[Federal Register Volume 87, Number 22 (Wednesday, February 2, 2022)]
[Proposed Rules]
[Pages 5767-5778]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-02041]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R6-ES-2018-0055; FF09E21000 FXES1111090FEDR 223]
RIN 1018-BD17
Endangered and Threatened Wildlife and Plants; Threatened Species
Status for Chapin Mesa Milkvetch and Designation of Critical Habitat;
Withdrawal
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule; withdrawal.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), withdraw the
proposed rule to list the Chapin Mesa milkvetch (Astragalus schmolliae)
as a threatened species under the Endangered Species Act of 1973, as
amended (Act). We concurrently withdraw the proposed rule to designate
critical habitat for the species. This withdrawal is based on our
conclusion that the conservation plan for Chapin Mesa milkvetch at Mesa
Verde National Park, and its associated implementation plan, in
addition to new standard operating procedures for fire management at
Mesa Verde National Park, reduce the threats to the species such that
it no longer meets the Act's definition of an ``endangered species'' or
a ``threatened species.'' Therefore, we are withdrawing our proposal to
list the Chapin Mesa milkvetch as a threatened species and our proposal
to designate critical habitat for the species.
DATES: The proposed rule that published on September 17, 2020 (85 FR
58224), to list the Chapin Mesa milkvetch as a threatened species and
to designate critical habitat for the Chapin Mesa milkvetch is
withdrawn on February 2, 2022.
ADDRESSES: Relevant documents used in the preparation of this
withdrawal are available on the internet at http://www.regulations.gov
at Docket No. FWS-R6-ES-2018-0055.
FOR FURTHER INFORMATION CONTACT: Ann Timberman, Western Colorado Field
Supervisor, U.S. Fish and Wildlife Service, Colorado Ecological
Services Office, 445 West Gunnison Ave., Suite 240, Grand Junction, CO
81501; telephone 970-243-2778. Persons who use a telecommunications
device for the deaf may call the Federal Relay Service at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Previous Federal Actions
On September 17, 2020, we proposed to list Chapin Mesa milkvetch as
a threatened species under the Act (16 U.S.C. 1531 et seq.), and to
designate critical habitat (85 FR 58224). Please refer to that proposed
rule for a detailed description of previous Federal actions concerning
Chapin Mesa milkvetch prior to 2020. The September 17, 2020, proposed
rule had a 60-day comment period, ending November 16, 2020. During this
public comment period, we invited the public to comment on the proposed
rule in light of draft conservation plans for the species from Mesa
Verde National Park (Park) and the Ute Mountain Ute Tribe. Since
publication of the proposed rule, the Park provided supplemental
information to their plan that allowed the Service to conclude the plan
is sufficiently certain to be implemented and effective, and we
consider this in making our final listing determination, in accordance
with the Policy for Evaluation of Conservation Efforts When Making
Listing Decisions (PECE) (68 FR 15100; March 28, 2003).
Supporting Documents
Prior to publishing the proposed listing rule (85 FR 58224;
September 17, 2020), we conducted a species status assessment (SSA) for
the Chapin Mesa milkvetch, with input and information provided by the
Park, the Colorado Natural Heritage Program, and the Ute Mountain Ute
Tribe. The results of this assessment are summarized in an SSA report,
which represents a compilation of the best scientific and commercial
data available concerning the status of the species, including the
past, present, and future stressors to this species (Service 2021a,
entire). Additionally, the SSA report contains our analysis of required
habitat and the existing conditions of that habitat. After
[[Page 5768]]
publication of the September 17, 2020, proposed listing rule, we
updated the SSA with newly available information, including the latest
precipitation data and updated values for seedling survival in the
burned subunit of the Chapin Mesa representative unit (Service 2021a,
entire).
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 six
appropriate subject matter specialists regarding our SSA report for
Chapin Mesa milkvetch. We received responses from five specialists. We
incorporated the results of this peer review process into the final SSA
report, which informed the underlying analysis and scientific basis for
this finding.
Summary of Comments and Recommendations
As stated above under Previous Federal Actions, on September 17,
2020, we published a proposed rule to list Chapin Mesa milkvetch as a
threatened species under the Act, and to designate critical habitat (85
FR 58224). The proposed rule had a 60-day comment period, ending
November 16, 2020. We also contacted appropriate State, Federal, and
Tribal agencies and other interested parties and invited them to
comment on the proposal. A newspaper notice inviting general public
comment was published in The Journal, a newspaper servicing Cortez,
Mancos, and Dolores, Colorado. We also sought peer review on the SSA
report (see Supporting Documents, above). All substantive information
regarding the listing of Chapin Mesa milkvetch that was provided during
peer reviews and the comment period has been incorporated directly into
this final determination or into our SSA report, as appropriate, or is
addressed below. Comments concerning the proposed critical habitat
designation for the species are not addressed here; given the decision
to withdraw the listing proposal, no further assessment of the proposed
critical habitat designation is necessary at this time.
Peer Review Comments
We reviewed all comments we received from the peer reviewers for
substantive issues and new information regarding Chapin Mesa milkvetch.
The peer reviewers provided additional information, clarifications, and
suggestions to improve the SSA report, which we incorporated directly
into the SSA report, or address in the responses to comments below. We
only address substantive comments from these reviewers below; we
resolved minor editorial comments in the text of the SSA report.
(1) Comment: One reviewer suggested that we needed more detail to
describe the methods researchers used to collect the monitoring data we
include in the SSA report.
Our Response: The purpose of the SSA is to gather and compile
information on the status of this species in order to assess its
current condition and project the species' future condition. Adding
detailed information on the monitoring methodologies our partners use
is not necessary to assess the current and future conditions for this
species in the SSA report, because these methods are adequately
described in other papers. More details on monitoring methods are
available in Anderson (2004), Rondeau et al. (2016), and Rondeau
(2017), which are cited throughout our SSA report.
(2) Comment: Some reviewers commented that we needed to incorporate
additional quantitative data, as qualitative data cannot answer the
questions that are most relevant to ensuring persistence and survival
of the species.
Our Response: Section 4 of the Act directs the Service to make
determinations on whether any species is an endangered or a threatened
species ``solely on the basis of the best scientific and commercial
data available'' (16 U.S.C. 1533(b)(1)(A)). In the SSA, we used
quantitative data when available, but, in some cases, qualitative data
is the best available information. We used this quantitative and
qualitative data to evaluate multiple metrics relevant to assessing the
resiliency of each representative unit. In the case of Chapin Mesa
milkvetch, given limited availability of quantitative data, we
evaluated the level of intact native understory and presence of exotic
plants qualitatively. However, even with qualitative evaluations for
these metrics, we were able to evaluate the resiliency of each
representative unit and summarize the current and future viability of
the species (Service 2021a, pp. 32-41); we acknowledge the
uncertainties inherent in this method in the SSA (Service 2021a, p.
33). These evaluations of current and future viability, which were
based on the best available scientific data, informed our determination
of species' status.
(3) Comment: One reviewer expressed concern that the only
monitoring data included in the SSA report are from monitoring that has
occurred on Chapin Mesa, and therefore does not cover the entire range
of the species.
Our Response: We agree that monitoring information from the rest of
the species' range would be useful. However, section 4 of the Act
directs the Service to make determinations whether any species is an
endangered or a threatened species ``solely on the basis of the best
scientific and commercial data available'' (16 U.S.C. 1533(b)(1)(A)).
Monitoring data from other representative units are not available to us
at this time.
(4) Comment: One reviewer commented that the SSA has no discussion
of current or future conservation actions being implemented.
Our Response: When the SSA report was originally written (2018), we
were not aware of any ongoing conservation actions. Following the
completion of the first version of the SSA report, draft conservation
plans from the Park and the Ute Mountain Ute Tribe became available
that discussed future conservation activities. However, we had not yet
evaluated these plans under our PECE policy, and the Park had not yet
completed its implementation plan. We have since updated our discussion
of conservation efforts in the SSA to incorporate relevant ongoing
conservation activities and information from the Park's conservation
plan and implementation plan for Chapin Mesa milkvetch at Mesa Verde
National Park; these conservation efforts also informed updated
analysis on species' status in this notice, in accordance with the
provisions of the PECE policy (Service 2021b, entire).
(5) Comment: One reviewer commented that Anderson (2004) includes a
plausible boundary for the population south of the Park based on
records and observations in the Ute Mountain Ute Tribal Park.
Our Response: The Anderson (2004) plausible boundary on Ute
Mountain Ute Tribal land was determined using an element occurrence
record from the Colorado Natural Heritage Program from 1987, and was
adapted to include major landscape features and jurisdictional
boundaries, because surveyors were not granted access to Ute Mountain
Ute land to conduct formal surveys. In order to accurately update or
expand this element occurrence record polygon for the Ute Mountain Ute
Tribal Park representative unit, we would need additional surveying on
Tribal lands and access to survey results. These data are not available
to us at this time; therefore, we consider the polygon used in the SSA
report to represent the best available scientific information on the
[[Page 5769]]
location of the species on Ute Mountain Ute Tribal lands.
(6) Comment: One reviewer suggested that the use of herbarium
specimens could confirm the historical distribution of the species, as
several regional herbaria hold specimens of Chapin Mesa milkvetch
collected prior to the 1945 description.
Our Response: We agree that such information could further confirm
our existing understanding of the historical distribution of this
species. However, the peer reviewer noted that the SSA's description of
historical distribution, which was based on information from sources
other than these herbarium records, was accurate, even without
consideration of these early herbarium specimens. These early specimens
were all collected from within or near Mesa Verde National Park, so
they only further confirm the accuracy of the information we cited from
other sources regarding where the species historically occurred. Thus,
referencing these herbarium specimen is not necessary in our SSA since
this additional detail would not have changed our understanding of the
species' range and viability.
(7) Comment: One reviewer commented that the reference to a
personal communication from Clow (2017, pers. comm.) implies that
survey work has been done recently on Ute Mountain Ute land.
Our Response: The Tribe has communicated to us that Chapin Mesa
milkvetch is present on Tribal land and we know that they have begun to
conduct surveys on their Tribal lands; however, no survey data were
provided to us for the SSA report or this final determination.
(8) Comment: One reviewer suggested including information from
literature on other species in the genus Astragalus, as many of the
references used in the SSA report are not peer-reviewed, nor publicly
available.
Our Response: For the purposes of the SSA report, we considered
references that are specific to Chapin Mesa milkvetch to be the best
available information, even though some were not peer-reviewed. We
considered information on closely related species, where applicable. We
have reviewed and considered the suggested references on the Astragalus
genus. Most of the references provided insights into other narrow
endemics that were not closely related to Chapin Mesa milkvetch.
However, one species, Astragalus microcymbus, occurs nearby and
exhibits prolonged dormancy, like Chapin Mesa milkvetch; as such, we
added this citation to the SSA report.
(9) Comment: One reviewer suggested including additional climate-
related information from the Climate Change Vulnerability Assessments
developed by the Colorado Natural Heritage Program and the Bureau of
Land Management (CNHP 2021).
Our Response: Because the species only occurs on Mesa Verde
National Park and the Ute Mountain Ute Tribal Park, we used climate
data specific to this region; therefore, we consider the information we
used in the SSA report to be the best available scientific information
on downscaled climate impacts. For more information on the climate
change analysis we considered, see the discussion of future climate
projections under Summary of Biological Status and Threats, below.
(10) Comment: One reviewer requested that we add more detailed
information about proposed fire management activities.
Our Response: We have included a table in section 3.1 of the SSA
report that describes existing and proposed impacts from fire
management activities in Mesa Verde National Park (Service 2021a, pp.
19-22).
(11) Comment: One reviewer commented that post-fire mitigation
could influence Chapin Mesa milkvetch if mitigation is conducted with
herbicides on a large scale.
Our Response: We consider the effects of post-fire herbicide
application in Appendix A of the SSA report. While direct effects from
herbicide use have occurred to individual Chapin Mesa milkvetch plants
in the past, there has not been evidence of population-level effects.
Additionally, the Park currently does not use herbicides on a large
scale (NPS 2018, p. 11). Therefore, we do not consider herbicides to be
a major driver of the species' condition and do not discuss them
further in the SSA report. For more detail on herbicides, see Appendix
A of the SSA report.
Public Comments
We received several comments in support of listing Chapin Mesa
milkvetch and designating critical habitat for the species. These
comments offered general support but did not provide additional
information for us to consider in our final listing decision. We
address substantive comments we received from public commenters below.
(12) Comment: The Ute Mountain Ute Tribe provided a comment stating
their commitment to taking an active role in conservation and asked the
Service to recognize the Tribe's right to manage plants and wildlife on
Tribal lands. The Tribe also requested that the Service review their
``Conservation Plan for the Chapin Mesa Milkvetch (Astragalus
schmolliae)'' (Ute Mountain Ute Tribe 2020, entire). The Tribe also
provided a list of conservation efforts that they have undertaken that
benefit the species.
Our Response: As requested, we reviewed the Tribal ``Conservation
Plan for the Chapin Mesa Milkvetch (Astragalus schmolliae)'' (Tribal
Plan). We commend the Tribe's commitment to conservation and appreciate
the efforts they have already undertaken to aid the species. We find
that this Tribal Plan, if implemented, would likely provide benefit to
the species; although, due to uncertainty in future levels of
implementation and effectiveness, future conservation efforts outlined
in the Tribal Plan were not considered in our final listing decision.
We do, however, recognize and value the conservation actions that the
Ute Mountain Ute Tribe has already completed and is currently
implementing to conserve this species, and we incorporated
consideration of these activities in our final listing determination.
(13) Comment: One commenter provided a comment in support of
listing the species as endangered rather than threatened. They
indicated that, as the species has only one potentially viable
population that could be wiped out by a single catastrophic event
(i.e., fire, fuel spill, illegal grazing) and as the species has low
adaptability, the Service should list it as an endangered species
rather than a threatened species.
Our Response: An ``endangered species'' is defined by the Act as
any species which is in danger of extinction throughout all or a
significant portion of its range. Our determination about whether
Chapin Mesa milkvetch warrants listing as endangered was informed by
our analysis of the species' current condition in our SSA, rather than
the projected future condition of the species, because the definition
of an ``endangered species'' states that the species is in danger of
extinction now. The species currently has a large representative
subunit (the unburned Chapin Mesa subunit) that is considered highly
resilient. Additionally, the species currently has more than one extant
population; all four representative units are currently in moderate
condition, providing for some additional redundancy and adaptive
capacity. Therefore, we determine that the current risk of extinction
is low, and the species is not currently in danger of extinction
throughout its range. For more information on our determination that
Chapin Mesa milkvetch does not
[[Page 5770]]
meet the Act's definition of an ``endangered species,'' see
Determination of Species Status, below.
However, even when we examine the projected future condition of the
species, in light of the new information in the Park's conservation
plan for Chapin Mesa milkvetch at Mesa Verde National Park, associated
implementation plan, and wildfire emergency response procedure, we now
find that Chapin Mesa milkvetch does not warrant listing as a
threatened species under the Act. First, we conclude it is not
plausible that a fuel spill or illegal grazing could occur to such an
extent that it extirpates the entire Chapin Mesa milkvetch
representative unit, particularly given its protected location on
National Park and Tribal Park lands. Thus, we did not consider these
stressors as part of our plausible future scenarios. Additionally,
based on the Park's commitments to maintain and restore pinyon-juniper
overstory, to conduct fire management such that it reduces the risk of
catastrophic wildfire in the Park while also minimizing impacts to the
species, and to quickly suppress fire, the resiliency, redundancy, and
representation of Chapin Mesa milkvetch, including the resiliency of
the Chapin Mesa representative unit, will likely remain the same or
better than current condition into the foreseeable future; thus, the
risk of extinction remains low for Chapin Mesa milkvetch into the
foreseeable future. Therefore, after assessing the best available
information, we conclude that Chapin Mesa milkvetch is not in danger of
extinction throughout all of its range nor is it likely to become so in
the foreseeable future. For more information on our determination that
Chapin Mesa milkvetch does not meet the Act's definition of a
``threatened species,'' see Determination of Species Status, below.
Background
A thorough review of the taxonomy, range and distribution, life
history, and ecology of the Chapin Mesa milkvetch is presented in the
SSA report (Service 2021a, pp. 3-14; available at http://www.regulations.gov at Docket No. FWS-R6-ES-2018-0055) and is briefly
summarized here. Chapin Mesa milkvetch is a narrow endemic, upright,
perennial herb primarily found on the tops of mesas in southwestern
Colorado in Montezuma County on land administered by the National Park
Service (NPS) and the Ute Mountain Ute Tribe. Chapin Mesa milkvetch is
a member of the family Fabaceae (legume family) and was known by the
common name Schmoll's milkvetch prior to 2015. The stems of Chapin Mesa
milkvetch are purplish below, green above, tall (45 to 60 centimeters
(cm) (18 to 24 inches)), branching from the base, with short, stiff,
appressed hairs (lying closely and flatly against the plant's surface)
on the foliage. Leaves are pinnate with 11 to 13 linear leaflets, 1 to
2 millimeters (0.04 to 0.08 inches) wide, and 1 to 3 cm (0.4 to 0.8
inches) long. Flowers are yellowish-white or cream colored, and 12 to
13 cm (4.7 to 5.1 inches) long with bracts that extend under the flower
that have black hairs. The distinguishing characteristic of the species
is the leathery pod (Service 2021a, pp. 3-4).
Chapin Mesa milkvetch plants emerge in early spring and usually
begin flowering in late April or early May. Flowering continues into
early or mid-June; fruit set begins in late May and occurs through
June; and, by late June, most fruits, while still attached to the
plant, have opened and released their seeds (Service 2021a, p. 6).
During very dry years, like many other Astragalus species, the plants
can remain dormant with no above-ground growth (Colyer 2003 in Anderson
2004, p. 11). Chapin Mesa milkvetch requires pollination by insects to
set fruit; the flowers require a strong insect for pollination because
the insect must force itself between the petals of the papilionaceous
(butterfly-shaped) flowers (Green 2012, p. 2).
The emergence and density of Chapin Mesa milkvetch are strongly
tied to winter precipitation. Years with ``wet'' winters (precipitation
falling primarily as snow) precede high density counts, and years with
dry winters translate to low or no emergence (Rondeau 2017, p. 3).
Climate requirements for seedling emergence and survival are not well
known; however, we infer that spring moisture is also critical, as
seedling survival relies on growing deep roots quickly (Rondeau 2017,
p. 9). It is likely that winter moisture coupled with winter
temperature is also important for seedlings due to available soil
moisture for seedling survival (Rondeau 2017, p. 16).
Chapin Mesa milkvetch's global distribution is constrained almost
entirely to the Chapin Mesa within the Park and the Ute Mountain Ute
Tribal Park in southern Colorado, with some outlying areas on
neighboring Park Mesa and West Chapin Spur, both of which are within
the boundaries of the Park (Rondeau 2017, p. 1). Chapin Mesa milkvetch
habitat occupies approximately 2,000 acres (ac) (809 hectares (ha)) in
the Park (CNHP 2010, pp. 12-19; Anderson 2004, pp. 25, 30). While the
species has been observed on the Ute Mountain Ute Tribal Park, we do
not know how much occupied habitat occurs there.
The habitat for Chapin Mesa milkvetch is dense pinyon-juniper
woodland of mesa tops, with deep, reddish, loess soil (Service 2021a,
p. 7). Pinyon-juniper trees are easily killed by fires and are slow to
regenerate (Romme et al. 2003, p. 344.). The historical fire regime of
the pinyon-juniper woodlands on the mesa tops of the Mesa Verde area is
characterized by lightning-caused, infrequent (around a 400-year
rotation), stand-replacing fires, as opposed to low-severity, stand-
thinning fires (Romme et al. 2003, p. 338; Floyd et al. 2004, p. 286).
The best available information indicates that the species consists
of one large, interconnected population. Like many rare plants, Chapin
Mesa milkvetch is globally rare, but is locally abundant throughout its
occupied habitat (Rondeau 2017, p. 1). Regular monitoring has occurred
in the Park since 2001 in established monitoring plots; however, the
best available scientific information does not allow estimating a
global population size or overall population density (Service 2021a, p.
4). The existing monitoring reports provide insights into the levels of
seedling survival in the Chapin Mesa representative unit, which we used
to characterize resiliency in the SSA (Rondeau 2020, entire). They also
provide information on the relationship between fire, seasonal
precipitation, and various demographic characteristics (e.g., plant
density and recruitment), which furthered our understanding of how and
when wildfire impacts the plant (Rondeau 2020, entire). Finally, these
monitoring reports provide information on plant density over time;
levels of germination over time; amount of fruit production over time;
age class ratios; and mortality rates over time in certain parts of the
species' range (Rondeau 2020, entire).
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
[[Page 5771]]
``endangered species'' or a ``threatened species'' because of any of
the following five factors:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
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
Service 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 (see 84 FR 45020, August 27, 2019, p. 45027). 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 (50 CFR 424.11(d)). 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 review of the best scientific and commercial data regarding
the status of the species, including an assessment of the potential
threats to the species. The SSA report does not represent a decision by
the Service on whether the species should be listed as an endangered or
threatened species under the Act. However, it does provide the
scientific basis that informs our regulatory decisions, which involve
the further application of standards within the Act and its
implementing regulations and policies. 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-R6-ES-2018-0055 on http://www.regulations.gov.
To assess Chapin Mesa milkvetch's 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 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 species' life-history needs at
the individual, population, and species level. The next stage involved
an assessment of the historical and current condition of the species'
demographics and habitat characteristics, including an explanation of
how the species arrived at its current condition. The final stage of
the SSA involved making predictions about the species' responses to
positive and negative environmental and anthropogenic influences.
Throughout all of these stages, we used the best available information
to characterize viability as the ability of a species to sustain
populations in the wild over time. We use this information to inform
our regulatory decision.
Summary of Biological Status and Threats
Below, we review the biological condition of the species and its
needed resources, as well as stressors and conservation efforts that
influence its condition, to assess the species' overall viability and
the risks to that viability. To evaluate the biological status of the
Chapin Mesa milkvetch both currently and into the future, we assessed a
range of conditions to consider the species' resiliency, redundancy,
and representation. Because Chapin Mesa milkvetch is considered to
consist of one large population, for the purposes of our analysis, we
divided the range of Chapin Mesa milkvetch into four representative
units, which are further broken down into subunits (Service 2021a, p.
24). The Chapin Mesa milkvetch needs multiple, sufficiently resilient
subunits distributed across its range to maintain populations into the
future and to avoid extinction (Service 2021a, pp. 7-13).
We evaluated a number of stressors with the potential to influence
the
[[Page 5772]]
health and resiliency of Chapin Mesa milkvetch populations, such as
competition with nonnative, invasive plant species (i.e., cheatgrass,
musk thistle, etc.); wildfire; drought; fire management activities;
development of infrastructure; trampling; herbivory; and effects of
climate change (Service 2021a, pp. 13-22). We found that the primary
drivers influencing the species' condition are the increased frequency
of large, high-intensity wildfires; increasing presence of invasive,
nonnative plants, especially cheatgrass; and the interaction between
these elements, as explained further under Summary of Factors
Influencing Viability, below, and in the SSA report (Service 2021a, pp.
27-33).
As described above, we divided the range of Chapin Mesa milkvetch
into four representative units (Chapin Mesa, West Chapin Spur, Park
Mesa, and Ute Mountain Ute Tribal Park) (Service 2021a, p. 24). We
considered representative units to be most resilient when (1) they do
not contain nonnative, invasive species or infrastructure development;
(2) the unit has sufficient pinyon-juniper canopy cover and intact
native understory; (3) seedling survival is sufficient in the unit; and
(4) winter and spring precipitation levels are sufficient in the unit
(Service 2021a, pp. 24-33). Our analysis found that all four Chapin
Mesa milkvetch analysis units currently have moderate levels of
resiliency, with one large, unburned subunit in good condition.
Given our uncertainty regarding the future effects of climate
change, as well as the other stressors, we projected the future
resiliency, redundancy, and representation of Chapin Mesa milkvetch
under three plausible future scenarios. Our three future scenarios
incorporate three climate scenarios developed by the North Central
Climate Science Center in Fort Collins, Colorado, for the San Juan
Basin in southwestern Colorado: (1) Hot and dry, (2) moderately hot,
and (3) warm and wet (Rondeau et al. 2017, Appendix D, pp. 15-21).
``Wet'' winters are correlated with high Chapin Mesa milkvetch density
counts, while dry winters translate to low or no emergence of Chapin
Mesa milkvetch in the spring (Rondeau 2017, p. 15). Data collected over
14 years of monitoring reveal a strong correlation between winter
precipitation (as snow) and the density of Chapin Mesa milkvetch plants
(Rondeau 2017, p. 15). However, climate change models forecast warmer
temperatures and a decrease in precipitation, or change in the timing
and type of precipitation, as compared to historical levels, by 2035
and through the end of the century (Rondeau et al. 2017, Appendix D,
pp. 15-21; Service 2021a, pp. 34-35).
We evaluated each of our three future scenarios in terms of how it
would be expected to impact resiliency, redundancy, and representation
of the species by the year 2035. We selected the year 2035 for our
evaluation of future scenarios based on available climate projections
specific to the San Juan Basin in southwestern Colorado, where Chapin
Mesa milkvetch habitat occurs, and based on available analyses on the
response of pinyon-juniper communities to these climate changes. These
climate models used downscaled data that model the range of plausible
future climate conditions for the region to project changes in certain
climate variables over time, predict the impact of these changes in
climate variables on wildfire frequency and extent, and illustrate the
impact of these climate changes and increased wildfire risk on the
specific pinyon-juniper communities that support Chapin Mesa milkvetch
under three climate scenarios (i.e., (1) hot and dry, (2) moderately
hot, and (3) warm and wet) (Rondeau et al, 2017, pp. 9-11; Appendix D,
pp. 15-21). However, these downscaled analyses provided insight into
the threat of wildfire and the response of pinyon-juniper communities
only through the year 2035 (pp. 9-11).
Under the same three climate scenarios, trends for temperature and
precipitation projected through 2035 will continue through 2100 in
southwestern Colorado (Appendix C, pp. 11-14); climate conditions could
still range from warm and wet to hot and dry by 2100 (Rondeau et al.
2017, Appendix C, pp. 11-14). More specifically, all three climate
scenarios predict conditions will warm even further by 2100, although
the extent to which the climate could warm by the end of the century
varies between scenarios (Rondeau et al. 2017, Appendix C, pp. 12-13).
Like the projections of climate conditions for 2035, these projections
of climate conditions through 2100 present uncertainty as to the extent
that precipitation patterns could change, with some scenarios
predicting wetter conditions and others predicting drier conditions
(Rondeau et al. 2017, Appendix C, p. 14). While projections for
temperature and precipitation in southwestern Colorado are available
further into the future than 2035, we do not know specifically how
these conditions could alter wildfire frequency or extent in pinyon-
juniper communities in southwestern Colorado nor how these communities
would respond to these climate conditions by the end of the century.
Thus, the best available information on how potential future climate
conditions could affect the specific ecological communities on which
Chapin Mesa milkvetch depends consider this ecological response only
through 2035 (Rondeau et al. 2017, pp. 9-11). Given the uncertainties
regarding wildfire risk and species' response past 2035, future
conditions further into the 21st century are less reliable and
foreseeable (see 84 FR 45020, August 27, 2019, p. 45027). We can,
however, make reliable predictions about the threats to and response of
Chapin Mesa milkvetch through 2035.
The future scenarios we evaluated for Chapin Mesa milkvetch through
2035 are as follows (scenarios are discussed in greater detail in the
SSA report (Service 2021a, pp. 34- 36)):
Scenario 1 (``Optimistic''): Continuation of the current
land management conditions under a ``warm and wet'' future climate
change model;
Scenario 2 (``Moderate''): Slight increase in fire
management activities (i.e., fuels reduction) and infrastructure
development under a ``moderately hot'' future climate change model; and
Scenario 3 (``Pessimistic''): Significant increase in fire
management activities and infrastructure development under a ``hot and
dry'' future climate change model.
Based on our analysis of future condition, the ``Pessimistic''
scenario is the only scenario under which resiliency could decrease for
the species within the foreseeable future, primarily due to the
increased risk of wildfire. Having a greater number of self-sustaining
units distributed across the known range of the species is associated
with an overall higher viability of the species into the future, as it
increases redundancy. We anticipate that the largest Chapin Mesa
milkvetch representative unit, Chapin Mesa, will continue to be
occupied under all three future scenarios, but with reduced levels of
resiliency under the ``Pessimistic'' scenario (Service 2021a, pp. 37-
41). This species inherently has, and has likely always had, a low
level of redundancy and representation due to its endemism. Because
there is only one large representative unit (Chapin Mesa) and three
very small representative units (West Chapin Spur, Park Mesa, and Ute
Mountain Ute Tribal Park), this species is at some risk from stochastic
and catastrophic events and may have low adaptability to changing
conditions (Service 2021a, p. 41). These future resiliency, redundancy,
and representation projections in the SSA also do not take into account
the
[[Page 5773]]
potential mitigating effects of the Park's conservation efforts, which
we discuss in additional detail below.
The SSA report (Service 2021a, entire) contains a more detailed
discussion of our evaluation of the biological status of the Chapin
Mesa milkvetch and the influences that may affect its continued
existence. Our conclusions are based upon the best available scientific
and commercial data.
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. To assess the current and
future condition of the species, we undertake an iterative analysis
that encompasses and incorporates the threats individually and then
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.
Summary of Factors Influencing Viability
As mentioned above under Regulatory Framework, a species may be
determined to be an endangered or threatened species due to one or more
of the five factors described in section 4(a)(1) of the Act. Potential
stressors to the Chapin Mesa milkvetch that we evaluated include
invasive, nonnative plants (Factor A); wildfires (Factor A); post-fire
mitigation (Factor A); wildfire and fuels management (Factor A);
trampling and herbivory (Factors A and C); development of
infrastructure (Factor A); drought (Factor A and Factor E); and effects
of climate change (Factor A and Factor E) (Service 2021a, pp. 13-22).
There is no evidence that overutilization (Factor B) of Chapin Mesa
milkvetch, disease (Factor C), or other natural or manmade factors
affecting the species (Factor E) are occurring. Existing regulatory
mechanisms (Factor D) are discussed further below.
We evaluated each potential stressor, including its source,
affected resources, exposure, immediacy, geographic scope, magnitude,
and impacts on individuals and populations, and our level of certainty
regarding this information, to determine which stressors were likely to
be drivers of the species' current condition (Service 2021a, Appendix
A). Our analysis found that the primary drivers of Chapin Mesa
milkvetch current and future condition are the increased frequency of
large, high-intensity wildfires; increasing presence of invasive,
nonnative plants, especially cheatgrass; and the interaction between
these elements, as explained further in the SSA report (Service 2021a,
pp. 14-33). We offer a summary of the analysis here.
Invasive, nonnative plants compete with Chapin Mesa milkvetch for
space, nutrients, and water, and their invasion has been facilitated by
the increased frequency of burns, as well as the creation of fire
breaks, that has occurred within Chapin Mesa milkvetch habitat (CNHP
2006, p. 4). Wildfire affects Chapin Mesa milkvetch and its habitat by
eliminating the fire-sensitive pinyon-juniper woodlands and native
understory that the species needs (Service 2021a, p. 15), thereby
opening up habitat to be colonized by nonnative grasses and clonal
shrub species. Pinyon-juniper woodlands that have been burned
extensively by wildfires in the past two decades are being replaced by
significant invasions of nonnative species (Floyd et al. 2006, p. 1).
Cheatgrass was not found in unburned woodland monitoring plots, whereas
cheatgrass invasion ranges from 8 to 58 percent cover in the burned
monitoring plots (Rondeau 2017, p. 11). We do not have percent cover
information on other invasive species within Chapin Mesa milkvetch
habitat at this time. The abundance of grasses, especially cheatgrass,
western wheatgrass (Pascopyrum smithii), and smooth brome (Bromus
inermis), within the species' habitat is outside the natural range of
variation, resulting in a lack of bare ground and biological soil
crust, preventing natural succession or return to the pinyon-juniper
woodland habitat that Chapin Mesa milkvetch needs, and also reducing
the reproductive vigor of Chapin Mesa milkvetch (Rondeau 2017, pers.
comm.).
Cheatgrass and other invasive, nonnative plant species have already
invaded different parts of the species' range to varying degrees. Five
large, high-intensity fires have occurred in the Park and on a large
portion of the adjacent Mesa Verde cuesta (i.e., long, sloping ridge)
in the last two decades (Floyd et al. 2004, pp. 270, 283). A total of
approximately 760.5 ac (307.8 ha) has burned out of the approximately
2,000 ac (809 ha) of Chapin Mesa milkvetch habitat in the Park; this
amounts to 38 percent of Chapin Mesa milkvetch habitat in the Park.
Climate projections for the San Juan Basin, Colorado, where Chapin Mesa
milkvetch occurs, include increased temperatures, more intense and
longer lasting heat waves, a longer fire season with greater frequency
and extent of fires, and an increased probability of drought, although
the extent of these increases varies between climate models and depends
partly on future management (Rondeau et al. 2017, p. 8). These factors
could exacerbate the frequency and extent of catastrophic wildfires and
the invasion of cheatgrass on Chapin Mesa milkvetch habitat in the
future.
Conservation and Management Activities
In this determination, we consider both existing ongoing
conservation and management activities that benefit Chapin Mesa
milkvetch and future conservation efforts that comply with the
Service's PECE policy. The Service's PECE policy (68 FR 15100; March
28, 2003) provides a policy framework and criteria for evaluating,
within a listing determination, conservation efforts that have not yet
been implemented or have not yet demonstrated whether they are
effective. For us to consider that a formalized conservation effort
contributes to forming a basis for not listing a species or for listing
a species as a threatened species rather than an endangered species, we
must find that the conservation effort is sufficiently certain to be
implemented and effective so as to have contributed to the elimination
or adequate reduction of one or more threats to the species identified
through the section 4(a)(1) analysis.
First, existing regulatory mechanisms (Factor D) and other ongoing
management efforts by the NPS and Ute Mountain Ute Tribe provide
benefits to Chapin Mesa milkvetch and lessen the influence of large,
high-intensity wildfire, invasive species, and development on species'
viability, as the species is located entirely within the Park and the
Ute Mountain Ute Tribal Park. Both the Park and the Tribe already
implement activities that reduce wildfire risk and preserve Chapin Mesa
milkvetch habitat. For example, since we published the proposed listing
rule for this species, the Park shared a wildfire emergency response
procedure with the Service, which governs all wildfire response in the
Park (NPS 2020, entire). According to the Park's wildfire emergency
response procedure, the Park will immediately and fully suppress
wildfires ``while minimizing damage to resources from fire or
suppression
[[Page 5774]]
operations'' (NPS 2020, p. 2). The Park also has multiple on-site
wildland firefighters, which facilitates quick response and suppression
of fire (Spencer 2021, pers. comm). The Park will incorporate fire
management measures currently in the conservation plan for Chapin Mesa
milkvetch at Mesa Verde National Park, in the associated implementation
plan, and in the wildfire emergency response procedure into a fire
management plan by 2022 (Spencer 2021, pers. comm., p. 2; NPS 2020,
entire).
Ute Mountain Ute Tribe: In January 2020, the Ute Mountain Ute Tribe
finalized a conservation plan (Tribal plan) for Chapin Mesa milkvetch,
which was adopted by Resolution by the Ute Mountain Ute Tribal Council
in February 2020 (Ute Mountain Ute Tribe 2020, entire). The Tribal plan
identifies conservation strategies that the Tribe will use on the Ute
Mountain Ute Indian Reservation to enhance the resiliency, redundancy,
and representation of Chapin Mesa milkvetch. The Tribal plan calls for
management decisions that mitigate direct and indirect impacts to the
species and result in the distribution of the species across high-
quality, contiguous habitat spanning a range of ecological conditions.
While we conclude that this Tribal plan, if implemented, would likely
provide benefit to the species, due to uncertainty in future levels of
implementation and effectiveness, future conservation efforts outlined
in the Tribal plan were not relied upon in our final listing decision.
However, we can consider the conservation actions that the Ute
Mountain Ute Tribe has completed and is currently undertaking to
conserve this species in our final determination, because conservation
actions already implemented and shown to be effective are not subject
to PECE. For example, in 2006, 2011, and 2018-2019, the Tribe created
fire breaks on the northern end of Chapin Mesa within the Tribal Park
to prevent the spread of large wildfires throughout the area (Ute
Mountain Ute Tribe 2021, p. 2). The Tribe is also participating in a
collaborative research project with the Park, the U.S. Geological
Survey, and Northern Arizona University ``to identify strategies to
enhance Pinyon-juniper resilience in the context of fuels management,
wildfire, and climate change'' and is beginning to monitor the species
on an annual basis (Ute Mountain Ute Tribe 2021, p. 1). Additionally,
the fact that the species' habitat occurs within a Tribal Park provides
additional protections, as the Tribe restricts human activities and
land uses within this area (Ute Mountain Ute Tribe 2021, p. 2). The
Tribal Park unit has limited road access in Chapin Mesa milkvetch
habitat; however, this road is not often used, except for guided tours
(Service 2021a, p. 31). This has likely limited the extent of any
habitat loss or other human-caused disturbances to the species' habitat
within the Tribal Park. Thus, both the Park and the Tribe are currently
managing their lands in a way that also benefits the species.
Future Conservation Effort: NPS Conservation Plan: In addition to
the activities that the Park and Tribe currently implement to protect
pinyon-juniper habitat and reduce wildfire risk, the Park also
finalized and approved the ``Conservation Plan for Chapin Mesa
milkvetch (Astragalus schmolliae) at Mesa Verde National Park'' (NPS
2018, entire; referred to as ``conservation plan'') in September 2018,
which details how the Park plans to conserve Chapin Mesa milkvetch in
the future. To provide further clarity on the objectives and strategies
in the conservation plan, the Park developed an implementation plan in
February 2021 (NPS 2021, entire), which ``takes objectives outlined in
the Chapin Mesa milkvetch Conservation Plan and outlines strategies to
meet these desired objectives. The goal of [the implementation plan] is
to provide a planned strategy to execute the Chapin Mesa milkvetch
conservation plan'' (NPS 2021, p. 3). The conservation plan, and
associated implementation plan, describe the Park's conservation effort
through detailing clear objectives, the strategies the Park will
implement to achieve the objectives, estimated timelines for carrying
out the strategies, funding sources, and Park staff responsible for
implementing each strategy. The implementation plan is a key component
in our determination that future conservation efforts within the Park
under the conservation plan meet the requirements of the PECE policy
(see analysis below).
The conservation plan's goal is to ``reduce threats and stressors
to the species to ensure the resiliency, redundancy and representation
of the species leading to a self-sustaining healthy population of
Chapin Mesa milkvetch. The most intact habitat and densest occurrences
will receive the highest level of protection coupled with restoration
of altered habitat'' (NPS 2018, p. 24). Conservation actions in the
conservation plan focus on identification and protection of intact
habitat, limitation of development, wildfire prevention, prompt
response to and restoration after wildfire, enhanced connectivity,
control of invasive plant species, and support of pollinators.
The Service evaluated the Park's conservation plan in accordance
with the PECE policy (68 FR 15100; March 28, 2003). Based on our
analysis (Service 2021b, entire), which is available at http://www.regulations.gov at Docket No. FWS-R6-ES-2018-0055 and which we
summarize here, we concluded that the Park's conservation plan, and
associated implementation plan, are sufficiently certain to be
implemented and effective such that they could be considered as part of
the basis for our final listing determination for the species. Using
the criteria in PECE (68 FR 15100; March 28, 2003), we evaluated the
certainty of implementation and effectiveness of conservation measures
in the conservation plan, and associated implementation plan. We
determined that the measures will be implemented and effective at
eliminating or reducing threats to the species because they will
protect intact pinyon-juniper habitat, reduce wildfire risk, and
restore degraded habitat (Service 2021b, entire). We have a high degree
of certainty that the measures will be implemented because the NPS has
a strong track record of implementing conservation measures similar to
those covered in the conservation plan, has the legal authority to
implement the plan, has detailed the funding source for each planned
activity, has provided an implementation schedule (i.e., the
implementation plan), and has approved the conservation plan (Service
2021b, entire). The Park has already dedicated portions of its base
budget towards carrying out Chapin Mesa milkvetch conservation and
monitoring (Spencer 2021, pers. comm., entire). The Park also has
already leveraged partnerships to secure funding and support of
projects that benefit the species (Spencer 2021, pers. comm., entire).
In both the implementation plan and the Superintendent's January 2021
letter to the Service, the Park indicates that it will use Park budgets
and recreation fees to implement the majority of measures in the
conservation plan, while pursuing additional funding through
partnerships (NPS 2021, p. 3; Spencer 2021, pers. comm., entire).
Further supporting the certainty of implementation, since the Park
finalized and approved the conservation plan in September 2018, the
Park has been implementing the strategies prescribed in the
conservation plan, activities they summarize in a January 20, 2021,
letter to the Service (Spencer 2021, pers. comm., entire). For example,
the Park has identified key areas for Chapin Mesa conservation and is
limiting disturbance
[[Page 5775]]
and development in these areas, has developed a wildfire emergency
response procedure, has funded a genetic study of the species, is
conducting soil analyses to determine suitable conditions for the
plant, has drafted a livestock removal implementation plan, and is
investigating methods to manage and restore pinyon-juniper habitat
(Spencer 2021, pers. comm., pp. 1-3). Over the past 3 years, the Park
has also successfully kept development below the limits established for
each of the three different types of habitat described in the
conservation plan, preserving important habitat for Chapin Mesa
milkvetch. The conservation plan has sufficient monitoring and adaptive
management provisions to ensure that all of the conservation measures
are implemented as planned and are effective at reducing threats to the
Chapin Mesa milkvetch.
Due to the certainty of implementation and effectiveness of the
conservation plan in accordance with PECE, we considered the
conservation plan's impacts on the species in our listing
determination. This conservation plan, and its associated
implementation plan, alter our understanding of the range of plausible
future scenarios presented in the SSA report; the projections of future
resiliency, redundancy, and representation in the SSA report; and the
risk associated with future stressors. In the SSA, Scenario 3 (the
``Pessimistic'' scenario) is the only scenario that would result in
worsened conditions for the plant. However, as we explain in additional
detail below, based on the commitments and strategies in the PECE-
compliant conservation plan, we know that the negative impacts of fire
management captured in the ``Pessimistic'' future scenario (Scenario 3)
will not occur (Service 2021b, entire).
In the September 17, 2020, proposed rule to list Chapin Mesa
milkvetch as a threatened species (85 FR 58224), we expressed
uncertainty regarding the benefits of the Park's management efforts,
specifically how development and fuels management activities in the
Park could impact the plant. In the proposed rule, we stated that
management activities conducted within the Park, such as fuels and fire
management, and the development of visitor-related infrastructure, may
have direct and indirect impacts to the species (85 FR 58224, September
17, 2020, p. 58230). In the proposed rule, we stated that while fuels
reduction activities may help decrease the likelihood of catastrophic
fires, they may also have detrimental impacts such as trampling,
creating surface disturbances and altering ecological conditions, or
facilitating nonnative species invasion, and that the development of
existing infrastructure, such as roads, parking lots, a wastewater
treatment facility, and buildings within the Park has resulted in a
loss of approximately 2 percent of Chapin Mesa milkvetch habitat (85 FR
58224, September 17, 2020, p. 58230). We also noted that several
additional infrastructure and fire management projects were planned or
under consideration within Mesa Verde National Park (85 FR 58224,
September 17, 2020, p. 58230).
The provisions in the Park's conservation plan now provide
assurances that alleviate these concerns about potential negative
impacts from development and fuels management. We know that any
increases in development predicted under Scenarios 2 and 3 would be
within the limits established in the conservation plan and any fire
management activities would be carried out with conservation measures
that minimize impacts to Chapin Mesa milkvetch (NPS 2018, pp. 24-30;
NPS 2021, pp. 4-22). For example, the conservation plan only allows the
Park to develop an additional 1.8 percent of Chapin Mesa milkvetch
``Level 1'' habitat (intact, old-growth pinyon juniper woodland) (NPS
2018, p. 27). Moreover, this development will incorporate minimization
measures to reduce impacts of any development on the species and its
habitat (Objectives 3 and 10 in NPS 2021, pp. 10-11, 21-22). The
conservation plan also limits the areas in which the Park will conduct
fuels treatments and details measures to minimize the impacts of these
treatments; while fuels treatments can help prevent catastrophic fire,
these activities can also incidentally negatively impact Chapin Mesa
milkvetch habitat through trampling, facilitation of cheatgrass
invasion, and small-scale burning of plants if Park staff members burn
excess fuel on top of Chapin Mesa milkvetch habitat. The conservation
plan dictates that the Park will only conduct fuels reduction
management in an additional 19 percent of Chapin Mesa milkvetch habitat
in the Park and that all of these treatments will include the adoption
of minimization measures to protect Chapin Mesa milkvetch and its
habitat, such as hand-carrying out fuels instead of pile burning, when
possible (NPS 2018, p. 14; Objectives 4, 5, 6, 8, and 10 in NPS 2021,
pp. 11-27, 18-19, 21-22). These minimization measures lessen the
potentially negative side-effects that fuels management could have on
Chapin Mesa milkvetch and its habitat and will result in a 50 percent
reduction of impacts to the species from fuels management in the future
(NPS 2018, p. 14; Objectives 4, 5, 6, 8, and 10 in NPS 2021, pp. 11-27,
18-19, 21-22). By reducing the intensity of treatments and
incorporating minimization measures, the fuels management detailed in
the conservation plan will likely provide a net benefit to Chapin Mesa
milkvetch because it will protect the species and its habitat from
large-scale, stand-replacing wildfires while reducing direct impacts of
treatments on the plant and its habitat.
Furthermore, according to the implementation plan, the Park ``will
not plan development or fuels management treatments on Park Mesa or
West Chapin Mesa Spur so that these sites can be retained for future
introductions or range expansions'' (NPS 2018, p. 27); in the
conservation plan, the Park commits to developing a plan for
reintroduction on Park Mesa (NPS 2018, pp. 30-31). The Park will
research and pursue an ex situ conservation effort (NPS 2018, p. 33;
NPS 2021, p. 27). Pending the outcomes of soil and habitat suitability
studies, the Park is also preserving 6,264 acres on North Chapin Mesa,
Park Mesa, and Moccasin Mesa in sufficient condition to allow for
introduction if necessary (Spencer 2021, pers. comm., p. 2; NPS 2018,
p. 31). If the Park deems reintroduction projects necessary and pursues
them, this reintroduction could provide additional redundancy for the
species in the future, though this remains uncertain and we did not
rely on these potential increases in our analysis of species status
(NPS 2021, pp. 11-12).
Additionally, the conservation plan's provisions address the threat
of nonnative, invasive vegetation that we identified as a concern in
the proposed rule. The risk of invasion of nonnative vegetation is
already low in areas with intact pinyon-juniper overstory. In the
conservation plan, the Park commits to maintaining minimal disturbance
and development in these areas with intact pinyon-juniper overstory to
reduce the likelihood of nonnative plant invasion in these highly
resilient areas. The Park also commits to recovering burned, degraded
areas such that pinyon-juniper trees are restored ``to more than 10
percent canopy cover'' and invasive plants are reduced ``to less than 5
percent cover,'' further reducing the risk invasive vegetation poses to
the species (NPS 2018, pp. 26, 29; NPS 2021, pp. 7-9, 19-21). The Park
is collaborating with the Tribe to research effective methods of
restoring pinyon-juniper habitat
[[Page 5776]]
(Spencer 2021, pers. comm., p. 3; NPS 2021, pp. 7-9).
The September 17, 2020, proposed rule (85 FR 58224) also attributed
risk of extinction in the foreseeable future to the high potential for
a future catastrophic event, such as a catastrophic wildfire, that
could affect all or a large portion of the species' range, given the
species' inherently limited redundancy and the fact that 97 percent of
the species' known range is concentrated in the Park. The conservation
plan, implementation plan, and the Park's new standard operating
procedures for wildfire management, which are documented in their 2020
wildfire emergency response procedure, also shed new light on these
concerns. As we explain above, the strategies and commitments in the
conservation plan and implementation plan indicate that the management
actions predicted in Scenario 3 will not occur in the future; we know
that the Park will not do less invasive species control, will not
significantly increase potentially detrimental fire management
activities, will not significantly increase development, and will not
open currently closed roads and trails (NPS 2018, pp. 24-30; NPS 2021,
pp. 4-22). Scenario 3 was the only scenario in the SSA report that
would result in worsened conditions for the species. However, while the
provisions in the conservation plan ensure that the management
components of this ``pessimistic'' future scenario will not occur, the
``hot and dry'' climate conditions associated with this scenario could
still happen (Service 2021a, p. 39). These climate conditions could
increase the frequency of wildfire 8-fold and the amount of area burned
11-fold, which partially influenced the worsened resiliency in this
future scenario in the SSA (Rondeau et al. 2017, pp. 10-11, 15-17,
Appendices C and D). However, these projected increased risks and
impacts of catastrophic wildfire assume no fire management or
prevention. Wildfire management and response measures in the Park's
conservation plan, implementation plan, and wildfire emergency response
procedure, which the Park has committed to incorporating into a long-
term fire management plan by 2022, ensure that the Park will take
action to prevent fire, while minimizing impacts of this management on
the species; they also ensure that the Park will respond to fire
immediately with the intent to fully suppress it (NPS 2018, pp. 27-29;
NPS 2020, entire; NPS 2021, pp. 12-17). These efforts decrease the
potential influence of climate change and associated wildfire on the
species in all future scenarios, further reducing the plausibility and
likelihood of the resiliency outcomes of the ``Pessimistic'' future
scenario, the only scenario in which the species' future resiliency
would worsen relative to current condition.
Determination of Species Status
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for determining
whether a species meets the definition of ``endangered species'' or
``threatened species.'' The Act defines an ``endangered species'' as a
species that is in danger of extinction throughout all or a significant
portion of its range and a ``threatened species'' as a species that is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range. The Act requires
that we determine whether a species meets the definition of an
``endangered species'' or ``threatened species'' because of any of the
following five factors:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the Chapin Mesa milkvetch. Potential stressors to the Chapin Mesa
milkvetch that we evaluated include invasive, nonnative plants (Factor
A); wildfires (Factor A); post-fire mitigation (Factor A); wildfire and
fuels management (Factor A); trampling and herbivory (Factors A and C);
development of infrastructure (Factor A); drought (Factor A and Factor
E); and effects of climate change (Factor A and Factor E) (Service
2021a, pp. 13-22). There is no evidence that overutilization (Factor B)
of Chapin Mesa milkvetch, disease (Factor C), or other natural or
manmade factors affecting the species (Factor E) are occurring.
Existing regulatory mechanisms (Factor D) are discussed above.
We evaluated each potential stressor, including its source,
affected resources, exposure, immediacy, geographic scope, magnitude,
and impacts on individuals and populations, and our level of certainty
regarding this information, to determine which stressors were likely to
be drivers of the species' current condition (Service 2021a, Appendix
A). Our analysis found that the primary drivers of the Chapin Mesa
milkvetch's current and future condition are the increased frequency of
large, high-intensity wildfires; increasing presence of invasive,
nonnative plants, especially cheatgrass; and the interaction between
these elements, as explained further in the SSA report (Service 2021a,
pp. 13-22).
Status Throughout All of Its Range
In our September 17, 2020, proposed rule to list Chapin Mesa
milkvetch as a threatened species (85 FR 58224), we concluded that the
species did not meet the definition of an endangered species under the
Act. The new information we received since we published that proposed
rule does not change our original conclusion regarding the species'
current risk of extinction. We still find that the Chapin Mesa
milkvetch is not currently in danger of extinction throughout its
range. The species currently has a large representative subunit (the
unburned Chapin Mesa subunit) that is considered highly resilient,
based on the quality of habitat conditions for Chapin Mesa milkvetch.
This large area of habitat (1,265 ac (512 ha)) in a highly resilient
subunit likely provides the Chapin Mesa milkvetch some ability to
withstand stochastic events, such as drought, that are within the
normal range of yearly variation, and to complete its life cycle.
Additionally, all four representative units are currently in moderate
condition, providing for some additional redundancy and representation,
given the relatively healthy status of multiple representative units
across the species' range. Moreover, three of these four units occur on
geographically separate mesa tops; the steep cliffs between these mesa
tops provide natural fire breaks between the representative units,
reducing the likelihood that a single wildfire could impact all four
representative units at the same time. In addition to these natural
fire breaks, the constructed fire break between the Park and the Ute
Mountain Ute Tribal Park further enhances redundancy of the species,
limiting the ability of a catastrophic wildfire to spread along Chapin
Mesa and impact representative units in both the Park and on Tribal
lands. Therefore, the risk of extinction now is low, and the species is
not currently in danger of extinction throughout its range.
The Act defines an ``endangered species'' as any species that is in
danger of extinction throughout all or a
[[Page 5777]]
significant portion of its range and a ``threatened species'' as any
species that is likely to become an endangered species within the
foreseeable future throughout all or a significant portion of its
range. As we discuss in detail under Summary of Biological Status and
Threats, the best available information on how potential future climate
conditions could affect the specific ecological communities on which
Chapin Mesa milkvetch depends considers this ecological response only
through 2035 (Rondeau et al. 2017, pp. 9-11). Given the uncertainties
regarding wildfire risk and species' response past 2035, future
conditions further into the 21st century are less reliable and
foreseeable (see 84 FR 45020, August 27, 2019, p. 45027). We can,
however, make reliable predictions about the threats to and response of
Chapin Mesa milkvetch through 2035. We thus consider the foreseeable
future for the Chapin Mesa milkvetch to be to the year 2035, given the
available climate data specific to the San Juan Basin in southwestern
Colorado, where Chapin Mesa milkvetch occurs, and based on the
available analyses on the response of pinyon-juniper communities to
these climate changes.
Based on the new information in the Park's conservation plan,
implementation plan, and wildfire emergency response procedure, we find
that the Chapin Mesa milkvetch is not likely to become endangered
within the foreseeable future throughout all of its range. First, we
now know that any increases in development predicted under Scenarios 2
and 3 would be within the limits established in the conservation plan
and any fire management activities would be carried out with
conservation measures that minimize impacts to Chapin Mesa milkvetch
(NPS 2018, pp. 24-30; NPS 2021, pp. 4-22). More generally, we know that
the Park's conservation plan and implementation plan indicate that the
management components of Scenario 3 will not come to fruition; we know
that the Park will not do less invasive species control, will not
significantly increase potentially detrimental fire management
activities, will not significantly increase development, and will not
open currently closed roads and trails (NPS 2018, pp. 24-30; NPS 2021,
pp. 4-22). Second, the Park's conservation plan, implementation plan,
and new wildfire emergency response procedure, which the Park has
committed to incorporating into a long-term fire management plan by
2022, ensure that the Park will take action to prevent fire, while
minimizing impacts of this management on the species; they also ensure
that the Park will respond to fire immediately with the intent to fully
suppress it (NPS 2018, pp. 27-29; NPS 2020, entire; NPS 2021, pp. 12-
17). These conservations efforts decrease the potential influence of
climate change and associated wildfire on the species in all future
scenarios, further reducing the plausibility and likelihood of the
outcomes of Scenario 3, the only scenario in which the species' future
condition would worsen relative to current condition.
Given the Park's commitments in the conservation plan and
implementation plan, which we describe in additional detail in Summary
of Factors Influencing Viability above, it is likely that the
resiliency of the representative units in the Park (Chapin Mesa, Park
Mesa, and West Chapin Spur) will remain the same as current condition
or improve in the foreseeable future due to habitat restoration efforts
and management of wildfire risk. These maintained or improved levels of
resiliency would continue to provide for reduced catastrophic risk and
enhanced ability to adapt to future environmental change, especially
considering the inherently limited range of this narrow endemic plant.
The four extant representative units distributed across three
geographically distinct mesa tops reduces the risk of losing all
individuals in a catastrophic fire, especially considering that the
separate mesa tops provide natural fire breaks that would prevent fire
from spreading between representative units. The constructed fire break
between Mesa Verde National Park and the Tribal Park further reduces
the likelihood of fire spreading along Chapin Mesa, between the Park
and Tribal land.
Even though much uncertainty remains as to the condition of Chapin
Mesa milkvetch occurrences on Tribal lands, both now and into the
future, we analyzed the status of the species based on the best
available information on the future of species' threats and
conservation efforts. While the Tribe is actively providing
conservation for the species, information about the future of the
species' threats and conservation is currently only available and
certain for the occurrences in the Park. However, the certainty of
implementation and effectiveness of conservation efforts in the Park,
in addition to the fire breaks between Mesa Verde National Park and the
Tribal Park, provided confidence that the species would maintain
sufficient levels of resiliency, redundancy, and representation into
the foreseeable future, even without similarly certain future
conservation commitments on Tribal lands.
The Park's implementation plan, which was provided after we
published the proposed rule, in addition to new standard operating
procedures for fire management at the Park, documented in the wildfire
emergency response procedure, thus reduce the likelihood of Chapin Mesa
milkvetch becoming an endangered species in the foreseeable future.
Therefore, based on the Park's commitments to maintain and restore
pinyon-juniper overstory, to conduct fire management such that it
reduces the risk of catastrophic wildfire in the Park while also
minimizing impacts to the species, and to quickly suppress fire, the
resiliency, redundancy, and representation of Chapin Mesa milkvetch
will likely remain the same or better than current condition into the
foreseeable future; thus, the risk of extinction remains low for Chapin
Mesa milkvetch into the foreseeable future. Therefore, after assessing
the best available information, we conclude that the Chapin Mesa
milkvetch is not in danger of extinction now nor is it likely to become
so in the foreseeable future throughout all of its range.
Status Throughout a Significant Portion of Its Range
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
in the foreseeable future throughout all or a significant portion of
its range. Having determined that the Chapin Mesa milkvetch is not in
danger of extinction or likely to become so in the foreseeable future
throughout all of its range, we now consider whether it may be in
danger of extinction or likely to become so in the foreseeable future
in a significant portion of its range--that is, whether there is any
portion of the species' range for which it is true that both (1) the
portion is significant; and (2) the species is in danger of extinction
now or likely to become so in the foreseeable future in that portion.
Depending on the case, it might be more efficient for us to address the
``significance'' question or the ``status'' question first. We can
choose to address either question first. Regardless of which question
we address first, if we reach a negative answer with respect to the
first question that we address, we do not need to evaluate the other
question for that portion of the species' range.
In undertaking this analysis for the Chapin Mesa milkvetch, 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
[[Page 5778]]
faces to identify any portions of the range where the species is
endangered or threatened.
Chapin Mesa milkvetch is a narrow endemic that functions as a
single, contiguous population and occurs within a very small area. As
described in the SSA report (Service 2021a, pp. 4-5), the species'
global distribution is constrained almost entirely to Chapin Mesa in
southern Colorado, with some outlying subunits on neighboring Park Mesa
and West Chapin Spur (Rondeau 2017, p. 1). Chapin Mesa milkvetch
habitat occupies approximately 2,000 ac (809 ha) in the Park (CNHP
2010, pp. 12-19; Anderson 2004, p. 25, 30). This species is considered
to consist of one large, interconnected population, and like many rare
plants, Chapin Mesa milkvetch is globally rare, but is locally abundant
throughout its occupied habitat (Rondeau 2017, p. 1). Thus, there is no
biologically meaningful way to break this limited range into portions,
and the threats that the species faces affect the species throughout
its entire range. This means that no portions of the species' range
have a different status from its rangewide status. Therefore, no
portion of the species' range can provide a basis for determining that
the species is in danger of extinction now or likely to become so in
the foreseeable future in a significant portion of its range, and we
find the species is not in danger of extinction now or likely to become
so in the foreseeable future in any significant portion of its range.
This is consistent with the courts' holdings in Desert Survivors v.
Department of the Interior, No. 16-cv-01165-JCS, 2018 WL 4053447 (N.D.
Cal. Aug. 24, 2018), and Center for Biological Diversity v. Jewell, 248
F. Supp. 3d, 946, 959 (D. Ariz. 2017).
Determination of Status
We have reviewed the best available scientific and commercial
information regarding the past, present, and future threats to the
Chapin Mesa milkvetch, and we have determined that Chapin Mesa
milkvetch does not meet the definition of an ``endangered species'' or
a ``threatened species'' in accordance with sections 3(6) and 3(20),
respectively, of the Act. Therefore, we are withdrawing our proposed
rule to list the Chapin Mesa milkvetch as a threatened species and to
designate critical habitat.
References Cited
A complete list of references cited in this document and the Chapin
Mesa milkvetch SSA report are available on the internet at http://www.regulations.gov at Docket No. FWS-R6-ES-2018-0055 and upon request
from the Colorado Ecological Services Office (see FOR FURTHER
INFORMATION CONTACT).
Authors
The primary authors of this document are the staff members of the
Colorado Ecological Services Office and the Mountain-Prairie Regional
Office.
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Martha Williams,
Principal Deputy Director, Exercising the Delegated Authority of the
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2022-02041 Filed 2-1-22; 8:45 am]
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