under the Act, we may determine that a
species is an endangered species or a threatened species because of 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. The determination to delist a
species must be based on an analysis of the same factors.
Under the Act, we must review the status of all listed species at
least once every 5 years. We must delist a species if we determine, on
the basis of the best available scientific and commercial data, that
the species is neither a threatened species nor an endangered species.
Our regulations at 50 CFR 424.11(e) identify four reasons why we might
determine a species shall be delisted: (1) The species is extinct, (2)
the species has recovered to the point at which it no longer meets the
definition of an endangered species or a threatened species, (3) new
information that has become available since the original listing
decision shows the listed entity does not meet the definition of an
endangered species or a threatened species, or (4) new information that
has become available since the original listing decision shows the
listed entity does not meet the definition of a species. Here, we have
determined that the dwarf-flowered heartleaf has recovered to the point
at which it no longer meets the definition of an endangered species or
a threatened species; therefore, we are delisting it.
Previous Federal Actions
Please refer to the proposed rule to delist the dwarf-flowered
heartleaf published on April 26, 2021 (86 FR 21994), for a detailed
description of previous Federal actions concerning this species.
Peer Review
A species status assessment (SSA) team prepared an SSA report for
the dwarf-flowered heartleaf. The SSA team was composed of Service
biologists, in consultation with other species experts. The SSA report
represents a compilation of the best scientific and commercial data
available concerning the status of the species, including the impact of
past, present, and future factors (both negative and beneficial)
affecting the species.
In accordance with our joint policy on peer review published in the
Federal Register on July 1, 1994 (59 FR 34270), and our August 22,
2016, memorandum updating and clarifying the role of peer review in
listing and recovery actions under the Act, we solicited independent
scientific review of the information contained in the dwarf-flowered
heartleaf SSA report. As discussed in the proposed rule, we sent the
SSA report to seven independent peer reviewers and received no
responses.
Summary of Changes from the Proposed Rule
In this final rule, we make no substantive changes to our April 26,
2021 (86 FR 21994), proposed rule. Minor, non-substantive changes have
been made throughout this final rule.
Summary of Comments and Recommendations
In the proposed rule published on April 26, 2021 (86 FR 21994), we
requested that all interested parties submit written comments on the
proposal by June 25, 2021. We also contacted appropriate Federal and
State agencies, Tribal entities, 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 Charlotte Observer and the Spartanburg Herald Journal.
We did not receive any requests for a public hearing. All substantive
information received during the comment period has either been
incorporated directly into this final determination or is addressed
below.
State Agency Comments
(1) Comment: The South Carolina Department of Natural Resources
(SCDNR) commented that delisting dwarf-flowered heartleaf is premature.
The SCDNR found that the SSA report presented: (1) flawed data on the
number of populations and range, in part because of ongoing taxonomic
research, but also because there are no recent observations of 41 (34
percent) of the reported 119 populations; and (2)
[[Page 30006]]
insufficient consideration of future threats in a rapidly growing
development area of South Carolina.
Our Response: Based on North Carolina Natural Heritage Program
(NCNHP) and South Carolina Heritage Trust Program data, the species
consists of 119 populations distributed across 13 counties in North and
South Carolina. The total number of populations was derived from
element occurrence (E.O.) data from the Natural Heritage Programs
(NHP). NHPs collect information on occurrences of rare plants, animals,
natural communities, and animal assemblages. Collectively, these are
referred to as ``elements of natural diversity'' or simply as
``elements.'' Specific occurrences of the elements are referred to as
``element occurrences''. For our analysis, we used population size as
the main driver of population resilience. E.O. data included a wide
range of years since the species was last observed at a given location
(1964-2017), although recent data and reports indicate the species
consists of 119 populations, some of that data is outdated. For the
purposes of this analysis, we only used EOs that were observed since
2005. We did this for several reasons. First, we did not want to assume
a population was still present if it had not been observed recently.
Second, we wanted to be consistent in what we considered ``current''
for both categorizing resilience and use in the habitat model. Third,
experts concurred that records as old as 12 years are still likely to
persist (number of years between 2005 and the SSA). Finally, there was
a natural data break in 2005, coinciding with the year the last 5-year
review was initiated. It is important to note that many of the
populations that were excluded from the analysis may still persist on
the landscape. In fact, many EOs for this species have persisted for
decades, despite not having intervening surveys to confirm their
persistence. Based on the exclusion of pre-2005 EOs, we considered a
conservative estimate of 78 populations distributed across the range of
dwarf-flowered heartleaf, although this may be an underestimate as
discussed above. We therefore used the best available scientific and
commercial data in our analyses.
With regard to any ongoing taxonomic research, any information
related to a taxonomic change is unpublished, and a new species has not
yet been described. Surveys conducted and reports completed by
Appalachian State University, referenced by SCDNR, were considered, and
are cited in the SSA report. An update to these studies has not been
provided. The Act requires the use of the best available scientific and
commercial information, but if that information is not available, it
cannot be incorporated into decision analyses or rules.
Our implementing regulations provide further guidance on whether a
particular taxon or population is a species or subspecies for the
purposes of the Act; under 50 CFR 424.11(a), the Service shall rely on
standard taxonomic distinctions and the biological expertise of the
Department of the Interior and the scientific community in determining
whether a particular taxon or population is a species for the purpose
of the Act. For our analysis, we assumed all EOs are dwarf-flowered
heartleaf (Hexastylis naniflora), which represents the best currently
available scientific and commercial data.
In response to the concern about potential future development in
South Carolina, our level of analysis for urbanization was consistent
throughout the range, and North Carolina and South Carolina were
included in the same analysis using the same standard data. We used
Slope, Land cover, Exclusion, Urbanization, Transportation, and
Hillshade (SLEUTH) data which incorporates the most recently available
information. We used three scenarios, projected out to the year 2040,
to capture the uncertainty related to the potential impacts to each
population's resiliency: status quo, targeted conservation, and high
development. Results of future projections within each scenario are
focused on current populations and potential habitat identified by the
maximum entropy (Maxent) model. Based on the life span of the species,
expert input, identification of development as the key risk factor
brought forward, uncertainty about future conditions, and lack of
knowledge about where additional populations may persist on the
landscape, we chose to project populations out to the year 2040 under
each scenario. We therefore thoroughly considered future threats of
development in our SSA report.
Public Comments
We reviewed all public comments for substantive issues and new
information regarding the species. Substantive comments we received
during the comment period are addressed below.
(2) Comment: One commenter indicated that the dwarf-flowered
heartleaf does not compete well with disturbance caused by
deforestation and suburbanization, yet many of the known populations
are facing encroaching development. Based upon unpublished data, the
commenter suggested that the decision to delist dwarf-flowered
heartleaf should be postponed for 2 years to allow the biodiversity
community to assess current knowledge. The commenter stated that
delisting now would increase the likelihood that certain areas would be
developed, and these habitats would be lost to any future efforts to
conserve the species and their genetic diversity.
Our Response: We are unable to delay our decision for 2 years
because we are required to make our determination whether a species
meets the definition of an endangered species or a threatened species
based on the best scientific and commercial data available at the time
of our rulemaking. Delisting a species does not prevent continued
research on a species, and all delisted species, including dwarf-
flowered heartleaf, are required to have a post-delisting monitoring
(PDM) plan. The PDM plan is used to verify that the dwarf-flowered
heartleaf remains secure from the risk of extinction after delisting.
The PDM plan was developed to ensure consistent reporting and as a
coordinating mechanism with conservation land entities.
In response to the commenter's concerns about development, we
included our analysis of dwarf-flowered heartleaf viability from the
SSA report in the proposed rule. Our analysis included habitat change
related to development, and we used projections of urban development to
assess this threat. Because impacts of urbanization are multi-faceted
and uncertain, we used three future scenarios to capture potential
impacts to species resiliency (status quo, targeted conservation, and
high development). Results of future projections within each scenario
were focused on current populations and potential habitat identified by
a Maxent model.
We used SLEUTH models to identify areas of urbanization in 2040.
Urban development was predicted to have negative impacts on several
current populations under all future scenarios. However, any
extirpation or loss of resiliency within individual populations was
offset by populations found to persist in the status quo and targeted
conservation scenarios. In the high development scenario, there was a
predicted loss of 6 populations (78 populations currently compared with
72 populations in 2040), with resiliency loss in several additional
populations. Regardless of scenario, the majority of the populations
expected to persist on the landscape in 2040 were of at least moderate
resiliency. Furthermore, given the relatively high number of
[[Page 30007]]
populations in at least moderate resiliency across each scenario,
redundancy remained similar to current conditions. Therefore, there
appears to be adequate resiliency and redundancy within the range of
dwarf-flowered heartleaf to withstand the impacts of urbanization into
the foreseeable future.
The overwhelming majority of dwarf-flowered heartleaf populations
have been discovered as a direct result of surveys conducted to ensure
compliance with the Act. We prepared the PDM plan, with input from the
NCNHP and the North Carolina Department of Transportation (NCDOT),
based largely on monitoring methods developed in March 2012 during a
field coordination meeting (Robinson and Padgett 2016, entire). This
plan is designed to detect substantial declines in dwarf-flowered
heartleaf occurrences with reasonable certainty and precision. Dwarf-
flowered heartleaf occurs mainly on private lands with a few
populations on public lands. NCNHP and NCDOT have monitored 25 of the
largest populations for at least 5 years to collect baseline data
(Service 2019, entire). As staff resources and funding allow, we expect
that current efforts to monitor and manage lands containing populations
of dwarf-flowered heartleaf will continue. The final PDM plan for the
species can be found at <a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No.
FWS-R4-ES-2019-0081.
(3) Comment: One commenter stated the Service should not delist the
dwarf-flowered heartleaf because it is a narrow endemic species found
only on a few soil types, soils that occur along streams, in bogs, and
on low bluffs.
Our Response: Narrow endemism, by itself, is not a basis for
determining that a species meets the definition of an endangered
species or a threatened species. Our analysis of the best available
scientific and commercial data indicate that the dwarf-flowered
heartleaf does not meet the definition of either an endangered species
or a threatened species. There has been a nearly four-fold increase in
the number of known populations since listing and the two prominent
threats identified--invasive, exotic species and habitat loss or
destruction--are not as significant as originally thought. Despite the
limited range of this species, threats have been eliminated or reduced
to the point that the dwarf-flowered heartleaf no longer meets the
definition of a threatened species or endangered species under the Act.
(4) Comment: One commenter indicated that there have been
suggestions that this species should be lumped with Hexastylis
heterophylla and perhaps H. virginiana. This classification would
artificially broaden its range while dismissing population differences.
It would make this species appear to be no longer threatened. The
cluster of closely related species is what would be expected when
populations have been isolated into groupings that no longer share a
gene pool. In this isolation, populations mutate, and a process of
speciation begins. It is the commenter's understanding that a recent
study has indicated that Hexastylis naniflora is in fact limited in
range to South Carolina and a southern portion of North Carolina and
that the plants in other North Carolina counties are in fact a
different species. The delisting proposal relies heavily upon the
existence of populations of the other species and protected populations
of the other species.
Our Response: Dwarf-flowered heartleaf was described by Blomquist
(1957, entire) in his revision of the North American members of the
genus Hexastylis. The dwarf-flowered heartleaf has been recognized as
part of the Virginica group, and this group was further subdivided into
three subgroups or complexes: Virginica, Shuttleworthii, and
Heterophylla (Blomquist 1957, pp. 8:255-281; Whittemore and Gaddy 1997,
pp. 3:54-58). Three species have been recognized in the Heterophylla
complex, Hexastylis naniflora, H. heterophylla, and H. minor; and field
biologists have generally recognized that considerable morphological
overlap occurs (Murrell et al. 2007, entire). Our analysis only
included EOs identified as H. naniflora and did not consider grouping
the species with any others in the Virginica group, subgroups, or
complexes. Thus, contrary to the commenter's statement, our
determination to delist the species was based only on EOs identified as
H. naniflora. Analyses on ecology, morphology, soil chemistry, pollen,
and molecular genetics have been evaluated for Hexastylis naniflora to
determine the boundaries within the Heterophylla complex (Murrell 2015,
entire; Wagner 2013, entire; Niedenberger 2010, entire; Service 2010 p.
10; Murrell et al. 2007, entire; Padgett 2004, entire). These analyses
support the continued recognition of these taxa as well-defined,
discrete species. The Service relies on standard taxonomic distinctions
and the scientific community in determining whether a particular taxon
or population is a species of the Act.
(5) Comment: One commenter stated that delisting this species is
contrary to the Act, does not acknowledge the substantial threats to
the continued existence of this species, ignores existing science, and
fails to obtain additional evidence needed to determine what action
should be taken with respect to the listing of the species. This
commenter further stated that contrary to the clear requirements of the
Act, it appears that the proposal to delist dwarf-flowered heartleaf
was the result of the U.S. Fish and Wildlife Service Southeast Region
emphasis on removal of protections for the species. This commenter
referred to a 2017 Southeast Region goal to delist, downlist, or
preclude the need for listing of 30 species per year as a quota system
that incentivizes decisions on species status based on meeting
arbitrary objectives, rather than evaluating a species' status based on
the best available science as required under the Act. This commenter
also stated that the best available scientific evidence is not a part
of the Service's analysis or proposal, and that the Service has not
initiated studies to determine the genetics of the populations.
Our Response: The NCNHP assessed threats to populations of dwarf-
flowered heartleaf they monitored from 2012-2016 (Robinson and Padgett
2016, pp. 7-8, 17-20). Threats that were observed, inferred, or
suspected to have an impact on populations were recorded and assigned a
ranking based on their severity, scope, and immediacy from field
observations. The rank (A to G) for each threat factor determined an
overall value for each threat observed at each population. Threats
observed during these years included development, incompatible forestry
practices, agriculture, trampling, invasive exotic species,
sedimentation, erosion, and road construction. Despite threats observed
in many of the populations surveyed, several of the populations
appeared to be stable during the 5-year survey period and no
significant changes in threats within populations were noted between
2012 and 2016. The SSA incorporated the best available scientific and
commercial data to characterize viability as the ability of a species
to sustain populations in the wild over time. We utilized this
information to inform our decision in the proposed rule and in this
final rule.
Since 2012, when our Ecological Services program in the Southeast
Region initiated its At-Risk Species initiative, we have placed an
increased emphasis on recovering species listed as threatened and
endangered under the Act and preventing the need to list at-risk
species through collaborative conservation. Our goal was to conserve 30
species by implementing proactive conservation actions that result in
[[Page 30008]]
downlisting or delisting species under the Act or precluding the need
to list these species under the Act. While the Southeast Region no
longer uses this specific metric as its goal, we continue to work
cooperatively with partners to recover species. In accordance with the
Act, all of our decisions are based on the best available scientific
and commercial data.
The determination to delist the dwarf-flowered heartleaf is based
on a thorough review of the best available scientific and commercial
data, which indicate that the threats to the species have been
eliminated or reduced to the point that the species no longer meets the
definition of a threatened species or endangered species under the Act.
(6) Comment: One commenter stated that removing dwarf-flowered
heartleaf from the protections of the Act will have an increased impact
on the plant in Greenville County, South Carolina. This commenter
stated that currently, under Greenville County's land development
regulations, the County Planning Commission and its staff reject or
require modifications of subdivision plans that impact rare plants and
their habitat. Last year, the commission rejected a proposed
development on Enoree Road in Travelers Rest which would have been
built over dwarf-flowered heartleaf and its habitat. They noted that
listing of this species was essential to protecting those plants.
Our Response: In the SSA report, urban development was predicted to
have negative impacts on several of the current populations under all
of our future scenarios. However, this loss of resilience and
extirpation of several populations was offset by the fact that several
populations were found to persist in the status quo and targeted
conservation scenarios. In the high development scenario, there was a
predicted loss of six populations, with loss of resilience in several
additional populations. Regardless of the scenario, the majority of the
populations on the landscape in 2040 exhibit high or moderate
resilience.
(7) Comment: The commenter expressed concern about the growing
impacts of climate change. These plants are in wet forests, near
waterbodies, and sometimes at the base of mature trees. The commenter
noted that changing climate will affect rain patterns, hydrology, and
forests. The commenter expressed concern that dwarf-flowered heartleaf
does not spread rapidly or grow rapidly, and are not well suited to
deal with changes in their environment or their forests. The commenter
further noted recent extended droughts, and a bad drought across the
region would have very negative consequences for this species.
Our Response: We considered the effects of increased drought in our
future scenarios, and the SSA identified the effects are likely related
to changes in soil moisture associated with potential increases in
drought. The broadened range (from 8 to 13 counties) and significantly
increased numbers of populations (24 to 78) since listing in 1989
contribute to the species' redundancy and resiliency that we find to be
sufficient to withstand perturbations from the potential increases in
drought in the foreseeable future.
Background
A thorough review of the taxonomy, life history, ecology, and
overall viability of the dwarf-flowered heartleaf is presented in the
SSA report on <a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No. FWS-R4-ES-
2019-0081. A summary of that information is presented here.
Dwarf-flowered heartleaf is a plant species endemic to the upper
Piedmont region of western North Carolina and upstate South Carolina.
It is a low-growing herbaceous plant in the birthwort family
(Aristolochiaceae). Although dwarf-flowered heartleaf is restricted in
range, it is not as rare as once thought (Service 2010, p. 15; NCNHP
2016, p. 4). When dwarf-flowered heartleaf was federally listed in
1989, the listing rule described 24 extant populations (and 1
extirpated population) distributed across 8 counties in the upper
Piedmont region of North and South Carolina. By 2018, the distribution
of this species may have been as high as 119 populations distributed
across 13 counties in both states. In North Carolina, it is found in
Alexander, Burke, Caldwell, Catawba, Cleveland, Gaston, Iredell,
Lincoln, Polk, and Rutherford Counties. In South Carolina, it is found
in Cherokee, Greenville, and Spartanburg Counties.
Dwarf-flowered heartleaf is historically known to have a restricted
range due to its habitat requirements. The habitat where dwarf-flowered
heartleaf exists is limited in size and scope due to a multitude of
factors including soil type, moisture availability, and slope aspect
(Padgett 2004, p. 81). This unique combination of factors limits not
only the range of dwarf-flowered heartleaf, but also the size of any
population.
Dwarf-flowered heartleaf occurs in Piedmont uplands on acidic
sandy-loam soils that are very deep and moderately permeable (Gaddy
1981, p. 7; 1987, pp. 186-196). Typical habitats for this species
include mesic to dry bluffs, slopes, or ravines in deciduous forests
that are frequently associated with mountain laurel (Kalmia latifolia)
(Padgett 2004, p. 114; Weakley 2015, p. 129; Service 2015, entire), or
in moist soils adjacent to creeks or streamheads, or along lakes and
rivers. Plants grow larger and have more frequent flowering in
floodplains along rivers, lakes, and streams (Newberry 1993, entire).
In 2013, a habitat suitability study was conducted to quantify the
habitat requirements for dwarf-flowered heartleaf, which may be used to
help identify the species when not in flower (relative to other
Hexastylis species' habitat preferences), find new populations, or
identify suitable sites for transplants (Wagner 2013, pp. 30-32). The
unit of measurement for population size in this species is a ``clump''
(rosette).
Recovery Criteria
A recovery plan for the dwarf-flowered heartleaf was not prepared;
therefore, specific delisting criteria were not developed for the
species. The North Carolina Plant Conservation and Protection Act (NC
Gen Stat section 106-202.12 (2022)) provides limited protection from
unauthorized collection and trade of plants listed under that statute.
However, this statute does not protect the species or its habitat from
destruction in conjunction with development projects or otherwise legal
activities. In South Carolina, plants are protected only from
disturbance where they occur on those properties owned by the State and
specifically managed as South Carolina Heritage Preserves (SC Code
section 51-17-80 (2023)). There are no other Federal or State statutes
that afford significant protections to dwarf-flowered heartleaf.
The majority of sites that have the potential to afford long-term
protection to the species have been protected as a direct result of the
provisions of section 7 of the Act. Through section 7 and voluntary
conservation actions, approximately 24 of the 78 populations are
permanently protected, and another 18 populations are partially
protected, greatly minimizing the likelihood of impacts due to
development. Additionally, tens of thousands of dwarf-flowered
heartleaf plants are conserved through a voluntary agreement with Duke
Energy along the Broad River. Another population is conserved at
Cowpens National Battlefield, managed by the U.S. National Park
Service, in upstate South Carolina. A third population is part of the
Broad River Greenway, a local park in North Carolina's Cleveland
County.
[[Page 30009]]
Furthermore, Foothills Conservancy, Catawba Lands Conservancy, and The
Nature Conservancy all protect sites with dwarf-flowered heartleaf
plants. The NCDOT is one of the greatest contributors to conservation
of the species, acquiring land and conserving multiple populations over
the years, including the land that became part of Cleveland County's
Broad River Greenway.
Regulatory and Analytical Framework
Regulatory Framework
Section 4 of the Act (16 U.S.C. 1533) and the implementing
regulations in title 50 of the Code of Federal Regulations set forth
the procedures for determining whether a species is an endangered
species or a threatened species, issuing protective regulations for
threatened species, and designating critical habitat for endangered and
threatened species. On April 5, 2024, jointly with the National Marine
Fisheries Service, the Service issued a final rule that revised the
regulations in 50 CFR part 424 regarding how we add, remove, and
reclassify endangered and threatened species and what criteria we apply
when designating listed species' critical habitat (89 FR 23919). This
final rule is now in effect and is incorporated into the current
regulations. Our analysis for this decision applied our current
regulations. Given that we proposed delisting this species under our
prior regulations (revised in 2019), we have also undertaken an
analysis of whether the decision would be different if we had continued
to apply the 2019 regulations and we concluded that the decision would
be the same. The analyses under both the regulations currently in
effect and the 2019 regulations are available on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
The Act defines an ``endangered species'' as a species that is in
danger of extinction throughout all or a significant portion of its
range, and a ``threatened species'' as a species that is likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range. The Act requires that we
determine whether any species is an endangered species or a threatened
species because of any of the following 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.
These factors represent broad categories of natural or human-caused
actions or conditions that could have an effect on a species' continued
existence. In evaluating these actions and conditions, we look for
those that may have a negative effect on individuals of the species, as
well as other actions or conditions that may ameliorate any negative
effects or may have positive effects. The determination to delist a
species must be based on an analysis of the same five factors.
We use the term ``threat'' to refer in general to actions or
conditions that are known to or are reasonably likely to negatively
affect individuals of a species. The term ``threat'' includes actions
or conditions that have a direct impact on individuals (direct
impacts), as well as those that affect individuals through alteration
of their habitat or required resources (stressors). The term ``threat''
may encompass--either together or separately--the source of the action
or condition or the action or condition itself.
However, the mere identification of any threat(s) does not
necessarily mean that the species meets the statutory definition of an
``endangered species'' or a ``threatened species.'' In determining
whether a species meets either definition, we must evaluate all
identified threats by considering the species' expected response and
the effects of the threats--in light of those actions and conditions
that will ameliorate the threats--on an individual, population, and
species level. We evaluate each threat and its expected effects on the
species, then analyze the cumulative effect of all of the threats on
the species as a whole. We also consider the cumulative effect of the
threats in light of those actions and conditions that will have
positive effects on the species--such as any existing regulatory
mechanisms or conservation efforts. The Secretary determines whether
the species meets the definition of an ``endangered species'' or a
``threatened species'' only after conducting this cumulative analysis
and describing the expected effect on the species.
The Act does not define the term ``foreseeable future,'' which
appears in the statutory definition of ``threatened species.'' Our
implementing regulations at 50 CFR 424.11(d) set forth a framework for
evaluating the foreseeable future on a case-by-case basis which is
further described in the 2009 Memorandum Opinion on the foreseeable
future from the Department of the Interior, Office of the Solicitor (M-
37021, January 16, 2009; ``M-Opinion,'' available online at <a href="https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf">https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf</a>).
The foreseeable future extends as far into the future as the U.S. Fish
and Wildlife Service and National Marine Fisheries Service can make
reasonably reliable predictions about the threats to the species and
the species' responses to those threats. We need not identify the
foreseeable future in terms of a specific period of time. We will
describe the foreseeable future on a case-by-case basis, using the best
available data and taking into account considerations such as the
species' life-history characteristics, threat-projection timeframes,
and environmental variability. In other words, the foreseeable future
is the period of time over which we can make reasonably reliable
predictions. ``Reliable'' does not mean ``certain''; it means
sufficient to provide a reasonable degree of confidence in the
prediction, in light of the conservation purposes of the Act.
Analytical Framework
The SSA report documents the results of our comprehensive
biological review of the best scientific and commercial data regarding
the status of the species, including an assessment of the potential
threats to the species. The SSA report does not represent our decision
on whether the species should be delisted. However, it does provide the
scientific basis that informs our regulatory decisions, which involve
the further application of standards within the Act and its
implementing regulations and policies.
To assess dwarf-flowered heartleaf viability, we used the three
conservation biology principles of resiliency, redundancy, and
representation (Shaffer and Stein 2000, pp. 306-310). Briefly,
resiliency is the ability of the species to withstand environmental and
demographic stochasticity (for example, wet or dry, warm or cold
years); redundancy is the ability of the species to withstand
catastrophic events (for example, droughts, large pollution events),
and representation is the ability of the species to adapt to both near-
term and long-term changes in its physical and biological environment
(for example, climate conditions, pathogen). In general, species
viability will increase with increases in resiliency, redundancy, and
representation (Smith et al. 2018, p. 306). Using these principles, we
identified the species' ecological requirements for survival and
reproduction at the individual, population, and species levels, and
[[Page 30010]]
described the beneficial and risk factors influencing the species'
viability.
The SSA process can be categorized into three sequential stages.
During the first stage, we evaluated individual species' life-history
needs. The next stage involved an assessment of the historical and
current condition of the species' demographics and habitat
characteristics, including an explanation of how the species arrived at
its current condition. The final stage of the SSA involved making
predictions about the species' responses to positive and negative
environmental and anthropogenic influences. Throughout all of these
stages, we used the best available information to characterize
viability as the ability of a species to sustain populations in the
wild over time, which we then used to inform our regulatory decision.
The following is a summary of the key results and conclusions from
the SSA report; the full SSA report can be found at Docket No. FWS-R4-
ES-2019-0018 on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Summary of Biological Status and Threats
In this discussion, we review the biological condition of the
species and its resources, and the threats that influence the species'
current and future condition, in order to assess the species' overall
viability and the risks to that viability. In addition, the SSA report
(Service 2018, entire) documents our comprehensive biological status
review for the species, including an assessment of the potential
threats to the species.
For the dwarf-flowered heartleaf to maintain viability, its
populations or some portion thereof must be resilient. Stochastic
factors that have the potential to affect dwarf-flowered heartleaf
include impacts to its habitat, particularly human development
pressures, but also changes in soil moisture associated with potential
increases in drought and presence of invasive species. Other factors
that influence the resiliency of dwarf-flowered heartleaf populations
include abundance within populations, and habitat factors such as soil
type, aspect, elevation, and land use. Influencing those factors are
elements of dwarf-flowered heartleaf ecology that determine whether
populations can grow to maximize habitat occupancy, thereby increasing
resiliency of populations. The following is a summary of this status
review and the best available scientific and commercial information
gathered since that time that have informed this decision.
The North Carolina Natural Heritage Program (NCNHP) assessed
threats in the populations of dwarf-flowered heartleaf they monitored
from 2012 through 2016 (Robinson and Padgett 2016, pp. 7-8, 17-20).
Threats that were observed, inferred, or suspected to have an impact on
populations were recorded and assigned a ranking based on field
observations of severity, scope, and immediacy. The rank (A through G)
for each threat factor determined an overall value for each threat
observed at each population. Threats observed during these years
included development; incompatible forestry practices; agriculture;
trampling; invasive, exotic species; sedimentation; erosion; and road
construction. In this final rule, we discuss the major threats
affecting the species, which include development, effects of increased
drought and invasive, exotic species. For a detailed discussion of all
threats affecting the species, see the SSA report available on <a href="https://www.regulations.gov">https://www.regulations.gov</a> at Docket No. FWS-R4-ES-2019-0018.
Development
Dwarf-flowered heartleaf populations occur in rapidly growing urban
areas within numerous counties in North and South Carolina. At the time
of listing, the species was determined to be most threatened by habitat
loss due to the conversion of land to residential, commercial, and
industrial use in these areas. Populations occurring in more rural
areas are also threatened by habitat alteration or loss from land
conversion to pasture or other agricultural uses, cattle grazing,
intensive timber harvesting, residential construction, and construction
of small ponds (Robinson 2016, p. 10; Robinson and Padgett 2016, p. 5).
The recent 5-year review for the species identified the most
recurrent source of habitat destruction as road and bridge improvement
projects, which is also the most common trigger for consultations under
section 7 of the Act involving dwarf-flowered heartleaf. Ten of the 27
largest populations (containing more than 1,000 rosettes) have been the
subject of section 7 consultations. Collectively, these projects have
adversely affected or were expected to affect approximately 22,135
rosettes (Service 2018, p. 31). In most cases, the section 7 process
resulted in avoidance or minimization of adverse effects through
relocation of plants and/or commitments of on-site protection.
Significant portions of other populations are located on properties
that have been purchased by NCDOT as off-site conservation measures in
association with these consultations. The purpose of these purchases is
to protect the dwarf-flowered heartleaf.
Other forms of economic development have also resulted in the
destruction or modification of habitats occupied by dwarf-flowered
heartleaf; in many cases, these activities also required section 7
consultations with the Service. Examples include the maintenance or
expansion of hydroelectric and drinking water reservoirs, construction
of an industrial development complex, and maintenance activities at a
regional airport. Collectively, these activities involved the loss or
relocation of several thousand rosettes.
Development was identified as a threat at 5 of 10 North Carolina
populations monitored by NCNHP (Robinson and Padgett 2016, pp. 17-19).
These 5 populations include 2 stand-alone EOs and 3 parent EOs with 18
sub-EOs. Of the 2 stand-alone EOs, 1 has a development threat rank of A
(moderate to severe, imminent threat for most (more than 60 percent) of
population, occurrences, or area) and 1 has a rank of B (moderate to
severe, imminent threat for a significant portion (20-60 percent) of
the population, occurrences, or area). Of the 18 sub-EOs, 9 have
development identified as a threat. Of the nine sub-EOs, one has a
development threat rank of A, one has a rank of B, one has a rank of E
(moderate to severe threat for a small proportion of population,
occurrences, or area), and six have a rank of F (low severity threat
for most or a significant proportion of population, occurrences, or
area). The two stand-alone EOs and two sub-EOs with the highest threat
ranks (A and B) are located in four populations. Based on the most
recent monitoring data, one is increasing, two are stable, and one is
decreasing (Robinson and Padgett 2016, p. 11). Even where development
is ranked as a high threat, impacts to dwarf-flowered heartleaf have
not been shown to be significant.
Development was identified as a threat at one of three South
Carolina populations monitored by NCNHP, and that population has a
development threat rank of E (Robinson and Padgett 2016, p. 20). Based
on the most recent monitoring data, this population is stable (Robinson
and Padgett 2016, p. 11).
The data therefore indicate that most dwarf-flowered heartleaf
populations have either remained stable or increased in the presence of
development. From 2012 to 2016, there were insignificant changes in the
severity of the threat of development observed in the field (NCNHP
2016, p. 8).
The North Carolina Plant Protection and Conservation Act (NC Gen
Stat section 106-202.12 (2022)) lists native
[[Page 30011]]
plants as threatened, endangered, or species of concern, and provides
limited protection from collection and trade of listed plants. However,
this statute does not protect the species or its habitat from
destruction in conjunction with development projects or otherwise legal
activities. In North Carolina, the NCNHP designates ``natural areas'',
which are sites with biological diversity significance due to the
presence of rare species or unique natural communities. The NCNHP works
with many conservation partners (State and Federal agencies,
conservation organization, land trusts, etc.) to implement voluntary
protection. Through partnerships, the most important natural areas are
purchased for permanent conservation. If a natural area is not
available for purchase, ecological significance can be recognized by a
voluntary registry agreement. Registry agreements consist of registered
heritage areas, which are voluntary conservation agreements between the
landowner and NCNHP to preserve the natural area and biological
diversity of the property. The NCNHP has four registry agreements that
include dwarf-flowered heartleaf.
In South Carolina, plants are protected only from disturbance where
they occur on those properties owned by the State and specifically
managed as South Carolina Heritage Preserves (SC Code section 51-17-80
(2023)). Heritage Preserves are protected areas that play a critical
role in conserving rare species and natural habitats. There is one
Heritage Preserve in South Carolina, which protects one population of
the dwarf-flowered heartleaf.
The overwhelming majority of dwarf-flowered heartleaf populations
have been discovered as a direct result of surveys conducted to ensure
compliance with the Act. The majority of sites that have the potential
to afford long-term protection to the species have been protected as a
result of consultations under section 7 of the Act, which directs
Federal agencies to avoid and minimize adverse effects to federally
listed species. Through section 7 and other voluntary conservation
actions, approximately 24 (31 percent) of the 78 current populations
are permanently protected, and another 18 populations (23 percent) are
partially protected, greatly minimizing the likelihood of impacts due
to development. Over 50 percent of dwarf-flowered heartleaf populations
will therefore remain under some form of protective mechanism from the
threat of development in the absence of the Act's protections.
Invasive, Exotic Species
Invasive, exotic plant species occur across the range of this
species. Plants such as English ivy (Hedera helix), Chinese privet
(Ligustrum sinense), Japanese honeysuckle (Lonicera japonica), and
Japanese stiltgrass (Microstegium vimineum) are known at several sites
that contain dwarf-flowered heartleaf (Service 2019 p. 15). Invasive,
exotic species were identified as a threat at 8 of 10 North Carolina
populations monitored by NCNHP (Robinson and Padgett 2016, pp. 17-19).
The 8 populations include 4 stand-alone EOs and 4 parent EOs with 19
sub-EOs. Of the 4 stand-alone EOs, 1 has an invasive threat rank of B
(moderate to severe, imminent threat for a significant portion (20-60
percent) of the population, occurrences, or area), 2 have a rank of F
(low severity threat for most or a significant proportion of
population, occurrences, or area), and 1 has a rank of G (low severity
threat for a small proportion of population, occurrences, or area). Of
the 19 sub-EOs, 9 have invasive, exotic species identified as a threat.
Of these 9 sub-EOs, 1 has an invasive threat rank of A (moderate to
severe, imminent threat for most (more than 60 percent) of population,
occurrences, or area), 4 have a rank of B, 2 have a rank of E (moderate
to severe threat for a small proportion of population, occurrences, or
area), and 2 have a rank of G. The one stand-alone EO and five sub-EOs
with the highest threat ranks (A and B) are located in three
populations. Based on the most recent monitoring data, one EO is
increasing, one is stable, and one is decreasing (Robinson and Padgett
2016, p. 11). Even where invasive, exotic species are ranked as a high
threat, impacts to dwarf-flowered heartleaf have not been shown to be
significant.
Invasive, exotic species were identified as a threat at all (three)
South Carolina populations monitored by NCNHP, and all sites had an
invasive threat rank of F (Robinson and Padgett 2016, p. 20). Based on
the most recent monitoring data, all populations are stable (Robinson
and Padgett 2016, p. 11).
In short, the data indicate that most dwarf-flowered heartleaf
populations have remained stable or increased in the presence of
invasive, exotic species. Despite the long-term presence of invasive,
exotic plants, from 2012 to 2016, there were no changes in the severity
of threats observed in the field significant enough to elevate the
threat ranks of the evaluated dwarf-flowered heartleaf populations
(NCNHP 2016, p. 8).
Climate
Accelerated changes in the environment is expected to increase the
frequency and extent of drought conditions across the southeastern
United States (Karl et al. 2009, entire). Increased frequency of severe
storms could lead to impacts if flooding duration or intensity
increased as a result. Increased flooding could decrease habitat
suitability through scouring and changes in soil moisture or wash
plants away. Warming in the Southeast is expected to be greatest in the
summer (National Climate Change Viewer (NCCV) 2016, unpaginated), which
is predicted to increase drought frequency, while annual mean
precipitation is expected to increase slightly, leading to increased
flooding events (Intergovernmental Panel on Climate Change (IPCC) 2013,
p. 7; NCCV 2016, unpaginated). Changes in climate may affect ecosystem
processes and communities by altering the abiotic conditions
experienced by biotic assemblages, resulting in potential effects on
community composition and individual species interactions (DeWan et al.
2010, p. 7).
In recent years, the Southeast has experienced moderate to severe
droughts, which many observers have implicated in population declines
and poor transplant survivorship (NCNHP 2016, entire). A wildfire
burned portions of one of the largest known populations in 2009
(Foothills Landfill in Caldwell County, NC; Golder and Associates,
2009, entire). However, observation suggests that the species was not
appreciably harmed by this fire (Service 2019 p. 33). Additionally, the
National Park Service (NPS) uses prescribed fire as a vegetation
management tool at Cowpens National Battlefield. The NPS's prescribed
burning activity includes the majority of the dwarf-flowered heartleaf
population on site and burning appears to have had no adverse effects
upon growth or flowering (Walker et al. 2009, p. 14).
Current Condition
Resiliency
For dwarf-flowered heartleaf to maintain viability, its
populations, or some portion thereof, must be resilient. Resiliency is
assessed at the level of populations and reflects a species' ability to
withstand stochastic events (events arising from random factors).
Resilient populations are better able to withstand disturbances such as
random fluctuations in reproductive rates and fecundity (demographic
stochasticity), variations in rainfall (environmental stochasticity),
and the effects of
[[Page 30012]]
anthropogenic activities. Stochastic factors that have the potential to
affect dwarf-flowered heartleaf include habitat impacts; increased
drought; and exotic, invasive species. Factors influencing the
resiliency of dwarf-flowered heartleaf populations include population
size, available habitat, and elements of dwarf-flowered heartleaf
ecology that determine whether populations can maximize habitat
occupancy.
The Natural Heritage Programs (NHP) collect information on
occurrences of rare plants, animals, natural communities, and animal
assemblages. Collectively, these are referred to as ``elements of
natural diversity'' or simply as ``elements.'' In recent years,
NatureServe and its member NHPs have devised mapping standards to
balance the need for fine-scale, highly site-specific element
occurrence (EO) records (required for monitoring and management) with
the need to aggregate these records in meaningful units of conservation
interest that may approximate biological populations (NatureServe 2002
unpaginated). We regard the NHP databases as the best repository for
known locations of the dwarf-flowered heartleaf (Service 2010, p. 41).
Populations are composed of both multiple sub-EOs and stand-alone EO
records. For the purpose of assessing resiliency, 78 populations
observed since 2005 were assessed due to the high confidence in their
persistence. These new populations observed are the result of
additional survey efforts.
To determine overall resiliency for populations, we used EO
viability ranks and expert opinion to bin population size classes into
corresponding resiliency categories. EO viability ranks for the species
include the following categories: excellent, good, fair, poor, extant,
historical, and failed to find. The primary factor in determining these
ranks is EO size (as quantified by number of clumps). Condition of
habitat (vegetation community and structure) and landscape context
(extent of suitable habitat and physical factors) are incorporated
secondarily. Recent reports (Robinson 2016, p. 7; Robinson and Padgett
2016, p. 4) focus monitoring studies on populations with greater than
1,000 individuals (assumed to be very viable). Because we do not have
habitat-level information for every population we assessed, we
synthesized available population size information and created four
resiliency categories as follows:
<bullet> Very high--populations with more than 1,000 individuals;
very high probability of persistence for 20 to 30 years at or above the
current population size.
<bullet> High--populations with 500 to 1,000 individuals;
moderately high probability of persistence for 20 to 30 years at or
above the current population size.
<bullet> Moderate--populations with 100 to 500 individuals; low
probability of persistence for 20 to 30 years at or above the current
population size.
<bullet> Low--populations with fewer than 100 individuals; low
probability of persistence for 20 to 30 years at or above the current
population size, and moderately high probability of extirpation.
Of the 78 populations assessed, 28 have very high resiliency, 5
have high resiliency, 26 have moderate resiliency, and 19 have low
resiliency.
Redundancy
Redundancy is also assessed at the species level and reflects a
species' ability to withstand catastrophic events (such as a rare
destructive natural event or episode involving many populations) by
spreading the risk of such an event across multiple, resilient
populations. We measured redundancy for dwarf-flowered heartleaf by the
number and distribution of resilient populations across the range of
the species. It is important to note that dwarf-flowered heartleaf has
a naturally limited range, so measures of redundancy reflect the
distribution within a relatively small area. Redundancy for dwarf-
flowered heartleaf is the total number and resiliency of population
segments and their distribution across the species' range.
We consider a catastrophe to be any population-level disturbance
with the potential to negatively influence population resiliency
outside of normal environmental and demographic stochasticity.
Disturbances often act quickly and often with devastating effects;
however, they can occur over long periods of time. A disturbance that
occurs as a relatively discrete event in time, such as a hurricane, is
referred to as a ``pulse'' disturbance, while more gradual or
cumulative pressures on a system are referred to as ``press''
disturbances. Both types of disturbances are part of the natural
variability of dwarf-flowered heartleaf ecological systems, and must be
considered when assessing redundancy. While there is certainly a
variety of potential pulse disturbances for the species (timber
harvest, hydrological alterations, road and right-of-way construction),
the primary potential catastrophic disturbances are press disturbances
from increased drought. These press disturbances have great potential
to affect ecosystem processes and communities by altering the
underlying abiotic conditions such as temperature and precipitation
changes (DeWan et al. 2010, pp. 7-10).
Representation
Because we lack genetic and ecological diversity data to
characterize representation for dwarf-flowered heartleaf, we decided
delineating representative units was not appropriate for this species.
However, in the absence of species-specific genetic and ecological
diversity information, we evaluated representation based on the extent
and variability of habitat characteristics across the geographical
range. Dwarf-flowered heartleaf occurs in two types of habitats
throughout the range. Typical habitats for this species include mesic
to dry bluffs, slopes, or ravines in deciduous forests that are
frequently associated with mountain laurel (Padgett 2004, entire;
Weakley 2015, entire; Service 2015, entire), or moist soils adjacent to
creeks, streamheads, or along lakes and rivers. This variation in
habitat type provides species representation in drier and wetter
habitats, demonstrating the species' ability to adapt to changing
environmental conditions.
Future Condition
Our analysis of the past, current, and future influences on dwarf-
flowered heartleaf revealed that there are several influences that may
pose risks to the future viability of the species. We assessed the
species future viability over a timeframe of 20 to 25 years, which
incorporates the relevant threats to the species and the species'
likely response to those threats. The current and ongoing threats
assessed in our analysis include the negative impacts of invasive
species, increased drought, and habitat changes resulting from
development. We selected this timeframe because it gives us the ability
to reliably predict into the future and to capture the uncertainty
related to the potential impacts to each population's resiliency. As
also described above, the term ``foreseeable future'' extends only so
far into the future as the Service can reasonably determine that both
the future threats and the species' responses to those threats are
likely. Data that are typically relevant to assessing the species'
biological response include species-specific factors such as lifespan,
reproductive rates or productivity, certain behaviors, and other
demographic factors. Where we had data over longer time frames, we
analyzed those data (e.g., climate data); however, for the factors most
influential in affecting the status of the dwarf-
[[Page 30013]]
flowered heartleaf, such as development and invasive species, we could
only reliably predict the magnitude of the primary threats and the
subsequent effects on dwarf-flowered heartleaf over a time frame of 20-
25 years. This provides a timeframe of reference observations that
enables the Service to predict future management scenarios for the
species and the species' response to threats and management actions.
Prior dwarf-flowered heartleaf conservation experience indicates that
this timeframe is the expected period over which implementation of
management practices (such as invasive species management) by
conservation partners and tracking of the species' response to managed
habitat improvement is reliable. Further, this time period coincides
with the SLEUTH urban growth models, allowing us to make reliable
predictions with respect to the threat of development. Therefore, we
used the 20-25 year timeframe in developing our projections of future
conditions for dwarf-flowered heartleaf.
Invasive, Exotic Species
As discussed above, invasive, exotic plants were identified as a
threat at the time of listing; however, this threat may not be as
significant as once thought. The NCNHP monitored 13 populations of
dwarf-flowered heartleaf and assessed threats at each population. Of
the monitored sites, only 9 percent of populations (1 of 11) where
invasive, exotic species are present are also in decline, indicating
the species has at least some capacity to withstand the presence of
invasive, exotic species. The number of known populations has increased
dramatically since listing as a result of increased survey effort, and
the invasive, exotic plant threat to many of the largest populations
has been observed to be low (NCNHP 2016, pp. 8, 17-20). Additionally,
and as noted above, the number of populations managed under
conservation ownership has increased. Therefore, we determine that
competition from invasive, exotic species will not be a significant
threat to dwarf-flowered heartleaf in the foreseeable future.
Climate
Our analysis under the Act includes consideration of ongoing and
projected changes in climate. The term ``climate'' is defined as the
long-term pattern of weather in a particular area. Various types of
changes in climate can 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 the effects of interactions of climate with
other variables (e.g., habitat fragmentation) (IPCC 2014, entire). In
our analyses, we use the judgment of the experts to weigh relevant
information, including uncertainty, in our consideration of various
aspects of increases in drought.
As part of the current, worldwide collaboration in climate
modelling under the IPCC, climate assessments of the full dataset of 30
climate models for historical and 21st century comparisons provide
predictions at scales ranging from global to county-level in the United
States (NCCV 2016 unpaginated). This global climate information has
been downscaled by the National Aeronautics and Space Administration to
scales relevant to our region of interest, and projected into the
future under two different scenarios of plausible emissions of
greenhouse gases (Alder and Hostetler 2017, p. 3). Using the NCCV and
assuming the representative concentration pathways (RCP) greenhouse gas
emission scenario RCP 8.5, we calculated projected annual mean changes
from 1981-2010 to those projected for 2025-2049 for maximum temperature
(+2.9 to 3.1 degrees Fahrenheit ([deg]F) (+1.611 to 1.722 degrees
Celsius ([deg]C)) in NC and +2.9 [deg]F +1.611 [deg]C in SC),
precipitation (+0.2 inches (in) (5.08 meters (mm)) per month for NC and
SC), soil storage (-0.1 to -0.2 in (-2.54 to -5.08 mm) for NC and -0.1
in (2.54 mm) SC), and evaporative deficit (no change for NC or SC) in
all counties where dwarf-flowered heartleaf occurs (Adler and Hostetler
2017, entire). We also calculated projected annual mean changes for the
RCP 4.5 scenario using the same timeframes for maximum temperature
(+2.5 to 2.7 [deg]F (+1.388 to 1.5 [deg]C) in NC and SC), precipitation
(+0.01 in (0.254 mm) per month for NC and SC), soil storage (-0.1 to -
0.2 in (-2.54 to -5.08 mm) for NC and -0.1 in (-2.54 mm) for SC), and
evaporative deficit (no change for NC or SC) in all counties where
dwarf-flowered heartleaf occurs (Adler and Hostetler 2017, entire).
Based on these results, all 13 counties within the range of dwarf-
flowered heartleaf will be subjected to higher temperatures (annual
mean increase of 2.6 [deg]F (1.44 [deg]C) (RCP 4.5) or 2.9 [deg]F
(1.611 [deg]C) (RCP 8.5)) and slightly higher precipitation (annual
mean increase of 0.1 in (2.54 mm) per month (RCP 4.5) or 0.2 in (5.08
mm) per month (RCP 8.5)) in 2025-2049 relative to the period of 1981-
2010. Because the average annual increase in precipitation is predicted
to be only slight, the loss in soil storage is likely primarily the
result of higher predicted temperatures.
Dwarf-flowered heartleaf is a long-lived perennial species. Several
populations have been revisited after decades and the species was still
stable. For example, one population in Rutherford County was first
observed in 1957, and was still extant when next observed in 2001
(NCNHP 2018, unpaginated). In their analyses of life-history traits in
relation to potential vulnerability to variability in demographic vital
rates caused by increased variability in climatic patterns, researchers
concluded that longer-lived species should be less influenced by
climate-driven increases in demographic variability (Morris et al.
2008, p. 22; Dalgleish et al. 2010, p. 216).
Within the family Aristolochiaeae, more than 50 percent of the
plant lineage is myrmecochorous (seed dispersal by ants) (Lengyel et
al. 2010, p. 49). Likewise, dwarf-flowered heartleaf employs
myrmecochory as a method for seed dispersal (Gaddy 1986, entire). While
species with ant-dispersed seeds have slower migration rates than
species with seeds that are adhesive or ingested (Brunet and Von Oheimb
1998, p. 429), myrmecochory provides for multiple adaptive advantages
for plants. Ants can disperse seeds to sites that might be nutrient-
enhanced or where plant fitness will be higher. Additionally, ants bury
seeds, which may protect them from fire and drought (Boyd 2001, p.
235), two conditions exacerbated by increases drought (Karl et al.
2009, entire).
Populations of dwarf-flowered heartleaf are located within various
ecological settings within the species' range. Dwarf-flowered heartleaf
occurs on Piedmont uplands on acidic sandy-loam soils that are very
deep and moderately permeable (Gaddy 1981, p. 7; 1987, pp. 186-196).
Typical habitats for this species include mesic to dry bluffs, slopes,
or ravines in deciduous forests that are frequently associated with
mountain laurel (Padgett 2004, p. 114; Weakley 2015, p. 129), or moist
soils adjacent to creeks or streamheads, or along lakes and rivers.
This variation in habitat type provides species representation in drier
and wetter habitats, demonstrating the species' ability to adapt to
different environmental conditions that could be brought on by changing
climate.
Development
As discussed above, development was identified as a threat at the
time of listing; however, the threat is not as significant as once
thought. The NCNHP monitored 13 populations of dwarf-flowered heartleaf
and assessed threats
[[Page 30014]]
at each population. In 8 of the 13 monitored populations, development
is identified as a threat. Of those 8 sites, only 12 percent of
populations are also in decline, indicating the species has at least
some capacity to withstand the threat of development. The number of
known populations has increased dramatically since listing and the
development threat posed at many of the largest populations is expected
to remain low (NCNHP 2016, pp. 8, 17-20).
We assessed three plausible future scenarios encompassing varying
levels of threats under status quo, targeted conservation, and high
development. Based on the life span of the species, expert input, and
uncertainty about future conditions, we projected population conditions
in 2040 under each scenario as described in the SSA report (Service
2018, p. 34). Results of future projections within each scenario are
focused on current populations and potential habitat identified by the
Maxent model as described below.
In constructing our scenarios, we considered two main influences by
which species viability projections could be affected: location of
additional populations (positive influence) and habitat loss and
fragmentation due to urban development (negative influence). Habitat
quantity can be negatively impacted by development or land use change
(particularly on private lands) or positively impacted by land
acquisition, restoration, and/or introductions into unoccupied sites
with existing suitable habitat.
We use the SLEUTH model to determine areas predicted to be
urbanized by 2040, a time period for which the models provide reliable
data. The SLEUTH model has been successfully applied worldwide over the
last 15 years to simulate land use change, including urbanization
(Clarke 1995, entire). The SLEUTH model predictions are broken down by
probabilities of urbanization, ranging from 0 to 100 percent. We chose
80 percent probability as our cutoff, as this cutoff has been used by
the U.S. Geological Survey and by us in other SSAs, and this threshold
represents a highly likely outlook for urbanization of the landscape.
To forecast viability using urban development projections, we assessed
the following:
<bullet> Percent increase in projected development within the range
of current populations; and
<bullet> Percent increase in projected development within areas
delineated as potential habitat by the Maxent habitat model.
We know that certain dwarf-flowered heartleaf populations have been
extirpated as the result of urban development in the past through loss
of habitat. However, there are no data available on the relationships
between urbanization and indirect impacts to dwarf-flowered heartleaf.
Because of this unknown, we attempted to capture potential impacts in
two ways. Our scenarios reflect a range of potential impacts from
nearby urban development. Also, we used two thresholds for percent
increase in urban development to capture potential deleterious effects:
25 percent and 50 percent. Our assumptions were that very small
increases in development are unlikely to negatively impact populations;
development increase of at least 25 percent of the area of current
populations was likely to have some negative impacts; and development
increase of at least 50 percent was likely to have significant impacts
to populations (Service 2018, p. 36).
We also assessed potential positive effects by integrating the
potential identification or rediscovery of additional populations
throughout the range into two of our scenarios (targeted conservation
and status quo). This is appropriate for several reasons. First,
discovery of new EOs is common; many of the populations we consider
under Current Condition, above, include detections that have occurred
within the last few years. Second, we did not include many older
detections (i.e., we only included detections since 2005), although
many of those detections are likely to persist. Several EOs have been
revisited after more than 10 years, and the species was still present.
For example, one such E.O. was first observed in 1957, next observed in
2001, and last observed in 2017. Based on the species' life history as
a long-lived perennial species, and confirmed by such observations, it
is reasonable to assume that populations will remain extant as long as
suitable habitat is present. Finally, there are many predicted suitable
habitat present within older EOs based on the Maxent model predictions
that were not included as current populations due to the relatively
long time since last observation.
The first step in identifying additional areas where dwarf-flowered
heartleaf is likely to be found in the future was to identify EOs from
populations that were last observed prior to 2005 (i.e., we define
current populations as those observed between 2005 and present day).
Although our focus is on pre-2005 EOs, where dwarf-flowered heartleaf
is likely to persist into the future, we also included current EOs
(2005-current day) in our analysis because we were interested in how
the pre-2005 EOs compared to those known to be persisting on the
landscape since 2005. Also, by including pre-2005 EOs that are within
current delineated populations, we can investigate whether current
populations might be predicted to contain more plants than the most
recent abundance estimate.
Once pre-2005 EOs were identified, we created a 1,000-m (3280.84
feet (ft)) buffer around the population and calculated a number of
useful metrics, including resiliency category based on the last known
abundance estimate, Maxent habitat model metrics, and the results of
the SLEUTH model to further refine a list of potential sites where the
species would likely occur within our 20-25-year projection window.
Resiliency categories were assessed using last known abundance in the
same way as populations assessed under Current Condition, above (i.e.,
low = fewer than 100 individuals; moderate = 100-500 individuals; high
= 500-1,000 individuals; very high = greater than 1,000 individuals).
We assessed two habitat metrics for pre-2005 EOs: average Maxent score
and percent Maxent classified as 0.8-1.0 score. Average Maxent score
indicates habitat suitability, where in general, the higher the score,
the higher quality the habitat, and was calculated by taking the mean
Maxent score of all potential habitat within the 1,000-m (3280.84 ft)
buffer. The percent Maxent classified as 0.8-1.0 represents the
percentage of all potential habitat within the 1,000-m buffer that
falls within the highest suitability habitat class. Together, these
habitat metrics give general estimates of habitat quantity and quality.
Finally, we calculated the total percentage of the 1,000-m buffer
around each E.O. that is projected to be urbanized in the year 2040, in
order to capture the primary risk factor of development when assessing
the areas where dwarf-flowered heartleaf is likely to persist.
Status Quo Scenario
Under the status quo scenario, we estimate that 75 populations will
persist throughout the range, and that there will be a range of impacts
from urbanization that are related to the percentage increase in urban
development and whether a population is protected or not. We assessed
population resiliency under the following assumptions:
<bullet> Two additional populations are identified as persisting
based on Maxent model metrics, last known abundance category, and total
predicted urbanization from SLEUTH modelling.
[[Page 30015]]
Six additional EOs within currently delineated populations not included
under Current Condition, above, are predicted to persist based on the
same metrics.
<bullet> Potential impacts of urban development based on SLEUTH
model projections focused on current delineated populations:
[cir] Protected areas:
[ssquf] Protected in perpetuity--no negative impacts from
urbanization; and
[ssquf] Voluntary protection/non-perpetuity--population drops one
resilience rank if percent increase in urbanization exceeds 50 percent
threshold.
[cir] Unprotected areas--population drops one resiliency rank if
percent increase in urbanization exceeds 25 percent threshold;
population drops two resiliency ranks if percent increase in
urbanization exceeds 50 percent threshold.
High Development Scenario
Under the high development scenario, we estimate no additional
populations will persist throughout the range, and that impacts from
urbanization are relatively high, and are also affected by whether a
population is protected or not. We assessed population resiliency under
the following assumptions:
<bullet> No additional populations are identified as persisting.
<bullet> Potential impacts of urban development based on SLEUTH
model projections focused on current delineated populations:
[cir] Protected areas:
[ssquf] Protected in perpetuity--population drops one resilience
rank if percent increase in urbanization exceeds 50 percent threshold;
and
[ssquf] Voluntary protection/non-perpetuity--population drops one
resiliency rank if percent increase in urbanization exceeds 25 percent
threshold; population drops two resiliency ranks if percent increase in
urbanization exceeds 50 percent threshold.
[cir] Unprotected areas--population drops one resiliency rank if
percent increase in urbanization exceeds 25 percent threshold;
population drops two resiliency ranks if percent increase in
urbanization exceeds 50 percent threshold; extirpation of populations
if percent increase in urbanization exceeds 90 percent threshold.
Targeted Conservation Scenario
Under the targeted conservation scenario, we estimate it is likely
that several additional populations (i.e., more than in the status quo
scenario) will persist throughout the range. This scenario accounts for
resilience (which is linked to abundance), habitat suitability (as
predicted by the model), projected urban development (from SLEUTH), and
protection status. In this scenario, conservation is happening through
various partners (e.g., State agencies, land trusts or other non-
profits, private individuals). The range of impacts from urbanization
are the same as in the status quo scenario. We assessed population
resiliency under the following assumptions:
<bullet> Six populations are identified as persisting based on
Maxent model metrics, last known abundance category, and total
predicted urbanization from SLEUTH modelling. Six additional EOs within
currently delineated populations not included under Current Condition,
above, are predicted to persist based on the same metrics.
<bullet> Potential impacts of urban development based on SLEUTH
model projections focused on current delineated populations:
[cir] Protected areas:
[ssquf] Protected in perpetuity--no impacts from urbanization; and
[ssquf] Voluntary protection/non-perpetuity--population drops one
resiliency rank if percent increase in urbanization exceeds 50 percent
threshold.
[cir] Unprotected areas--population drops one resiliency rank if
percent increase in urbanization exceeds 25 percent threshold;
population drops two resiliency ranks if percent increase in
urbanization exceeds 50 percent threshold.
Future Resiliency
Status Quo Scenario
In the status quo scenario, we predict 75 of the 78 populations of
dwarf-flowered heartleaf will be extant in 2040. The predicted
resiliency of the extant populations are as follows: very high (27);
high (6); moderate (23); low (17); and 2 additional populations
identified as persisting, with an unknown resiliency. Six EOs within
currently delineated populations not included under Current Condition,
above, are predicted to persist, but resiliency is unchanged because
each of the populations are already predicted to be of very high
resiliency. When comparing future population resiliency to current
condition, a few populations drop in their resiliency category. One
current population of very high resiliency is predicted to drop to high
resiliency; two moderate resiliency populations are predicted to drop
to low resiliency; and five populations (one currently moderate and
four currently low) are predicted to be extirpated due to urban
development.
High Development Scenario
In the high development scenario, we predict 72 of the 78
populations of dwarf-flowered heartleaf will remain extant in 2040. The
predicted resiliency of the extant populations are as follows: very
high (27); high (4); moderate (25); and low (16). No additional
populations are identified as persisting. When comparing future
population resiliency to current condition, a few populations drop in
their resiliency category. One current population of very-high
resiliency is predicted to drop to moderate resiliency; one high
resiliency population is predicted to drop to moderate resiliency; two
moderate resiliency populations are predicted to drop to low
resiliency; and six populations (one currently moderate and five
currently low) are predicted to be extirpated due to urban development.
Targeted Conservation Scenario
In the targeted conservation scenario, we predicted 79 populations
of dwarf-flowered heartleaf will be extant in 2040. The predicted
resiliency of the extant populations are as follows: very high (27);
high (6); moderate (23); low (17); and 6 additional populations
identified as persisting, with an unknown resiliency. Six EOs within
currently delineated populations not included under Current Condition,
above, are predicted to persist, but resiliency is unchanged because
each of the populations are already predicted to be of very high
resiliency. When comparing future population resiliency to current
condition a few populations drop in their resiliency category. One
current population of very high resiliency is predicted to drop to high
resiliency; two moderate resiliency populations are predicted to drop
to low resiliency; and five populations (one currently moderate and
four currently low) are predicted to be extirpated due to urban
development.
Viability Summary
Future viability of dwarf-flowered heartleaf under all three
scenarios is summarized in table 1, below. Urban development is
predicted to have negative impacts on several of the current
populations under all of our scenarios. However, this loss of
resiliency and extirpation of a few populations is offset in the status
quo and targeted conservation scenarios by the persistence of several
additional populations. In the high development scenario, there is a
predicted loss of six populations, with loss of resiliency in
[[Page 30016]]
several additional populations. However, in all three scenarios, the
majority of the populations are expected to persist in 2040 at a level
of at least moderate resiliency.
Given the relatively high number of populations across each
scenario, redundancy remains similar to current conditions. We
therefore conclude that there will be adequate redundancy within the
range of dwarf-flowered heartleaf to withstand the impacts of localized
catastrophic press disturbances; however, the species' range is
relatively small, making it potentially vulnerable to long-term
catastrophic events.
Because dwarf-flowered heartleaf has a very limited range, and
after consulting with experts, we decided that delineating
representative units was not appropriate. It is worth noting that in
two of our scenarios (status quo and targeted conservation), additional
populations are found to persist in South Carolina, an area where there
are relatively few current populations. Based on a habitat distribution
model, there is potential dwarf-flowered heartleaf habitat throughout
the species range. Additional plants may be present in these areas but
would need to be confirmed via surveys. Although we did not delineate
representative units, our scenarios do not predict declines in species
representation.
Table 1--Viability Summary for Dwarf-Flowered Heartleaf Under Three Future Scenarios (Projected to Year 2040)
and Compared to Current Condition
----------------------------------------------------------------------------------------------------------------
High Targeted
Current Status quo development conservation
condition scenario scenario scenario
----------------------------------------------------------------------------------------------------------------
Very-High Resiliency.................................. 28 27 27 27
High Resiliency....................................... 5 6 4 6
Moderate Resiliency................................... 26 23 25 23
Low Resiliency........................................ 19 17 16 17
Extirpated............................................ n/a 5 6 5
Persisting............................................ n/a 2 0 6
---------------------------------------------------------
Total Populations................................. 78 75 72 79
----------------------------------------------------------------------------------------------------------------
We note that, by using the SSA framework to guide our analysis of
the scientific information documented in the SSA report, we have not
only analyzed individual effects on the species, but we have also
analyzed their potential cumulative effects. We incorporate the
cumulative effects into our SSA analysis when we characterize the
current and future condition of the species. Our assessment of the
current and future conditions encompasses and incorporates the threats
individually and cumulatively. Our current and future condition
assessment is iterative because it accumulates and evaluates the
effects of all the factors that may be influencing the species,
including threats and conservation efforts. Because the SSA framework
considers not just the presence of the factors, but to what degree they
collectively influence risk to the entire species, our assessment
integrates the cumulative effects of the factors and replaces a
standalone cumulative effects analysis.
Determination of Dwarf-Flowered Heartleaf's Status
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for determining
whether a species meets the definition of an endangered species or a
threatened species. The Act defines an endangered species as a species
that is in danger of extinction throughout all or a significant portion
of its range, and a threatened species as a species that is likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range. The Act requires that we
determine whether a species meets the definition of an endangered
species or a threatened species because of any of the following
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.
Status Throughout All of Its Range
After evaluating threats to the species and assessing the
cumulative effect of the threats under the section 4(a)(1) factors, we
find that the present or threatened destruction, modification, or
curtailment of dwarf-flowered heartleaf habitat (Factor A), which was
the basis for listing the species, is no longer a threat. We assessed
the best scientific and commercial data available regarding the past,
present, and future threats faced by the dwarf-flowered heartleaf. When
dwarf-flowered heartleaf was listed, the two prominent threats
identified were invasive, exotic plants and habitat loss or
destruction. As discussed above, invasive, exotic species are not as
significant a threat to dwarf-flowered heartleaf as originally thought.
Only 1 of the 11 monitored populations where invasive, exotic species
occur was identified as declining. Additionally, dwarf-flowered
heartleaf has the capacity to withstand habitat loss and destruction
due to development. Of the 78 populations evaluated, 75 percent are
characterized as being either very high, high, or moderately resilient,
and many are stable or increasing.
The species currently has significant redundancy (78 populations),
resilient populations (33 of 78 evaluated populations with high or very
high viability), and representation in 2 different ecological settings.
Even under our high development scenario, only two high or very high
viability populations are predicted to have lower viability as a result
of development. Therefore, we do not believe that competition from
invasive, exotic species or habitat loss and destruction are
significant threats to the species.
Additionally, since listing, there has been a nearly four-fold
increase in the number of known populations. Of the 78 populations
evaluated in the SSA report, 24 populations (31 percent) have permanent
protection and 18 populations (23 percent) have partial protection
through voluntary agreements or other commitments of management. We
conclude that the species is currently not in danger of extinction
throughout all of its range.
In order to more closely examine the future threat posed by habitat
loss or destruction, we analyzed three different future development
scenarios to the year 2040. Under all scenarios evaluated, 56 of the
currently known 78
[[Page 30017]]
populations remain in very high, high, and moderate resiliency,
compared to 59 populations under current conditions. Only a small
number (five or six) of currently low resiliency populations are
predicted to become extirpated under all scenarios evaluated. The
species will continue to occur across its range, redundancy will remain
high to moderately high, and representation will continue in its
current condition providing current levels of adaptive capacity.
Of the 78 populations evaluated in the SSA report, 24 populations
(31 percent) have permanent protection and 18 populations (23 percent)
have partial protection through voluntary agreements or other
commitments of management, reducing the likelihood of development
impacting those populations. Recent examination of the species also
identified increased drought and invasive species as potential future
threats. The species' broadened range (from 8 counties to 13) and
significantly increased numbers of known populations (24 to 119) since
listing in 1989 indicate that the dwarf-flowered heartleaf benefits
from sufficient redundancy and resiliency to withstand perturbations
from increased drought as well as from invasive species. Thus, after
assessing the best available scientific and commercial information, we
conclude that the dwarf-flowered heartleaf is not in danger of
extinction now or likely to become so in the foreseeable future
throughout all of its range.
Status Throughout a Significant Portion of Its Range
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
within the foreseeable future throughout all or a significant portion
of its range. Having determined that the dwarf-flowered heartleaf is
not in danger of extinction or likely to become so within the
foreseeable future throughout all of its range, we now consider whether
it may be in danger of extinction or likely to become so in the
foreseeable future in a significant portion of its range--that is,
whether there is any portion of the species' range for which both (1)
the portion is significant; and, (2) the species is in danger of
extinction or likely to become so in the foreseeable future in that
portion. Depending on the case, it might be more efficient for us to
address the ``significance'' question or the ``status'' question first.
We can choose to address either question first. Regardless of which
question we address first, if we reach a negative answer with respect
to the first question that we address, we do not need to evaluate the
other question for that portion of the species' range.
In undertaking this analysis for dwarf-flowered heartleaf, we chose
to address the status question first. We began by identifying portions
of the range where the biological status of the species may be
different from its biological status elsewhere in its range. For this
purpose, we considered information pertaining to the geographic
distribution of (a) individuals of the species, (b) the threats that
the species faces, and (c) the resiliency condition of populations.
We evaluated the range of the dwarf-flowered heartleaf to determine
if the species is in danger of extinction now or likely to become so
within the foreseeable future in any portion of its range. The range of
a species can theoretically be divided into portions in an infinite
number of ways. We focused our analysis on portions of the species'
range that may meet the Act's definition of an endangered species or a
threatened species. For the dwarf-flowered heartleaf, we considered
whether the threats or their effects on the species are greater in any
biologically meaningful portion of the species' range than in other
portions such that the species is in danger of extinction now or likely
to become so within the foreseeable future in that portion. We examined
the following threats: development, invasive and exotic species, and
increased drought, including cumulative effects.
The NCNHP monitored 13 populations of dwarf-flowered heartleaf
throughout the species' range. Eleven of the 13 populations had
invasive, exotic species identified as a threat, indicating that
invasive, exotic species are found throughout the range and not
concentrated in any specific location. Effects of increased drought, as
discussed previously, are very uniform throughout the range (NCCV 2016
unpaginated). The opportunity for habitat loss and destruction due to
development is higher on privately owned lands that could be sold for
future development (Clarke 1995, entire). Of the 78 populations
evaluated, we determined that 31 percent are permanently protected and
another 23 percent are partially protected (i.e., voluntary landowner
agreements). The unprotected populations are spread throughout the
species' range and not geographically clustered together. While there
is some variability in the habitats occupied by dwarf-flowered
heartleaf across its range, the basic ecological components required
for the species to complete its life cycle are present throughout the
habitats occupied by the 78 populations of the species.
We found no biologically meaningful portion of the dwarf-flowered
heartleaf range where threats are impacting individuals differently
from how they are affecting the species elsewhere in its range such
that the status of the species in that portion differs from its status
in any other portion of the species' range.
Therefore, we find that the species is not in danger of extinction
now or likely to become so within the foreseeable future in any
significant portion of its range. This does not conflict with the
courts' holdings in Desert Survivors v. Department of the Interior, 321
F. Supp. 3d 1011, 1070-74 (N.D. Cal. 2018), and Center for Biological
Diversity v. Jewell, 248 F. Supp. 3d 946, 959 (D. Ariz. 2017) because,
in reaching this conclusion, we did not apply the aspects of 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),
including the definition of ``significant,'' that those court decisions
held to be invalid.
Determination of Status
Our review of the best available scientific and commercial data
available indicates that the dwarf-flowered heartleaf does not meet the
definition of an endangered species or a threatened species in
accordance with sections 3(6) and 3(20) of the Act. In accordance with
our regulations at 50 CFR 424.11(e)(2) currently in effect, dwarf-
flowered heartleaf has recovered to the point at which it no longer
meets the definition of an endangered species or a threatened species.
Therefore, we are removing the dwarf-flowered heartleaf from the List
of Endangered and Threatened Plants.
Effects of This Rule
This rule revises 50 CFR 17.12(h) by removing the dwarf-flowered
heartleaf from the Federal List of Endangered and Threatened Plants. On
the effective date of this rule (see DATES, above), the prohibitions
and conservation measures provided by the Act, particularly through
sections 7 and 9, will no longer apply to the dwarf-flowered heartleaf.
Federal agencies will no longer be required to consult with the Service
under section 7 of the Act in the event that activities they authorize,
fund, or carry out may affect the dwarf-flowered heartleaf. There is no
critical habitat designated for this species, so there will be no
effect to 50 CFR 17.96.
[[Page 30018]]
Post-Delisting Monitoring
Section 4(g)(1) of the Act requires us, in cooperation with the
States, to implement a monitoring program for not less than 5 years for
all species that have been recovered. Post-delisting monitoring (PDM)
refers to activities undertaken to verify that a species delisted due
to recovery remains secure from the risk of extinction after the
protections of the Act no longer apply. The primary goal of PDM is to
monitor the species to ensure that its status does not deteriorate, and
if a decline is detected, to take measures to halt the decline so that
proposing it as an endangered or threatened species is not again
needed. If at any time during the monitoring period, data indicate that
protective status under the Act should be reinstated, we can initiate
listing procedures, including, if appropriate, emergency listing.
We have prepared a PDM plan for dwarf-flowered heartleaf. We
published a notice of availability of a draft PDM plan with the
proposed delisting rule (86 FR 21994). We did not receive any comments
on the plan. Therefore, we consider the plan final. As discussed in the
proposed rule, the PDM plan: (1) summarizes the status of dwarf-
flowered heartleaf at the time of proposed delisting; (2) describes
frequency and duration of monitoring; (3) discusses monitoring methods
and potential sampling regimes; (4) defines what potential triggers
will be evaluated to address the need for additional monitoring; (5)
outlines reporting requirements and procedures; (6) proposes a schedule
for implementing the PDM plan; and (7) defines responsibilities. It is
our intent to work with our partners towards maintaining the recovered
status of the dwarf-flowered heartleaf.
Required Determinations
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, May 4, 1994), Executive Order 13175
(Consultation and Coordination with Indian Tribal Governments), the
President's memorandum of November 30, 2022 (Uniform Standards for
Tribal Consultation; 87 FR 74479, December 5, 2022), and the Department
of the Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with recognized Federal
Tribes and Alaska Native Corporations on a government-to-government
basis. In accordance with Secretary's 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 have determined that no Tribes will be affected by this
final rule because no Tribal lands, sacred sites, or resources will be
affected by the removal of the dwarf-flowered heartleaf from the List
of Endangered and Threatened Plants.
References Cited
A complete list of references cited in this rulemaking is available
on the internet at <a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No. FWS-R4-
ES-2019-0081 and upon request from the Asheville Ecological Services
Field Office (see FOR FURTHER INFORMATION CONTACT, above).
Authors
The primary authors of this final rule are staff members of the
Service's Species Assessment Team and the Asheville Ecological Services
Field Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Signing Authority
Paul Souza, Regional Director, Region 8, Exercising the Delegated
Authority of the Director of the U.S. Fish and Wildlife Service,
approved this action on June 13, 2025, for publication. On June 26,
2025, Paul Souza authorized the undersigned to sign the document
electronically and submit it to the Office of the Federal Register for
publication as an official document of the U.S. Fish and Wildlife
Service.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as set forth below:
PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245,
unless otherwise noted.
Sec. 17.12 [Amended]
0
2. In Sec. 17.12, amend paragraph (h) by removing the entry for
``Hexastylis naniflora'' under FLOWERING PLANTS from the List of
Endangered and Threatened Plants.
Madonna Baucum,
Regulations and Policy Chief, Division of Policy, Economics, Risk
Management, and Analytics of the Joint Administrative Operations, U.S.
Fish and Wildlife Service.
[FR Doc. 2025-12196 Filed 7-7-25; 8:45 am]
BILLING CODE 4333-15-P
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