Endangered and Threatened Wildlife and Plants; Removing Arenaria cumberlandensis (Cumberland Sandwort) From the Federal List of Endangered and Threatened Plants, 45685-45698 [2021-17468]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 86, Number 155 (Monday, August 16, 2021)]
[Rules and Regulations]
[Pages 45685-45698]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-17468]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2019-0080; FXES11130900000-212-FF09E22000]
RIN 1018-BD82


Endangered and Threatened Wildlife and Plants; Removing Arenaria 
cumberlandensis (Cumberland Sandwort) From the Federal List of 
Endangered and Threatened Plants

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are removing 
Cumberland sandwort (Arenaria cumberlandensis) from the Federal List of 
Endangered and Threatened Plants (List). This determination is based on 
a thorough review of the best available scientific and commercial data, 
which indicate that Cumberland sandwort has recovered and no longer 
meets the definition of an endangered or a threatened species under the 
Endangered Species Act of 1973, as amended (Act). Our review shows that 
threats to the species identified at the time of listing (i.e., timber 
harvesting, trampling from recreational uses, and digging for 
archaeological artifacts) have been reduced to the point that they no 
longer pose a threat to the species, and the known range and abundance 
of Cumberland sandwort have increased. Our review also indicates that 
potential effects of projected climate change are not expected to cause 
the species to become endangered in the foreseeable future. 
Accordingly, the prohibitions and conservation measures provided by the 
Act will no longer apply to this species.

DATES: This rule is effective September 15, 2021.

ADDRESSES: The proposed rule and this final rule, supporting documents, 
the post-delisting monitoring plan, and the comments received on the 
proposed rule are available at https://www.regulations.gov under Docket 
No. FWS-R4-ES-2019-0080.

FOR FURTHER INFORMATION CONTACT: Daniel Elbert, Field Supervisor, U.S. 
Fish and Wildlife Service, Tennessee Ecological Services Field Office, 
446 Neal Street, Cookeville, TN 38501; telephone (931) 528-6481. 
Individuals who use a telecommunications device for the deaf (TDD), may 
call the Federal Relay Service at (800) 877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, a species may be 
removed from the Federal List of Endangered and Threatened Plants 
(List) (``delisted'') if it is determined that the species has 
recovered and no longer meets the definition of an endangered or 
threatened species. Removing a species from the List can only be 
completed by issuing a rule.
    What this document does. This rule delists Cumberland sandwort 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 or threatened species because of one or more 
of the five factors described in section 4(a)(1) of the Act: (A) The 
present or threatened destruction, modification, or curtailment of its 
habitat or range; (B) overutilization for commercial, recreational, 
scientific, or educational purposes; (C) disease or predation; (D) the 
inadequacy of existing regulatory mechanisms; or (E) other natural or 
manmade factors affecting its continued existence. We must consider 
these same factors in delisting a species.
    We have determined that Cumberland sandwort is not in danger of 
extinction now nor likely to become so in the foreseeable future based 
on a comprehensive review of its status and listing factors. 
Specifically, our recent review indicated: (1) An increase in the known 
number of occurrences of the species within its geographically 
restricted range, and increased abundance in some occurrences; (2) 
resiliency to existing and potential threats; (3) the protection of 66 
extant occurrences located on Federal and State conservation lands by 
regulations or management plans to prevent habitat destruction or 
removal of plants; and (4) the implementation of beneficial management 
practices. Accordingly, Cumberland sandwort no longer meets the 
definition of an endangered or threatened species under the Act.
    Peer review and public comment. 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 of listing actions under the Act, we sought peer 
review of our April 27, 2020, proposed rule to delist the species (85 
FR 23302). The Service sent the proposed rule to five independent peer 
reviewers and received three responses. The purpose of peer review is 
to ensure that our determination is based on scientifically sound data, 
assumptions, and analyses. The peer reviewers have expertise in the 
biology, habitat, and threats to the species.

Previous Federal Actions

    On April 27, 2020, we published in the Federal Register (85 FR 
23302) a proposed rule to remove Cumberland sandwort from the Federal 
List of Endangered and Threatened Plants (i.e., to delist the species). 
Please refer to that proposed rule for a detailed description of 
previous Federal actions concerning this species. The proposed rule and 
supplemental documents are provided at https://www.regulations.gov under 
Docket No. FWS-R4-ES-2019-0080.

[[Page 45686]]

Summary of Changes From the Proposed Rule

    We made no substantive changes to the proposed rule in this final 
rule. We made minor editorial changes in this rule in response to 
comments we received on the proposed rule.

Summary of Comments and Recommendations

    In our April 27, 2020, proposed rule to delist Cumberland sandwort 
(85 FR 23302), we requested that all interested parties submit written 
comments on the proposed delisting and our draft post-delisting 
monitoring (PDM) plan by June 26, 2020. We also contacted appropriate 
Federal and State agencies, scientific experts and organizations, and 
other interested parties and invited them to comment on the proposed 
delisting and draft PDM plan. A newspaper notice inviting general 
public comments was published in the Fentress Courier (major local 
newspaper) and also announced using online and social media sources. We 
received one substantive comment from the public, which is discussed 
below under (1) Comment, and no requests for a public hearing.
    In addition, we reviewed all comments we received from the peer 
reviewers for substantive issues and new information regarding the 
proposed delisting rule and PDM plan for Cumberland sandwort. The peer 
reviewers generally concurred with our methods and conclusions, and 
they provided additional information, clarifications, and suggestions 
to improve the final delisting rule. Peer reviewer comments are 
summarized below under (2) Comment through (4) Comment, and 
incorporated into this final rule as appropriate.
    (1) Comment: One commenter expressed concern that the unique 
habitat of the species would be less protected if the species were 
delisted.
    Our response: Cumberland sandwort habitats on both State and 
Federal conservation lands will remain protected by rules, regulations, 
or plans governing the establishment or management of those lands. The 
species is also still State-protected where it occurs. At this time, 
Cumberland sandwort meets the standard for delisting under the Act: It 
no longer meets the Act's definitions of an ``endangered species'' or a 
``threatened species.'' We will continue to work with recovery partners 
to maintain the species' recovered state and conduct post-delisting 
monitoring, as well.
    (2) Comment: One peer reviewer requested clarification concerning 
whether abundance estimates, in addition to hand drawn maps and the 
numbers of patches depicted on the maps, were used in determining 
population resiliency indices and evaluating population trends. The 
reviewer also asked how estimates of abundance were determined.
    Our response: We explain below under Framework for Monitoring and 
Evaluating Trends that we used visual estimates of abundance or 
discrete counts of individuals, where available, to supplement data 
provided on hand drawn maps when determining population resiliency 
indices and evaluating population trends.
    (3) Comment: One peer reviewer informed us that data on global 
forest loss (https://earthenginepartners.appspot.com/science-2013-global-forest) were available to use in quantifying forest loss in 
portions of the watersheds where Cumberland sandwort is found.
    Our response: We used the data available at the reference provided 
by the peer reviewer to provide an objective basis for evaluating 
whether we correctly identified evidence of logging activity in forests 
near Cumberland sandwort occurrences. Based on this evaluation, we 
correctly identified locations where logging activities had taken place 
in the vicinity of Cumberland sandwort occurrences when preparing the 
April 27, 2020, proposed rule to delist Cumberland sandwort (85 FR 
23302).
    (4) Comment: One peer reviewer asked whether disturbance from 
recreational use was likely to increase in proportion to human 
population growth and increased participation in outdoor activities. 
The reviewer also asked how Cumberland sandwort population trends in 
sites where management had occurred to reduce the threat of inadvertent 
trampling by recreationists compared to population trends in unmanaged 
sites where the threat of trampling existed.
    Our response: We address this comment below under Habitat Loss and 
Curtailment of Range where we discuss the lack of a clear trend in 
available data regarding visitation rates to lands where Cumberland 
sandwort occurs. We also added a discussion comparing population trends 
in sites where protective measures have been installed to reduce the 
threat of trampling to trends that have been observed in other sites 
where the risk of trampling has been previously recorded but no 
protective measures have been installed.

Final Delisting Determination

Species Information

    Below, we present a thorough review of the taxonomy, life history, 
ecology, and overall status of this plant, referencing data from the 
2013 5-year review (Service 2013) where appropriate.

Taxonomy

    Cumberland sandwort (Arenaria cumberlandensis), a member of the 
Pink family (Caryophyllaceae), was first recognized and described as a 
species in 1979 (Wofford and Kral 1979, entire). This species, along 
with several other species of Arenaria, was transferred to the genus 
Minuartia while retaining the specific epithet (McNeill 1980, entire). 
The species is listed as Minuartia cumberlandensis (Wofford and Kral) 
McNeill in A Fifth Checklist of Tennessee Vascular Plants (Chester et 
al. 2009, p. 43), the Integrated Taxonomic Information System (ITIS) 
(2019), and Flora of North America (2019). However, an examination of 
the taxonomy of Minuartia using DNA sequences determined that all 
species in Minuartia section Uninerviae should be elevated to genus 
Mononeuria, along with Geocarpon minimum (Dillenberger and Kadereit 
2014, p. 79). The Flora of the Southern and Mid-Atlantic States 
accepted this recommendation, assigning the name Mononeuria 
cumberlandensis (B.E. Wofford & Kral) Dillenberger & Kadereit to 
Cumberland sandwort (Weakley 2015, p. 820). Although changes have been 
made to the species' taxonomy since the time of listing, we are 
removing the species from the List of Endangered and Threatened Plants 
using the name by which it was initially listed, Arenaria 
cumberlandensis (=Mononeuria cumberlandensis).

Species Description

    The following description of Cumberland sandwort is modified from 
Wofford and Kral (1979, pp. 257-259) and Kral (1983, pp. 363-364). This 
species is a delicate perennial that occurs in small cushionlike 
clumps, with upright stems 10 to 15 centimeters (cm) (4 to 6 inches 
(in)) tall that are slender and triangular in shape. Leaves are 
opposite, 2 to 3 cm (0.8 to 1.2 in) long and 1 to 3 millimeters (mm) 
(0.04 to 0.12 in) wide, and are thin and bright green in color, with 
glassy margins. Basal leaves are longer and wider than those at the top 
of the stems. The flowers are symmetrical, five-parted, and usually 
solitary at the end of the stems. The sepals (a part of the flower that 
provides protection for the flower

[[Page 45687]]

in bud and sometimes provides support for petals when in bloom) are 
green and inconspicuously three-veined, and the white petals usually 
have five green veins. The fruit is a 3- to 3.5-mm-long (0.12- to 0.14-
in) ovoid capsule containing numerous reddish-brown reticulated (having 
the form or appearance of a net) seeds that are 0.5 to 0.7 mm (0.02 to 
0.03 in) long.
    The mild conditions of the sheltered habitat where Cumberland 
sandwort occurs allow rosettes (circular arrangement of leaves) to 
persist through winter and produce abundant, leafy stems in the spring 
(Winder 2004, p. 5). The species flowers from May through August, with 
some flowers persisting as late as November (Wofford and Kral 1979, p. 
259; Winder 2004, p. 5).

Habitat

    Cumberland sandwort inhabits fine-grained, sandy soils that 
comprise the floors of the interior of ``rockhouses'' (cave-like 
recesses produced by differential weathering of sandstone). These 
habitats are typically behind the dripline of overlying cliffs, ledges, 
and solution pockets of cliffs, where these features are found in 
Pennsylvanian sandstones on the Cumberland Plateau in southern Kentucky 
and northern Tennessee (Horton 2017, entire). The species occupies 
sites that generally share characteristics of high levels of shade, 
moisture, and humidity, and relatively constant, cool temperatures 
(Wofford and Smith 1980, p. 7), although some smaller occurrences 
occupy drier and warmer sites. Few other species are directly 
associated with Cumberland sandwort microsites, but the following 
species are important indicators that suitable habitat conditions are 
present within a given rockhouse or bluff site: Silene rotundifolia 
(round-leaved catchfly); Thalictrum clavatum (mountain meadow-rue); 
Heuchera parviflora (little-flowered alumroot); Ageratina luciae-
brauniae (Lucy Braun's snakeroot); Stenanthium diffusum (diffuse 
feather-bells); and the bryophytes Vittaria appalachiana (Appalachian 
shoestring fern), Bryoxiphium norvegicum (Norway bryoxiphium moss), and 
Scopelophila cataractae (cataract scopelophila moss) (Tennessee 
Department of Environment and Conservation (TDEC) 2011b, p. 5).

Distribution

    When Cumberland sandwort was listed as endangered (53 FR 23745; 
June 23, 1988), the species was known from 11 occurrences (Wofford and 
Smith 1980, pp. 9-18), which were treated as 5 populations. Of these 
occurrences, 1 was in McCreary County, Kentucky, and 10 were 
distributed among four Tennessee counties (Fentress, Morgan, Pickett, 
and Scott). The species recovery plan (Service 1996, pp. 6-8) reported 
that 28 occurrences were extant (including the 11 from the June 23, 
1988, listing rule), 27 of which were partly or entirely located on 
publicly owned conservation lands. One of these 28 occurrences was in 
McCreary County, Kentucky, and the remaining 27 were distributed among 
the four Tennessee counties reported in the listing rule. All 
occurrences reported in the listing rule and species recovery plan were 
located in the South Fork Cumberland River drainage. Of these 28 
occurrences, all but 3 were extant as of 2017 (TNHID 2018).
    As explained below, documentation to verify past or present 
existence is lacking for two of the three occurrences we did not 
determine to be extant as of 2017, raising questions regarding their 
validity. The ``Middle Creek 2'' occurrence reported in the recovery 
plan was apparently based on an observation reported by a National Park 
Service (NPS) archaeologist, but staff of the TDEC Division of Natural 
Areas (TDNA) were unable to confirm the presence of Cumberland sandwort 
at the mapped location, which they attribute to a mapping error when 
the occurrence was reported. The Morgan County, Tennessee, occurrence 
reported in the recovery plan, with only the site name ``Sunbright'' 
given for location information, also cannot be verified. No citation 
was provided in the recovery plan for this record, and no record 
existed for this site in the Tennessee Natural Heritage Inventory 
Database (TNHID) (2018), maintained by the Natural Heritage Program at 
TDNA. A search of herbarium records for Cumberland sandwort from Morgan 
County, Tennessee, produced no specimens from the vicinity of Sunbright 
(SERNEC Data Portal 2018). However, a new extant occurrence record was 
documented in TNHID for Scott County, based on the label for a specimen 
collected in 2002 from a site not previously known to be occupied by 
Cumberland sandwort.
    The Big Branch occurrence reported in the recovery plan was not 
recorded in the TNHID (2018), so no attempts have been made to relocate 
this occurrence. Staff from NPS reported the occurrence in comments 
provided after reviewing the draft recovery plan (NPS 1995). We 
provided information to TDNA on the Big Branch occurrence reported by 
NPS, and there is now a historical record for this occurrence in the 
TNHID.
    In order to evaluate the current status of Cumberland sandwort, we 
used data from Natural Heritage Programs in Kentucky (KNHP 2018) and 
Tennessee (TNHID 2018) to determine the location and condition of 
mapped element occurrences. An element occurrence (E.O.) is a 
fundamental unit of information in the NatureServe Natural Heritage 
methodology, and is defined as ``an area of land and/or water in which 
a species . . . is, or was present'' (NatureServe 2004). There were 64 
extant occurrences of Cumberland sandwort reported in the 2013 5-year 
review. As of 2018, there were 71 extant occurrences, distributed among 
the five counties where the species was reported to be extant when the 
recovery plan was published: 1 in McCreary County, Kentucky (Kentucky 
Natural Heritage Program (KNHP) 2018); 1 in Morgan County, 26 in 
Fentress County, 38 in Pickett County, and 5 in Scott County, Tennessee 
(TNHID 2018). Of these occurrences, 12 occur within the Obey River 
drainage in Tennessee; 11 of these occurrences have been discovered 
since 2005 on recently acquired, State-owned conservation lands, and 1 
on privately owned lands in 2016. The remaining 59 occurrences lie 
within the South Fork Cumberland River drainage, and all but 1 of these 
occurrences is in Tennessee. Four of the occurrences in the South Fork 
Cumberland River drainage are located on privately owned lands in 
Tennessee; the remainder are located on State or Federal conservation 
lands. In addition to these 71 natural occurrences of Cumberland 
sandwort, one introduced occurrence has been established in McCreary 
County, Kentucky, on the Daniel Boone National Forest (DBNF) (Pence et 
al. 2011, entire).

Population Genetics

    In a study of populations in Tennessee, Cumberland sandwort was 
found to possess ``fairly high'' levels of genetic variation (Winder 
2004, pp. 16-19). Observed levels of heterozygosity were consistent 
with expected effects of frequent mating among closely related 
individuals, or inbreeding (Winder 2004, p. 19), a common phenomenon in 
small populations due to the greater likelihood that most or all 
individuals in the population will be closely related (Allendorf and 
Luikart 2007, p. 306). Greater genetic similarity was found among 
populations within about 4 kilometers (km) (2.5 miles (mi)) of one 
another, but a wide range of values were observed at distances of 4 to 
25 kilometers (2.5 to 15.5 mi), beyond

[[Page 45688]]

which populations were consistently dissimilar (Winder 2004, p. 27). 
Thus, Cumberland sandwort populations generally are genetically 
independent of one another and have been for a significant period of 
time, with possible exceptions where gene flow could occur among 
densely clustered populations in close geographic proximity to one 
another (Winder 2004, p. 28). The majority of the genetic variation 
found in the species is retained within a central cluster of 
populations located in Pickett County, Tennessee, and in Laurel Fork 
(Fentress County), Tennessee (Winder 2004, p. 37). The genetic 
structure of the sole Kentucky population and its relation to sites 
sampled in Tennessee are unknown.

Framework for Monitoring and Evaluating Trends

    The TDEC Natural Heritage Program began monitoring Cumberland 
sandwort in Tennessee during 2000, visually estimating abundance in 34 
sites as part of a project to conduct surveys for new locations and 
update records for previously known occurrences of the species (TDEC 
2000, entire). The number of occurrences monitored has increased to 55, 
and TDEC has categorized sites into three tiers of differing priority, 
with the highest priority sites (i.e., Tier 1) being the most 
frequently monitored (TDEC 2007, p. 5):
     Tier 1 sites have a history of site disturbance related to 
recreational use or illicit digging of Native American artifacts.
     Tier 2 sites face fewer immediate threats in the less 
frequently visited sites they occupy.
     Tier 3 sites faced no imminent threats at the time of 
categorization.
    Designating tiers provides for more frequent monitoring of sites 
with a greater likelihood of being adversely affected by known threats 
that could warrant management intervention. Tier 1 sites are monitored 
every 1 to 3 years, Tier 2 sites every 3 to 6 years, and Tier 3 sites 
every 6 to 10 years (TDEC 2007, p. 5). In addition to monitoring during 
2000 and 2006 (before the tier system was developed), TDEC monitored 
Tier 1 sites during 2010 and 2011 (TDEC 2011a, entire), 2014 (TDEC 
2014, entire), and 2017 (TDEC unpublished data). Tier 2 sites were 
monitored during 2011 through 2012 (TDEC 2012, entire), and Tier 3 
sites were monitored during 2016 and 2017 (TDEC unpublished data).
    The Service receives monitoring data in the form of written reports 
and occurrence-level summary data provided in the TNHID (2018). We used 
these summary data to determine which sites in each tier had been 
monitored in 2 or more years, making it possible to assess whether 
Cumberland sandwort had declined, remained stable, or increased either 
in estimated abundance or area occupied. Available abundance data were 
typically produced by visually estimating numbers of plants, although 
precise count data were available in some instances. Based on data 
provided in the TNHID, 18 occurrences are in Tier 1, 24 in Tier 2, and 
13 in Tier 3 for which such data were available. Tier 1 occurrences 
have been monitored an average of 4.7 times, with time between initial 
and the most recent monitoring events averaging 15.8 years. Tier 2 
occurrences have been monitored an average of 2.4 times over an average 
timespan of 8.4 years. Tier 3 occurrences have been monitored an 
average of 2.4 times over an average timespan of 12.1 years. Fifteen 
occurrences in Tennessee have been monitored only once or have not, as 
yet, been assigned to a monitoring tier.
    After reviewing all available monitoring data, TDEC assessed 
whether individual occurrences had declined, remained stable, or 
increased over the time that they have been monitored (McCoy 2018, 
pers. comm.). However, statistical trend analysis of Cumberland 
sandwort monitoring data from Tennessee is not feasible for two 
reasons: first, estimates of abundance generated in 2000 and in later 
monitoring events lack adequate precision for statistically analyzing 
change in abundance over time, and second, visual estimates of area 
occupied by the species can introduce potential for observer bias 
because these areas are not precisely measured. However, the 
preparation of hand-drawn maps by TDEC botanists, beginning with the 
initial monitoring effort in 2000, allows tracking persistence and 
stability of individual patches within occupied sites and detecting 
substantial changes in their estimated size. Maps are also updated to 
depict new patches that might form due to recruitment of individuals in 
previously unoccupied habitat. Estimates of abundance, where available, 
provided supplemental data for qualitatively evaluating trends within 
mapped patches of habitat. Based on the best available data, of the 18 
Tier 1 occurrences, 2 demonstrate evidence of decline, 13 are stable, 
and 3 have increased. Of the 24 Tier 2 occurrences that have been 
monitored on two or more occasions, 5 demonstrate evidence of decline, 
18 are stable, and 1 has increased. Of the 13 Tier 3 occurrences, 2 
have declined, 10 are stable, and 1 has increased (McCoy 2018, pers. 
comm.).

Recovery

    Section 4(f) of the Act (16 U.S.C. 1531 et seq.) directs us to 
develop and implement recovery plans for the conservation and survival 
of endangered and threatened species unless we determine that such a 
plan will not promote the conservation of the species. Recovery plans 
must, to the maximum extent practicable, include objective, measurable 
criteria which, when met, would result in a determination, in 
accordance with the provisions of section 4 of the Act, that the 
species be removed from the list.
    Recovery plans provide a roadmap for us and our partners on methods 
of enhancing conservation and minimizing threats to listed species, as 
well as measurable criteria against which to evaluate progress towards 
recovery and assess the species' likely future condition. However, they 
are not regulatory documents and do not substitute for the 
determinations and promulgation of regulations required under section 
4(a)(1) of the Act. A decision to revise the status of a species, or to 
delist a species is ultimately based on an analysis of the best 
scientific and commercial data available to determine whether a species 
is no longer an endangered species or a threatened species, regardless 
of whether that information differs from the recovery plan.
    There are many paths to accomplishing recovery of a species, and 
recovery may be achieved without all criteria being fully met. For 
example, one or more criteria may have been exceeded while other 
criteria may not yet be accomplished. In that instance, we may 
determine that the threats are minimized sufficiently and that the 
species is robust enough that it no longer meets the definition of an 
endangered species or a threatened species. In other cases, we may 
discover new recovery opportunities after having finalized the recovery 
plan. Parties seeking to conserve the species may use these 
opportunities instead of methods identified in the recovery plan. 
Likewise, we may learn new information about the species after we 
finalize the recovery plan. The new information may change the extent 
to which existing criteria are appropriate for identifying recovery of 
the species. The recovery of a species is a dynamic process requiring 
adaptive management that may, or may not, follow all of the guidance 
provided in a recovery plan.
    The Cumberland Sandwort Recovery Plan (Service 1996, pp. iv, 10) 
included

[[Page 45689]]

recovery criteria to indicate when threats to the species have been 
adequately addressed and prescribed actions that were thought to be 
necessary for achieving those criteria. Below we discuss our analysis 
of available data and our determination as to whether recovery criteria 
for Cumberland sandwort have been achieved.

Recovery Criteria

    The objective of the recovery plan is to delist the Cumberland 
sandwort. Recovery criteria in the plan state that Arenaria 
cumberlandensis (Cumberland sandwort) will be considered for 
reclassification from endangered to threatened status when 30 
geographically distinct, self-sustaining occurrences are protected in 
four counties in Tennessee and Kentucky and have maintained stable or 
increasing numbers for 5 consecutive years. The species will be 
considered for delisting when 40 geographically distinct, self-
sustaining occurrences are protected and have maintained statistically 
stable or increasing numbers for 5 consecutive years. At least 12 of 
these occurrences must be in counties other than Pickett County, 
Tennessee.
    Methods were chosen for monitoring that minimize trampling of 
Cumberland sandwort and disturbance of the sandy soil substrate the 
species occupies. The tradeoff of using this method to minimize 
disturbance is the inability to statistically analyze trends for 
individual occurrences or Cumberland sandwort as a species. To address 
this limitation, we developed a framework for using available 
distribution and monitoring data, aerial photography, and qualitative 
assessment of trends for each occurrence to evaluate whether recovery 
criteria for Cumberland sandwort have been achieved.
    Using this framework, we assessed the species' viability based on 
the three conservation biology principles of resiliency, 
representation, and redundancy (Shaffer and Stein 2000, entire). 
Resiliency is the ability to sustain populations in the face of 
environmental variation and transient perturbations. To be resilient, a 
species must have healthy populations that are able to sustain 
themselves through the range of possible environmental conditions. The 
greater the number of healthier populations, the more resiliency a 
species possesses. Representation is the range of variation or adaptive 
diversity found in a species, and is the source of a species' ability 
to adapt to near- and long-term changes in the environment. Maintaining 
adaptive diversity requires conserving both ecological and genetic 
diversity, which enable a species to be more responsive and adaptive to 
change and, therefore, more viable. Finally, redundancy protects 
species against the unpredictable and highly consequential events for 
which adaptation is unlikely, allowing them to withstand catastrophic 
events. Redundancy spreads risk and is best achieved by having multiple 
populations widely distributed across a species' range.
    We characterized the resiliency of 69 of the 71 extant Cumberland 
sandwort occurrences using available data on three factors (complete 
data were not available for two of the extant occurrences): Occurrence 
size expressed as estimated abundance or areal coverage, recorded 
observations of threats causing disturbance to plants or the substrates 
in which they were rooted, and assessment of general forest conditions 
from recorded observations or evaluation of aerial photography, for the 
reasons that follow. Occurrence size influences resiliency because 
smaller populations are at greater risk of (1) losing genetic variation 
due to drift (change in the frequency of alleles in a population due to 
random, stochastic events), and (2) inbreeding, which decreases the 
likelihood that an individual will receive pollen from a compatible 
mate and produce viable offspring (Allendorf and Luikart 2007, pp. 122-
123). Small populations also may face higher risks of extinction due to 
diminished resilience to demographic and environmental stochasticity 
(M[uuml]nzbergov[aacute] 2006, p. 143). Demographic stochasticity is 
the variation in vital rates (i.e., probabilities of survival and 
reproduction) among individuals of a given age or life-cycle stage, at 
a given point in time, while environmental stochasticity is variation 
in vital rates over time, affecting all individuals of a given age or 
stage similarly (Lande 1988, p. 1457). Incorporating available data 
regarding disturbance to Cumberland sandwort plants or the substrates 
where they occur into the resiliency assessment serves as a proxy 
indicating whether physical conditions are appropriate to support 
multiple life stages. Undisturbed substrates contribute to Cumberland 
sandwort resiliency by providing suitable sites for germination, 
growth, and reproduction to occur. Similarly, evaluating forest 
condition in the vicinity of Cumberland sandwort occurrences is a proxy 
indicating whether ecological conditions are likely to support 
resilience to environmental variation. The presence of contiguous 
forest vegetation in the vicinity of Cumberland sandwort occurrences 
helps to maintain suitable hydrology and microclimate, potentially 
buffering severity of stress resulting from environmental 
perturbations, such as drought. We evaluated representation by 
considering the distribution of resilient occurrences among the 
counties and watersheds from which the species is known. Finally, we 
evaluated redundancy based on the overall number of resilient 
occurrences distributed throughout its range.
    In evaluating resiliency, we used estimates of abundance, where 
available, combined with estimates of areal coverage to provide a basis 
for categorizing occurrences into groups of low, medium, or high 
abundance. Occurrences with fewer than 100 individuals (Heschel and 
Page 1995, pp. 128-131; M[uuml]nzbergov[aacute] 2006, p. 148) or with 
areal coverage less than 1 square meter (m\2\) were ranked ``low''; 
occurrences with 100-1,000 individuals or with areal coverage ranging 
from 1 to 5 m\2\ were ranked ``medium''; and occurrences with more than 
1,000 individuals or areal coverage greater than 5 m\2\ were ranked 
``high.'' We ranked substrate conditions at each occurrence based on 
recorded observations of threats (TDEC 2011b, pp. 37-44). Substrate 
conditions were ranked ``high'' for sites with no record of 
disturbance; ``medium'' for sites with moderate risk of exposure to the 
threat based on limited historical evidence of digging for 
archeological artifacts (i.e., relic digging) or trampling by humans or 
wildlife in limited areas within available habitat; and ``low'' for 
sites with high risk of exposure as indicated by recent evidence of 
relic digging or trampling throughout available habitat. We used aerial 
imagery available through Google Earth ProTM to determine 
whether forests in the general vicinity of Cumberland sandwort 
occurrences exhibited signs of timber harvest, as indicated by 
substantially reduced tree densities; presence of logging equipment 
trails; or conversion to nonnative, evergreen forest types. We used 
available data on global forest loss to provide an objective basis for 
confirming our determination of locations where timber harvest was 
suspected to have taken place (Hansen et al. 2013, entire). Forest 
conditions were ranked ``high'' in locations where late seral forest 
was present upslope and downslope of occupied sites and in adjacent 
areas; ``medium'' in locations where risk of exposure to the threat was 
moderate based on evidence of logging having occurred within the prior 
15

[[Page 45690]]

years in the vicinity of, but not immediately upslope, downslope, or 
adjacent to, occurrences; and ``low'' in sites where risk of exposure 
was high based on evidence of logging within the prior 15 years in the 
forest immediately surrounding the occupied habitat.
    Of the 69 occurrences that we could evaluate for all three 
resiliency factors, 12 were ranked as low in abundance, 27 ranked 
medium, and 30 ranked high. Substrate conditions ranked low at 12, 
medium at 25, and high at 32 occurrences. We were able to evaluate 
forest conditions at all 71 extant occurrences, with the following 
results: 8 occurrences ranked low, 3 ranked medium, and 60 ranked high.
    Using the ranks for the three resiliency factors (abundance, 
substrate condition, and forest condition), we calculated an overall 
resiliency index for 68 of the 70 Tennessee occurrences (see Table 1, 
below) and the sole Kentucky occurrence. We assigned numerical scores 
of one for factor ranks of ``low,'' two for ``medium'' ranks, and three 
for ``high'' ranks. Using these scores, we calculated a weighted 
average, wherein factor ranks for abundance were given twice the weight 
of factor ranks for substrate and forest condition, due to the 
importance of population size in maintaining genetic variation and 
determining resilience to demographic and environmental stochasticity 
(Sgr[ograve] et al. 2011, p. 329). The resulting resiliency index for 
an occurrence ranges from one to three and is categorized as follows:
     Low rank for scores of 1.5 or less;
     Low-medium rank for scores greater than 1.5 and less than 
2.0;
     Medium rank for scores greater than 2.0 and less than 2.5;
     Medium-high rank for scores greater than 2.5 and less than 
3.0;
     High rank for scores of 3.0.
    Available data for the Kentucky occurrence indicate that the 
species abundance rank is medium at that location and that the 
occurrence is not exposed to threats from trampling or relic digging. 
This location, in Big South Fork National Scenic River and Recreation 
Area (BSF), is protected from timber harvesting, and available data 
indicate that surrounding forests are undisturbed. These factors 
produced an overall resiliency rank of medium for this occurrence.
    In Tennessee, 56 occurrences had overall resiliency ranks of medium 
or higher. Table 1 shows the resiliency ranks for 68 of the 70 
Tennessee occurrences. All of the stable and increasing trends in the 
medium, medium-high, and high resiliency ranks represent counts of 
occurrences considered self-sustaining, as required by recovery 
criteria.

                                    Table 1--Resiliency Index Ranks for Cumberland Sandwort Occurrences in Tennessee
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Monitoring tier                           Trend                   Low         Low- medium       Medium       Medium- high        High
--------------------------------------------------------------------------------------------------------------------------------------------------------
One.......................................  Decline.....................               2  ..............  ..............  ..............  ..............
                                            Stable......................               1               1               7               4  ..............
                                            Increase....................  ..............  ..............  ..............               2               1
Two.......................................  Decline.....................               3  ..............               2  ..............  ..............
                                            Stable......................               2  ..............              10               3               2
                                            Increase....................  ..............  ..............  ..............               1  ..............
Three.....................................  Decline.....................               1  ..............               1  ..............  ..............
                                            Stable......................  ..............  ..............               4               3               3
                                            Increase....................  ..............  ..............               1  ..............  ..............
Other.....................................  n/a.........................               1               1               7  ..............               5
                                                                         -------------------------------------------------------------------------------
    Total.................................  ............................              10               2              32              13              11
--------------------------------------------------------------------------------------------------------------------------------------------------------

    For the purpose of evaluating Cumberland sandwort's status with 
respect to recovery criteria, we define self-sustaining to include 
those populations that had an overall resiliency index rank of medium 
or higher and that TDEC determined were stable or increasing (see Table 
1, above) based on available monitoring data, as described above in 
Species Information. For the Kentucky occurrence, available data 
indicate that the occurrence is stable. We consider 66 occurrences on 
Federal or State conservation lands (see Table 2, below), as well as 2 
occurrences located on private lands where land use is restricted by 
conservation easements, to be protected. Using these definitions, 42 
protected occurrences (including the 1 in Kentucky) are self-sustaining 
(Table 1, above, presents data for Tennessee). These occurrences have 
been known to exist for an average of 21 years, with a range of 7 to 44 
years spanning the first and most recent observations recorded for the 
species in these sites. These data support the conclusion that one 
criterion for removing Cumberland sandwort from the List has been 
exceeded, i.e., that there be at least 40 geographically distinct, 
protected, and self-sustaining occurrences that have been stable or 
increasing for at least 5 years.

   Table 2--Land Ownership for 66* Cumberland Sandwort Occurrences on
                  Federal and State Conservation Lands
------------------------------------------------------------------------
                                                           Number of
             Agency                    Land unit         occurrences *
------------------------------------------------------------------------
National Park Service...........  Big South Fork      27.
                                   National Scenic
                                   River and
                                   Recreation Area
                                   (BSF).
Tennessee Division of Forestry    Pickett State       29 (4 partially on
 (TDF).                            Forest (PSF).       TSP lands).
Tennessee Division of Natural     Pogue Creek Canyon  7.
 Areas.                            State Natural
                                   Area (PCNA).
Tennessee State Parks (TSP).....  Pickett CCC         7 (4 partially on
                                   Memorial State      TDF lands).
                                   Park (PSP).
------------------------------------------------------------------------
* Number of occurrences in this table sums to 70, but 4 occurrences
  occupy habitats spanning adjacent lands owned by TDF and TSP and are
  counted only once for the total.


[[Page 45691]]

    The recovery criteria in the recovery plan also require that at 
least 12 of the protected, self-sustaining occurrences be located 
outside of Pickett County, Tennessee, which provides for redundancy 
across areas of representation within the species' geographic range. Of 
the 42 occurrences meeting the criterion of being protected and self-
sustaining, 28 are located in Pickett County, Tennessee; 13 are located 
elsewhere in Tennessee (9 in Fentress County, 4 in Scott County); and 1 
is located in McCreary County, Kentucky. Thus, this delisting criterion 
is also exceeded.
    Another measure of representation for the species is its 
distribution among major watersheds in which it is found. The recovery 
plan reported in 1996 that the species was known only from the South 
Fork Cumberland watershed, but it is now also known from 12 occurrences 
in the Obey River watershed in Tennessee. Of the 42 occurrences meeting 
the recovery criterion that there be at least 40 geographically 
distinct, protected, and self-sustaining occurrences, 2 are located in 
the Obey River watershed. The low number of occurrences in this 
watershed meeting this criterion is primarily due to the recent 
discovery of many of the occurrences in this watershed and the 
consequent lack of repeat observations. In addition to the two 
occurrences in the Obey River watershed meeting the recovery criterion 
above, nine occurrences on protected lands have resiliency indices of 
medium or higher.
    Our assessment of the viability of Cumberland sandwort supports the 
determination that the recovery criteria for delisting the species have 
been satisfied. The discussion above demonstrates that there are more 
than 40 protected and self-sustaining occurrences of the species, 
distributed among four counties in Tennessee and one in Kentucky.

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for listing 
species, reclassifying species, or removing species from listed status. 
We may determine that a species is an endangered or threatened species 
due to one or more of the five factors described in section 4(a)(1) of 
the Act: (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.
    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 now and in the 
foreseeable future.
    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. The term 
foreseeable future extends only so far into the future as we can 
reasonably determine that both the future threats and the species' 
responses to those threats are likely. In other words, the foreseeable 
future is the period of time in which we can make reliable predictions. 
``Reliable'' does not mean ``certain''; it means sufficient to provide 
a reasonable degree of confidence in the prediction. Thus, a prediction 
is reliable if it is reasonable to depend on it when making decisions.
    It is not always possible or necessary to define foreseeable future 
as a particular number of years. Analysis of the foreseeable future 
uses the best scientific and commercial data available and should 
consider the timeframes applicable to the relevant threats and to the 
species' likely responses to those threats in view of its life-history 
characteristics. 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.
    A recovered species is one that no longer meets the Act's 
definition of endangered or threatened. Determining whether the status 
of a species has improved to the point that it can be delisted or 
downlisted requires consideration of the same five factors identified 
above for listing a species. When Cumberland sandwort was listed as 
endangered in 1988, the identified threats (factors) influencing its 
status were the modification and loss of habitat and curtailment of 
range (Factor A), the inadequacy of State or Federal mechanisms to 
protect its habitat at that time (Factor D), and its limited 
distribution and low abundance in some populations (Factor E). The 
following analysis evaluates these previously identified threats, any 
other threats currently facing the species, as well as any other 
threats that are reasonably likely to affect the species in the 
foreseeable future following the delisting and the removal of the Act's 
protections.
    To establish the foreseeable future for the purpose of determining 
whether Cumberland sandwort meets the definition of an endangered or 
threatened species, we evaluated trends from historical data on 
distribution and abundance, ongoing conservation efforts, factors 
currently affecting the species, and predictions of future climate 
change. Structured monitoring of Cumberland sandwort populations began 
in 2000, but records of initial observations for occurrences range from 
1973 to 2017, with an average of 18 years between the earliest and most 
recent recorded observations for a given occurrence. The period of 
observation is 30 or more years for 16 occurrences,

[[Page 45692]]

which vary in population size and threat exposure. These historical 
data provide insight into Cumberland sandwort's exposure and response 
to potential threats under varying conditions. When combined with our 
knowledge of factors affecting the species, available data allow us to 
reasonably predict future conditions, albeit with diminishing precision 
over time. Given our understanding of the best available data, we 
consider the foreseeable future for Cumberland sandwort to be 
approximately 30 years for the purposes of this rule.
    In assessing threats to Cumberland sandwort, we consider the 
exposure of individual occurrences to suspected stressors, available 
data on the species' response to those stressors where they have been 
observed, and efforts undertaken to reduce exposure into the future. As 
noted above in Recovery Criteria, available data indicate that the 
Kentucky occurrence is not exposed to threats that would result in 
modification or destruction of habitat.

Habitat Loss and Curtailment of Range

    In the rule listing the Cumberland sandwort (53 FR 23745; June 23, 
1988), the primary threats identified for the species were the 
destruction and modification of habitat due to trampling by 
recreational users of the rockhouse and bluff habitats where the 
species occurs, trampling and soil disturbance from looting of 
archeological artifacts (i.e., relic digging), and timber harvesting in 
or adjacent to occupied sites.
    In Tennessee, the potential for trampling or soil disturbance from 
recreational use, wildlife, or relic digging has been noted at 38 sites 
where Cumberland sandwort occurs, with varying degrees of exposure and 
actual risk for adversely affecting the species (TDEC 2011b, pp. 40-44; 
TNHID 2018). In one of these sites (E.O. 78), signs of trampling and a 
fire pit were observed on the rockhouse floor in 2007 (TNHID 2018), but 
Cumberland sandwort plants are located on ledges and solution pockets 
on the bluff where they are not exposed to trampling. Additionally, no 
fire pit was observed during a site visit by the Service in February 
2019. Of the other 37 sites where risk of trampling or soil disturbance 
has been recorded during monitoring or other site visits, available 
data indicate that Cumberland sandwort faces high risk of exposure in 
12 of them and moderate risk in the other 25. Cumberland sandwort 
abundance has declined at 6 of the 12 sites with high exposure risk, 
while 6 have remained stable. Declines in abundance have been observed 
at only three of the sites with moderate risk of exposure, while 
increases have been observed at three others. The remaining 19 sites 
with moderate risk of exposure to the threat of trampling or soil 
disturbance have remained stable. Thus, while the potential threat of 
trampling or soil disturbance has been noted at many sites, Cumberland 
sandwort faces a high risk of actual exposure in less than 20 percent 
of occurrences. Under conditions of moderate exposure risk, the species 
has demonstrated low vulnerability to being adversely affected, having 
maintained stable populations in most instances. Regardless of the 
level of exposure risk, no occurrences are known to have been 
extirpated as a result of trampling or soil disturbance from 
recreational use, wildlife, or relic digging.
    Protective features, including fences, boardwalks, barricades, 
rerouted trails, or informational signs, have been installed at 8 of 
the 37 occurrences discussed above, protecting specific habitats 
occupied by Cumberland sandwort (Service 2013, pp. 13-14; TDEC 2016, p. 
3). Seven of these sites where management has occurred to reduce the 
threat of trampling have remained stable or seen increases in 
Cumberland sandwort, whereas 20 of the 30 sites where the risk of 
trampling has been noted but not managed have remained stable. This 
information indicates that management efforts have been effective at 
reducing adverse effects, especially when considering that such 
management was provided in sites where the greatest threats were 
present. The seven occurrences at PCNA are protected from recreational 
activities by the State's efforts to survey proposed alignments for new 
trails and route them away from sites with Cumberland sandwort. 
Measures such as these reduce or preclude the species' exposure to the 
threat of trampling from recreationists using trails on public lands 
where the species occurs.
    Available data reveal the lack of a clear trend in visitation rates 
to recreational lands where Cumberland sandwort occurs. The BSF 
experienced an overall decline in annual visitation levels from 
892,322, in 1995, to 643,135 in 2015 (NPS 2020). Conversely, PSP, saw 
an overall increase from 223,397 to 271,889 annual visitors between 
2009 and 2013 (Tennessee State Parks, no date). We are not aware of 
data regarding predicted trends in future visitation for these parks, 
nor are data available to estimate what proportion of visitors use 
trails where Cumberland sandwort is located.
    Timber harvest occurs at PSF, but does not occur at BSF, PSP, or 
PCNA, limiting the potential magnitude of this activity, determined at 
the time of listing to be a threat to Cumberland sandwort, to less than 
half of the sites on conservation lands. During the course of 
evaluating forest conditions in the vicinity of Cumberland sandwort 
occurrences, we observed that timber harvests had been conducted in the 
general vicinity of 10 occurrences at PSF, during the period between 
approximately 2008 and 2017. Timber harvests occurred upslope or 
downslope of seven of these occurrences, creating a high risk for 
exposure to potential effects of this threat, and in the general 
vicinity of three occurrences, where exposure risk was moderate. 
Sometime prior to 1999, the forest was converted to pasture on the 
plateau top above an eleventh occurrence, located on privately owned 
lands. Based on these data, timber harvests or forest conversion to 
pasture have taken place near approximately 15 percent of Cumberland 
sandwort sites. Data were available to evaluate trends for 10 of these 
11 occurrences, showing that 3 have declined and 7 have remained 
stable. Monitoring data collected by TDEC since 2016 at three of these 
declining occurrences revealed no adverse effects from logging 
activities. These data support the conclusion that timber harvests in 
the vicinity of Cumberland sandwort occurrences that do not directly 
impact the species or its habitat may pose little threat in terms of 
indirect effects. This conclusion is also supported by observations 
from visits we conducted in February 2019 to four occurrences with 
nearby timber harvests, in which no adverse effects from off-site 
timber removal were detectable. Based on these observations, we 
conclude that our estimates of forest condition ranks, discussed above 
in Recovery Criteria, likely underestimate the resiliency of 
occurrences in those instances where forest condition ranks were 
reduced due to evidence of nearby logging activities.
    While some Cumberland sandwort occurrences are exposed to potential 
habitat-related stressors that might, in certain situations, adversely 
affect the species, available monitoring data indicate that the species 
is less vulnerable to these threats than was determined at the time of 
listing. When Cumberland sandwort is removed from the List (see DATES, 
above), our post-delisting monitoring plan (see Post-delisting 
Monitoring, below) identifies 50 occurrences that will be monitored 
over a period of at least 5 years following delisting, including 27 
occurrences where risks of exposure to

[[Page 45693]]

soil disturbance or trampling, effects of nearby timber harvests, or 
the two combined have been moderate to high. Continuing to monitor 
sites where Cumberland sandwort is or could be exposed to potential 
threats that were previously determined to place the species at risk of 
extinction will provide an opportunity to work with land managers to 
avoid or minimize adverse effects should the threats increase in 
severity or extent.
    In our analysis of Cumberland sandwort's resiliency, discussed 
above in Recovery Criteria, we incorporated available data regarding 
threats that could potentially modify habitat or curtail the species' 
range. We determined that 42 occurrences currently meet the criterion 
of being protected and self-sustaining. These occurrences have been 
known to exist for an average of 21 years, with a range of 7 to 44 
years from the first to the most recent observations recorded for the 
species in these sites. In addition to these 42 occurrences, 9 
occurrences are protected in the Obey River watershed and 2 in the 
South Fork Cumberland watershed in Tennessee for which sufficient 
monitoring data for evaluating trends in abundance or threats is 
lacking. However, seven of these occurrences in the Obey River drainage 
have no evidence of substrate or forest disturbance and are located in 
PCNA, where TDEC (no date, pp. 10-11) surveys potential trail routes to 
prevent new trail construction that would expose occurrences to threats 
from recreational uses. No other potential threats to the habitats at 
PCNA have been documented. The two occurrences in the South Fork 
Cumberland drainage are located in BSF and are not affected by any 
known threats because they are remotely located from trail access and 
protected from timber harvest.
    Thus, available data indicate that Cumberland sandwort is resilient 
to the factors discussed above that were determined at the time of 
listing to constitute a threat of habitat modification or curtailment 
of the species' range. Additionally, management actions have been 
effective at reducing potential adverse effects of disturbance 
associated with recreational activities at sites where those activities 
are most prevalent.

Limited Distribution and Small Population Sizes

    The listing rule for Cumberland sandwort (53 FR 23745; June 23, 
1988) identified the species' restricted distribution, limited to a 
small portion of the Cumberland Plateau in northern Tennessee and 
southern Kentucky, and the small size of many populations, as factors 
increasing the risks of population loss and potential extinction of the 
species. The species is still restricted to a small portion of the 
Cumberland Plateau, but the number of known occurrences has increased 
from 11 at the time of listing (Wofford and Smith 1980, pp. 9-18; 53 FR 
23745, June 23, 1988) to 71 currently (TNHID 2018). Three projects have 
been funded to support searches for new Cumberland sandwort occurrences 
(Kentucky State Nature Preserves Commission (KSNPC) 1991, entire; TDEC 
2000, entire; TDEC 2008, entire). The single search effort that 
occurred in Kentucky, only in McCreary County, did not expand the known 
range of Cumberland sandwort, but confirmed the known occurrence 
located in Big Spring Hollow and documented that thousands of plants 
were present at two sites mapped at the occurrence (KSNPC 1991, 
entire). Searches conducted in Tennessee in 2000 (TDEC 2000, entire) 
and 2006-2007 (TDEC 2008, entire) produced records for 30 new 
occurrences on conservation lands in Fentress, Pickett, and Scott 
Counties, Tennessee. In addition to these three Cumberland sandwort 
survey projects, surveys at PCNA for prospective trail routes have 
produced records for six additional occurrences on conservation lands 
in Fentress County (TNHID 2018). These survey efforts, funded in part 
by the Service via the Act's section 6 grants to State agencies for 
endangered species recovery, contributed greatly to increasing the 
species' distribution to the 71 extant occurrences known today.
    Fourteen protected and self-sustaining occurrences are located 
outside of Pickett County, satisfying the recovery criterion concerning 
geographic distribution. Also, 12 of the 71 occurrences are located in 
the Obey River watershed in Tennessee, increasing the species' 
distribution beyond the South Fork Cumberland watershed, to which the 
species was thought to be restricted at the time of listing.
    The 1988 listing rule discussed small population size as a threat 
to many occurrences, but did not include information on population 
sizes known at the time or specify the number of individuals or the 
size of habitat area occupied that would be necessary to buffer against 
extinction risk. As discussed above in Recovery Criteria, we used 
available data to evaluate the species' abundance at known occurrences. 
We consider populations consisting of fewer than 100 individuals or 
occupying less than 1 m\2\ of habitat to be at heightened risk of (1) 
losing genetic variation due to drift (change in the frequency of 
alleles in a population due to random, stochastic events), and (2) 
inbreeding, which decreases the likelihood that an individual will 
receive pollen from a compatible mate and produce viable offspring 
(Allendorf and Luikart 2007, pp. 122-123). However, we note that the 
risk of inbreeding depression due to unavailability of incompatible 
mates might be low for Cumberland sandwort, as self-compatibility 
apparently evolved twice in geographically distant populations of the 
closely related congener Mononeuria (=Arenaria) glabra at the edges of 
that species' range (Wyatt 1984, p. 815). Based on available data, 12 
populations consist of fewer than 100 individuals or occupy less than 1 
m\2\ of habitat. Six of these 12 have been known to persist as small 
populations for lengths of time ranging from 24 to 41 years, indicating 
that even small populations are likely to persist when threats are 
minimized (TNHID 2018). The remaining six were discovered in 2000 or 
later. In contrast, 27 occurrences contain 100-1,000 individuals or 
occupy 1 to 5 m\2\ of habitat, and 30 occurrences contain more than 
1,000 individuals or occupy greater than 5 m\2\ of habitat. Estimates 
of abundance available for 24 of the largest occurrences indicate that 
they collectively hold at least 67,000 Cumberland sandwort individuals. 
These data demonstrate that risks associated with small population size 
are a potential threat likely affecting less than 20 percent of the 71 
extant Cumberland sandwort occurrences. Despite the potential risks 
associated with small population sizes, available data demonstrate 
long-term persistence of Cumberland sandwort at all sites where 
abundance is low and stable or increasing trends at more than 60 
percent of the small populations for which trend data are available. 
Thus, available data support the conclusion that small population size 
is neither a widespread threat to Cumberland sandwort nor has it been 
demonstrated to place populations at high risk of decline or 
extirpation.
    Techniques for micropropagating, cryopreserving, and outplanting 
Cumberland sandwort have been developed and successfully applied to 
establish an introduced population at DBNF (Pence et al. 2011, entire), 
which is not counted among the 71 extant occurrences discussed above. 
This introduced population has grown from an initial outplanting of 63 
individuals to 255 individuals, representing multiple life stages, as 
of 2017 (Taylor

[[Page 45694]]

2018, pers. comm.). Eight years after initial outplanting, the genetic 
variation in this population, which was established in 2005 from seven 
genetic lines, was approaching levels of genetic diversity comparable 
to the source population (Philpott et al. 2014, entire). The Missouri 
Botanical Garden (MBG) has seeds in storage from BSF and PSP that were 
collected in 1991, 1994, 2005, and 2014 (Dell 2018, pers. comm.). 
Collections were made at multiple points in time to maintain seed 
viability in storage. While a cultivated source of plants is not 
currently maintained ex situ, the need for doing so is mitigated by the 
development of methods to micropropagate the species from cuttings and 
by availability of seeds in ex situ collections, providing two 
potential methods for propagating the species should it become 
necessary to do so.
    Available data support the determination that Cumberland sandwort 
is not likely to become endangered in the foreseeable future due to 
limited distribution or small population sizes.

Effects of Climate Change

    Our analyses under the Act include consideration of ongoing and 
projected changes in climate. The terms ``climate'' and ``climate 
change'' are defined by the Intergovernmental Panel on Climate Change 
(IPCC). The term ``climate change'' thus refers to a change in the mean 
or variability of one or more measures of climate (e.g., temperature or 
precipitation) that persists for an extended period, typically decades 
or longer, whether the change is due to natural variability, human 
activity, or both (IPCC 2014, pp. 119-120). A recent compilation of 
climate change and its effects is available from reports of the IPCC 
(IPCC 2014, entire).
    The IPCC concluded that evidence of warming of the climate system 
is unequivocal (IPCC 2014, pp. 2, 40). Numerous long-term climate 
changes have been observed including changes in arctic temperatures and 
ice, widespread changes in precipitation amounts, changes in ocean 
salinity, and aspects of extreme weather including heavy precipitation 
and heat waves (IPCC 2014, pp. 40-44). Since 1970, the average annual 
temperature across the Southeast has increased by about 2 degrees 
Fahrenheit ([deg]F), with the greatest increases occurring during 
winter months. The geographic extent of areas in the Southeast region 
affected by moderate to severe spring and summer drought has increased 
over the past three decades by 12 and 14 percent, respectively (Karl et 
al. 2009, p. 111). These trends are expected to increase. Rates of 
warming are predicted to more than double in comparison to what the 
Southeast has experienced since 1975, with the greatest increases 
projected for summer months. Depending on the emissions scenario used 
for modeling change (IPCC 2000, entire), average temperatures are 
expected to increase by 2.5 degrees Celsius ([deg]C) (4.5 [deg]F) 
(scenario B1) to 5 [deg]C (9 [deg]F) (scenario A2) by the 2080s (Karl 
et al. 2009, p. 111). While there is considerable variability in 
rainfall predictions throughout the region, increases in evaporation of 
moisture from soils and loss of water by plants in response to warmer 
temperatures are expected to contribute to increased frequency, 
intensity, and duration of drought events (Karl et al. 2009, p. 112).
    We used the National Climate Change Viewer (NCCV), a climate-
visualization tool developed by the U.S. Geological Survey (USGS), to 
generate future climate projections across the range of Cumberland 
sandwort. The NCCV is a web-based tool for visualizing projected 
changes in climate and water balance at watershed, State, and county 
scales (USGS 2017). This tool uses air temperature and precipitation 
data from 30 downscaled climate models for two Representative 
Concentration Pathway (RCP) scenarios, RCP 4.5 and RCP 8.5, as input to 
a simple water-balance model to simulate changes in the surface water 
balance over historical and future time periods, providing insight into 
potential for climate-driven changes in water resources. To evaluate 
the maximum effects of climate change in the future, we used 
projections from RCP 8.5, which is the most aggressive emissions 
scenario wherein greenhouse gases (GHGs) rise unchecked through the end 
of the century, to characterize projected future changes in climate and 
water resources, averaged across the five counties encompassing the 
range of Cumberland sandwort. The projections estimate change in mean 
annual values, comparing the period 1981 through 2010 with 2050 through 
2074, for maximum and minimum temperature, monthly precipitation and 
runoff, snowfall, soil water storage, and evaporative deficit.
    Within the range of Cumberland sandwort, the NCCV projects that, 
under the more extreme RCP 8.5 scenario, maximum temperature will 
increase by 3.2 [deg]C (5.7 [deg]F), minimum temperature will increase 
by 3.1 [deg]C (5.6 [deg]F), precipitation will increase by 5.36 mm (0.2 
in) per month, soil water storage will decrease by 12.2 mm (0.5 in) 
annually, and evaporative deficit will increase by 4.6 mm (0.2 in) per 
month. Projected changes in snowfall are negligible. These estimates 
indicate that, despite projected minimal increases in annual 
precipitation, anticipated increases in maximum and minimum 
temperatures will offset those gains, leading to a net loss in 
projected runoff and soil water storage. The most notable change with 
respect to water balance between the two time periods is that soil 
storage projections are projected to be significantly reduced during 
the months of June through November for the period 2050 through 2074. 
Based on these projections, Cumberland sandwort will on average be 
exposed to increased temperatures across its range, which, despite 
limited increases in precipitation, are expected to decrease soil water 
available during the growing season.
    Assessments of vulnerability of federally listed plants in 
Tennessee to projected climate change have been conducted by two 
different groups (Glick et al. 2015, entire; Kwit 2018, pers. comm.) 
using version 2.1 of NatureServe's Climate Change Vulnerability Index 
(CCVI) (Young et al. 2015, entire). The CCVI is an assessment tool that 
combines results of downscaled climate predictions, characterizing 
direct exposure to projected climate change, with readily available 
information about a species' natural history, distribution, and 
landscape circumstances, which together influence sensitivity to 
change, to predict whether it will likely suffer a range contraction 
and/or population reductions due to the effects of climate change. For 
these assessments using the CCVI, climate change projections were based 
on ensemble climate predictions, representing a median of 16 major 
global circulation models and using a ``middle of the road'' scenario 
(i.e., emission scenario A1B of the IPCC (IPCC 2000, entire)) for GHG 
emissions (Young et al. 2015, p. 14) instead of the more extreme 
scenario that we used in the NCCV to project the climate and water 
balance changes reported above. From these two assessments, Cumberland 
sandwort was ranked as either ``presumed stable'' (Glick et al. 2015, 
p. 40) or ``moderately vulnerable'' (Kwit 2018, pers. comm.), the 
latter indicating the species' abundance and/or range extent within the 
geographical area assessed would likely decrease by 2050 (Young et al. 
2015, p. 45).
    The disparate results between these two assessments conducted using 
the same tool illustrate that there is some subjectivity involved in 
evaluating aspects of a species' biology and ecology as they relate to 
CCVI sensitivity factors used to model potential vulnerability to

[[Page 45695]]

projected climate change. In the case of Cumberland sandwort, differing 
judgements of the species' physiological dependence on specific thermal 
and hydrological niches, restriction to uncommon geological features, 
and potential for phenological response to changing climate resulted in 
different outcomes with respect to predicted vulnerability to climate 
change. In the assessment that ranked Cumberland sandwort as moderately 
vulnerable, each of these factors were individually ranked as being 
more likely to increase the species' overall vulnerability than in the 
contrasting assessment that produced a rank of presumed stable.
    Despite having produced different vulnerability ranks, both 
assessments ranked Cumberland sandwort among the least vulnerable to 
projected climate change of the federally listed plant species 
evaluated in Tennessee (Glick et al. 2015, p. 40; Kwit 2018, pers. 
comm.). While the rank of moderately vulnerable indicates that 
Cumberland sandwort would likely decrease in abundance and/or range 
extent by 2050, neither assessment using the CCVI predicted that the 
species would decrease significantly in abundance and/or range extent. 
Factors contributing to potential resilience of the species to 
projected climate change include the topographic complexity of the 
landscape it occupies, general lack of fragmentation among habitats 
where the species occurs, high abundance at some occurrences, and the 
fact that most occurrences are located on conservation lands where 
known threats can be monitored and managed.
    Evidence of Cumberland sandwort's potential resilience to the 
threat of increased drought frequency and intensity is provided by 
examining available monitoring data in relation to drought records 
available from 2000 through present. We acquired data from the U.S. 
Drought Monitor (USDM) summarizing the number of weeks that the 
geographic area where Cumberland sandwort occurs experienced 
``extreme'' or ``exceptional'' droughts for periods of more than 2 
consecutive weeks (USDM 2019). Since 2000, the four Tennessee counties, 
where all but one Cumberland sandwort occurrence are located, have 
experienced periods of such drought during 2007, 2008, and 2016. 
Prolonged drought conditions began during the last half of June 2007, 
and extended into late winter or spring of 2008, depending on the 
county. ``Extreme'' or ``exceptional'' drought conditions in these 
counties started again sometime between August and October 2008, ending 
in early December. During June 2007 through the end of 2008, these 
counties experienced between 26 and 53 cumulative weeks of ``extreme'' 
or ``exceptional'' drought conditions for periods that lasted 2 or more 
consecutive weeks. These counties did not experience such drought 
conditions again until a 3-week period during November 2016.
    To determine whether any population declines recorded through 
monitoring corresponded with documented periods of local drought, we 
examined available data (TNHID 2018) for all sites where monitoring has 
encompassed the two drought periods discussed above. There were 20 
occurrences with data spanning this time range, only one (Tennessee 
E.O. 7) of which was judged to have declined. More than 450 plants were 
estimated to have been present at this site in November 2007, and 351 
plants were counted at the site in September 2017. Cumberland sandwort 
was estimated to have occupied approximately 4 m\2\ of habitat in both 
years. This site's medium rank for abundance did not change over this 
time period. The other 19 sites remained stable over the time period 
encompassing the drought conditions discussed above, with the exception 
of three that increased. Available monitoring data, when considered in 
conjunction with data documenting droughts of extreme or exceptional 
severity within the range of Cumberland sandwort, indicate that the 
species is resilient to this climate phenomenon. Small populations are 
likely the most vulnerable to reductions or loss due to climate change. 
Monitoring data spanning the time period of the droughts discussed 
above were available for three occurrences with fewer than 100 
individuals or that were less than 1 m\2\ in size, all of which 
remained stable. Thus, we conclude that climate change will not pose a 
threat to the viability of the species into the foreseeable future.

Cumulative Effects

    The stressors discussed in the analysis above could work in concert 
with each other and result in a cumulative adverse effect to Cumberland 
sandwort; that is, one stressor may make the species more vulnerable to 
other threats. For example, stressors discussed under Factor A that 
individually do not rise to the level of a threat could together result 
in habitat degradation or loss. In instances where multiple habitat 
stressors act in concert with small population sizes, occurrences might 
lack resilience needed for population stability or growth. However, the 
potential stressors we identified either have not occurred to the 
extent originally anticipated at the time of listing, or appear to be 
either well-tolerated by the species or adequately managed as described 
in this final rule to delist the species. Our analysis has identified 
no rangewide threats or stressors with significant effects to all 
occurrences. We characterized the presence and relative severity of 
threats resulting from disturbances of substrates or altered forest 
conditions. Only 7 of the 71 extant occurrences were found to be 
potentially exposed to both substrate disturbance and altered forest 
condition. For reasons discussed below in Inadequacy of Existing 
Regulatory Mechanisms, we do not anticipate stressors to increase on 
conservation lands where nearly all of the occurrences are located. 
Furthermore, the increases documented in the number and size of many 
occurrences since the species was listed do not indicate that 
cumulative effects of various activities and stressors are affecting 
the viability of the species at this time or into the future.

Existing Regulatory Mechanisms

    The Commonwealth of Kentucky and the State of Tennessee both list 
Cumberland sandwort as an endangered species. Conservation efforts are 
directed towards such species by the Office of Kentucky Nature 
Preserves (OKNP, formerly KSNPC) and TDEC, using funding and 
authorities provided through cooperative agreements with the Service 
under section 6 of the Act for endangered species recovery. When 
Cumberland sandwort is delisted (see DATES, above), these agencies will 
no longer receive such funding specifically for Cumberland sandwort 
conservation efforts, but could allocate a portion of overall funds 
they receive for post-delisting monitoring of the species.
    The Kentucky Rare Plants Recognition Act, Kentucky Revised Statutes 
(KRS), chapter 146, sections 600-619, directs the OKNP to identify 
plants native to Kentucky that are in danger of extirpation within 
Kentucky and report every 4 years to the Governor and General Assembly 
on the conditions and needs of these endangered or threatened plants. 
The list of endangered or threatened plants in Kentucky is found in the 
Kentucky Administrative Regulations, title 400, chapter 3:040. The 
statute also recognizes the need to develop and maintain information 
regarding distribution, population, habitat needs, limiting factors, 
other biological data, and requirements for the survival of plants 
native to Kentucky. However, this statute does not include any 
regulatory prohibitions of activities or direct protections for any 
species included in the list. It is expressly stated

[[Page 45696]]

in KRS 146.615 that this list of endangered or threatened plants shall 
not obstruct or hinder any development or use of public or private 
land. Furthermore, the intent of this statute is not to ameliorate the 
threats identified for the species, but to provide information on the 
species.
    The Tennessee Rare Plant Protection and Conservation Act of 1985 
(see Tennessee Code, title 70, chapter 8, part 3) authorizes the TDEC 
to, among other things, conduct investigations on species of rare 
plants throughout the State of Tennessee; maintain a listing of species 
of plants determined to be endangered, threatened, or of special 
concern within the State; and regulate the sale or export of endangered 
species via a licensing system. This statute forbids persons from 
knowingly uprooting, digging, taking, removing, damaging, destroying, 
possessing, or otherwise disturbing for any purpose, any endangered 
species from private or public lands without the written permission of 
the landowner, lessee, or other person entitled to possession and 
prescribes penalties for violations. The TDEC may use the list of 
threatened and special concern species when commenting on proposed 
public works projects in Tennessee, and the department shall encourage 
voluntary efforts to prevent the plants on this list from becoming 
endangered species. It may not, however, be used to interfere with, 
delay, or impede any public works project.
    Cumberland sandwort listing under these State laws may continue 
following Federal delisting, although Federal delisting may prompt 
changes in the species' status in Kentucky or Tennessee. However, we 
are unaware of any planned changes to State protections at this time.
    Cumberland sandwort habitats on both State and Federal conservation 
lands will remain protected by rules, regulations, or plans governing 
the establishment or management of those lands, relevant sections of 
which are summarized below. As noted above in Table 2, 66 of the 71 
extant Cumberland sandwort occurrences are located on Federal or State 
conservation lands at BSF, PSF, PCNA, and PSP.
    Establishment of the BSF was authorized by section 108 of the Water 
Resources Development Act of 1974 (Pub. L. 93-251, March 7, 1974). The 
NPS manages the 125,000-acre (ac) BSF according to prescriptions 
established for eight management zones in Alternative D of the Final 
General Management Plan/Environmental Impact Statement for Big South 
Fork National River and Recreation Area, Kentucky and Tennessee (NPS 
2005, entire). Under this management framework, habitats occupied by 
Cumberland sandwort and those that are potentially suitable for the 
species fall within the Sensitive Resource Protection Zone, which is 
managed to reflect natural processes and for careful protection from 
unnatural degradation (NPS 2005, pp. 31-40). As a result, this 
designation provides adequate protection to the 27 occurences within 
the BSF.
    The 20,887-ac PSF was established in 1935, on lands donated to the 
State of Tennessee by Stearns Coal and Lumber Company (Tennessee 
Department of Agriculture 2019). The rules of the Tennessee Department 
of Agriculture Division of Forestry (Tennessee Administrative Code 
(TAC), chapter 0080-7-1, Protection of State Forests) prohibit 
destruction or damaging of any natural resource or collection of plants 
or botanical specimens, unless authorized by permit from the district 
forester. Pickett Civilian Conservation Corps (CCC) Memorial State Park 
is situated within the PSF, but as a State park is managed under 
separate rules from the State forest lands surrounding it. The rules of 
the Tennessee Department of Environment and Conservation (TAC, chapter 
0400-02-02, Public Use and Recreation) prohibit users of State parks 
from destroying, digging, cutting, removing, or possessing any tree, 
shrub, or other plant, except as permitted by the Assistant 
Commissioner of Parks and Recreation (see TAC 0400-02-02-.18). Permits 
may only be issued for scientific or educational purposes (see TAC 
0400-02-02-.23). The 3,000-ac PCNA is contiguous to PSF and very near 
PSP, the latter of which provides local management of the natural area, 
albeit according to more protective regulations applicable to 
designated State natural areas. The Tennessee Natural Areas 
Preservation Act of 1971 forbids the unauthorized removal or 
destruction of any rare, threatened, or endangered species of plants in 
any natural areas, with civil penalties of up to $10,000 per day for 
each day during which the prohibited act occurs (see Tennessee Code, 
title 11, chapter 14, part 1, section 11-14-115). Thus, we do not 
anticipate stressors to increase on conservation lands where nearly all 
of the occurrences are located. For the reasons discussed above, we 
conclude that regulatory mechanisms are adequate to address threats 
that could result in habitat loss or curtailment of the species range 
into the foreseeable future.

Determination of Cumberland Sandwort'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 endangered species or 
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 
``endangered species'' or ``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, and 
considering the comments we received, we have found that since listing 
under the Act, Cumberland sandwort representation has increased with 
the discovery of occurrences in the Obey River watershed. Redundancy 
also has increased from 11 occurrences at the time of listing to 71 
occurrences known to be extant, including 25 of the 28 occurrences that 
were included in the species recovery plan (Service 1996, pp. 6-8). An 
assessment of resiliency of these occurrences, taking into account 
estimated abundance, substrate condition, and forest condition, 
indicates that 57 occurrences ranked medium or higher, which we 
consider to be resilient. Of these resilient occurrences, 42 meeting 
and exceeding recovery criteria because they are self-sustaining and 
located on protected land. Of the 15 resilient occurrences that are not 
counted towards meeting recovery criteria, 10 are located on protected 
lands but lack a sufficient number of observations over time to judge 
trends in their abundance and evaluate whether they are self-
sustaining; thus, we expect they will also contribute to the species' 
overall resiliency and redundancy, ensuring its ability to withstand 
future catastrophic events (but we are not relying upon these 10 to 
make this final

[[Page 45697]]

determination). Because Cumberland sandwort has increased in 
representation and redundancy, generally, and in particular with 
respect to numbers of resilient, self-sustaining, and protected 
occurrences, we have determined that the species is currently viable 
and expect this species to be viable into the foreseeable future.
    We have carefully assessed the best scientific and commercial 
information available regarding the threats faced by Cumberland 
sandwort in developing the April 27, 2020, proposed rule (85 FR 23302) 
and this final rule. Threats reported at the time of listing related to 
habitat loss and curtailment of range (Factor A) have been managed in 
many locations, and available data indicate the species possesses 
greater resilience to effects of substrate disturbance from trampling 
and various activities and to effects of timber harvesting in nearby 
areas than was determined at the time of listing. We have analyzed or 
evaluated potential effects of climate change and low population size 
(Factor E) and determined that they are not significant threats to the 
species now nor are they likely to be in the foreseeable future (as 
defined above). Although the Cumberland sandwort will no longer receive 
the protections of the Act once it is delisted (see DATES, above), the 
remaining regulatory mechansims (Factor D) are adequate to protect 
Cumberland sandwort from threats to its habitat, given the fact that 66 
of the 71 extant occurrences are located on Federal or State 
conservation lands. Considering the effect of current and future 
stressors to the species, and taking into account applicable 
conservation measures and the existing regulatory mechanisms, the 
species is not currently in danger of extinction, nor is it 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 
in the foreseeable future throughout all or a significant portion of 
its range. Having determined that Cumberland sandwort is not in danger 
of extinction or likely to become so in 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 it is true that both (1) the 
portion is significant; and (2) the species is in danger of extinction 
now 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 Cumberland sandwort, we choose to 
address the status question first--we consider information pertaining 
to the geographic distribution of both the species and the threats that 
the species faces to identify any portions of the range where the 
species is endangered or threatened. For Cumberland sandwort, we 
considered whether the threats are geographically concentrated in any 
portion of the species' range at a biologically meaningful scale. We 
examined the following threats: Habitat modification and curtailment of 
range, including cumulative effects.
    The range of Cumberland sandwort is restricted to a small 
geographic area in portions of five counties, with high similarity in 
geological and ecological conditions among occupied sites. Within this 
geographic area, the species is known from two watersheds, South Fork 
Cumberland and Obey River, where there are 59 and 12 extant 
occurrences, respectively. Therefore, applying the process described 
above, we first evaluated the status of Cumberland sandwort to 
determine if any threats or population declines were concentrated in 
any specific portion of the range. Threats related to habitat 
modification or curtailment of range primarily affect occurrences in 
the South Fork Cumberland drainage. Our analysis of the species' 
resilience (see above, Recovery), which integrated information on 
abundance and threats, determined that 45 of the occurrences within the 
South Fork Cumberland and all of the occurrences within the Obey River 
drainages had resiliency indices of medium or higher. We have 
determined that 40 of these resilient occurrences in the South Fork 
Cumberland and 2 in the Obey River drainages are protected and 
contribute towards achieving the recovery criteria. The presence of 40 
protected and self-sustaining occurrences in the South Fork Cumberland 
indicates that threats are not concentrated in this drainage so as to 
affect the representation, redundancy, or resiliency of Cumberland 
sandwort. Nine protected occurrences in the Obey River watershed have 
resiliency indices of medium or higher, but lack sufficient monitoring 
data to evaluate trends in abundance and determine whether they are 
self-sustaining. Due to their locations on protected lands, primarily 
within PCNA where proposed trail routes are surveyed to minimize 
adverse effects to Cumberland sandwort (TDEC no date, pp. 10-11), we 
expect that these nine occurrences will remain stable for the 
foreseeable future, adding to the resilience, representation, and 
redundancy afforded by the 42 occurrences currently considered to 
contribute to achieving recovery criteria. Based on the distribution of 
42 protected and self-sustaining occurrences among the two watersheds, 
all located on conservation lands managed according to rules, 
regulations, or management plans (NPS 2005, pp. 31-39; TDEC no date, 
entire) that protect Cumberland sandwort, we have determined that 
threats related to habitat modification or curtailment of range are not 
concentrated in any portion of the species' range so as to affect its 
representation, redundancy, or resiliency.
    We found no concentration of threats in any portion of Cumberland 
sandwort's range at a biologically meaningful scale. Therefore, no 
portion of the species' range can provide a basis for determining that 
the species is in danger of extinction now or likely to become so in 
the foreseeable future in a significant portion of its range, and we 
find the species is not in danger of extinction now or likely to become 
so in the foreseeable future in any significant portion of its range. 
This is consistent with the courts' holdings in Desert Survivors v. 
Department of the Interior, No. 16-cv-01165-JCS, 2018 WL 4053447 (N.D. 
Cal. Aug. 24, 2018), and Center for Biological Diversity v. Jewell, 248 
F. Supp. 3d, 946, 959 (D. Ariz. 2017).

Determination of Status

    Our review of the best available scientific and commercial 
information indicates that Cumberland sandwort is not in danger of 
extinction nor likely to become an endangered species within the 
foreseeable future throughout all or a significant portion of its 
range. Therefore, we find that Cumberland sandwort 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. Therefore, we are 
removing the species from the List of Endangered and Threatened Plants.

Effects of This Rule

    This final rule revises 50 CFR 17.12(h) to remove Cumberland 
sandwort from the Federal List of Endangered and Threatened Plants. The 
prohibitions and

[[Page 45698]]

conservation measures provided by the Act, particularly through 
sections 7 and 9, will no longer apply to Cumberland sandwort. Federal 
agencies will no longer be required to consult with us under section 7 
of the Act in the event that activities they authorize, fund, or carry 
out may affect Cumberland sandwort. There is no critical habitat 
designated for Cumberland sandwort; therefore, this rule does not 
affect 50 CFR 17.96.
    This rule will not affect Cumberland sandwort's status as an 
endangered or threatened species under State laws or suspend any other 
legal protections provided by those laws. States may have more 
restrictive laws protecting wildlife and plants, and these will not be 
affected by this Federal action. However, this final rule may prompt 
either Kentucky or Tennessee to remove protection for Cumberland 
sandwort under their endangered species laws, although we are not aware 
of any such intention at this time.

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 delisted due to recovery. 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 endangered or threatened 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. At the conclusion of the monitoring period, we will review all 
available information to determine if re-listing, the continuation of 
monitoring, or the termination of monitoring is appropriate.
    Section 4(g) of the Act explicitly requires that we cooperate with 
the States in development and implementation of PDM programs. However, 
we remain ultimately responsible for compliance with section 4(g) and, 
therefore, must remain actively engaged in all phases of PDM. We also 
seek active participation of other entities that are expected to assume 
responsibilities for the species' conservation after delisting.
    We prepared a PDM plan for Cumberland sandwort (Service 2020). The 
plan describes:
    (1) The Cumberland sandwort's condition at the time of delisting;
    (2) Thresholds or triggers for potential monitoring outcomes and 
conclusions;
    (3) Frequency and duration of monitoring;
    (4) Monitoring methods, including sampling considerations;
    (5) Data compilation and reporting procedures and responsibilities; 
and
    (6) A proposed PDM implementation schedule, including timing and 
responsible parties.
    It is our intent to work with our partners to maintain the 
recovered status of the Cumberland sandwort.

Required Determinations

National Environmental Policy Act

    We have determined that we do not need to prepare an environmental 
assessment or environmental impact statement, as defined in the 
National Environmental Policy Act (42 U.S.C 4321 et seq.), in 
connection with regulations adopted pursuant to section 4(a) of the 
Endangered Species Act. We published a notice outlining our reasons for 
this determination in the Federal Register on October 25, 1983 (48 FR 
49244).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994, 
``Government-to-Government Relations with Native American Tribal 
Governments'' (59 FR 22951), Executive Order 13175 (Consultation and 
Coordination with Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
Tribes in developing programs for healthy ecosystems, to acknowledge 
that Tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to Tribes. We have determined that no Tribes will 
be affected by this rule because no Tribal lands, sacred sites, or 
resources will be affected by the removal of Cumberland sandwort from 
the List of Endangered and Threatened Plants.

References Cited

    A complete list of references cited is available at https://www.regulations.gov under Docket Number FWS-R4-ES-2019-0080, or upon 
request from the Tennessee Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT).

Author

    The primary authors of this rule are the staff members of the 
Tennessee Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

    Accordingly, we amend part 17, subchapter B of chapter I, title 50 
of the Code of Federal Regulations, as 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; 4201-4245, unless 
otherwise noted.


Sec.  17.12   [Amended]

0
2. Amend Sec.  17.12 in paragraph (h) by removing the entry for 
``Arenaria cumberlandensis'' under ``FLOWERING PLANTS'' from the List 
of Endangered and Threatened Plants.

Martha Williams,
Principal Deputy Director, Exercising the Delegated Authority of the 
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2021-17468 Filed 8-13-21; 8:45 am]
BILLING CODE 4333-15-P