Endangered and Threatened Wildlife and Plants; Removing Arenaria cumberlandensis (Cumberland Sandwort) From the Federal List of Endangered and Threatened Plants, 23302-23315 [2020-08398]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 85, Number 81 (Monday, April 27, 2020)]
[Proposed Rules]
[Pages 23302-23315]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-08398]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2019-0080; FXES11130900000C2-189-FF09E42000]
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: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
remove Cumberland sandwort (Arenaria cumberlandensis) from the Federal 
List of Endangered and Threatened Plants (List). We also announce the 
availability of a draft post-delisting monitoring (PDM) plan for the 
Cumberland sandwort. We seek information, data, and comments from the 
public on this proposed rule and on the associated draft PDM plan. If 
this proposal is finalized, the Cumberland sandwort will be removed 
from the List.

DATES: We will accept comments received or postmarked on or before June 
26, 2020. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59 
p.m. Eastern Time on the closing date. We must receive requests for 
public hearings, in writing, at the address shown in FOR FURTHER 
INFORMATION CONTACT by June 11, 2020.

ADDRESSES: You may submit comments on this proposed rule and draft PDM 
plan by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. In the Search box, enter FWS-R4-ES-2019-0080, 
which is the docket number for this rulemaking. Then, click on the 
Search button. On the resulting page, in the Search panel on the left 
side of the screen, under the Document Type heading, click on the 
Proposed Rule box to locate this document. You may submit a comment by 
clicking on ``Comment Now!''
    (2) By hard copy: Submit by U.S. mail to: Public Comments 
Processing, Attn: FWS-R4-ES-2019-0080; U.S. Fish and Wildlife Service, 
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We request that you send comments only by the methods described 
above. We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Public Comments, below, for more information).
    Document availability: The proposed rule, draft PDM plan, and 
supporting documents are available at https://www.regulations.gov under 
Docket No. FWS-R4-ES-2019-0080.

FOR FURTHER INFORMATION CONTACT: Lee Andrews, Field Supervisor, U.S. 
Fish and Wildlife Service, Tennessee Ecological Services Field Office, 
446 Neal Street, Cookeville, Tennessee, 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 Endangered Species Act of 
1973, as amended (Act), we are required to conduct a review of all 
listed species at least once every 5 years (5-year review) to review 
their status and determine whether they should be classified 
differently or removed from listed status. In our 2013 5-year review 
for the Cumberland sandwort, we recommended reclassifying the species 
from endangered to threatened. We initiated another 5-year review for 
the species on May 7, 2018 (83 FR 20093), and determined the species 
met the criteria for delisting. Therefore, we are publishing this 
proposed rule to delist the species.
    What this document does. This document proposes to remove the 
Cumberland sandwort from the List. It also announces the availability 
of a draft PDM plan for the Cumberland sandwort. This determination is 
based on a thorough review of the best available scientific and 
commercial data, which indicate that the Cumberland sandwort has 
recovered and no longer meets the definition of an endangered or a 
threatened species under the 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 threaten 
the species, and the Cumberland sandwort has increased in abundance and 
range. 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.
    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. We must 
consider the same factors in removing a species from the List 
(delisting) in determining whether a species meets the definition of an 
endangered species or a threatened species.
    Here, we have determined that the Cumberland sandwort may be 
considered for delisting based on recovery. 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 (Factor A) 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. While 
some habitats occupied by Cumberland sandwort are exposed to these 
potential stressors, many are protected from these activities, and 
available data support the determination that the species is more 
resilient to these threats than was assumed at the time of listing. The 
listing rule also discussed limited distribution and small population 
size (Factor E), along with inadequate regulatory mechanisms for 
preventing habitat destruction (Factor D), as factors contributing to 
the species' endangerment. However, our review of the status of and 
listing factors for the Cumberland sandwort indicated: (1) An increase 
in the 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

[[Page 23303]]

or management plans to prevent habitat destruction or removal of 
plants; and (4) the implementation of beneficial management practices. 
Accordingly, the Cumberland sandwort no longer meets the definition of 
an endangered or threatened species under the Act.
    Peer review. We are requesting comments from independent 
specialists to ensure that we base our determination on scientifically 
sound data, assumptions, and analyses.

Information Requested

Public Comments

    We want any final rule resulting from this proposal to be as 
accurate and effective as possible. Therefore, we invite tribal and 
governmental agencies, the scientific community, industry, and other 
interested parties to submit data, comments, and new information 
concerning this proposed rule. The comments that will be most useful 
and likely to influence our decision are those that are supported by 
data or peer-reviewed studies and those that include citations to, and 
analyses of, applicable laws and regulations. Please make your comments 
as specific as possible and explain the basis for them. In addition, 
please include sufficient information with your comments to allow us to 
authenticate any scientific or commercial data you reference or 
provide. In particular, we are seeking comments on:
    (1) Biological data regarding the Cumberland sandwort, including 
the locations of any additional occurrences, survey data, or other 
relevant information;
    (2) Relevant data concerning any threats (or lack thereof) to the 
Cumberland sandwort;
    (3) Additional information regarding the range, distribution, life 
history, ecology, and habitat of the Cumberland sandwort;
    (4) Current or planned activities within the geographic range of 
the Cumberland sandwort that may negatively impact or benefit the 
Cumberland sandwort; and
    (5) The draft PDM plan and the methods and approach detailed in it.
    Please note that submissions merely stating support for or 
opposition to the action under consideration without providing 
supporting information, although noted, will not be considered in 
making a determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is an endangered or threatened 
species must be made ``solely on the basis of the best scientific and 
commercial data available.''
    In developing a final determination on this proposed action, we 
will take into consideration all comments and any additional 
information we receive. Such information may lead to a final rule that 
differs from this proposal. All comments and recommendations, including 
names and addresses, will become part of the administrative record.
    You may submit your comments and materials concerning the proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    We will post your entire comment--including your personal 
identifying information--on https://www.regulations.gov. If you provide 
personal identifying information in your comment, you may request at 
the top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov.

Public Hearing

    Section 4(b)(5)(E) of the Act provides for one or more public 
hearings on this proposal, if requested. We must receive requests for a 
public hearing, in writing, at the address shown in FOR FURTHER 
INFORMATION CONTACT by the date shown in DATES. We will schedule a 
public hearing on this proposal, if requested, and announce the date, 
time, and place of the hearing, as well as how to obtain reasonable 
accommodations, in the Federal Register at least 15 days before the 
hearing.

Peer Review

    In accordance with our policy 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 will solicit the expert opinions of at least three 
appropriate and independent specialists regarding the science in this 
proposed rule and the draft PDM plan. The purpose of such review is to 
ensure that we base our decisions on scientifically sound data, 
assumptions, and analyses. The peer reviewers will be selected based 
upon their expertise in the Cumberland sandwort's biology, habitat, and 
physical or biological factors that will inform our determination. We 
will send peer reviewers copies of this proposed rule and the draft PDM 
plan immediately following publication of this proposed rule in the 
Federal Register. We will invite them to comment, during the public 
comment period, on the specific assumptions and conclusions regarding 
this proposed delisting rule and the associated draft PDM plan. We will 
summarize the opinions of these reviewers in the final decision 
documents, and we will consider their input and any additional 
information we receive as part of our process of making a final 
decision on this proposal and draft PDM plan. Such communication may 
lead to a final decision that differs from this proposal.

Previous Federal Actions

    On June 23, 1988, we listed the Cumberland sandwort as endangered, 
due to the threat of habitat destruction or modification resulting from 
unintended trampling by recreational users of public lands, 
unauthorized digging of Native American artifacts, and timber 
harvesting, combined with the low number of occurrences known to exist 
at the time of listing and low abundance at most occurrences (53 FR 
23745). On June 20, 1996, we released a recovery plan for the 
Cumberland sandwort (Service 1996). We completed another 5-year review 
for the Cumberland sandwort on December 23, 2013. This 5-year review 
summarized all new information accumulated on the species since the 
publication of the species' recovery plan and recommended 
reclassification to threatened status. We initiated a third 5-year 
review for the species on May 7, 2018 (83 FR 20093), and, based on our 
review of available data we gathered during preparation of that 5-year 
review, and presented herein, we have determined that the recovery 
criteria for delisting the species have been met. This rule will, 
therefore, equate to our 5-year review. We are providing the 2013 5-
year review as a supplemental document to the proposed rule at https://www.regulations.gov at (Docket No. FWS-R4-ES-2019-0080) or https://www.fws.gov/southeast/endangered-species-act/five-year-reviews/.
    For additional details on previous Federal actions, including 
recovery actions, see discussion under the Recovery section of the 
preamble, below.

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.

[[Page 23304]]

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 there have been 
changes to the species' taxonomy since the time of listing, we are 
proposing to remove the species from the List of Endangered and 
Threatened Plants using the name by which it was initially listed, 
Arenaria cumberlandensis (=Mononeuria cumberlandensis).

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 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) (Winder 2004, p. 37). 
The genetic structure of the lone Kentucky population and its relation 
to sites sampled in Tennessee are unknown.

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 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 inches) 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 lucae-braunae 
(Lucy Braun's snakeroot), Stenanthium diffusum (diffuse reather-bells) 
and the bryophytes Vittaria appalachiana (Appalachian shoestring fern), 
Bryoxiphium norvegicum (Norway bryoxiphium moss), and Scopelophila 
cataractae (cataract scopelophila moss) (TDEC 2011b, p. 5).

Distribution

    When Cumberland sandwort was listed as endangered, the species was 
known from 11 occurrences (Wofford and Smith 1980, pp. 9-18), which 
were treated as 5 populations (53 FR 23745, June 23, 1988). 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 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 4 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 occurrence reported in 
the recovery plan, with only the site name ``Sunbright'' given for 
location information, also cannot be verified. No

[[Page 23305]]

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 5 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, 26 in Fentress, 38 
in Pickett, and 5 in Scott Counties, 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 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).

Framework for Monitoring and Evaluating Trends

    The TDEC Natural Heritage Program began monitoring Cumberland 
sandwort in Tennessee during 2000, 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 
highest priority sites to be 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 two or more years, making it possible to assess whether 
Cumberland sandwort had declined, remained stable, or increased either 
in estimated abundance or area occupied. 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. 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 occassions, 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 directs us to develop and implement 
recovery plans for the conservation and survival of threatened and 
endangered species unless we determine that such a plan will not 
promote the conservation of the species. Recovery plans are not 
regulatory documents and are instead intended to: (1) Establish goals 
for long-term conservation of a listed species; (2) define criteria 
that are designed to indicate when the threats facing a species have 
been removed or reduced to such an extent that the species may no 
longer need the protections of the Act; and (3) provide guidance to our 
Federal, State, and other governmental and non-governmental partners on 
methods to minimize threats to listed species. 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

[[Page 23306]]

have been accomplished, yet the Service may judge that, overall, the 
threats have been minimized sufficiently, and the species is robust 
enough, to reclassify the species from endangered to threatened or 
perhaps delist the species. In other cases, recovery opportunities may 
have been recognized that were not known at the time the recovery plan 
was finalized. These opportunities may be used instead of methods 
identified in the recovery plan.
    Likewise, information on the species may be learned that was not 
known at the time the recovery plan was finalized. The new information 
may change the extent that criteria need to be met for recognizing 
recovery of the species. In short, recovery of species is a dynamic 
process requiring adaptive management that may, or may not, fully 
follow the guidance provided in a recovery plan.
    The Cumberland Sandwort Recovery Plan (see Previous Federal 
Actions, above) included 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 good and bad years. 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. 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). Undisturbed substrates contribute to Cumberland 
sandwort resiliency by providing suitable sites for germination, 
growth, and reproduction to occur. Also, 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 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 non-native, 
evergreen forest types. Forest conditions were ranked ``high'' in 
locations where late seral forest was present upslope and downslope of 
occupied sites and in adjacent areas;

[[Page 23307]]

``medium'' in locations where risk of exposure to the threat was 
moderate based on evidence of logging having occurred within the prior 
15 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 3 resiliency 
factors, 12 were ranked as low in abundance, 27 ranked medium, and 30 
occurrences 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 3 resiliency factors (abundance, substrate 
condition, and forest condition), we calculated an overall resiliency 
index for 68 of the 70 Tennessee occurrences (table 1) and the lone 
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 ranging from 2.0 to 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 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 all 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 (Table 1) 
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 (Table 2), 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 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. 
This exceeds one criterion for removing Cumberland sandwort from the 
List--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
   [Note: Number of occurrences in table sums to 70, but 4 occurrences
  occupy habitats spanning adjacent lands owned by TDF and TSP and are
                      counted only once for total]
------------------------------------------------------------------------
                                                            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 Forest    29 (4 partially
 (TDF).                          (PSF).                  on TSP lands).
Tennessee Division of Natural   Pogue Creek Canyon      7.
 Areas.                          State Natural Area
                                 (PCNA).
Tennessee State Parks (TSP)...  Pickett CCC Memorial    7 (4 partially
                                 State Park (PSP).       on TDF lands).
------------------------------------------------------------------------


[[Page 23308]]

    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, presumably for the purpose of 
increasing representation and redundancy 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 any occurrences in this watershed and 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, and we 
expect that they will be self-sustaining and contribute to the species 
representation of resilient occurrences into the foreseeable future.
    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 4 counties in Tennessee and 1 in Kentucky.

Summary of Factors Affecting the Species

    Section 4 of the Act 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.
    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.
    The Act does not define the term ``foreseeable future.'' However, 
our implementing regulations at 50 CFR 424.11(d) (84 FR 45020) codify 
that the term ``foreseeable future'' extends only so far into the 
future as the Service can reasonably determine that the conditions 
potentially posing a danger of extinction in the foreseeable future are 
probable. The Service will describe the foreseeable future on a case-
by-case basis, using the best available data and taking into account 
considerations such as the species' life-history characteristics, 
threat-projection timeframes, and environmental variability. The 
Service need not identify the foreseeable future in terms of a specific 
period of time, but may instead explain the extent to which we can 
reasonably determine that both the future threats and the species' 
responses to those threats are probable. To establish the foreseeable 
future for the purpose of determining whether Cumberland sandwort meets 
the definition of a threatened or endangered 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, 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, for the purposes of this rule we consider the 
foreseeable future for Cumberland sandwort to be approximately 30 
years.
    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 lone 
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 (EO 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

[[Page 23309]]

abundance has declined at 6 of the 12 sites with high exposure risk, 
while 5 have remained stable. Trend data are not available for the 
twelfth site, which was discovered in 2014. 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.
    Protective features, including fences, boardwalks, barricades, 
rerouted trails, and/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). 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.
    Timber harvest occurs at PSF, but does not occur at BSF, PSP, or 
PCNA, limiting the potential magnitude of this activity, assumed 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--3 have declined and 7 have 
remained stable. Monitoring data collected by TDEC at three of these 
occurrences since 2016 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 assumed at the time of 
listing. In the event Cumberland sandwort is removed from the List, our 
draft post-delisting monitoring plan (see Post-delisting Monitoring, 
below) identifies 50 occurrences to be monitored over a period of at 
least 5 years following delisting, including 27 occurrences where risks 
of exposure to 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 exposed to potential threats 
that were previously assumed 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 spanning the first and 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 the threat of habitat 
modification or curtailment of the species' range has been addressed.

Limited Distribution and Small Population Sizes

    The listing rule for Cumberland sandwort 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) to 71 currently (TNHID 
2018). Three projects have been funded to support searches for new 
Cumberland sandwort occurrences (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 Section 6 
grants to state agencies for endangered species recovery, contributed 
greatly to increasing the species' distribution to the 71 extant 
occurrences known today.

[[Page 23310]]

    Fourteen protected and self-sustaining occurrences are located 
outside of Pickett County, satisfying the recovery criterion concerning 
geographic distribution. And 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 listing rule discussed small population size as a threat to 
many occurrences, but did not include information on population sizes 
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 the 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 poulations 
are likely to persist for the foreseeable future (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 small population size is not a threat to the species, affecting 
less than 20 percent of the 71 extant Cumberland sandwort occurrences.
    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 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 4.5 [deg]F (scenario B1) to 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,

[[Page 23311]]

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 degrees Celsius ([deg]C) (5.7 degrees [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, 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), in contrast to the more extreme 
scenario that we used in the NCCV to project 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 
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 become extinct within that timeframe or 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). The USDM is jointly produced by the 
National Drought Mitigation Center at the University of Nebraska-
Lincoln, the United States Department of Agriculture, and the National 
Oceanic and Atmospheric Administration. 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 EO 
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 3 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

[[Page 23312]]

will not threaten 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, e.g., 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 proposal to delist the species. Our analysis has identified no 
range-wide 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 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.

Inadequacy of 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 KSNPC and TDEC, using funding and 
authorities provided through cooperative agreements with the Service 
under section 6 of the Act for endangered species recovery. Should 
Cumberland sandwort be delisted, these agencies would 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, section 600-619, directs the KSNPC 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 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 
(T.C.A. 11-26-201) 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 status in Kentucky or Tennessee. However, we are unaware of 
any planned changes to State protections at this time.
    Further, Cumberland sandwort habitats on both state and federal 
conservation lands would 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 1, 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 Act of 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 be 
carefully protected from unnatural degradation (NPS 2005, pp. 31-40).
    The 20,887-ac PSF was established in 1935 on lands donated to the 
State of Tennessee by Stearns Coal and Lumber Company (retrieved March 
13, 2019 from https://www.tn.gov/agriculture/forests/state-forests/pickett.html). The Rules of the Tennessee Department of Agriculture 
Division of Forestry, 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 CCC Memorial State Park is situated within 
the PSF. The Rules of the Tennessee Department of Environment and 
Conservation, Chapter 0400-0202 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 (Rule 0400-02-02-.18). 
Permits may only be issued for scientific or educational purposes (Rule 
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. 
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

[[Page 23313]]

each day during which the prohibited act occurs (T.C.A Sec.  11-14-
1115). 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 inadequacy of regulatory mechanisms 
will not threaten the viability of the species 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, 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. An assessment of resiliency of these occurrences, taking into 
account estimated abundance, substrate condition, and forest condition, 
indicates that 57 ranked medium or higher, which we consider to be 
resilient. Of these resilient occurrences, 42 are counted towards 
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 proposed 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 expect this species to 
persist into the future.
    We have carefully assessed the best scientific and commercial 
information available regarding the threats faced by the Cumberland 
sandwort in developing this proposed 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 assumed 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 nor are likely to be in the 
foreseeable future as defined above. Although not all state and federal 
regulatory mechanisms (Factor D) will be in effect in the event that 
Cumberland sandwort is delisted, those remaining are likely to be 
adequate to protect the 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. The net effect of 
current and foreseeable future stressors to the species, after 
considering applicable conservation measures and the existing 
regulatory mechanisms, is not sufficient to cause the species to meet 
the definition of an endangered or threatened species. Thus, after 
assessing the best available information, we conclude that the 
Cumberland sandwort no longer meets the definition of endangered or 
threatened under the Act 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 the 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. The range of a species can 
theoretically be divided into portions in an infinite number of ways, 
so we first screen the potential portions of the species' range to 
determine if there are any portions that warrant further consideration. 
To do the ``screening'' analysis, we ask whether there are portions of 
the species' range for which there is substantial information 
indicating that: (1) The portion may be significant; and, (2) the 
species may be, in that portion, either in danger of extinction or 
likely to become so in the foreseeable future. For a particular 
portion, if we cannot answer both questions in the affirmative, then 
that portion does not warrant further consideration and the species 
does not warrant listing because of its status in that portion of its 
range. Conversely, we emphasize that answering both of these questions 
in the affirmative is not a determination that the species is in danger 
of extinction or likely to become so in the foreseeable future 
throughout a significant portion of its range--rather, it is a step in 
determining whether a more-detailed analysis of the issue is required.
    If we answer these questions in the affirmative, we then conduct a 
more thorough analysis to determine whether the portion does indeed 
meet both of the ``significant portion of its range'' prongs: (1) The 
portion is significant and (2) the species is, in that portion, either 
in danger of extinction or likely to become so in the foreseeable 
future. Confirmation that a portion does indeed meet one of these 
prongs does not create a presumption, prejudgment, or other 
determination as to whether the species is an endangered species or 
threatened species. Rather, we must then undertake a more detailed 
analysis of the other prong to make that determination. Only if the 
portion does indeed meet both prongs would the species warrant listing 
because of its status in a significant portion of its range.
    At both stages in this process--the stage of screening potential 
portions to identify any portions that warrant further consideration 
and the stage of undertaking the more detailed analysis of any portions 
that do warrant further consideration--it might be more efficient for 
us to address the ``significance'' question or the ``status'' question 
first. Our selection of which question to address first for a 
particular

[[Page 23314]]

portion depends on the biology of the species, its range, and the 
threats it faces. 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 second question for that 
portion of the species' range.
    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 the 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, p. 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 have reviewed other potential threats and conclude that none of 
them are concentrated in any portion of the species' range so as to 
affect the representation, redundancy, or resiliency of the species.
    Therefore, we conclude, based on this screening analysis, that no 
portions of the Cumberland sandwort's range warrant further 
consideration to determine whether the species may be in danger of 
extinction or likely to become so in the foreseeable future in a 
significant portion of its range. Thus, we conclude that the species is 
not an endangered species or threatened species based on its status in 
a significant portion of its range. Our approach to analyzing 
significant portions of the species' range in this determination 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); Center for Biological Diversity v. Jewell, 248 F. Supp. 3d, 
946, 959 (D. Ariz. 2017); and Center for Biological Diversity v. 
Everson, 2020 WL 437289 (D.D.C. Jan. 28, 2020).

Determination of Status

    Our review of the best available scientific and commercial 
information indicates that the 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 
propose to remove the Cumberland sandwort from the List of Endangered 
and Threatened Plants.

Effects of This Proposed Rule

    This proposal, if made final, would revise 50 CFR 17.12 (h) to 
remove the Cumberland sandwort from the Federal List of Endangered and 
Threatened Plants. The prohibitions and conservation measures provided 
by the Act, particularly through sections 7 and 9, would no longer 
apply to Cumberland sandwort. Federal agencies would no longer be 
required to consult with us under section 7 of the Act to ensure that 
any action authorized, funded, or carried out by them is not likely to 
jeopardize the Cumberland sandwort's continued existence.
    This rule will not affect Cumberland sandwort's status as a 
threatened or endangered species under State laws or suspend any other 
legal protections provided by those laws. States may have more 
restrictive laws protecting wildlife, and these will not be affected by 
this Federal action. However, this proposed rule may prompt either 
Kentucky or Tennessee to remove protection for the 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 to monitor for not less than 
5 years the status of all species that are 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 have prepared a draft PDM Plan for Cumberland sandwort (Service 
2018). The draft 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; and
    (5) Data compilation and reporting procedures and responsibilities.
    The draft plan also proposes a PDM implementation schedule 
including timing and responsible parties.

[[Page 23315]]

    Concurrent with this proposed delisting rule, we announce the draft 
plan's availability for public review at https://www.regulations.gov 
under Docket Number FWS-R4-ES-2019-0080. Copies can also be obtained 
from the Service's Tennessee Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT). We seek information, data, and comments 
from the public regarding the draft PDM plan.

Required Determinations

Clarity of the Proposed Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (a) Be logically organized;
    (b) Use the active voice to address readers directly;
    (c) Use clear language rather than jargon;
    (d) Be divided into short sections and sentences; and
    (e) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in ADDRESSES. To better help us 
revise the rule, your comments should be as specific as possible. For 
example, you should tell us the numbers of the sections or paragraphs 
that are unclearly written, which sections or sentences are too long, 
the sections where you feel lists or tables would be useful, etc.

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, 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. We have determined that 
there are no tribal lands that may be affected by this proposal.

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 Field Supervisor, Tennessee Field Office (see FOR 
FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this document are the staff members of the 
Tennessee Ecological Services Field Office (see FOR FURTHER INFORMATION 
CONTACT).

List of Subjects in 50 CFR Part 17

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

Proposed Regulation Promulgation

    Accordingly, we propose to 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(h) by removing the entry for ``Arenaria 
cumberlandensis'' under ``FLOWERING PLANTS'' from the List of 
Endangered and Threatened Plants.

Aurelia Skipwith,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2020-08398 Filed 4-24-20; 8:45 am]
 BILLING CODE 4333-15-P