Endangered and Threatened Wildlife and Plants; Threatened Species Status for Bartram's Stonecrop With a Section 4(d) Rule, 48545-48569 [2021-18476]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 86, Number 166 (Tuesday, August 31, 2021)]
[Rules and Regulations]
[Pages 48545-48569]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-18476]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2018-0104; FF09E21000 FXES11110900000 212]
RIN 1018-BD35


Endangered and Threatened Wildlife and Plants; Threatened Species 
Status for Bartram's Stonecrop With a Section 4(d) Rule

AGENCY: Fish and Wildlife Service, Interior.

[[Page 48546]]


ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine 
threatened species status under the Endangered Species Act of 1973 
(Act), as amended, for Bartram's stonecrop (Graptopetalum bartramii), a 
plant known from Arizona and Mexico. We also issue a final rule under 
the authority of section 4(d) (a ``4(d) rule'') of the Act that 
provides measures that are necessary and advisable to provide for the 
conservation of Bartram's stonecrop. We have determined that 
designation of critical habitat for Bartram's stonecrop is not prudent.

DATES: This rule is effective September 30, 2021.

ADDRESSES: This final rule is available on the internet at https://www.regulations.gov under Docket No. FWS-R2-ES-2018-0104 and at https://www.fws.gov/southwest/. Comments and materials we received, as well as 
supporting documentation we used in preparing this rule, are available 
for public inspection at https://www.regulations.gov under Docket No. 
FWS-R2-ES-2018-0104.

FOR FURTHER INFORMATION CONTACT: Jeff Humphrey, U.S. Fish and Wildlife 
Service, Arizona Ecological Services Field Office, 9828 North 31st 
Avenue, #C3, Phoenix, AZ 85051-2517. Persons who use a 
telecommunications device for the deaf (TDD) may call the Federal Relay 
Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, a species may be 
listed as endangered or threatened throughout all or a significant 
portion of its range. Listing a species as an endangered or threatened 
species can only be completed by issuing a rule. Further, under the 
Act, any species that is determined to be an endangered or threatened 
species requires critical habitat to be designated, to the maximum 
extent prudent and determinable.
    What this document does. This rule lists Bartram's stonecrop 
(Graptopetalum bartramii) as a threatened species. This document also 
finalizes a rule under the authority of section 4(d) of the Act that 
provides measures that are necessary and advisable to provide for the 
conservation of Bartram's stonecrop.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species based on any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. We have determined that Bartram's stonecrop faces 
the following threats: Reduction in water availability (Factors A and 
E); erosion, sedimentation, and burial (Factors A and E); trampling 
(Factor E); altered fire regime (Factors A and E); loss of shade 
(Factors A and E); altered flooding regime (Factors A and E); drought 
(Factors A and E); illegal collection (Factor B); and small population 
size (Factor E). The existing regulatory mechanisms are not adequate to 
address these threats such that the species does not meet the Act's 
definition of an endangered or threatened species (Factor D).
    Section 4(a)(3) of the Act requires the Secretary of the Interior 
(Secretary) to designate critical habitat concurrent with listing to 
the maximum extent prudent and determinable. In this case, we have 
found that the designation of critical habitat for Bartram's stonecrop 
is not prudent at this time.
    Peer review and public comment. A species status assessment (SSA) 
team prepared an SSA report for Bartram's stonecrop. The SSA team was 
composed of Service biologists, in consultation with other species 
experts. The SSA report represents a compilation of the best scientific 
and commercial data available concerning the status of the species, 
including the impacts of past, present, and future factors (both 
negative and beneficial) affecting the species. We sought the expert 
opinions of three independent and knowledgeable specialists regarding 
the species status assessment (SSA) report and received responses from 
two reviewers. These peer reviewers generally concurred with our 
methods and conclusions, and provided additional information, 
clarifications, and suggestions to improve the SSA. We also considered 
all comments and information we received from the public during the 
comment period for the proposed listing of Bartram's stonecrop.

Previous Federal Actions

    On December 6, 2019, we published in the Federal Register (84 FR 
67060) a proposed rule to list Bartram's stonecrop as a threatened 
species under the Act (16 U.S.C. 1531 et seq.). Our proposed rule 
included a proposed 4(d) rule for Bartram's stonecrop. The December 6, 
2019, rule also proposed to list the beardless chinchweed (Pectis 
imberbis) as an endangered species and designate critical habitat for 
the species. We addressed our proposal to list the beardless chinchweed 
as an endangered species and designate critical habitat for that 
species in a separate Federal Register document on June 15, 2021. 
Please refer to the December 6, 2019, proposed rule for a detailed 
description of previous Federal actions concerning Bartram's stonecrop 
that occurred prior to December 6, 2019.

Summary of Changes From the Proposed Rule

    In preparing this final rule, we reviewed and fully considered 
comments from the public on the proposed rule. We did not make any 
substantive changes to this final rule after consideration of the 
comments we received. We updated the SSA report (to version 2.0) based 
on comments and additional information provided as follows:
    (1) We included updated survey information provided to the Service 
and other reports of additional occurrences we received.
    (2) We incorporated additional information regarding stressors to 
specific populations provided by land managers.
    (3) We made many small, nonsubstantive clarifications and 
corrections throughout the SSA report and this rule, including under 
Summary of Biological Status and Threats, below, in order to ensure 
better consistency, clarify some information, and update or add new 
references. We considered whether this additional information altered 
our analysis of the magnitude or severity of threats facing the 
species. We conclude that the information we received during the 
comment period for the proposed rule did not change our previous 
analysis of the magnitude or severity of threats facing the species or 
our determination that Bartram's stonecrop is a threatened species.

I. Final Listing Determination

Background

    Bartram's stonecrop is a small, succulent, perennial plant and a 
member of the Crassulaceae family. It occurs in shaded evergreen 
woodlands on rocky canyon outcrops at elevations ranging from 3,500 to 
6,800 ft. The species is particularly susceptible to reductions in 
water availability, altered fire regime, and the effects of small 
population size. Most populations are very small, with 58 percent of 
extant populations throughout the range of the species supporting fewer 
than 50 individuals. These small populations

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are particularly vulnerable to extirpation.

Current Condition of Bartram's Stonecrop

    Since 1924, we are aware of three populations that have been 
extirpated in the United States in recent years, and another that has 
contracted in size. Currently, 50 extant Bartram's stonecrop 
populations occur across 12 mountain ranges, nine in southern Arizona 
and three in northern Mexico. In addition, the southeastern Arizona 
landscape has experienced many changes since the 1890s, resulting from 
intensive cattle grazing, water development, and fire suppression 
(e.g., Bahre 1991, entire). These impacts may have reduced the range or 
number of populations and individuals. The U.S. populations total 4,628 
individuals within occupied habitats that total approximately 7 
hectares (17 acres). This estimate includes 10 plants from two U.S. 
populations (Gardner Canyon East and Thomas Canyon) and one Mexico 
population (Sierra La Estancia) that have not been revisited since the 
initial survey in 1980.
    Please refer to the December 6, 2019, proposed rule to list 
Bartram's stonecrop with a species-specific rule under section 4(d) of 
the Act (84 FR 67060) and the SSA report for a full summary of species 
information. Both are available on our Southwest Region website at 
https://www.fws.gov/southwest/ and at https://www.regulations.gov under 
Docket No. FWS-R2-ES-2018-0104.

Regulatory and Analytical Framework

Regulatory Framework

    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 is an ``endangered species'' or a ``threatened 
species.'' The Act defines an endangered species as a species that is 
``in danger of extinction throughout all or a significant portion of 
its range,'' and a threatened species as a species that is ``likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range.'' The Act requires that we 
determine whether any species is an ``endangered species'' or a 
``threatened species'' because of any of the following factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    These factors represent broad categories of natural or human-caused 
actions or conditions that could have an effect on a species' continued 
existence. In evaluating these actions and conditions, we look for 
those that may have a negative effect on individuals of the species, as 
well as other actions or conditions that may ameliorate any negative 
effects or may have positive effects.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the expected response by the species, 
and the effects of the threats--in light of those actions and 
conditions that will ameliorate the threats--on an individual, 
population, and species level. We evaluate each threat and its expected 
effects on the species, then analyze the cumulative effect of all of 
the threats on the species as a whole. We also consider the cumulative 
effect of the threats in light of those actions and conditions that 
will have positive effects on the species, such as any existing 
regulatory mechanisms or conservation efforts. The Secretary determines 
whether the species meets the definition of an ``endangered species'' 
or a ``threatened species'' only after conducting this cumulative 
analysis and describing the expected effect on the species now and in 
the foreseeable future.
    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis. The term 
``foreseeable future'' extends only so far into the future as the 
Services can reasonably determine that both the future threats and the 
species' responses to those threats are likely. In other words, the 
foreseeable future is the period of time in which we can make reliable 
predictions. ``Reliable'' does not mean ``certain''; it means 
sufficient to provide a reasonable degree of confidence in the 
prediction. Thus, a prediction is reliable if it is reasonable to 
depend on it when making decisions.
    It is not always possible or necessary to define foreseeable future 
as a particular number of years. Analysis of the foreseeable future 
uses the best scientific and commercial data available and should 
consider the timeframes applicable to the relevant threats and to the 
species' likely responses to those threats in view of its life-history 
characteristics. Data that are typically relevant to assessing the 
species' biological response include species-specific factors such as 
lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological status review for the species, including an assessment of 
the potential threats to the species. The SSA report does not represent 
a decision by the Service on whether the species should be listed as an 
endangered or threatened species under the Act. It does, however, 
provide the scientific basis that informs our regulatory decisions, 
which involve the further application of standards within the Act and 
its implementing regulations and policies. The following is a summary 
of the key results and conclusions from the SSA report; the full SSA 
report can be found at Docket No. FWS-R2-ES-2018-0104 on https://www.regulations.gov and at https://www.fws.gov/southwest/.
    To assess Bartram's stonecrop viability, we used the three 
conservation biology principles of resiliency, redundancy, and 
representation (Shaffer and Stein 2000, pp. 306-310). Briefly, 
resiliency supports the ability of the species to withstand 
environmental and demographic stochasticity (for example, wet or dry, 
warm or cold years), redundancy supports the ability of the species to 
withstand catastrophic events (for example, droughts, large pollution 
events), and representation supports the ability of the species to 
adapt over time to long-term changes in the environment (for example, 
climate changes). In general, the more resilient and redundant a 
species is and the more representation it has, the more likely it is to 
sustain populations over time, even

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under changing environmental conditions. Using these principles, we 
identified the species' ecological requirements for survival and 
reproduction at the individual, population, and species levels, and 
described the beneficial and risk factors influencing the species' 
viability.
    The SSA process can be categorized into three sequential stages. 
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical 
and current condition of the species' demographics and habitat 
characteristics, including an explanation of how the species arrived at 
its current condition. The final stage of the SSA involved making 
predictions about the species' responses to positive and negative 
environmental and anthropogenic influences. This process used the best 
available information to characterize viability as the ability of a 
species to sustain populations in the wild over time. We use this 
information to inform our regulatory decision.

Summary of Biological Status and Threats

    In this discussion, we review the biological condition of the 
species and its resources, and the threats that influence the species' 
current and future condition, in order to assess the species' overall 
viability and the risks to that viability. Bartram's stonecrop occurs 
between elevations of 3,500 to 6,800 ft in Madrean woodlands with oaks, 
junipers, pines and species found in more mesic (wet) areas including 
sycamores, cottonwoods, and willows. The species typically occurs on 
rocky outcrops in deep, narrow canyons in heavy cover of litter and 
shade; and typically within 10 meters (m; 32.8 feet (ft)) of flowing or 
intermittent water. Bartram's stonecrop requires adequate precipitation 
to maintain soil moisture, cooler temperatures, and humidity in the 
microenvironment and for germination, growth and reproduction. Based on 
microhabitats in which the species is typically found, species needs 
include crevices (with or without soil) for seeds to lodge and 
germinate, shade and deep leaf litter to help maintain soil moisture, 
and a humid microhabitat in this arid environment. In addition, the 
habitat must support sufficient Bartram's stonecrop pollinators (e.g., 
flies, bees, and butterflies) including plants for pollinator foraging 
and nesting within pollinator flight distance of Bartram's stonecrop 
populations. To maintain the species' viability, populations with 
multiple subpopulations and overall high abundance must be distributed 
across the species range and represent a range of environmental 
conditions. These populations must experience recruitment that exceeds 
mortality.
    Several stressors influence whether Bartram's stonecrop populations 
will grow to maximize habitat occupancy, which increases the resiliency 
of a population to stochastic events. We evaluated the past, current, 
and future stressors (i.e., negative changes in the resources needed by 
Bartram's stonecrop) that influence the viability of the species. We 
describe these stressors on viability in detail in chapter 4 of the SSA 
report (Service 2020a, entire). Stressors that have the potential to 
affect Bartram's stonecrop's population resiliency include:
     Loss of water in nearby drainages from climate change 
(drought) and mining;
     Altered fire regime resulting from fires ignited by 
recreationists, cross-border human activity, and lightning and 
exacerbated by nonnative plants;
     Altered precipitation, drought, flooding, and freezing 
regime from current and future climate change;
     Erosion, sedimentation, and burial from mining, recreation 
trails and roads, cross-border human activity, and post-wildfire 
runoff;
     Trampling from humans, and trampling and herbivory from 
wildlife and livestock;
     Illegal collection; and
     Small population size exacerbating all other stressors.
    The largest risk to viability of the species is caused by the loss 
of habitat and includes: (1) Groundwater extraction and prolonged 
drought that reduce nearby water levels and humidity within Bartram's 
stonecrop habitat; and (2) altered fire regimes leading to erosion of 
Bartram's stonecrop habitat, sedimentation and burial of individuals by 
post-fire runoff, and loss of overstory shade trees. These stressors 
play a large role in the future viability of Bartram's stonecrop, 
especially for smaller populations. These stressors are currently 
reducing and are expected to continue to reduce nearby water levels, 
shade, and humidity within Bartram's stonecrop habitat or directly 
impact individuals.

Loss of Water

    Dewatering of streams from mining operations may lead to overstory 
canopy losses and subsequent loss of shade, as well as reductions in 
spring and stream flow and humidity in nearby Bartram's stonecrop 
populations. The Rosemont Mine Final Environmental Impact Statement 
(Statement) notes that no Bartram's stonecrop individuals were found in 
the project area or the footprint of the associated actions; however, 
individuals growing in the analysis area could experience indirect 
impacts from groundwater drawdown (USFS 2013a, p. 676). According to 
the Statement, the proposed mine pit would create a permanent drawdown 
of the water table, and groundwater would flow toward the pit and be 
lost to evaporation (USFS 2013a, p. 339). The Bartram's stonecrop 
plants growing just southwest of the proposed Rosemont Mine were 
analyzed in the Rosemont Final Environmental Impact Statement (USFS 
2013a, pp. 346-350). The predicted groundwater drawdown in the affected 
population at the end of active mining is 0.1-5 feet, depending on the 
site assessed and the model used. At 20 years from the mine closure, 
the predicted drawdown increases to a maximum of 15-20 feet. The water 
would be perpetually replenished in part by groundwater from the 
regional aquifer, and the pit would act as a hydraulic sink. Given that 
Bartram's stonecrop is consistently found in locations with nearby 
springs or other water sources, the loss of groundwater and changes in 
soil moisture and humidity are expected to negatively affect the plant. 
For example, loss of groundwater in the unmapped spring in Box Canyon/
Sycamore Canyon confluence, between Ruelas Spring and the Singing 
Valley Road residences, could substantially impact Bartram's stonecrop 
plants growing nearby (just southwest of the proposed Rosemont Mine).
    Mining claims, trenching and exploration drilling activities, and a 
few active and proposed mines are present in Bartram's stonecrop's 
range. Many currently undeveloped areas of locatable mineral deposits 
may be explored and/or mined in the future. We do not know the full 
extent of future mine activity within the range of Bartram's stonecrop; 
however, a number of proposed mines are identified for development 
within Bartram's stonecrop habitat. The range of current and projected 
mining activities varies from 1 to 10 per sky island mountain range 
with Bartram's stonecrop occurrences (USFS 2012, entire). The loss or 
reduction of groundwater, stream flow, or spring flow in or near a 
Bartram's stonecrop population due to mining-related activities could 
lead to extirpation of that population.

Altered Fire Regime

    Wildfire frequency in western forests from the mid-1980s to the 
present has nearly quadrupled compared to 1970-1985. The timing, 
frequency, extent, and destructiveness of wildfires are

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expected to continue to increase (Westerling et al. 2006, p. 943), 
given historical land management actions, an increase in fire starts 
from cross-border human activity and recreationists (e.g., from 
campfires, cigarettes, target shooting), nonnative plant invasion, and 
continuing drought conditions (Westerling et al. 2006, p. 940; 
FireScape 2016, entire; Fire Management Information System 2016, p. 2). 
Direct impacts of fire include burning of Bartram's stonecrop 
individuals, resulting in injury, reduction in reproductive structures, 
or plant mortality. Indirect impacts of fire on Bartram's stonecrop may 
include increased runoff of floodwaters, post-fire flooding, deposition 
of debris and sediment originating in the burned area, erosion, changes 
in vegetation community composition and structure, increased presence 
of nonnative plants, alterations in the hydrologic and nutrient cycles, 
and loss of overstory canopy shade essential to maintaining Bartram's 
stonecrop microhabitat (Griffis et al. 2000, p. 243; Crawford et al. 
2001, p. 265; Hart et al. 2005, p. 167; Smithwick et al. 2005, p. 165; 
Stephens et al. 2014, p. 42; Ferguson 2014, p. 43; Ferguson 2016a, p. 
26). Fire primarily alters hydrology and erosion processes by 
consumption of the protective canopy, ground cover, and organic matter. 
When plants and litter are removed by fire, ground surface protection 
is decreased, less rainfall is intercepted, and less infiltration 
occurs (Pierson et al. 2011, p. 443). The exposed bare soil becomes 
susceptible to increased runoff generation and sediment detachment and 
transport (Pierson et al. 2011, p. 444). Amplified runoff post-fire 
carries sediment (Pierson et al. 2011, p. 443), causing erosion or 
burial of Bartram's stonecrop plants.
    We are aware of 11 wildfires that occurred in known Bartram's 
stonecrop sites from 2007-2017, killing some Bartram's stonecrop 
individuals and removing shade in some sites (Ferguson 2014, pp. 9-10, 
15, 28-29; Ferguson 2016a, p. 13; Ferguson 2016b, entire; Ferguson 
2017b, p. 32; Ferguson 2017c, p. 2). Although we do not have pre-fire 
population counts in any population, two of the largest Bartram's 
stonecrop populations occur in sky island mountain ranges that have had 
the fewest acres burned from 2010-2017, which indicates these 
populations may have experienced less of the detrimental effects of 
fire than smaller populations. Wildfires have burned in all nine sky 
island mountain ranges of southern Arizona with known Bartram's 
stonecrop occurrences within the last decade. Wildfire could 
potentially cause extirpation of small Bartram's stonecrop populations 
throughout the range of the species and have negative impacts on larger 
populations. Bartram's stonecrop seeds are very tiny, reside at or near 
the soil surface (Shohet 1999, p. 48), and show no characteristics that 
would promote survival in a wildfire.
    The nonnative plants in the uplands surrounding and within 
Bartram's stonecrop populations include nonnative grass species such as 
Lehmann's lovegrass and rose natal, both of which have numerous 
advantages over native grasses. Lehmann's lovegrass resprouts from 
roots and tiller nodes not killed by hot fire, is not hampered by the 
reduction in mycorrhizae associated with fire and erosion, responds to 
winter precipitation when natives grasses are dormant, produces copious 
seed earlier than native grasses, maintains larger seedbanks than 
native grasses, and has higher seedling survival and establishment than 
native grasses during periods of drought (Service 2020a, p. 50). Rose 
natal is capable of growing in low moisture situations, has prolific 
seed production, and has stems that root from the nodes (Stokes et al. 
2011, p. 527). Both species outcompete native plants, reduce structural 
and spatial diversity of habitats, and increase biomass and fuel loads, 
increasing the fire frequency. Nonnative grasses have been reported 
with Bartram's stonecrop individuals in four instances, at Sycamore 
Canyon, French Joe Canyon, Shaw Canyon, and Juniper Flat populations, 
and upslope of several populations of Bartram's stonecrop in the 
Dragoon Mountains, increasing the likelihood of fire occurrence and 
subsequent impacts to these populations (Heritage Database Management 
System, E.O. ID 55; Simpson 2017, pers. comm.). Nonnative plant species 
increase the frequency and severity of wildfires; such wildfires can 
directly and indirectly impact individuals and populations.

Altered Precipitation, Drought, Flooding, and Freezing Regimes

    The southwestern United States is warming and experiencing severe 
droughts of extended duration, changes in amount of snowpack and timing 
of snowmelt, and changes in timing and severity of precipitation and 
flooding (Garfin et al. 2014, entire). The effects of a changing 
climate are important considerations in the analysis of the stressors 
to Bartram's stonecrop, including increased nonnative competition 
(described above) and altered fire regimes during times of altered 
precipitation and drought. To analyze the effects of a changing climate 
to Bartram's stonecrop, we relied on the Intergovernmental Panel on 
Climate Change's (IPCC) Fifth Assessment (IPCC 2014, entire) and IPCC 
Climate Change 2013--The Physical Science Basis (IPCC 2013, entire). 
Four emission scenarios, referred to as Representative Concentration 
Pathways (RCPs), were developed for the IPCC report (IPCC 2014, p. 57). 
We evaluated the effects of climate change on Bartram's stonecrop using 
RCP 4.5 and RCP 8.5 to bracket the range of environmental variability. 
The IPCC report (2014) expresses confidence that emissions will fall 
within the RCP 4.5-8.5 range.
    Precipitation is bimodal within the mountain ranges where Bartram's 
stonecrop occurs, with winter snow and rain, and summer monsoon rain. 
Fall and winter (October through March) precipitation is needed for 
Bartram's stonecrop germination, and both summer (July and August) and 
fall (October and November) precipitation is needed for Bartram's 
stonecrop flower production. Flowering is triggered by fall rains and 
does not occur during periods of water stress (Shohet 1999, pp. 22, 25, 
36, 39). Altered precipitation timing and form (i.e., snow versus 
rain), as well as reduced precipitation in the winter and spring and 
prolonged drought, are important stressors influencing the viability of 
Bartram's stonecrop due to impacts on moisture availability for 
germination, growth, and flowering. In addition, due to increased 
nonnative competition during times of reduced precipitation and 
drought, impacts from these stressors to Bartram's stonecrop 
populations would be exacerbated.
    Altered precipitation timing and form (snow versus rain), as well 
as reduced winter and spring precipitation and prolonged drought, are 
currently occurring and projected to increase or be altered from normal 
in the Southwest (Garfin et al. 2014, entire). Recently, there has been 
a decrease in the amount of snowpack, earlier snowmelt, and increased 
drought severity in the Southwest (Garfin et al. 2013, entire; Garfin 
2013b, p. 465). Further, more wintertime precipitation is falling as 
rain rather than snow in the western United States (IPCC 2013, p. 204; 
Garfin 2013b p. 465). This means that the amount of runoff in the 
spring when snow melts is reduced, as is soil moisture. Late winter-
spring mountain snowpack in the Southwest is predicted to continue to 
decline over the 21st century under RCP 4.5 and 8.5 because of 
increased temperature (Garfin et al.

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2013, pp. 6, 119). Reduced rain and snow, earlier snowmelt, and drying 
tendencies cause a reduction in late-spring and summer runoff. Together 
these effects, along with increases in evaporation, result in lower 
soil moisture by early summer (Garfin 2013, p. 117).
    Precipitation timing and amount impact the germination, growth, and 
flowering of Bartram's stonecrop, resulting in the loss of individuals 
and recruitment, and overall reducing the population size. Climatic 
events such as reduced snowpack, earlier snowmelt, and increased 
drought are regional and will impact all populations of Bartram's 
stonecrop.
    In the Southwest, the period since 1950 has been warmer than any 
period of comparable length in at least 600 years, and average daily 
temperatures for the 2001-2010 decade were the highest in the time 
period including 1901-2010 (Garfin et al. 2013, p. 3). Fewer cold waves 
and more heat waves occurred over the Southwest during 2001-2010 
compared to average decadal occurrences in the 20th century. More 
frequent hot and fewer cold temperature extremes over most land areas 
are predicted on daily and seasonal timescales, as global mean surface 
temperature increases (IPCC 2014, p. 58). Heat waves are predicted to 
occur with a higher frequency and longer duration (IPCC 2014, p. 58). 
Occasional cold winter extremes will continue to occur (IPCC 2014, p. 
60). Surface temperatures in the Southwest are predicted to increase 
substantially over the 21st century, with more warming in summer and 
fall than in winter and spring. Summer heat waves will become longer 
and hotter, while winter cold snaps will become less frequent but not 
necessarily less severe (Garfin et al. 2013, p. 6; Garfin et al. 2014, 
p. 464).
    When temperatures rise, evapotranspiration rates also increase and 
soil moisture decreases. An increase in evapotranspiration results in 
water loss from the plant and increases stress on the plant. This 
increase in stress impacts photosynthesis, respiration, transpiration, 
water use efficiency, leaf conductance, growth rate, vigor, and gas 
exchange. These impacts result in reduced growth, flowering, and seed 
production, and, therefore, reduce overall recruitment and population 
numbers.
    Along with projected warming and increased evapotranspiration, 
droughts in parts of the Southwest will become hotter, more severe, and 
more frequent (Garfin et al. 2013, pp. 6, 137-138). Future droughts are 
projected to be substantially hotter, and for major river basins such 
as the Colorado River Basin, drought is projected to become more 
frequent, intense, and longer lasting than in the historical record. 
This projection of intensified drought conditions on the Colorado River 
is not due to changes in precipitation, but rather due directly to 
warming and its effect on reducing soil moisture (Garfin 2013, p. 138).
    Although rare species in the southwestern United States evolved 
with drought, recent changes in temperature and rainfall patterns 
present stressful conditions of increased magnitude compared to what 
the species faced. Some species may shift their distributions in 
response to warming of the climate (McLaughlin et al. 2002, p. 6070). 
However, it is highly unlikely that Bartram's stonecrop would be able 
to shift its range naturally to keep up with current and high projected 
rates of climate change due to its overall population decline and 
inability to maintain current populations. Because plants are not 
mobile, expanding the distribution of this species is dependent on seed 
dispersal. Bartram's stonecrop seeds are small and limited in dispersal 
ability (Ferguson 2020). Given their geographic location in the 
landscape (i.e., in canyons with springs and streams), it is possible 
that seeds are transported by water and that populations may have been 
founded by a single individual plant or seed (Shohet 1999, p. 58). 
Seeds may also be dispersed via gravity and wind. Seedling distribution 
studies indicate gravity is the most likely dispersal mechanism as 
seeds are fusiform shaped (elliptical like a football) (Ferguson 2020, 
pers. comm.). Further, extant populations are small, which limits the 
amount of seed production for dispersal. It is highly unlikely that 
under elevated environmental stress associated with climate change, the 
species would be able to both maintain populations and colonize new 
areas with more suitable climate conditions. Thus, localized 
extirpations over portions of Bartram's stonecrop's range could result.

Erosion, Sedimentation, and Burial

    Bartram's stonecrop typically occurs on steep slopes with erodible 
soils and in areas susceptible to rock fall, making the plant 
particularly vulnerable to physical damage to its environment (Phillips 
et al. 1982, p. 10; Shohet 1999, p. 50; Ferguson 2014, p. 42; Ferguson 
2016a, pp. 15, 26). Soil erosion can result in the burial of individual 
plants, loss of soil where the plant is rooted, or dislodgment of 
plants. While displaced plants may re-root (Shohet 1999, pp. 50-51, 
60), it is more likely that these plants will not survive (Ferguson 
2015, p. 2). Soil disturbance and erosion within or above Bartram's 
stonecrop habitat may occur from a variety of activities, including 
livestock and wildlife movement; the placement and maintenance of 
infrastructure, trails, and roads; and recreationists or other 
individuals traveling along established trails or cross country 
(Phillips et al. 1982, p. 10; Shohet 1999, p. 60; Ferguson 2014, p. 42; 
NPS 2015, p. 4; Ferguson 2016a, p. 26).
    Direct removal of Bartram's stonecrop individuals and substrate due 
to erosion or burial of individuals may also occur due to the placement 
of mineral extraction sites and debris piles. Erosion from test pits 
(an excavation made to examine the subsurface conditions of a potential 
mine site) has been documented to remove portions of habitat occupied 
by Bartram's stonecrop in Flux Canyon (Phillips et al. 1982, pp. 9-10).

Trampling

    The trampling of individual Bartram's stonecrop plants may occur 
from a variety of activities, including livestock and wildlife 
movement; the placement and maintenance of infrastructure, trails, and 
roads; and recreationists or other individuals traveling along 
established trails or cross country (Phillips et al. 1982, p. 10; 
Shohet 1999, p. 60; Ferguson 2014, p. 42; NPS 2015, p. 4; Ferguson 
2016a, p. 26). Populations may be particularly impacted during periods 
of unusual recreational use. We considered trampling as a stressor in 
our analysis of future viability only when it may impact a population 
with fewer than 50 individuals, as more minor stressors are exacerbated 
in small populations.

Illegal Collection

    The illegal collection of succulents is known to occur, and is 
often difficult to detect. Illegal collection of Bartram's stonecrop 
individuals has been reported, and the effect of collection is more 
pronounced in small populations. More than half (58 percent) of 
Bartram's stonecrop populations contain fewer than 50 individuals. The 
lifespan of Bartram's stonecrop plants has been estimated at 5-10 
years, allowing sufficient time for discovery and collection.
    Bartram's stonecrop is an attractive and small plant not available 
from nurseries that can be easily collected by gardeners and succulent 
enthusiasts. This stressor was first noted in 1982, when exact 
localities were excluded from a summary report due to the possibility 
of illegal collection. Tagged

[[Page 48551]]

individuals were uprooted and taken from two sites in the Santa Rita 
Mountains in 1997-1998. Plants in close proximity to trails have higher 
discovery potential and are therefore more likely to be collected. 
Collectors advertise in internet forums seeking Bartram's stonecrop 
seedlings or rooted cuttings. The similar southern Arizona species, 
Graptopetalum rusbyi (San Francisco leatherpetal), is cultivated and 
legally available for sale from plant nurseries. However, Bartram's 
stonecrop is more difficult to propagate and maintain in captivity and 
is therefore vulnerable to collection from the wild because collectors 
cannot find them for purchase in nurseries. Small populations may not 
be able to recover from collection, especially if mature, reproductive 
Bartram's stonecrop individuals are removed. The removal of mature 
plants reduces the overall reproductive effort of the population, 
thereby reducing the overall resilience of the population. While 
documented instances of collection are limited, the impacts from 
collection can be profound for small populations.

Small Populations

    Small population size affects Bartram's stonecrop population 
resiliency, as all stressors are exacerbated in populations with only a 
small number of individuals (fewer than 50). Small populations are less 
able to recover from losses caused by random environmental changes 
(Shaffer and Stein 2000, pp. 308-310), such as fluctuations in 
reproduction (demographic stochasticity), variations in rainfall 
(environmental stochasticity), or changes in the frequency or severity 
of disturbances, such as wildfires. Twenty-nine of the 50 extant 
Bartram's stonecrop populations in the United States contain fewer than 
50 individuals. Losses due to mining, erosion, trampling, collection, 
herbivory, fire, severe frost, or other stressors mentioned above are 
exacerbated in small populations and have the potential to seriously 
damage or completely remove these small populations.
    In summary, the stressors that pose the largest risk to future 
species viability are primarily related to habitat changes: Groundwater 
extraction from mining, long-term drought, and alteration in wildfire 
regime. These stressors may reduce nearby water levels, shade, and 
humidity within Bartram's stonecrop habitat and may directly impact 
individuals. Other important stressors include erosion or trampling 
from livestock, wildlife, or human activities; illegal collection; 
herbivory of Bartram's stonecrop individuals or their shade trees by 
wildlife and insects; abnormal freezing or flooding events; or other 
stressors that have the potential to seriously damage or completely 
remove small populations. Synergistic interactions among altered 
precipitation, nonnative grasses, drought, and increased temperatures 
cumulatively and cyclically impact Bartram's stonecrop, and all 
stressors are exacerbated in small populations.

Population Resiliency of Bartram's Stonecrop

    To determine current condition, we assessed each population in 
terms of its resiliency. Our analysis of the past, current, and future 
stressors on the resources that Bartram's stonecrop needs for long-term 
viability revealed a number of stressors influencing this species. Four 
Bartram's stonecrop populations contain nonnative grasses, and 
nonnative grasses are present upslope from several additional 
populations. Further, altered fire regimes have the potential to affect 
all Bartram's stonecrop populations. This altered fire regime enhances 
the spread of nonnatives. Consequently, all Bartram's stonecrop 
populations will be further impacted by nonnative grasses in the 
future. Altered precipitation, increased temperatures, increased 
evapotranspiration, decreased soil moisture, and decreased winter and 
spring precipitation are current and ongoing environmental conditions 
impacting all populations of Bartram's stonecrop and exacerbating an 
altered fire regime.
    Many currently undeveloped areas of locatable mineral deposits may 
be explored or mined in the future. We do not know the full extent of 
future mine activity within Bartram's stonecrop's range; however, 12 
mining projects are currently ongoing or proposed within 8 kilometers 
(5 miles) of Bartram's stonecrop populations in Arizona. The range of 
current and projected mining activities varies from 1 to 10 per 
mountain range with Bartram's stonecrop occurrences (USFS 2012, 
entire). One population, Sycamore Canyon (115 adult individuals in 
2016), would be affected by groundwater drawdown due to the Rosemont 
Mine. Sycamore Canyon currently exhibits high resiliency. Further, this 
species is illegally collected and sold. Synergistic interactions among 
wildfire, nonnative grasses, decreased precipitation, and increased 
temperatures cumulatively and cyclically impact Bartram's stonecrop, 
and all stressors are exacerbated in small populations. In addition, 
over half of extant Bartram's stonecrop populations are small; 
therefore, loss due to erosion, trampling, collection, herbivory, fire, 
severe frost, or other stressors have the potential to seriously damage 
or completely remove these small populations.
    Resiliency categories of low, moderate, and high are characterized 
by relative levels of abundance, number of subpopulations and the 
spatial distribution of groups, seed production, recruitment, and 
extent of suitable habitat. The categories of conditions used to 
determine population resiliency are further described in the SSA report 
(Service 2020a, table 5.12) and the proposed listing rule (84 FR 67060, 
December 6, 2019, p. 84 FR 67069). Of the 50 extant populations, 2 
populations (4 percent) exhibit high resiliency (also described as high 
condition), 40 populations (80 percent) are in moderate condition, and 
8 populations (16 percent) are in low condition. Many small populations 
exhibit moderate resiliency due to other demographic and habitat 
factors considered in the analysis of resiliency including number of 
subpopulations, recruitment, riparian elements, precipitation, and 
shade. Thus, the resiliency analysis of a population with a low 
abundance score and high scores in several or all the other categories 
of resiliency factors may result in an averaged score in the moderate 
resiliency category. The current resiliency of the known Bartram's 
stonecrop populations is shown in table 1.

                           Table 1--Bartram's Stonecrop Current Population Resiliency
----------------------------------------------------------------------------------------------------------------
                                                                       Number of
             Sky island                        Population             individuals        Current resiliency
----------------------------------------------------------------------------------------------------------------
Baboquivari.........................  Brown Canyon................             115  Moderate.
                                      Sabino Wash.................               3  Low.
                                      Thomas Canyon...............              10  Moderate.
Chiricahua..........................  Echo Canyon.................             186  Moderate.

[[Page 48552]]

 
                                      Indian Creek................               0  Extirpated.
Dragoon.............................  Carlink Canyon..............               0  Extirpated.
                                      Jordan Canyon...............             415  Moderate.
                                      Sheephead...................              45  Moderate.
                                      Slavin Gulch................               9  Moderate.
                                      Stronghold Canyon East......             388  Moderate.
                                      Stronghold Canyon West......             557  High.
Empire..............................  Empire Mountains............               0  Extirpated.
Mule................................  Juniper Flat................             798  Moderate.
Pajarito-Atascosa...................  Alamo Canyon................             134  Moderate.
                                      Holden Canyon...............               9  Low.
                                      Sycamore Canyon.............             313  High.
                                      Warsaw Canyon...............              13  Moderate.
Patagonia...........................  Alum Gulch..................              52  Moderate.
                                      Flux Canyon.................             123  Moderate.
Rincon..............................  Bear Creek..................             171  Moderate.
                                      Chimenea-Madrona Canyon.....              29  Low.
                                      Chimenea Canyon Side Branch.              35  Moderate.
                                      Distillery..................               3  Moderate.
                                      Happy Valley North..........               1  Low.
                                      Happy Valley South..........              41  Moderate.
                                      Italian Spring Canyon.......              30  Moderate.
                                      North Branch Turkey Creek...              11  Moderate.
                                      Posta Quemada...............               3  Moderate.
                                      Rincon Creek................              38  Moderate.
                                      Rincon Peak.................               2  Moderate.
                                      Shaw Canyon.................              19  Moderate.
                                      South Branch Turkey Creek...               7  Moderate.
                                      Tanque Verde Ridge Trail....              90  Moderate.
                                      Tres Pipas Canyon...........               4  Moderate.
                                      West Branch Deer Creek......              10  Moderate.
Santa Rita..........................  Adobe Canyon................              82  Moderate.
                                      Bond Canyon.................              51  Moderate.
                                      Cave Canyon.................              50  Moderate.
                                      Gardner Canyon East.........              10  Moderate.
                                      Gardner Canyon West.........              14  Moderate.
                                      Josephine Canyon............              76  Moderate.
                                      Madera Canyon...............             145  Moderate.
                                      Sawmill Canyon..............              36  Moderate.
                                      Squaw Gulch.................              55  Moderate.
                                      Sycamore Canyon.............             115  Moderate.
                                      Temporal Gulch..............              27  Moderate.
                                      Walker Canyon...............              19  Moderate.
Whetstone...........................  Deathtrap Canyon............             135  Moderate.
                                      French Joe Canyon...........              87  Low.
                                      Guindani Canyon.............               3  Moderate.
Sierra Las Avispas, Sonora..........  Sierra Las Avispas..........               2  Low.
Sierra La Escuadra, Chihuahua.......  Near Colonia Pacheco........              46  Low.
Sierra La Estancia, Chihuahua.......  Cuarenta Casas..............              10  Low.
----------------------------------------------------------------------------------------------------------------

Bartram's Stonecrop Representation

    No genetic studies have been conducted within or among the 53 
Bartram's stonecrop historical populations in southern Arizona and 
Mexico. Mountain ranges that have only one or two populations, or have 
only one subpopulation per population, or low numbers of individuals 
per population with several miles between mountain ranges, may not be 
as genetically diverse because pollination or transport of seeds 
between populations may be very limited or nonexistent. Some genetic 
exchange likely occurs within populations containing many 
subpopulations, groups, or in populations with high abundance.
    However, Bartram's stonecrop may exhibit some level of genetic 
diversity in response to elevational and other environmental variation 
between locations. The species occurs on multiple substrate types and 
at a range of elevations (3,500 to 6,800 feet), providing potential for 
local adaptation and genetic differentiation among populations. This 
range in elevation provides a variety of climatic conditions for the 
species to inhabit. Due to the loss of four populations, it is possible 
that there has been a loss of genetic diversity.
    In three populations, plants have been reported over many decades, 
indicating that these populations may have the genetic and 
environmental diversity to adapt to changing conditions. The species 
currently occurs across 50 populations in 12 mountain ranges; 
therefore, we expect some level of genetic diversity exists among 
mountain ranges.

Bartram's Stonecrop Redundancy

    Bartram's stonecrop populations in the United States and Mexico are 
naturally fragmented between mountain ranges. Currently, 50 extant 
Bartram's stonecrop populations are spread across

[[Page 48553]]

12 different mountain ranges in southern Arizona and northern Mexico. 
Although this may imply some level of redundancy across the range of 
Bartram's stonecrop, 43 of the 50 extant populations contain fewer than 
150 total individual plants. Further, 29 populations have 50 
individuals or fewer, and 3 populations have been extirpated over 
recent (approximately 10) years. Given the distance of the mountain 
ranges with Bartram's stonecrop populations from each other, natural 
gene exchange or re-establishment following extirpation of populations 
within a mountain range is unlikely. In addition, the Mule Mountains 
contain a large number of Bartram's stonecrop individuals, but are 
represented by a single population approximately 38 kilometers (23.6 
miles) away from the nearest population, making natural re-
establishment of populations unlikely.

Future Condition of Bartram's Stonecrop

    We used the best available information to forecast the future 
viability of Bartram's stonecrop. Maintaining multiple resilient 
populations over time (viability) depends on moisture in the 
microenvironment maintained by shade from overstory vegetation, spring 
and winter precipitation, proximity to water, and vegetation litter. We 
expect all extant Bartram's stonecrop populations to experience changes 
to these habitat characteristics to varying degrees. In addition, 
direct impacts to Bartram's stonecrop through being dislodged, buried, 
or collected will continue to impact the species.
    We note that, by using the SSA framework to guide our analysis of 
the scientific information documented in the SSA report, we have not 
only analyzed individual effects on the species, but we have also 
analyzed their potential cumulative effects. We incorporate the 
cumulative effects into our SSA analysis when we characterize the 
current and future condition of the species. Our assessment of the 
current and future conditions encompasses and incorporates the threats 
individually and cumulatively. Our current and future condition 
assessment is iterative because it accumulates and evaluates the 
effects of all the factors that may be influencing the species, 
including threats and conservation efforts. Because the SSA framework 
considers not just the presence of the factors, but to what degree they 
collectively influence risk to the entire species, our assessment 
integrates the cumulative effects of the factors and replaces a 
standalone cumulative effects analysis.
    Acknowledging inherent uncertainties regarding the scope of the 
stressors manifesting and the species' response, we forecasted future 
conditions of Bartram's stonecrop under four plausible future scenarios 
(see chapter 6 of the SSA report; Service 2020a, pp. 104-124). The 
scenarios span a range of potential stressors that are occurring or 
will occur in the future that will influence the future status of the 
species and the effects of those stressors on the species. We analyzed 
future projections in 10-year and 40-year timeframes because this is 
within the range of predictions of available hydrological and climate 
change model forecasts and is within the period of the Rosemont Mine 
effects. Forty years represents eight generations of Bartram's 
stonecrop, which allows us to assess reproductive effects on the 
species and allows populations to have opportunities to rebound. The 
10-year time step also represents a reasonable timeframe to judge the 
species' short-term vulnerability to stressors at the current level, 
without projecting changes to stressors that longer timeframes would 
provide. Thus, the future scenarios forecast the viability of Bartram's 
stonecrop over the next 40 years. The following stressors were 
considered at different levels of impact for each scenario:
     Mining activity--water extraction, excavation, burial, 
shade reduction;
     Altered fire regime--lightning, recreation, cross-border 
human activity, nonnative plants;
     Climate effects (water)--reduction in available water 
including precipitation, soil moisture, humidity, surface water, 
aquifer recharge, reduction in riparian vegetation, increased number of 
days without water;
     Climate effects (other)--dislodging from flooding events, 
seedling desiccation, flowering halt, shade removed; and
     Effects to individual plants (applied to populations with 
fewer than 50 individuals)--recreation, collection, trampling, 
livestock or wildlife grazing and herbivory.
    The levels of stressors assessed in each scenario are described in 
greater detail in chapter 6 of the SSA report (Service 2020a, pp. 104-
124).
    The first scenario (``continuation'') evaluates the condition of 
Bartram's stonecrop if impacts from drought, climate change, and other 
stressors continue as in the near past, while the other scenarios 
evaluate the response of the species to changes in those risks. 
Scenario 1 is evaluated at the 10-year time step. The second scenario 
(``conservation'') assumes impacts from drought, climate change, and 
other stressors continue as in the near past and also takes into 
account realistically possible additional protective measures, which 
may or may not happen. Scenarios 2, 3, and 4 are evaluated at the 40-
year time step. The third scenario (``moderate effects'') assesses an 
increase in stressors to populations with changes in climate as 
projected in a lower (RCP 4.5) emissions scenario along with increases 
in other stressors. The final scenario (``major effects'') assesses a 
further increase in stressors to populations, with changes in climate 
projected at a higher (RCP 8.5) emissions scenario, and with additional 
increases in other stressors. These scenarios are described in more 
detail in chapter 6 of the SSA report (Service 2020a).
    In scenario 1, we assess impacts to Bartram's stonecrop from 
drought, climate change, and other stressors that continue as in the 
near past. Based on climate change projections, emissions will continue 
at the same rate as the near past, resulting in continued impacts to 
the species. In this scenario, we expect the viability of Bartram's 
stonecrop to be characterized by a loss of resiliency, representation, 
and redundancy from the current levels. At the 10-year time step, no 
populations would exhibit high resiliency, 9 populations would exhibit 
moderate resiliency, 41 populations would exhibit low resiliency and be 
more susceptible to loss, and no additional populations would be 
extirpated.
    In scenario 2, we assess impacts to Bartram's stonecrop from 
drought, climate change, and other stressors that continue as in 
scenario 1 but with conservation measures implemented that provide a 
benefit to the species (e.g., nonnative control, forest thinning, and 
prevention of human-caused wildfire). Climate change impacts are 
projected to continue at the current rate, and no conservation measures 
address drying of habitat. In this scenario, we expect the viability of 
Bartram's stonecrop to be characterized by similar levels of 
representation and redundancy and slightly lower levels of resiliency 
than it exhibits under the current condition. Because current stressors 
remain in place, conservation measures improve the resiliency of 
populations, but this effect is overshadowed by the impact of continued 
climate change and drought at the current level.
    The third scenario assesses ``moderate effects'' to Bartram's 
stonecrop with impacts to the species evaluated at the

[[Page 48554]]

40-year time step. Under this scenario, water flow reduction due to 
drought and groundwater extraction continues to reduce the humid 
microhabitat for this species. Cross-border traffic continues, and risk 
of catastrophic wildfire is high due to dry conditions; invasion of 
nonnatives in the uplands; and increased risk of fire starts from 
illegal activity, recreation, and natural causes. Mining impacts 
individuals in the Patagonia and Santa Rita Mountains. Collection, 
trampling, freezing, herbivory, and human impacts also continue at 
current or increased levels.
    Under this scenario, within the 40-year timeframe, we expect 
Bartram's stonecrop's viability to be characterized by lower levels of 
resiliency, representation, and redundancy than it has currently, which 
are already reduced as described above. In 40 years, we expect that 
none of the 50 extant populations would exhibit high resiliency, 2 
populations would exhibit moderate resiliency, 35 populations would 
exhibit low resiliency, and 13 additional populations would be 
extirpated, further reducing species redundancy and representation 
(table 2, below; see table 6.6 in the SSA report (Service 2020a)). 
Under the moderate effects scenario, because of stressors described 
above, 45 populations would be reduced from their current condition 
(for population level projections, see figure 6.3 and table 6.6 in the 
SSA report (Service 2020a)). In this scenario, two of the three small 
populations in Mexico will be extirpated due to the amount of 
nonnatives contributing to fire, reduction in precipitation, increase 
in drought, and low resiliency of a small population.
    Under scenario 4, ``major effects'', we expect the viability of 
Bartram's stonecrop to be characterized by lower levels of resiliency, 
representation, and redundancy than under scenario 3. At the 40-year 
time step, no populations exhibit high resiliency, one would exhibit 
moderate resiliency, 16 would exhibit low resiliency, and 36 
populations would be extirpated, further reducing redundancy and 
connectivity.
    Please refer to the SSA report (Service 2020a, entire) for a more 
detailed discussion of our evaluation of the biological status of 
Bartram's stonecrop, the influences that may affect its continued 
existence, and the modeling efforts undertaken to further inform our 
analysis.

                                          Table 2--Bartram's Stonecrop Population Current and Future Resiliency
--------------------------------------------------------------------------------------------------------------------------------------------------------
         Mountain range            Population name    Current condition       Scenario 1          Scenario 2          Scenario 3          Scenario 4
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baboquivari....................  Brown Canyon......  Moderate..........  Moderate...........  Moderate..........  Moderate..........  Low.
                                 Sabino Wash.......  Low...............  Low................  Low...............  Low...............  Extirpated.
                                 Thomas Canyon.....  Moderate..........  Low................  Low...............  Low...............  Low.
Chiricahua.....................  Echo Canyon.......  Moderate..........  Moderate...........  Moderate..........  Low...............  Low.
                                 Indian Creek......  Extirpated........  Extirpated.........  Extirpated........  Extirpated........  Extirpated.
Dragoon........................  Carlink Canyon....  Extirpated........  Extirpated.........  Extirpated........  Extirpated........  Extirpated.
                                 Jordan Canyon.....  Moderate..........  Moderate...........  Moderate..........  Low...............  Low.
                                 Sheephead.........  Moderate..........  Low................  Low...............  Low...............  Low.
                                 Slavin Gulch......  Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                 Stronghold Canyon   Moderate..........  Moderate...........  Moderate..........  Low...............  Low.
                                  E..
                                 Stronghold Canyon   High..............  Moderate...........  Moderate..........  Moderate..........  Moderate.
                                  W.
Empire.........................  Empire Mts........  Extirpated........  Extirpated.........  Extirpated........  Extirpated........  Extirpated.
Mule...........................  Juniper Flat......  Moderate..........  Low................  Moderate..........  Low...............  Low.
Pajarito-Atascosa..............  Alamo Canyon......  Moderate..........  Low................  Low...............  Low...............  Low.
                                 Holden Canyon.....  Low...............  Low................  Low...............  Extirpated........  Extirpated.
                                 Sycamore Canyon...  High..............  Moderate...........  Moderate..........  Low...............  Low.
                                 Warsaw Canyon.....  Moderate..........  Low................  Low...............  Extirpated........  Extirpated.
Patagonia......................  Alum Canyon.......  Moderate..........  Low................  Low...............  Extirpated........  Extirpated.
                                 Flux Canyon.......  Moderate..........  Low................  Low...............  Extirpated........  Extirpated.
Rincon.........................  Bear Creek........  Moderate..........  Moderate...........  Moderate..........  Low...............  Low.
                                 Chimenea-Madrona    Low...............  Low................  Low...............  Low...............  Extirpated.
                                  Canyon.
                                 Chimenea Canyon     Moderate..........  Low................  Moderate..........  Low...............  Extirpated.
                                  Side Branch.
                                 Distillery Canyon.  Moderate..........  Low................  Moderate..........  Extirpated........  Extirpated.
                                 Happy Valley North  Low...............  Low................  Low...............  Extirpated........  Extirpated.
                                 Happy Valley South  Moderate..........  Low................  Moderate..........  Low...............  Extirpated.
                                 Italian Spring      Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                  Canyon.
                                 North Branch        Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                  Turkey Creek.
                                 Posta Quemada       Moderate..........  Low................  Moderate..........  Low...............  Extirpated.
                                  Canyon.
                                 Rincon Creek......  Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                 Rincon Peak.......  Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                 Shaw Canyon.......  Moderate..........  Low................  Moderate..........  Extirpated........  Extirpated.
                                 South Branch        Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                  Turkey Creek.
                                 Tanque Verde Ridge  Moderate..........  Moderate...........  Moderate..........  Low...............  Low.
                                  Trail.
                                 Tres Pipas Canyon.  Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                 West Branch Deer    Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                  Creek.
Santa Rita.....................  Adobe Canyon......  Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                 Bond Canyon.......  Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                 Cave Canyon.......  Moderate..........  Low................  Low...............  Extirpated........  Extirpated.
                                 Gardner Canyon      Moderate..........  Low................  Low...............  Extirpated........  Extirpated.
                                  East.
                                 Gardner Canyon      Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                  West.
                                 Josephine Canyon..  Moderate..........  Moderate...........  Moderate..........  Low...............  Low.
                                 Madera Canyon.....  Moderate..........  Low................  Low...............  Low...............  Low.
                                 Sawmill Canyon....  Moderate..........  Low................  Low...............  Extirpated........  Extirpated.
                                 Squaw Gulch.......  Moderate..........  Low................  Low...............  Low...............  Extirpated.
                                 Sycamore Canyon...  Moderate..........  Low................  Low...............  Extirpated........  Extirpated.
                                 Temporal Gulch....  Moderate..........  Low................  Low...............  Low...............  Low.
                                 Walker Canyon.....  Moderate..........  Low................  Low...............  Low...............  Extirpated.
Whetstone......................  Deathtrap Canyon..  Moderate..........  Low................  Low...............  Low...............  Low.
                                 French Joe Canyon.  Low...............  Low................  Low...............  Low...............  Extirpated.
                                 Guindani Canyon...  Moderate..........  Low................  Low...............  Low...............  Extirpated.
Sierra Las Avispas, Sonora.....  Sierra Las Avispas  Low...............  Low................  Low...............  Extirpated........  Extirpated.

[[Page 48555]]

 
Sierra La Escuadra, Chihuahua..  Near Colonia        Low...............  Low................  Low...............  Low...............  Low.
                                  Pacheco.
Sierra La Estancia, Chihuahua..  Cuarenta Casas....  Low...............  Low................  Low...............  Extirpated........  Extirpated.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Summary of Comments and Recommendations

    In our December 6, 2019, proposed rule (84 FR 67060), we requested 
that all interested parties submit written comments on the proposal by 
February 4, 2020. We also contacted appropriate Federal and State 
agencies, scientific experts and organizations, and other interested 
parties and invited them to comment on the proposed rule. Newspaper 
notices inviting general public comment were published in the Arizona 
Daily Star on December 9, 2019, and the Sierra Vista Herald on December 
13, 2019. We did not receive any requests for a public hearing. All 
substantive information provided during the comment period either has 
been incorporated directly into the final rule or is addressed below.

Peer Reviewer Comments

    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), and our August 22, 
2016, memorandum updating and clarifying the role of peer review of 
listing actions under the Act, we sought the expert opinions of three 
appropriate specialists regarding the 2018 SSA report. The peer 
reviewers have expertise that includes familiarity with Bartram's 
stonecrop and its habitat, biological needs, and threats. We received 
responses from two specialists, which informed the SSA report and 
proposed rule. The purpose of peer review is to ensure that our listing 
determinations and 4(d) rules are based on scientifically sound data, 
conclusions, and analyses.
    In the development of the final rule, we solicited further expert 
opinion on stressors and the effect of stressors as analyzed in the SSA 
from six knowledgeable specialists with scientific expertise that 
included familiarity with Bartram's stonecrop and its habitat, 
biological needs, and threats (Service 2020b, entire). We reviewed all 
comments we received from the specialists for substantive issues and 
new information regarding Bartram's stonecrop. The reviewers generally 
concurred with our methods and conclusions, and provided additional 
information, clarifications, and suggestions to improve the updated SSA 
report and final rule. Peer reviewer comments and expert opinions are 
incorporated into the SSA report (Service 2020a) and this final rule as 
appropriate.

Public Comments

    We received 17 public comments in response to the proposed rule. We 
reviewed all comments we received during the public comment period for 
substantive issues and new information regarding the proposed rule. 
Seven commenters provided substantive comments or new information 
concerning the proposed listing and 4(d) rule for Bartram's stonecrop. 
Below, we provide a summary of the substantive issues raised in the 
public comments we received; however, comments outside the scope of the 
proposed rule, and those without supporting information, did not 
warrant an explicit response and, thus, are not presented here. 
Identical or similar comments have been consolidated and a single 
response provided.
    (1) Comment: A commenter indicated that the Service did not notify 
the public of the imminent listing of the species and the public needs 
more time to respond.
    Response: On August 8, 2012, we announced our 90-day finding that a 
petition to list Bartram's stonecrop as endangered or threatened under 
the Act presented substantial information indicating that listing of 
the species may be warranted (77 FR 47352). At that time, we requested 
data or other information from the public regarding the species to 
inform our status review and determination if listing is warranted. In 
response to publication of the 90-day finding, increased interest in 
Bartram's stonecrop and its status led to additional surveys and 
research beginning in 2013. On October 23, 2017, we sent a letter to 
interested parties, landowners, and Tribes indicating that an SSA would 
be conducted for Bartram's stonecrop to inform our listing 
determination, and we again requested scientific and commercial data or 
other information on the species.
    In addition, the species has been included on our National Listing, 
which is publicly available on our website, since 2016. We updated the 
workplan in May 2019 and listed the 12-month finding for Bartram's 
stonecrop as a FY 2018 carryover action. The court-ordered settlement 
agreement of October 11, 2019, that stipulates delivery of a 12-month 
finding to the Federal Register by November 29, 2019, is also publicly 
available.
    Finally, the December 6, 2019, proposed rule (84 FR 67060) opened a 
60-day public comment period on the proposed listing and proposed 4(d) 
rule for Bartram's stonecrop.
    As such, we complied with all requirements of the Act and conclude 
that the public was afforded adequate notice of the proposed listing of 
Bartram's stonecrop.
    (2) Comment: Three commenters stated that relying on the 
conservation biology concepts of resiliency, redundancy, and 
representation to make the proposed listing determination is improper, 
as they are not found in the Act or the Service's implementing 
regulations and their meanings are uncertain, creating confusion if 
criteria for listing are being followed.
    Response: The SSA framework is an analytical approach developed by 
the Service to deliver foundational science for informing decisions 
under the Act (Smith et al. 2018, entire). The SSA characterizes 
species viability (defined as the ability to sustain populations in the 
wild over time) based on the best scientific understanding of current 
and future abundance and distribution within the species' ecological 
settings using the conservation biology principles of resiliency, 
redundancy, and representation (Shaffer and Stein 2000, pp. 308-311). 
To sustain populations over time, a species must have the capacity to 
withstand: (1) Environmental and demographic stochasticity and 
disturbances (resiliency), (2) catastrophes (redundancy), and (3) novel 
changes in its biological and physical environment (representation). A 
species with a high degree of resiliency, representation, and 
redundancy is better able to adapt to novel changes and to tolerate 
environmental stochasticity and catastrophes. In general, species 
viability will increase and the risk of extinction will decrease with 
increases in resiliency, redundancy, and

[[Page 48556]]

representation (Smith et al. 2018, p. 306). The SSA provides decision-
makers with a scientifically rigorous characterization of a species' 
status and the likelihood that the species will sustain populations 
over time, along with key uncertainties in that characterization. The 
Bartram's stonecrop SSA provides the best scientific information 
available to guide a determination of whether or not Bartram's 
stonecrop is in danger of extinction now or in the foreseeable future.
    Notwithstanding our use of resiliency, redundancy, and 
representation as scientific concepts helpful in assessing and 
describing a species' viability and extinction risk, we adhere to all 
requirements of the Act in making our listing determinations. This 
includes applying the Act's definitions of an endangered species and a 
threatened species, as well as an assessment of the 5 listing factors 
(see Regulatory Framework, below).
    (3) Comment: Three commenters suggested the Service's discussion of 
its proposed 4(d) rule for Bartram's stonecrop conflicts with the Act 
and erroneously extends the ``take'' prohibition for fish and wildlife 
to a plant species.
    Response: The Act and its implementing regulations set forth a 
series of general prohibitions and exceptions that apply to endangered 
plants. The prohibitions of section 9(a)(2) of the Act, codified at 50 
CFR 17.61, make it illegal for any person subject to the jurisdiction 
of the United States to: Import or export; remove and reduce to 
possession from areas under Federal jurisdiction; maliciously damage or 
destroy on any such area; remove, cut, dig up, or damage or destroy on 
any other area in knowing violation of any law or regulation of any 
State or in the course of any violation of a State criminal trespass 
law; deliver, receive, carry, transport, or ship in interstate or 
foreign commerce, by any means whatsoever and in the course of a 
commercial activity; or sell or offer for sale in interstate or foreign 
commerce an endangered plant. Certain exceptions apply to employees of 
the Service, the National Marine Fisheries Service, other Federal land 
management agencies, and State conservation agencies.
    The final 4(d) rule for Bartram's stonecrop provides for the 
conservation of the species by applying all of the prohibitions listed 
in section 9(a)(2) of the Act and 50 CFR 17.61 that are applicable to 
an endangered plant, except as otherwise authorized or permitted at 50 
CFR 17.61(c)(2) and (3), 50 CFR 17.71(b), and 50 CFR 17.72.
    In the December 6, 2019, proposed rule (84 FR 67060, p. 84 FR 
67086), we also describe a range of activities that have potential to 
impact Bartram's stonecrop, including:
     Unauthorized handling or collecting of the species;
     Ground-disturbing activities where the species occurs;
     Activities that would affect pollinators where the species 
occurs and in the surrounding area;
     Activities that would promote high-severity wildfires 
where the species occurs;
     Activities that would reduce shade, reduce proximity to 
water, and lower the water table such that the cooler, humid 
microenvironment is affected; and
     Herbicide applications where the species occurs.
    These activities are provided as examples of actions that may 
affect Bartram's stonecrop, and as such would be subject to section 7 
consultation for projects with a Federal nexus, and are not intended to 
be a list of prohibitions under the final 4(d) rule for Bartram's 
stonecrop.
    (4) Comment: Several commenters stated that Service botanists have 
not visited sites with Bartram's stonecrop and that if more surveys are 
done, more plants will be found as Bartram's stonecrop is a small 
cactus with one-inch flowers that are hard to see. For example, the 
species has been discovered at 16 new locations since 2015.
    Response: Bartram's stonecrop is a succulent with specific habitat 
requirements and is detectable in bloom and out of bloom by trained 
botanists. All researchers involved with Bartram's stonecrop surveys, 
including the Service, the National Park Service (NPS), the U.S. Forest 
Service (USFS), and the Arizona Game and Fish Department, as well as 
other academic and commercial entities, are experienced in both plant 
and habitat identification. Increased survey efforts since 2013 by such 
qualified individuals have led to newly discovered Bartram's stonecrop 
populations or groups. We are aware of 70 total elemental occurrences 
(Arizona Game and Fish Department, Heritage Database Management System) 
in the 50 extant U.S. Bartram's stonecrop populations. Of these, all 
but seven occurrences from five populations have been located or 
revisited since 2010 (Service 2020a, tables 5.2-5.11).
    Following extensive survey efforts in Arizona and Mexico, we are 
now aware of 872 new individuals from the United States and Mexico 
since the SSA report was initially written (Service 2020a, entire). For 
example, between 2018 and 2020, numerous surveys for Bartram's 
stonecrop were conducted in the Rincon Mountains, and 13 additional 
Bartram's stonecrop populations were located (Service 2020a, pp. 89-
90), including 1 population previously considered to be extirpated that 
contained one individual in 2019 (Service 2020a, p. 15). Similarly, 
recent surveys in the Santa Rita Mountains resulted in a newly 
discovered group of 55 individuals in Madera Canyon. We are also now 
aware of additional information from a private researcher's surveys 
beginning in 2012. We have incorporated this and all verified 
information regarding species occurrences in the revised SSA report 
(version 2.0) and this final rule. Although the newly discovered 
individuals contribute to the overall abundance of Bartram's stonecrop 
and may increase the resiliency of some populations, the threats to the 
species and the effect of those threats on the species remain such that 
the species is likely to become in danger of extinction within the 
foreseeable future. This additional information did not alter our 
conclusion that the species meets the Act's definition of a threatened 
species.
    (5) Comment: Four commenters felt that there is not enough evidence 
to conclude that Bartram's stonecrop populations are declining. 
Specifically, the Mule Mountains population has increased in size to 
798 individuals and the statement in the proposed rule that there has 
been a contraction in size is outdated.
    Response: The 2015 survey of the Mule Mountains Juniper Flat 
population noted 798 individuals. This information is included in the 
SSA report (Service 2018, pp. 50, 71, 79, 80; Service 2020a, pp. 52, 
72, 80, 81) and December 6, 2019, proposed rule (84 FR 67060). 
Extensive efforts during the 2015 survey located a larger group of 
plants within the known population. The newly discovered group of 798 
plants is located approximately 300 meters from a southernmost group 
removed in a scouring flood and subsequent drying of the habitat. 
Therefore, if the larger group of Bartram's stonecrop plants co-
occurred with the smaller group, but was not observed, then the overall 
Juniper Flat population has contracted with the loss of the smaller 
group. No additional surveys or observed occurrences in the Mule 
Mountains have been reported to the Service since 2015.
    The statement regarding a ``general state of population decline'' 
has been removed in this final rule as we acknowledge that populations 
fluctuate over time. However, we do not expect

[[Page 48557]]

populations extirpated due to drying of habitat to rebound over time as 
suitable habitat conditions would not be present. Specifically, drying 
of habitat has been linked to decreased abundance and extirpation of 
populations in the Chiricahua, Dragoon, Empire, Santa Rita, and Rincon 
mountains, including a group of plants from the largest population at 
Juniper Flat. In three of these instances, extirpation was associated 
with the drying of habitat, which rendered it no longer suitable for 
the species.
    (6) Comment: Two commenters suggested that the moist canyons where 
Bartram's stonecrop have been found are associated with the attraction 
of the public and botanists to these locations, and that survey bias 
and poor detectability can result in the mischaracterization of 
Bartram's stonecrop habitat. Several commenters questioned the 
characterization of Bartram's stonecrop's habitat needs with respect to 
moisture and proximity to water.
    Response: The Service completed a robust SSA based on the best 
available scientific and commercial information. Bartram's stonecrop is 
a species found in Madrean woodlands, and does not appear to be a 
riparian species dependent on shallow ground water. The best available 
information on Bartram's stonecrop indicates the species occurs near 
water sources (springs, seeps, or intermittent streams), which may 
provide humidity and create suitable microclimate conditions. The deep, 
narrow canyons and associated overstory species provide shade during a 
portion of the day and create a cooler temperature, and the vegetation 
litter promotes retention of soil moisture and contributes to the humid 
microenvironment. Of 56 extant Bartram's stonecrop subpopulations with 
microhabitat condition documented, 78.6 percent were found within 10 
meters of an intermittent or perennial streambed, an additional 14.3 
percent were found between 11 and 20 meters from an intermittent or 
perennial streambed, and 7.1 percent were located more than 20 meters 
from an intermittent or perennial streambed. Researchers searched for 
plants at varying distances from streambeds, but note most plants were 
found nearer streambeds. In general, botanists visit many different 
habitat types in southern Arizona, and few Bartram's stonecrop 
individuals have been located outside of habitats with relatively humid 
microhabitat conditions, as described in the SSA report (Service 2020a, 
pp. 18, 24).
    (7) Comment: A commenter notes that other Bartram's stonecrop 
populations are being discovered, and at least one of the presumed 
extirpated populations (Rincon North) cannot really be determined to be 
gone.
    Response: The discovery of 872 additional individuals and new 
groups of plants in Arizona and Mexico, as described in our response to 
Comment (4), above, represent substantial survey effort by multiple 
groups. The 2015 survey of the population referenced (referred to as 
Happy Valley North in the SSA report) did not locate any Bartram's 
stonecrop individuals. However, in 2019, a single plant was located 
within this population. We have incorporated the updated information 
into the revised SSA report and describe the Happy Valley North 
population as extant. However, we note that one individual does not 
indicate a robust population and consider this population to be in very 
poor condition.
    (8) Comment: A commenter indicated we did not solicit information 
from Cecile Shohet, who conducted research on Bartram's stonecrop for a 
Master's of Science thesis.
    Response: As required by the Act (16 U.S.C. 1533(b)(1)), we based 
the listing decision on the best available scientific and commercial 
information. We worked in partnership with numerous agencies and 
organizations to visit most of the known U.S. locations of Bartram's 
stonecrop occurrences at least once (with some long-term monitoring 
initiated), as well as a portion of the Mexico populations. Although 
information from 1983-2010 is limited, we used the best available 
information to assess the species' current and future conditions. The 
U.S. Forest Service, National Park Service, Service, industry 
surveyors, and other researchers gathering information on Bartram's 
stonecrop have increased survey efforts since 2013 in suitable habitat 
in Arizona and Mexico. At a minimum, recent surveys and research on 
Bartram's stonecrop have occurred each year from 2013 to 2020.
    A solicitation for peer review of the SSA report was sent to Ms. 
Shohet on October 16, 2017, and no response was received. We solicited 
Ms. Shohet's expert opinion on specific aspects of the SSA and have 
incorporated all information received following the publication of the 
December 6, 2019, proposed rule in the revised SSA.
    (9) Comment: Three commenters stated that there is little to no 
evidence that drying has contributed to the extirpation of Bartram's 
stonecrop populations.
    Response: Bartram's stonecrop occurs only in habitat near water 
sources with a relatively moist and humid microenvironment and 
occasionally occurs in lower abundance in habitat farther away from 
water. As such, we determined that the humid microhabitat conditions 
are a need for species viability (ability to sustain populations in the 
wild over time). Changes to required habitat conditions, including 
drying, are expected to negatively affect Bartram's stonecrop 
populations and contribute to reductions in abundance and population 
extirpation. Bartram's stonecrop seedlings are particularly susceptible 
to desiccation, and resurveys have shown large losses in this size 
class.
    Drying of habitat associated with population or group extirpations 
has been observed in the Carlink Canyon, Empire Mountains, and Mule 
Mountains. Extirpations occurring in drying habitat are unlikely to be 
recolonized since suitable conditions for Bartram's stonecrop are no 
longer present. When suitable habitat is lost and not restored, 
Bartram's stonecrop experiences an increased risk of extirpation and 
extinction.
    (10) Comment: The commenters stated that several morphological and 
metabolic characteristics of Bartram's stonecrop are not discussed in 
the proposed rule despite their important role in determining the 
habitat requirements of Bartram's stonecrop. These characteristics 
include a thick waxy covering on the epidermis, Crassulacean acid 
metabolism that results in stomata only opening at night, a shallow 
root system, and succulent leaves massed together as a rosette.
    Response: Crassulacean acid metabolism (CAM) plants minimize 
photorespiration and save water by separating the steps of carbon 
dioxide fixation and the Calvin cycle (used to turn carbon dioxide into 
sugar) in time, between day and night. Reducing photorespiration 
decreases wasted energy and decreases sugar synthesis. Approximately 6 
percent of flowering plants are known to use CAM. CAM species vary 
widely in the efficacy and use of CAM, and many maintain the ability to 
conduct photosynthesis without reducing photorespiration during part of 
the day, part of the season, and/or part of their lifecycle. All or 
nearly all members of the nearly worldwide plant family Crassulaceae 
have the ability to perform CAM, and they occupy a range of 
microhabitats. Most taxa grow in arid habitats such as rocks and rock 
fissures under otherwise more humid climatic conditions, or in mountain 
regions in moderately arid

[[Page 48558]]

areas, and are largely absent from hot deserts and arid lowlands. 
Therefore, it is not possible to predict a plant's habitat based solely 
on knowing that it performs CAM.
    Bartram's stonecrop exhibits morphological features characteristic 
of other Crasulaceae including a waxy covering of the leaves, a shallow 
root system, and the arrangement of the leaves in a rosette. These 
features are also found in succulents that occur in drier habitats and 
may act to promote water conservation, but do not alter the habitat 
requirements of Bartram's stonecrop.
    (11) Comment: A commenter noted that hundreds of plants and animals 
are at the northern fringe of their range in southern Arizona and are 
common and safe in Mexico.
    Response: Historical distributions of Bartram's stonecrop 
populations are focused in southern Arizona, with some disjunct 
populations in northern Mexico. There have been surveys for this 
species in Mexico, and numerous biologists from Mexico have been 
consulted regarding its presence in the country. Habitat has been 
altered extensively in Mexico, and limited populations of Bartram's 
stonecrop have been located there; therefore, we do not find it 
reasonable to conclude that the species is common or safe in Mexico.
    (12) Comment: A commenter claimed that surveys by Sanchez-Escalante 
in Mexico were rushed, and occurred in the wrong habitat and at the 
wrong time of year.
    Response: The researcher Sanchez-Escalante spent 35 days exploring 
55 sites in Sonora and Chihuahua, and covered 6,900 kilometers with a 
team of trained botanists with the specific aim of locating populations 
of six identified rare plant species in appropriate habitats. Two new 
Bartram's stonecrop populations were located and two historical 
Bartram's stonecrop populations were confirmed out of 11 suitable 
habitat locations surveyed. These surveys were conducted during the 
flowering season in late September when the plants are most visible. 
Therefore, we concluded the Sanchez-Escalante surveys were conducted 
using appropriate methods. Thus, we base our current understanding of 
the Bartram's stonecrop occurrences in Sonora and Chihuahua on the best 
available scientific information.
    (13) Comment: A commenter mentioned that regular visitation is 
necessary to attain information on bloom period, seed production, 
reproduction method, pollinators, precipitation and growth 
relationships, and genetic diversity.
    Response: We are aware of limited information regarding the life 
history and species characteristics the commenter mentioned. The 
current knowledge of Bartram's stonecrop phenology and reproduction is 
described in the SSA report (Service 2020a, p. 20). The inflorescence 
stalks of Bartram's stonecrop individuals grow for 30-40 days in July 
and August before coming to their full height, with flowers opening 
primarily between September and November (Kearney and Peebles 1951, p. 
361; Phillips et al. 1982, pp. 2, 7; Shohet 1999, p. 25). Flowering is 
triggered by fall rains and does not occur during periods of water 
stress (Shohet 1999 pp. 22, 25, 36, 39). Seed dispersal occurs from 
November to December.
    Bartram's stonecrop requires pollinators for reproduction. The 
major pollinators of Bartram's stonecrop are true flies and house 
flies, although honey bees may also play a role in pollination. Other 
species that have been noted on Bartram's stonecrop include wasps, 
butterflies, and bee flies (Shohet 1999, p. 41; Ferguson 2014, p. 26; 
Ferguson 2017b, p. 13). Fertilization success is greatest in earliest 
opening flowers, possibly due to more pollinators being available 
earlier in the season, although having a long period of flowering 
increases overall chance of pollination (Shohet 1999, p. 57).
    The full relationship between precipitation and plant growth in 
each life stage has not been fully elucidated. However, winter 
precipitation is needed for germination, although some germination 
likely occurs following summer rains. Summer (July and August) and fall 
(October and November) precipitation is needed for flower production. 
We are supporting current research into the specific microhabitat 
requirements for Bartram's stonecrop including site characteristics of 
overstory vegetation, associated plant species, substrate 
characteristics, litter depth and character, local insolation and 
shade, soil temperature and soil moisture, and distance to perennial 
water. These studies will provide information on temperature and 
humidity parameters throughout the flowering, germination, and early 
seedling growth of the plants. Further studies will inform conservation 
and recovery efforts for the species.
    (14) Comment: A commenter claimed the Service did not do due 
diligence to list threats or make determinations, but used the 
petitioner's list of threats. Three commenters also opined that the 
Service's analysis of stressors and classification of the current 
condition is speculative and not based on hard data.
    Response: The Service's determination to list the species is based 
on a thorough, scientific analysis that was subject to appropriate peer 
review. Although there are threats noted in common between the 
Bartram's stonecrop SSA report and the petition to list the species 
(CBD 2010), there are also differences. The petition calls out mining, 
livestock grazing, and recreation as the primary threats to Bartram's 
stonecrop. The SSA analysis determined the following primary influences 
on viability: Loss of water availability; erosion, sedimentation, and 
burial; altered fire regime; and loss of shade. We based our analyses 
on the best available information, which included recent studies of and 
surveys for Bartram's stonecrop by the National Park Service, U.S. 
Forest Service, the Service, and private researchers.
    (15) Comment: A commenter claimed the Service lacks basic knowledge 
about the biology and habitat requirements of Bartram's stonecrop and 
is not following the mandate to base listing decisions on the best 
scientific and commercial data available.
    Response: We based this final listing determination on the best 
available scientific and commercial information, and the commenter did 
not provide any new information for us to consider. The best available 
information on Bartram's stonecrop indicates the species occurs near 
water sources (springs, seeps, or intermittent streams), which may 
provide humidity and create suitable microclimate conditions. The deep, 
narrow canyons and associated overstory species provide shade during a 
portion of the day and create a cooler temperature, and the vegetation 
litter promotes retention of soil moisture and contributes to the humid 
microenvironment. Additional Bartram's stonecrop biology and habitat 
research is ongoing, and results will inform future Service actions. In 
assessing the viability of Bartram's stonecrop, the best available 
scientific and commercial data provide information about some aspects 
of species' biology and habitat requirements, but may not represent a 
full and complete knowledge of the species. We drew reasonable 
conclusions about other aspects of the species' biology and 
requirements based on similar species, similar habitats, and best 
available information.
    (16) Comment: A commenter indicated that managed livestock and wild 
ungulate grazing reduce fuels for fires and requested all language 
relating to domestic livestock threatening Bartram's stonecrop be 
removed from the SSA report and the rule.

[[Page 48559]]

    Response: Livestock grazing is not noted in the SSA report or the 
rule as a major threat to Bartram's stonecrop. Rather, the Bartram's 
stonecrop SSA report concluded that because Bartram's stonecrop 
typically occurs on steep terrain, the plants are largely protected 
from grazing. However, trampling may occur when cattle graze in areas 
where Bartram's stonecrop occurs. Mortality may be caused by direct 
trampling by livestock (Searle and Meyer 2020, p. 6), and dislodging of 
soils by the hard edges of hooves may lead to increased erosion or 
burial of nearby plants, affecting Bartram's stonecrop individuals in 
areas with livestock grazing pressure. Therefore, while grazing is not 
a major threat to the species, trampling and direct mortality act as 
stressors to Bartram's stonecrop in some circumstances, and the effect 
of livestock is analyzed in the SSA report.
    (17) Comment: A commenter suggested using past climate data at a 
local level rather than modelling projections when discussing climate 
as a threat.
    Response: In the Bartram's stonecrop SSA report, figures 4.11a-c 
show both the past and projected mean daily maximum temperatures in 
Cochise, Pima, and Santa Cruz Counties, Arizona (Service 2020a, pp. 63-
67). The data for past mean daily maximum temperatures also indicate 
increases in temperature in all three counties. Modelling projections 
based on the Intergovernmental Panel on Climate Change Fifth Assessment 
report (IPCC 2014, entire) and future climate projections from the 
National Climate Explorer Tool (USGS 2017a, entire) downscaled to 
county level were used to discuss climate change and the effects of 
current and future changes on Bartram's stonecrop. Section 4.3 of the 
SSA (USFWS 2020, pp. 37-51) describes these modelling projections in 
greater detail.
    (18) Comment: A commenter stated that demographic and environmental 
stochasticity are naturally occurring phenomena for which Bartram's 
stonecrop plants are very well adapted.
    Response: Demographic and environmental stochasticity are naturally 
occurring phenomena (Shaffer 1981, p. 131). However, Bartram's 
stonecrop populations adapted to naturally occurring phenomena now 
experience the additional stressors related to a changing fire regime, 
nonnative species, and the effects of a changing climate beyond the 
scope of normal occurrence. For example, effects due to a changing 
climate, coupled with other stressors, can have a cumulative impact 
resulting in greater than anticipated decline in rare species (Souther 
and McGraw 2014, pp. 1471-1472). In addition, populations that 
experience variability in abundance must maintain a minimum viable 
population to be able to repopulate after a demographic or 
environmental stochastic event or catastrophe (Holsinger and Falk 1991, 
p. 45). Following a stochastic event that extirpates a population, 
suitable habitat for Bartram's stonecrop must be present, including 
humidity and shade, to provide conditions for potential recolonization 
or regrowth. Rangewide (including Mexico), 29 of the 50 Bartram's 
stonecrop populations (58 percent) are small (fewer than 50 
individuals). When the effect of small population size exacerbates 
other stressors beyond those naturally occurring phenomena that 
Bartram's stonecrop has adapted to, population abundance may be reduced 
to the extent that repopulation does not occur.
    (19) Comment: Three commenters stated the analysis of mining as a 
threat is cursory, unsupported, and overstates the likelihood of mining 
projects occurring within the range of the species. They noted that no 
mining projects outside of Rosemont are specifically identified and 
that the Service used an outdated 2012 document/map for this 
discussion. The commenters also stated that there is no evidence that 
loss of water from mining operations is a significant threat to 
Bartram's stonecrop and noted that the shade trees associated with 
Bartram's stonecrop habitat do not rely on groundwater. Therefore, the 
proposed rule overstated water drawdown from mining as a threat.
    Response: Mining is expected to affect Bartram's stonecrop 
individuals and populations in several ways. The direct removal of 
Bartram's stonecrop individuals due to erosion or burial from mineral 
extraction sites, test pits, and debris piles is expected to impact 
small populations. Fragmentation of Bartram's stonecrop populations due 
to placement of mining operations and associated activities can 
interfere with pollination and reproduction (Rathcke and Jules 1993, p. 
276). Due to uncertainty regarding the effect of fugitive dust or heavy 
metal pollution generated by mining operations on Bartram's stonecrop's 
growth and vigor, these potential stressors were not analyzed. The 
primary threat to Bartram's stonecrop analyzed with regard to mining 
was the loss of overstory shade trees due to dewatering of nearby 
streams and groundwater drawdown.
    Bartram's stonecrop-associated shade trees include the following 
riparian obligate species: Salix sp. (willow), Populus sp. 
(cottonwood), and Platanus sp. (sycamore). Within the following 
Bartram's stonecrop locations, the associated overstory includes 
riparian trees that provide between 50 and 80 percent shade to the 
sites: (1) Penasco Canyon: Willow; (2) Stronghold East: Ash; (3) Cave 
Canyon: Sycamore; (4) Josephine Canyon: Cottonwood and willow; (5) 
Santa Rita Sycamore Canyon: Ash; (6) Madera Canyon: Sycamore; (7) 
Jordan Canyon: Cottonwood, ash, and willow; (8) Warsaw/Old Glory 
Canyons: Willow; (9) Sawmill Canyon: Sycamore; and (10) Death Trap 
Canyon: Ash. Our response to Comment (6), above, describes the 
importance of riparian shade trees in maintaining the microhabitat 
needed by Bartram's stonecrop.
    Dewatering of streams in the vicinity of mining operations may lead 
to overstory canopy changes and loss of shade, as well as reduction in 
spring and stream flow and humidity in nearby Bartram's stonecrop 
populations. One mine has been proposed in the Santa Rita Mountains. 
Bartram's stonecrop individuals and populations in the analysis area 
could experience indirect impacts from groundwater drawdown (USFS 
2013a, p. 676). According to the Rosemont Final Environmental Impact 
Statement (USFS 2013a, p. 339), the proposed mine pit would create a 
permanent drawdown of the water table, and groundwater flowing toward 
the pit would be lost to evaporation. The water would be perpetually 
replenished in part by groundwater from the regional aquifer, and the 
pit would act as a hydraulic sink. The Bartram's stonecrop plants 
growing just southwest of the proposed Rosemont Mine were analyzed in 
the Rosemont Final Environmental Impact Statement (USFS 2013a, pp. 346-
350). The predicted groundwater drawdown in the affected population at 
the end of active mining is 0.1-5 feet, depending on the site assessed 
and the model used. At 20 years from the mine closure, the predicted 
drawdown increases to a maximum of 15-20 feet.
    In our analysis, we describe a range of potential mining scenarios 
that may affect Bartram's stonecrop: (1) Ongoing mining activity, (2) 
one to three new mining activities across the range of the species, and 
(3) greater than three new mining activities across the range of the 
species, to represent future levels of stressors to Bartram's stonecrop 
from mining. We used the information from Coronado National Forest 
Mining Activity (USFS 2012) to develop these plausible ranges of 
potential activities. We are not aware of any other sources regarding 
potential mining activities;

[[Page 48560]]

however, we welcome any new information on the likelihood of mining 
impacts to inform subsequent Service actions.
    (20) Comment: A commenter notes that Bartram's stonecrop rock 
habitat should minimize wildfire, erosion, sedimentation, and burial, 
and that the 12-month finding for Hexalectris colemanii concluded that 
wildfire was not a risk, yet it occurs in the same habitat as Bartram's 
stonecrop.
    Response: The crevices in the rock habitat where Bartram's 
stonecrop occurs provide shade, shelter, and soil moisture retention, 
and they provide the plant some protection from burning due to a lack 
of surrounding vegetation serving as fuel for fire in the rocky 
terrain. However, overstory tree and shrub species that provide shade 
to Bartram's stonecrop plants may be impacted by fire. Due to the 
location of plants in crevices or shallow soil pockets in steep 
canyons, adherence to substrate or soil is tenuous, and plants can be 
easily dislodged due to post-fire flooding, foot traffic, eroding soil, 
or falling rocks.
    Unlike Bartram's stonecrop, Hexalectris colemanii (Coleman's 
coralroot) is an almost exclusively subterranean species and is likely 
capable of resprouting following fire. In addition, the threats of 
nonnative plants (e.g., Eragrostis lehmanniana (Lehmann's lovegrass) 
and Melinis repens (rose natal)) were not considered to be threats to 
the Coleman's coralroot (78 FR 76795; December 19, 2013), but are 
considered to be a threat to Bartram's stonecrop. These nonnative 
plants increase fire risk and alter the fire regime (frequency and 
severity) within Bartram's stonecrop habitat.
    We are aware of 11 wildfires that occurred in known Bartram's 
stonecrop sites from 2007-2017, killing some Bartram's stonecrop 
individuals and removing shade in some sites. Wildfires have burned in 
all nine sky island mountain ranges of southern Arizona with known 
Bartram's stonecrop occurrences within the last decade. Wildfire could 
potentially cause extirpation of small Bartram's stonecrop populations 
throughout the range of the species and have negative impacts on larger 
populations. Bartram's stonecrop seeds are very tiny, reside at or near 
the soil surface (Shohet 1999, p. 48), and show no characteristics that 
would promote survival in a wildfire.
    (21) Comment: Three commenters stated that there is no evidence 
that erosion, sedimentation, or burial are significant threats to 
Bartram's stonecrop.
    Response: Erosion, sedimentation, and burial of Bartram's stonecrop 
individuals may occur as a result of mining, livestock pressure, 
recreation trails and roads, flooding events, cross border human 
activity, and post-wildfire runoff. Bartram's stonecrop is found in 
crevices or shallow soil pockets in steep canyons where adherence to 
substrate or soil is necessarily tenuous. Individual plants can be 
easily dislodged from these positions due to flooding, foot traffic, 
eroding soil, or falling rocks. Individuals dislodged by erosion and 
covered by rock fall have been observed in the Rhyolite Canyon 
subpopulation (Service 2020a, p. 76). Similarly, more than a half dozen 
individuals dislodged from trailside infrastructure were lost to 
erosion in the Madera population (Shohet 1999, p. 60). The effects of 
erosion, sedimentation, and burial and the loss of Bartram's stonecrop 
individuals are exacerbated in small populations.
    (22) Comment: Some commenters stated that fire may not be so 
important for this species and that an altered fire regime poses an 
uncertain threat to Bartram's stonecrop.
    Response: The Madrean evergreen woodlands of the sky islands where 
Bartram's stonecrop occurs have evolved with frequent low-severity fire 
with an interval of 10 to 30 years between relatively widespread fires 
in the pine-dominant forests (Swetnam et al. 2010, p. 4). Due to a 
variety of human activities in the landscape (e.g., excessive livestock 
grazing, fuelwood cutting, nonnative introduction and expansion, and 
fire suppression starting around the turn of the last century through 
the mid-1900s), these woodlands now have high fuel loads, and high-
severity fires are becoming increasingly more common (Swetnam et al. 
2010, p. 11; FireScape 2016, entire). There is no evidence that such 
large, stand-replacing fires occurred historically; for example, fire-
scar studies have revealed that only low-intensity surface fire regimes 
occurred within the range of Bartram's stonecrop for the past three to 
five centuries (Swetnam et al. 2010, p. 15).
    Crevices provide shade, shelter, and soil moisture retention, and 
offer Bartram's stonecrop plants protection from burning due to a lack 
of surrounding vegetation for fuel in the rocky terrain. Regardless, 
Bartram's stonecrop individuals have been burned. We are aware of 11 
wildfires that occurred in known Bartram's stonecrop sites from 2007-
2017, killing some Bartram's stonecrop individuals and removing shade 
in some sites (Ferguson 2014, pp. 9-10, 15, 28-29; Ferguson 2016a, p. 
13; Ferguson 2016b, entire; Ferguson 2017c, p. 32; Ferguson 2017h, p. 
2). Wildfires have burned in all nine sky island mountain ranges of 
southern Arizona with known Bartram's stonecrop occurrences within the 
last decade. Wildfire could potentially cause extirpation of small 
Bartram's stonecrop populations throughout the range of the species and 
have negative impacts on larger populations. Bartram's stonecrop seeds 
are very tiny, reside at or near the soil surface (Shohet 1999, p. 48), 
and show no characteristics that would promote survival in a wildfire.
    Indirect threats to the species from fire include increased runoff 
of floodwaters, post-fire flooding that may scour habitat, deposition 
of debris and sediment originating in the burned area that could cover 
individuals, erosion of habitat, changes in vegetation community 
composition and structure, increased presence of nonnative plants, 
alterations in the hydrologic and nutrient cycles, and loss of 
overstory canopy shade essential for maintaining Bartram's stonecrop 
microhabitat.
    (23) Comment: A commenter expressed that Bartram's stonecrop should 
be listed as endangered and critical habitat should be designated.
    Response: When making a listing decision for a species under the 
Act, the Service must determine if the current status of the species 
indicates it is in danger of extinction throughout all or a significant 
portion of its range (an endangered species) or likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range (a threatened species). In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the expected response by the species, 
and the effects of the threats--in light of those actions and 
conditions that will ameliorate the threats--on an individual, 
population, and species level. We evaluate each threat and its expected 
effects on the species, and then analyze the cumulative effect of all 
of the threats on the species as a whole. We also consider the 
cumulative effect of the threats in light of those actions and 
conditions that will have positive effects on the species--such as any 
existing regulatory mechanisms or conservation efforts. The Secretary 
determines whether the species meets the Act's definition of an 
``endangered species'' or a ``threatened species'' only after 
conducting this cumulative analysis and describing the expected effect 
on the species now and in the foreseeable future.

[[Page 48561]]

    We reviewed the potential risk factors (i.e., threats or stressors) 
that are affecting Bartram's stonecrop now and into the future. While 
there are multiple stressors affecting Bartram's stonecrop, the best 
available information indicates that these threats are not immediately 
impacting Bartram's stonecrop such that the species meets the 
definition of an endangered species under the Act.
    Section 4(a)(3) of the Act requires the Secretary of the Interior 
(Secretary) to designate critical habitat concurrent with listing to 
the maximum extent prudent and determinable. The designation of 
critical habitat may not be prudent if the species is threatened by 
taking or other human activity and identification of critical habitat 
can be expected to increase the degree of such threat to the species. 
Bartram's stonecrop is an attractive and small plant that can be easily 
collected by gardeners and succulent enthusiasts. This stressor was 
first noted in 1982, and observed in 1997-1998. Three researchers 
described the potential for collection of Bartram's stonecrop and 
factors that may make collection more likely. The lifespan of Bartram's 
stonecrop plants has been estimated at 5-10 years, allowing sufficient 
time for discovery and collection. As noted in the August 8, 2012, 90-
day finding for this species (77 FR 47352), small populations may not 
be able to recover from collection, especially if the mature, 
reproductive plants are removed. The removal of mature plants reduces 
the overall reproductive effort of the population, thereby reducing the 
overall resilience of the population. While documented instances of 
collection are limited, the impacts from collection can be profound for 
small populations. In this case, we have found that the designation of 
critical habitat for Bartram's stonecrop is not prudent at this time as 
it would be likely to put the species at higher risk of collection.
    (24) Comment: The commenters state that there is no evidence that 
illegal collection of Bartram's stonecrop individuals is a significant 
threat and that illegal collection is unlikely due to the short 
lifespan of the species and difficulty growing it horticulturally.
    Response: The illegal collection of succulents is known to occur, 
and is often difficult to detect. Illegal collection of Bartram's 
stonecrop individuals has been reported, and the threat from it is more 
pronounced in small populations such as those in which the species 
occurs. More than half (58 percent) of Bartram's stonecrop populations 
contain fewer than 50 individuals. The lifespan of Bartram's stonecrop 
plants has been estimated at 5-10 years, allowing sufficient time for 
discovery and collection.
    Bartram's stonecrop is an attractive and small plant not available 
from nurseries that can be easily collected by gardeners and succulent 
enthusiasts. This stressor was first noted in 1982, when exact 
localities were excluded from a summary report due to the possibility 
of illegal collection. Tagged individuals were uprooted and taken from 
two sites in the Santa Rita Mountains in 1997-1998. Plants in close 
proximity to trails have higher discovery potential and are therefore 
more likely to be collected. Collectors advertise in internet forums 
seeking Bartram's stonecrop seedlings or rooted cuttings. The similar 
southern Arizona species, Graptopetalum rusbyi (San Francisco 
leatherpetal), is cultivated and legally available for sale from cactus 
nurseries. However, Bartram's stonecrop is more difficult to propagate 
and maintain in captivity and is therefore vulnerable to collection 
from the wild because collectors cannot find them for purchase in 
nurseries. Small populations may not be able to recover from 
collection, especially if the mature, reproductive plants are removed. 
The removal of mature plants reduces the overall reproductive effort of 
the population, thereby reducing the overall resilience of the 
population. While documented instances of collection are limited, the 
impacts from collection can be profound for small populations.
    (25) Comment: The commenters state that there is no evidence that 
trampling is a significant threat to Bartram's stonecrop.
    Response: As Bartram's stonecrop is typically found in shady 
canyons, the possibility of individuals being lost to trampling 
remains. Trampling of individuals (direct mortality or damage due to 
crushing) related to recreation activities has been observed 
historically. Human traffic within Bartram's stonecrop populations can 
cause soil erosion and plant loss, including damage from researchers. 
Individual Bartram's stonecrop were trampled in a group of plants that 
bordered a campsite (Shohet 1999, p. 60). Westland Resources (2013, p. 
19) noted that the potential placement of a trail through Bartram's 
stonecrop populations may impact individual plants. A Bartram's 
stonecrop plant in a group located within 10 meters (32.8 feet) of a 
frequently used hiking trail was covered by rock fall (Ferguson 2016a, 
pp. 14-15). Threats to individuals can be particularly important to 
small populations.
    (26) Comment: Some commenters state that altered precipitation, 
drought, and flooding regimes pose an uncertain threat to Bartram's 
stonecrop, and that freezing is not detrimental unless severe.
    Response: The southwestern United States is warming and 
experiencing severe droughts of extended duration, decreased stream 
flows, changes in amount and timing of snow melt, and changes in timing 
and severity of precipitation and flooding (CLIMAS 2014, entire). The 
seasonality and general precipitation requirements for Bartram's 
stonecrop are described in detail in the SSA report (chapter 2, p. 26). 
Bartram's stonecrop occurs in habitats and microhabitats with a higher 
soil moisture, humidity, and vegetative community indicative of more 
mesic conditions than other succulents. Drying of habitats and more 
arid conditions have been associated with population extirpation. 
Bartram's stonecrop and its habitat are very susceptible to drought, 
loss of humidity, increases in temperature, and increased intensity of 
storms and flooding (NPS 2015, p. 4).
    Bartram's stonecrop occurs in Madrean woodlands characterized by 
warm, wet summers and mild winters. Precipitation within the sky island 
mountain ranges is bimodal, with winter snow and rain, and summer 
monsoon rain. Mean annual precipitation in these habitats is 10-17 
inches, with more than 50 percent occurring in summer. The winter snow 
and rain coincide with Bartram's stonecrop seed germination and growth. 
Winter precipitation is needed for Bartram's stonecrop germination 
(although some germination likely occurs following summer rains), and 
both summer (July and August) and fall (captured partially in the 
October and November ``winter'' data) precipitation is needed for 
Bartram's stonecrop flower production.
    The current and projected future trends in precipitation in the 
range of Bartram's stonecrop are discussed in the SSA report's sections 
2.6 and 4.5 (Service 2020a, pp. 26, 54-68). The region has experienced 
serious drought (a prolonged period of abnormally low rainfall) in 
recent decades (Bowers 2005, p. 421; Garfin et al. 2013, p. 3; CLIMAS 
2014, entire). Winter precipitation, in particular, has decreased over 
the past century, as recorded by weather stations within sky island 
mountain ranges containing Bartram's stonecrop (see SSA report, figures 
2.6a-h) (Service 2020a, pp. 27-30). Winter precipitation is projected 
to decrease in the southwestern United States (IPCC 2013, p. 1080).

[[Page 48562]]

    Precipitation is projected to decrease in the future with climate 
change, although it is expected to be more intense when it does occur 
(Seager et al. 2007, p. 1181; Karl et al. 2009, pp. 24, 33). Some 
projections suggest an overall similar amount of precipitation in the 
Southwest, but that it will be distributed differently in timing and 
intensity (Zhang et al. 2012, p. 390). Most climate change scenarios 
predict that the American Southwest will also become warmer during the 
21st century (Overpeck et al. 2012, p. 5; Karl et al. 2009, p. 129), 
and the frequency of droughts is projected to increase by the end of 
the 21st century.
    Continuing drought, increased temperatures, and increased 
evapotranspiration are expected to reduce vegetation cover and shade in 
Bartram's stonecrop habitat through overstory tree loss (Ferguson 2014, 
p. 42). Such tree mortality has already been observed in Bartram's 
stonecrop populations, negatively impacting available microhabitat 
(Ferguson 2016a, pp. 12, 17, 26). Drought or reduced water resources 
disproportionately affect seedlings, as this stage is particularly 
vulnerable to desiccation.
    Bartram's stonecrop plants are almost always located near water 
sources (springs, seeps, or intermittent streams), but above the 
floodline (Phillips et al. 1982, p. 4; Shohet 1999, p. 22; NPS 2014, p. 
2). Crevices above the floodline offer protection from typical flood 
events. Bartram's stonecrop needs crevices in solid bedrock or in 
shallow soil pockets on rock ledges and cliffs in deep, narrow canyons 
above normal flood levels to avoid seeds and plants being washed away 
during flood events. An increase in the flood frequency or intensity 
could result in an increase in the number of plants dislodged.
    Based on climate change projections, it is likely that the severity 
of storm events will increase, resulting in more runoff, more severe 
flooding events, and more erosion and sedimentation affecting 
populations, especially following wildfire events in the uplands. 
Rainfall events in the southwestern United States are projected to be 
less frequent but more intense, and larger flood events are expected to 
be more common in the future (Karl et al. 2009, p. 24). Erosion and 
soil loss from such storm events may increase with higher peak stream 
flows. Flooding can remove Bartram's stonecrop individuals occurring 
near the stream's edge and has the potential to remove entire small 
populations (Phillips et al. 1982, p. 10; The Nature Conservancy 1987, 
p. 2; Ferguson 2014, p. 42; Ferguson 2016a, p. 26; NPS 2015, p. 4; 
Ferguson 2017b, p. 15). One group within a Bartram's stonecrop 
population was extirpated due to dislodging from a flooding event 
followed by drying of habitat (The Nature Conservancy 1987, p. 2).
    Bartram's stonecrop is susceptible to damage from freezing events 
(Ferguson 2014, pp. 23, 40). An early season frost was reported in one 
Bartram's stonecrop population, and a hard frost is suspected of 
killing all plants in another population (Indian Creek) in 2011. Frost 
events are not projected to decrease in severity (Kodra et al. 2011, p. 
3).
    Because continuing drought, more severe freezing events, and 
increased high intensity rainfall events all pose threats to Bartram's 
stonecrop across the range of the species, this stressor is considered 
in our analysis of future species viability. We conclude that abnormal 
freezing events can seriously damage or completely remove small 
populations.
    (27) Comment: Three commenters indicated that the Service's 
conclusion that small and isolated populations are a threat to 
Bartram's stonecrop is incorrect.
    Response: Small population size has the potential to decrease 
Bartram's stonecrop population resiliency, as all stressors are 
exacerbated in populations with only a small number of individuals. 
Small populations are less able to recover from losses caused by random 
environmental changes (Shaffer and Stein 2000, pp. 308-310), such as 
fluctuations in reproduction (demographic stochasticity), variations in 
rainfall (environmental stochasticity), or changes in the frequency or 
severity of wildfires.
    Most known Bartram's stonecrop populations are small, with over 
half of known individuals of the species residing in five populations. 
Twenty-nine of the 50 extant known Bartram's stonecrop populations (58 
percent) rangewide contain fewer than 50 individuals, and 43 
populations (86 percent) contain fewer than 150 individuals. The effect 
of more minor threats such as erosion, trampling, and illegal 
collection are all increased when Bartram's stonecrop populations are 
already small.

Determination of Bartram's Stonecrop's Status

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for determining 
whether a species meets the definition of an endangered species or a 
threatened species. The Act defines ``endangered species'' as a species 
in danger of extinction throughout all or a significant portion of its 
range, and ``threatened species'' as a species 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 
summarize our findings below. We have carefully assessed the best 
scientific and commercial information available regarding the past, 
present, and future threats to Bartram's stonecrop.
    Bartram's stonecrop has experienced population declines, and three 
populations have been lost entirely. Currently, 50 extant Bartram's 
stonecrop populations contain 4,682 individuals in the United States 
and Mexico. Four Bartram's stonecrop populations contain nonnative 
grasses and several more are near nonnative grasses resulting in 
current habitat loss and continued loss in the future (Factor A). 
Further, an altered fire regime (Factors A and E) impacts all 
populations currently or in the near future and drives the spread of 
nonnatives (Factor A), exacerbating the encroachment of nonnative 
grasses. Consequently, all remaining populations of Bartram's stonecrop 
are impacted by nonnative grasses now or will be in the near future. 
Altered precipitation (Factors A and E), increased temperatures 
(Factors A and E), and decreased annual precipitation (Factors A and E) 
are current and ongoing regional conditions that are impacting all 
populations of Bartram's stonecrop. These environmental conditions 
exacerbate an altered fire regime, driving the spread of nonnative 
grasses with competitive advantages over native grasses during periods 
of drought. Many currently undeveloped areas of locatable mineral 
deposits may be explored or mined in the future (Factors A and E). The 
range of current and projected mining activities varies from 1 to 10 
per mountain range with Bartram's stonecrop occurrence (USFS 2012, 
entire). One population, Sycamore

[[Page 48563]]

Canyon (115 adult individuals), will be affected by groundwater 
drawdown due to the Rosemont Mine, which will impact the shade and 
moist microclimate this species needs (Factor A). This species is known 
to be collected and sold (Factor B), and plants in close proximity to 
trails or roads have higher discovery potential and are, therefore, 
more likely to be collected. Twenty-nine of 50 populations (58 percent) 
are small (fewer than 50 individuals) (Factor E). Erosion (Factors A 
and E), trampling (Factor E), collection (Factor B), herbivory 
(predation) (Factor C), and fire (Factors A and E) have the potential 
to reduce or completely remove these small populations. Synergistic 
interactions among wildfire, nonnative grasses, decreased 
precipitation, and increased temperatures cumulatively and cyclically 
impact Bartram's stonecrop, and all stressors are exacerbated in small 
populations (Factor E). The existing regulatory mechanisms (Factor D) 
do not address the majority of the threats to the species. Conservation 
efforts have not yet been implemented for this species.
    We find Bartram's stonecrop to face increased vulnerability to the 
current and future threats due to the small population sizes of the 
majority of populations (Factor E). Small populations are susceptible 
to the loss of genetic diversity, genetic drift, and inbreeding. 
Currently 47 populations spread across nine mountain ranges in the 
United States and three ranges in Mexico exist as single populations 
(i.e., no subpopulations to provide further resiliency in case of 
extirpation). The mountain ranges are widely separated (14-42 
kilometers (8.7-26 miles) apart) and may not be genetically diverse 
because pollination or transport of seeds between populations may be 
very limited. This could mean that between-population genetic diversity 
may be greater than within-population diversity (Smith and Wayne 1996, 
p. 333; Lindenmayer and Peakall 2000, p. 200). Further, there may have 
been a loss of genetic diversity in the three extirpated populations. 
However, it is likely that the species' genetic representation will be 
lost given the impacts to populations through the reduction in the 
number of individuals per population and the loss of populations 
(Factor E). In addition, it is likely that ecological representation 
will continue to decline as those populations at lower elevations are 
lost due to reduced precipitation and increased temperatures (Factor 
E).
    Regulatory mechanisms (Factor D) and other management efforts by 
USFS and NPS provide some benefit to Bartram's stonecrop, as the 
majority of known populations are located on USFS (67 percent of the 
area of populations) and NPS (22 percent) owned and managed lands. The 
Coronado National Forest Land and Resource Management Plan (Plan) 
includes actions to control nonnative invasive species, restore habitat 
for federally listed species, and contribute to the recovery of 
federally listed species (USFS 2018, pp. 38, 41, 44, 46, 49, and 175). 
The Plan recognizes Bartram's stonecrop occurrences on the Coronado 
National Forest (USFS 2018, pp. 54). The Arizona Department of 
Agriculture protects native plants including Bartram's stonecrop under 
the 2009 Arizona Native Plan Law (Arizona Revised Statutes Title 3. 
Agriculture Sec.  3-903) and removal is restricted to salvage of the 
plants. However, these efforts have not been able to ameliorate the 
threat of nonnative plant species and the altered fire regime and 
effects of drought.
    The overall range of the species has not been significantly 
reduced, although three populations are extirpated due to habitat 
alteration. Currently, 50 extant populations in 12 mountain ranges 
provides a level of protection from catastrophic events now and in the 
near future. While there are multiple stressors to the remaining 
populations, these stressors are not immediately impacting all 
populations such that Bartram's stonecrop is currently in danger of 
extinction. The stressors that pose the largest risk to future species 
viability are primarily related to habitat changes: Groundwater 
extraction from mining, long-term drought, and alteration in wildfire 
regime. These stressors are occurring and impacting Bartram's stonecrop 
and will continue to do so within the next 40 years. We chose a 
foreseeable future of 40 years (approximately 2060) because this is 
within the range of predictions of available hydrological and climate 
change model forecasts, is within the time period of the Rosemont Mine 
effects, and represents eight generations of Bartram's stonecrop, which 
allows us to assess reproductive effects on the species and allows the 
species opportunities to rebound. The primary sources we examined in 
determining future scenarios include the RCP 4.5 and 8.5 models in the 
IPCC (2013 and 2014, entire) and Garfin et al. (2013, entire). In 
addition, we examined literature pertaining to wildfire frequency and 
severity, including Westerling et al. (2006), FireScape (2016), and 
Fire Management Information System (2016). An increase in temperature 
results in increased evapotranspiration rates and soil drying, 
resulting in the effects of future droughts becoming more severe 
(Garfin 2013, pp. 137-138) and wildfires becoming more frequent and of 
increased intensity. The threats to Bartram's stonecrop act 
synergistically to influence the viability of the species. For example, 
decreased water availability and invasion of nonnative grasses promote 
higher severity and frequency of fires, while the effect of fires in 
Bartram's stonecrop habitat is to promote nonnative grass invasion and 
increase the likelihood of post-fire runoff and loss of shade trees.
    We find that Bartram's stonecrop is likely to become an endangered 
species throughout all of its range within the foreseeable future. It 
is facing threats across its range that have led to reduced resiliency, 
redundancy, and representation, and we expect the species to continue 
to decline into the future. Thus, after assessing the best available 
information, we conclude that Bartram's stonecrop is not currently in 
danger of extinction, but is likely to become in danger of extinction 
within the foreseeable future throughout all of its range.

Status Throughout a Significant Portion of Its Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. The court in Center for Biological Diversity v. Everson, 
2020 WL 437289 (D.D.C. Jan. 28, 2020) (Center for Biological 
Diversity), vacated the aspect of the Final Policy on Interpretation of 
the Phrase ``Significant Portion of Its Range'' in the Endangered 
Species Act's Definitions of ``Endangered Species'' and ``Threatened 
Species'' (79 FR 37578; July 1, 2014) that provided that the Services 
do not undertake an analysis of significant portions of a species' 
range if the species warrants listing as threatened throughout all of 
its range. Therefore, we proceed to evaluating whether the species is 
endangered in a significant portion of its range--that is, whether 
there is any portion of the species' range for which both (1) the 
portion is significant; and (2) the species is in danger of extinction 
in that portion. Depending on the case, it might be more efficient for 
us to address the ``significance'' question or the ``status'' question 
first. We can choose to address either question first. Regardless of 
which question we address first, if we reach a negative answer with 
respect to the first question that we address, we do

[[Page 48564]]

not need to evaluate the other question for that portion of the 
species' range.
    Following the court's holding in Center for Biological Diversity, 
we now consider whether there are any significant portions of the 
species' range where the species is in danger of extinction now (i.e., 
endangered). In undertaking this analysis for Bartram's stonecrop, we 
choose to address the status question first--we consider information 
pertaining to the geographic distribution of both the species and the 
threats that the species faces to identify any portions of the range 
where the species is endangered.
    For Bartram's stonecrop, we considered whether the threats are 
geographically concentrated in any portion of the species' range at a 
biologically meaningful scale. We examined the following primary 
threats to the species: Reduction in water availability; altered fire 
regime; effects of climate change; and erosion, sedimentation, and 
burial. Loss due to trampling, collection, herbivory, severe frost, or 
other stressors also have the potential to impact individual Bartram's 
stonecrop plants. The effects of these threats are exacerbated in small 
populations. Altered precipitation, drought, flooding, and freezing 
regimes from current and future climate change are issues for all 
Bartram's stonecrop populations. Synergistic interactions among 
wildfire, nonnative grasses, decreased precipitation, and increased 
temperatures cumulatively and cyclically impact all Bartram's stonecrop 
populations. Some populations are expected to be affected by threats 
due to varying causes. For example, a higher risk of fires as a result 
of cross-border human activity is expected in the Baboquivari, 
Chiricahua, Mule, Pajarito-Atascosa, Santa Rita, Patagonia, and 
Whetstone mountains, while a higher risk of fires as a result of 
recreationists is expected in the Chiricahua, Dragoon, Pajarito-
Atascosa, Patagonia, Rincon, and Santa Rita mountains. We found no 
concentration of threats in any portion of Bartram's stonecrop's range 
at a biologically meaningful scale. Thus, there are no portions of the 
species' range where the species has a different status from its 
rangewide status. Therefore, no portion of the species' range provides 
a basis for determining that the species is in danger of extinction in 
a significant portion of its range, and we determine that the species 
is likely to become in danger of extinction within the foreseeable 
future throughout all of its range. This is consistent with the courts' 
holdings in Desert Survivors v. Department of the Interior, No. 16-cv-
01165-JCS, 2018 WL 4053447 (N.D. Cal. Aug. 24, 2018), and Center for 
Biological Diversity v. Jewell, 248 F. Supp. 3d, 946, 959 (D. Ariz. 
2017).

Determination of Status

    Our review of the best available scientific and commercial 
information indicates that Bartram's stonecrop meets the Act's 
definition of a threatened species. Therefore, we are listing Bartram's 
stonecrop as a threatened species in accordance with sections 3(20) and 
4(a)(1) of the Act.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened species under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing results in public awareness, and 
conservation by Federal, State, Tribal, and local agencies; private 
organizations; and individuals. The Act encourages cooperation with the 
States and other countries and calls for recovery actions to be carried 
out for listed species. The protection required by Federal agencies and 
the prohibitions against certain activities are discussed, in part, 
below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Section 4(f) of the Act calls for the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the stressors to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning consists of preparing draft and final recovery 
plans, beginning with the development of a recovery outline and making 
it available to the public within 30 days of a final listing 
determination. The recovery outline guides the immediate implementation 
of urgent recovery actions and describes the process to be used to 
develop a recovery plan. Revisions of the plan may be done to address 
continuing or new stressors to the species, as new substantive 
information becomes available. The recovery plan also identifies 
recovery criteria for review of when a species may be ready for 
reclassification from endangered to threatened (``downlisting'') or 
removal from protected status (``delisting''), and methods for 
monitoring recovery progress. Recovery plans also establish a framework 
for agencies to coordinate their recovery efforts and provide estimates 
of the cost of implementing recovery tasks. Recovery teams (composed of 
species experts, Federal and State agencies, nongovernmental 
organizations, and stakeholders) are often established to develop 
recovery plans. When completed, the recovery outline, draft recovery 
plan, and the final recovery plan will be available on our website 
(https://www.fws.gov/endangered), or from our Arizona Ecological 
Services Field Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration of native vegetation, research, captive propagation and 
reintroduction, and outreach and education. The recovery of many listed 
species cannot be accomplished solely on Federal lands because their 
range may occur primarily or solely on non-Federal lands. To achieve 
recovery of these species requires cooperative conservation efforts on 
private, State, and Tribal lands.
    Following publication of this final rule, funding for recovery 
actions will be available from a variety of sources, including Federal 
budgets, State programs, and cost share grants for non-Federal 
landowners, the academic community, and nongovernmental organizations. 
In addition, pursuant to section 6 of the Act, the State of Arizona 
will be eligible for Federal funds to implement management actions that 
promote the protection or recovery of Bartram's stonecrop. Information 
on our grant programs that are available to aid species recovery can be 
found at https://www.fws.gov/grants.
    Section 8(a) of the Act (16 U.S.C. 1537(a)) authorizes the 
provision of limited financial assistance for the development and 
management of programs that the Secretary of the Interior determines to 
be necessary or useful for the conservation of endangered or threatened 
species in foreign countries. Sections 8(b) and 8(c) of the Act (16 
U.S.C. 1537(b) and (c)) authorize the Secretary to encourage 
conservation programs for foreign listed

[[Page 48565]]

species, and to provide assistance for such programs, in the form of 
personnel and the training of personnel.
    Please let us know if you are interested in participating in 
recovery efforts for Bartram's stonecrop. Additionally, we invite you 
to submit any new information on this species whenever it becomes 
available and any information you may have for recovery planning 
purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as an 
endangered or threatened species and with respect to its critical 
habitat, if any is designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
part 402. Section 7(a)(2) of the Act requires Federal agencies to 
ensure that activities they authorize, fund, or carry out are not 
likely to jeopardize the continued existence of any endangered or 
threatened species or destroy or adversely modify its critical habitat. 
If a Federal action may affect a listed species or its critical 
habitat, the responsible Federal agency must enter into consultation 
with the Service.
    Federal agency actions within the species' habitat that may require 
conference or consultation or both as described in the preceding 
paragraph include management and any other landscape-altering 
activities on Federal lands administered by the U.S. Forest Service 
(Coronado National Forest), Bureau of Land Management, U.S. Customs and 
Border Protection, and National Park Service (Chiricahua National 
Monument and Saguaro National Park).
    The Act and its implementing regulations set forth a series of 
general prohibitions and exceptions that apply to endangered plants. 
The prohibitions of section 9(a)(2) of the Act, codified at 50 CFR 
17.61, make it illegal for any person subject to the jurisdiction of 
the United States to: Import or export; remove and reduce to possession 
from areas under Federal jurisdiction; maliciously damage or destroy on 
any such area; remove, cut, dig up, or damage or destroy on any other 
area in knowing violation of any law or regulation of any State or in 
the course of any violation of a State criminal trespass law; deliver, 
receive, carry, transport, or ship in interstate or foreign commerce, 
by any means whatsoever and in the course of a commercial activity; or 
sell or offer for sale in interstate or foreign commerce an endangered 
plant. Certain exceptions apply to employees of the Service, the 
National Marine Fisheries Service, other Federal land management 
agencies, and State conservation agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered plants under certain circumstances. Regulations 
governing permits are codified at 50 CFR 17.62. With regard to 
endangered plants, a permit may be issued for scientific purposes or 
for enhancing the propagation or survival of the species. There are 
also certain statutory exemptions from the prohibitions, which are 
found in sections 9 and 10 of the Act.
    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a final listing 
on proposed and ongoing activities within the range of a listed 
species. The discussion below regarding protective regulations under 
section 4(d) of the Act complies with our policy.

II. Final Rule Issued Under Section 4(d) of the Act

Background

    Section 4(d) of the Act contains two sentences. The first sentence 
states that the Secretary of the Interior (Secretary) shall issue such 
regulations as he deems necessary and advisable to provide for the 
conservation of species listed as threatened. The U.S. Supreme Court 
has noted that statutory language like ``necessary and advisable'' 
demonstrates a large degree of deference to the agency (see Webster v. 
Doe, 486 U.S. 592 (1988)). Conservation is defined in the Act to mean 
the use of all methods and procedures which are necessary to bring any 
endangered species or threatened species to the point at which the 
measures provided pursuant to the Act are no longer necessary. 
Additionally, the second sentence of section 4(d) of the Act states 
that the Secretary may by regulation prohibit with respect to any 
threatened species any act prohibited under section 9(a)(1), in the 
case of fish or wildlife, or section 9(a)(2), in the case of plants. 
Thus, the combination of the two sentences of section 4(d) provides the 
Secretary with wide latitude of discretion to select and promulgate 
appropriate regulations tailored to the specific conservation needs of 
the threatened species. The second sentence grants particularly broad 
discretion to the Service when adopting the prohibitions under section 
9.
    The courts have recognized the extent of the Secretary's discretion 
under this standard to develop rules that are appropriate for the 
conservation of a species. For example, courts have upheld rules 
developed under section 4(d) as a valid exercise of agency authority 
where they prohibited take of threatened wildlife, or include a limited 
taking prohibition (see Alsea Valley Alliance v. Lautenbacher, 2007 
U.S. Dist. Lexis 60203 (D. Or. 2007); Washington Environmental Council 
v. National Marine Fisheries Service, 2002 U.S. Dist. Lexis 5432 (W.D. 
Wash. 2002)). Courts have also upheld 4(d) rules that do not address 
all of the threats a species faces (see State of Louisiana v. Verity, 
853 F.2d 322 (5th Cir. 1988)). As noted in the legislative history when 
the Act was initially enacted, ``once an animal is on the threatened 
list, the Secretary has an almost infinite number of options available 
to him with regard to the permitted activities for those species. He 
may, for example, permit taking, but not importation of such species, 
or he may choose to forbid both taking and importation but allow the 
transportation of such species'' (H.R. Rep. No. 412, 93rd Cong., 1st 
Sess. 1973).
    Exercising this authority under section 4(d), we have developed a 
rule that is designed to address Bartram's stonecrop's specific 
stressors and conservation needs. Although the statute does not require 
the Service to make a ``necessary and advisable'' finding with respect 
to the adoption of specific prohibitions under section 9, we find that 
this rule as a whole satisfies the requirement in section 4(d) of the 
Act to issue regulations deemed necessary and advisable to provide for 
the conservation of Bartram's stonecrop. As discussed above under 
Determination of Bartram's Stonecrop's Status, we have concluded that 
Bartram's stonecrop is likely to become in danger of extinction within 
the foreseeable future due to groundwater extraction and prolonged 
drought expected to reduce nearby water levels and humidity within 
Bartram's stonecrop's microenvironment, and altered fire regimes 
leading to erosion of Bartram's stonecrop habitat that could dislodge 
plants, to sedimentation that could cover individuals, and to loss of 
overstory shade trees. In addition, collection, trampling, herbivory, 
flooding, and dislodging and burial from recreationists, cross-border 
violators, and domestic and wild animals contribute to the risk of 
extinction within the foreseeable future due to the majority of 
populations being small and

[[Page 48566]]

isolated. The provisions of this 4(d) rule will promote conservation of 
Bartram's stonecrop by encouraging management of the landscape in ways 
that meet both land management considerations and the conservation 
needs of Bartram's stonecrop. The provisions of this rule are one of 
many tools that the Service will use to promote the conservation of 
Bartram's stonecrop.

Provisions of the 4(d) Rule

    This 4(d) rule provides for the conservation of Bartram's stonecrop 
by prohibiting the following activities, except as otherwise authorized 
or permitted: Import or export; certain acts related to removing, 
damaging, and destroying; delivery, receipt, transport, or shipment in 
interstate or foreign commerce in the course of commercial activity; or 
sale or offering for sale in interstate or foreign commerce.
    As discussed under Summary of Biological Status and Threats, above, 
multiple factors are affecting the status of Bartram's stonecrop. A 
range of activities have the potential to impact Bartram's stonecrop, 
including:
    (1) Unauthorized damage or collection of Bartram's stonecrop from 
lands under Federal jurisdiction; and
    (2) Malicious destruction or degradation of the species or 
associated habitat on lands under Federal jurisdiction, including:
    (a) The intentional introduction of nonnative organisms that 
compete with or consume Bartram's stonecrop;
    (b) Ground-disturbing activities that impact the species or its 
habitat;
    (c) Activities that would affect pollinators where the species 
occurs and in the surrounding area;
    (d) Activities that would promote high-severity wildfires where the 
species occurs; and
    (e) Activities that would reduce shade or lower the water table 
such that the cooler, humid microenvironment is affected.
    These activities are provided as examples of actions that may 
affect Bartram's stonecrop and are not intended to be a list of 
prohibitions under the final 4(d) rule for Bartram's stonecrop. As a 
whole, the 4(d) rule will help in the efforts to recover Bartram's 
stonecrop by prohibiting activities that damage individuals and 
populations and providing exceptions to those prohibitions for 
permitted or conservation activities.
    We may issue permits to carry out otherwise prohibited activities, 
including those described above, involving threatened plants under 
certain circumstances. Regulations governing permits are codified at 50 
CFR 17.72, which states that ``the Director may issue a permit 
authorizing any activity otherwise prohibited with regard to threatened 
species.'' That regulation also states, ``The permit shall be governed 
by the provisions of this section unless a special rule applicable to 
the plant is provided in sections 17.73 to 17.78.'' We interpret that 
second sentence to mean that permits for threatened species are 
governed by the provisions of section 17.72 unless a special rule, 
which we have defined to mean a species-specific 4(d) rule, provides 
otherwise. We recently promulgated revisions to section 17.71 providing 
that section 17.71 will no longer apply to plants listed as threatened 
in the future. We did not intend for those revisions to limit or alter 
the applicability of the permitting provisions in section 17.72, or to 
require that every species-specific 4(d) rule spell out any permitting 
provisions that apply to that species and species-specific 4(d) rule. 
To the contrary, we anticipate that permitting provisions would 
generally be similar or identical for most species, so applying the 
provisions of section 17.72 unless a species-specific 4(d) rule 
provides otherwise would likely avoid substantial duplication. 
Moreover, this interpretation brings section 17.72 in line with the 
comparable provision for wildlife at 50 CFR 17.32, in which the second 
sentence states, ``Such permit shall be governed by the provisions of 
this section unless a special rule applicable to the wildlife, 
appearing in sections 17.40 to 17.48, of this part provides 
otherwise.'' Under 50 CFR 17.12 with regard to threatened plants, a 
permit may be issued for the following purposes: For scientific 
purposes, to enhance propagation or survival, for economic hardship, 
for botanical or horticultural exhibition, for educational purposes, or 
for other purposes consistent with the purposes and policy of the Act. 
Additional statutory exemptions from the prohibitions are found in 
sections 9 and 10 of the Act.
    We recognize the special and unique relationship with our State 
natural resource agency partners in contributing to conservation of 
listed species. State agencies often possess scientific data and 
valuable expertise on the status and distribution of endangered, 
threatened, and candidate species of wildlife and plants. State 
agencies, because of their authorities and their close working 
relationships with local governments and landowners, are in a unique 
position to assist the Services in implementing all aspects of the Act. 
In this regard, section 6 of the Act provides that the Services shall 
cooperate to the maximum extent practicable with the States in carrying 
out programs authorized by the Act. Therefore, any qualified employee 
or agent of a State conservation agency that is a party to a 
cooperative agreement with the Service in accordance with section 6(c) 
of the Act, who is designated by his or her agency for such purposes, 
will be able to conduct activities designed to conserve Bartram's 
stonecrop that may result in otherwise prohibited activities without 
additional authorization.
    Nothing in this 4(d) rule changes in any way the recovery planning 
provisions of section 4(f) of the Act, the consultation requirements 
under section 7 of the Act, or the ability of the Service to enter into 
partnerships for the management and protection of Bartram's stonecrop. 
However, interagency cooperation may be further streamlined through 
planned programmatic consultations for the species between Federal 
agencies and the Service.

III. Critical Habitat

Background

    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features:
    (a) Essential to the conservation of the species, and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Our regulations at 50 CFR 424.02 define the geographical area 
occupied by the species as an area that may generally be delineated 
around species' occurrences, as determined by the Secretary (i.e., 
range). Such areas may include those areas used throughout all or part 
of the species' life cycle, even if not used on a regular basis (e.g., 
migratory corridors, seasonal habitats, and habitats used periodically, 
but not solely by vagrant individuals).
    Conservation, as defined at section 3 of the Act, means to use and 
the use of all methods and procedures that are necessary to bring an 
endangered or threatened species to the point at which the measures 
provided pursuant to the Act are no longer necessary. Such methods and 
procedures include, but

[[Page 48567]]

are not limited to, all activities associated with scientific resources 
management such as research, census, law enforcement, habitat 
acquisition and maintenance, propagation, live trapping, and 
transplantation, and, in the extraordinary case where population 
pressures within a given ecosystem cannot be otherwise relieved, may 
include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the requirement that Federal agencies ensure, in consultation 
with the Service, that any action they authorize, fund, or carry out is 
not likely to result in the destruction or adverse modification of 
critical habitat. The designation of critical habitat does not affect 
land ownership or establish a refuge, wilderness, reserve, preserve, or 
other conservation area. Such designation does not allow the government 
or public to access private lands. Such designation does not require 
implementation of restoration, recovery, or enhancement measures by 
non-Federal landowners. Where a landowner requests Federal agency 
funding or authorization for an action that may affect a listed species 
or critical habitat, the Federal agency would be required to consult 
with the Service under section 7(a)(2) of the Act. However, even if the 
Service were to conclude that the proposed activity would result in 
destruction or adverse modification of the critical habitat, the 
Federal action agency and the landowner are not required to abandon the 
proposed activity, or to restore or recover the species; instead, they 
must implement ``reasonable and prudent alternatives'' to avoid 
destruction or adverse modification of critical habitat.
    Under the first prong of the Act's definition of critical habitat, 
areas within the geographical area occupied by the species at the time 
it was listed are included in a critical habitat designation if they 
contain physical or biological features (1) which are essential to the 
conservation of the species and (2) which may require special 
management considerations or protection. For these areas, critical 
habitat designations identify, to the extent known using the best 
scientific and commercial data available, those physical or biological 
features that are essential to the conservation of the species (such as 
space, food, cover, and protected habitat). In identifying those 
physical or biological features that occur in specific occupied areas, 
we focus on the specific features that are essential to support the 
life-history needs of the species, including, but not limited to, water 
characteristics, soil type, geological features, prey, vegetation, 
symbiotic species, or other features. A feature may be a single habitat 
characteristic or a more complex combination of habitat 
characteristics. Features may include habitat characteristics that 
support ephemeral or dynamic habitat conditions. Features may also be 
expressed in terms relating to principles of conservation biology, such 
as patch size, distribution distances, and connectivity.
    Under the second prong of the Act's definition of critical habitat, 
we can designate critical habitat in areas outside the geographical 
area occupied by the species at the time it is listed, upon a 
determination that such areas are essential for the conservation of the 
species. When designating critical habitat, the Secretary will first 
evaluate areas occupied by the species. The Secretary will only 
consider unoccupied areas to be essential where a critical habitat 
designation limited to geographical areas occupied by the species would 
be inadequate to ensure the conservation of the species. In addition, 
for an unoccupied area to be considered essential, the Secretary must 
determine that there is a reasonable certainty both that the area will 
contribute to the conservation of the species and that the area 
contains one or more of those physical or biological features essential 
to the conservation of the species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Further, our Policy on 
Information Standards under the Endangered Species Act (published in 
the Federal Register on July 1, 1994 (59 FR 34271)), the Information 
Quality Act (section 515 of the Treasury and General Government 
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)), 
and our associated Information Quality Guidelines, provide criteria, 
establish procedures, and provide guidance to ensure that our decisions 
are based on the best scientific data available. They require our 
biologists, to the extent consistent with the Act and with the use of 
the best scientific data available, to use primary and original sources 
of information as the basis for recommendations to designate critical 
habitat.
    When we are determining which areas should be designated as 
critical habitat, our primary source of information is generally the 
information from the SSA report and information developed during the 
listing process for the species. Additional information sources may 
include any generalized conservation strategy, criteria, or outline 
that may have been developed for the species; the recovery plan for the 
species; articles in peer-reviewed journals; conservation plans 
developed by States and counties; scientific status surveys and 
studies; biological assessments; other unpublished materials; or 
experts' opinions or personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. We recognize that critical habitat designated at a 
particular point in time may not include all of the habitat areas that 
we may later determine are necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated area is unimportant or may not be needed 
for recovery of the species. Areas that are important to the 
conservation of the species, both inside and outside the critical 
habitat designation, will continue to be subject to: (1) Conservation 
actions implemented under section 7(a)(1) of the Act; (2) regulatory 
protections afforded by the requirement in section 7(a)(2) of the Act 
for Federal agencies to ensure their actions are not likely to 
jeopardize the continued existence of any endangered or threatened 
species; and (3) the prohibitions found in section 9 of the Act. 
Federally funded or permitted projects affecting listed species outside 
their designated critical habitat areas may still result in jeopardy 
findings in some cases. These protections and conservation tools will 
continue to contribute to recovery of this species. Similarly, critical 
habitat designations made on the basis of the best available 
information at the time of designation will not control the direction 
and substance of future recovery plans, habitat conservation plans 
(HCPs), or other species conservation planning efforts if new 
information available at the time of these planning efforts calls for a 
different outcome.

Prudency Determination

    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12), require that, to the maximum extent 
prudent and determinable, the Secretary shall designate critical 
habitat at the time the species is determined to be an endangered or 
threatened species. Our regulations (50 CFR 424.12(a)(1)) state that 
the Secretary may, but is not required to, determine that a designation 
would not be prudent in the following circumstances:
    (i) The species is threatened by taking or other human activity and 
identification of critical habitat can be

[[Page 48568]]

expected to increase the degree of such threat to the species;
    (ii) The present or threatened destruction, modification, or 
curtailment of a species' habitat or range is not a threat to the 
species, or threats to the species' habitat stem solely from causes 
that cannot be addressed through management actions resulting from 
consultations under section 7(a)(2) of the Act;
    (iii) Areas within the jurisdiction of the United States provide no 
more than negligible conservation value, if any, for a species 
occurring primarily outside the jurisdiction of the United States;
    (iv) No areas meet the definition of critical habitat; or
    (v) The Secretary otherwise determines that designation of critical 
habitat would not be prudent based on the best scientific data 
available.
    In the proposed listing rule (84 FR 67060; December 6, 2019), we 
determined that designation of critical habitat for Bartram's stonecrop 
would not be prudent. However, we invited public comment and requested 
information on the threats of taking or other human activity, on 
Bartram's stonecrop and its habitat, and the extent to which 
designation might increase those threats.
    During the comment period, we did not receive any substantive 
comments, or any comments that would require us to change the not 
prudent determination or our rationale for it (see 84 FR 67060, 
December 6, 2019, p. 84 FR 67088). Therefore, we restate our conclusion 
that the designation of critical habitat is not prudent, in accordance 
with 50 CFR 424.12(a)(1), because Bartram's stonecrop faces a threat by 
collection, and designation can reasonably be expected to increase the 
degree of these threats to the species by making location information 
more readily available.

Required Determinations

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

    It is our position that, outside the jurisdiction of the U.S. Court 
of Appeals for the Tenth Circuit, we do not need to prepare 
environmental analyses pursuant to the National Environmental Policy 
Act (NEPA; 42 U.S.C. 4321 et seq.) in connection with listing a species 
as an endangered or threatened species under the Act. We published a 
notice outlining our reasons for this determination in the Federal 
Register on October 25, 1983 (48 FR 49244). This position was upheld by 
the U.S. Court of Appeals for the Ninth Circuit (Douglas County v. 
Babbitt, 48 F.3d 1495 (9th Cir. 1995), cert. denied 516 U.S. 1042 
(1996)).

Government-to-Government Relationship With Tribes

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

References Cited

    A complete list of references cited in the SSA report and this 
rulemaking is available on the internet at https://www.regulations.gov 
under Docket No. FWS-R2-ES-2018-0104 and upon request from the Arizona 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this final rule are the staff members of the 
U.S. Fish and Wildlife Service Species Assessment Team and the Arizona 
Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

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

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

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

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


0
2. Amend Sec.  17.12 in paragraph (h), the List of Endangered and 
Threatened Plants, by adding an entry for ``Graptopetalum bartramii'' 
in alphabetical order under Flowering Plants to read as follows:


Sec.  17.12  Endangered and threatened plants.

* * * * *
    (h) * * *

----------------------------------------------------------------------------------------------------------------
                                                                                          Listing citations and
         Scientific name              Common name        Where listed         Status         applicable rules
----------------------------------------------------------------------------------------------------------------
        Flowering Plants
 
                                                  * * * * * * *
Graptopetalum bartramii.........  Bartram's           Wherever found....  T              86 FR [INSERT Federal
                                   stonecrop.                                             Register PAGE WHERE
                                                                                          THE DOCUMENT BEGINS],
                                                                                          8/31/2021; 50 CFR
                                                                                          17.73(a). \4d\
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------


0
3. Add Sec.  17.73 to read as follows:


Sec.  17.73  Special rules--flowering plants.

    (a) Graptopetalum bartramii (Bartram's stonecrop)--(1) 
Prohibitions. The following prohibitions apply to Graptopetalum 
bartramii, except as provided under paragraph (a)(2) of this section:
    (i) Import or export. It is unlawful to import or to export any 
Graptopetalum bartramii. Any shipment in transit through the United 
States is an importation and an exportation,

[[Page 48569]]

whether or not it has entered the country for customs purposes.
    (ii) Remove and reduce to possession. It is unlawful to remove and 
reduce to possession the species from areas under Federal jurisdiction; 
maliciously damage or destroy the species on any such area; or remove, 
cut, dig up, or damage or destroy the species on any other area in 
knowing violation of any law or regulation of any State or in the 
course of any violation of a State criminal trespass law.
    (iii) Interstate or foreign commerce. It is unlawful to deliver, 
receive, carry, transport, or ship in interstate or foreign commerce, 
by any means whatsoever, and in the course of a commercial activity, 
any Graptopetalum bartramii.
    (iv) Sale or offer for sale. (A) It is unlawful to sell or to offer 
for sale in interstate or foreign commerce any Graptopetalum bartramii.
    (B) An advertisement for the sale of any Graptopetalum bartramii 
which carries a warning to the effect that no sale may be consummated 
until a permit has been obtained from the Service, shall not be 
considered an offer for sale within the meaning of this paragraph.
    (v) It is unlawful to attempt to commit, solicit another to commit, 
or cause to be committed, any of the acts described in this paragraph 
(a)(1).
    (2) Exceptions from prohibitions. The following exceptions from 
prohibitions apply to Graptopetalum bartramii:
    (i) A person may apply for a permit in accordance with 50 CFR 17.72 
that authorizes an activity otherwise prohibited by this paragraph for 
Graptopetalum bartramii.
    (ii)(A) Any employee or agent of the Service, any other Federal 
land management agency, or a State conservation agency, who is 
designated by that agency for such purposes, may, when acting in the 
course of official duties, remove and reduce to possession 
Graptopetalum bartramii from areas under Federal jurisdiction without a 
permit if such action is necessary to:
    (1) Care for a damaged or diseased specimen;
    (2) Dispose of a dead specimen; or
    (3) Salvage a dead specimen which may be useful for scientific 
study.
    (B) Any removal and reduction to possession pursuant to this 
paragraph must be reported in writing to the U.S. Fish and Wildlife 
Service within 5 days. The specimen may only be retained, disposed of, 
or salvaged in accordance with written directions from the Service.
    (iii) Any qualified employee or agent of the Service or of a State 
conservation agency which is a party to a cooperative agreement with 
the Service in accordance with section 6(c) of the Act, who is 
designated by that agency for such purposes, may, when acting in the 
course of official duties, remove, cut, dig up, damage, or destroy 
Graptopetalum bartramii on areas under Federal jurisdiction.
    (b) [Reserved].

Martha Williams,
Principal Deputy Director Exercising the Delegated Authority of the 
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2021-18476 Filed 8-30-21; 8:45 am]
BILLING CODE 4333-15-P