# Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Slickspot Peppergrass (Lepidium papilliferum)

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A2023-09219

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** May 4, 2023
- **Citation:** 88 FR 28874

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R1-ES-2010-0071; FF09E21000 FXES1111090FEDR 223]
RIN 1018-BE61
Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Slickspot Peppergrass (Lepidium papilliferum)

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service or USFWS), finalize the designation of critical habitat for slickspot peppergrass (
Lepidium papilliferum
) under the Endangered Species Act of 1973 as amended (Act). In total, approximately 31,569 hectares (78,009 acres) in Ada, Elmore, Gem, Payette, and Owyhee Counties in Idaho fall within the boundaries of the final critical habitat designation. The effect of this final rule is to designate critical habitat for the slickspot peppergrass, which is a threatened species under the Act.

DATES:

This rule is effective June 5, 2023.

ADDRESSES:

This final rule is available on the internet at
https://www.regulations.gov,
under Docket No. FWS-R1-ES-2010-0071, and at
https://www.fws.gov/species/slickspot-peppergrass-lepidium-papilliferum.
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-R1-ES-2010-0071.

The coordinates or plot points or both from which the maps are generated are included in the decision file for this critical habitat designation and are available at
https://www.regulations.gov,
under Docket No. FWS-R1-ES-2010-0071, and at
https://www.fws.gov/species/slickspot-peppergrass-lepidium-papilliferum.
Additional supporting information that we developed for this critical habitat designation will be available on the Service's website (
https://www.fws.gov/species/slickspot-peppergrass-lepidium-papilliferum
), at
https://www.regulations.gov,
or both.

FOR FURTHER INFORMATION CONTACT:

Lisa Ellis, State Supervisor, U.S. Fish and Wildlife Service, Idaho Fish and Wildlife Office, 1387 S Vinnell Way, Room 368, Boise, ID 83709; telephone 208-378-5243. Individuals in the United States who are deaf, deafblind, hard of hearing, or have a speech disability may dial 711 (TTY, TDD, or TeleBraille) to access telecommunications relay services. Individuals outside the United States should use the relay services offered within their country to make international calls to the point-of-contact in the United States.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule.
Under the Act, 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. Designations and revisions of critical habitat can only be completed only by issuing a rule through the Administrative Procedure Act rulemaking process. We reinstated slickspot peppergrass as a threatened species under the Act effective September 16, 2016 (81 FR 55058, August 17, 2016), published an updated revised proposed rule to designate critical habitat on July 23, 2020 (85 FR 44584), and are now finalizing our designation of critical habitat for the species.

What this rule does.
This final rule designates critical habitat for slickspot peppergrass on approximately 31,569 hectares (ha) (78,009 acres (ac)) in Ada, Elmore, Gem, Payette, and Owyhee Counties in Idaho.

The basis for our action.
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. Section 3(5)(A) of the Act defines critical habitat as (i) the specific areas within the geographic area occupied by the species, at the time it is listed, on which are found those physical or biological features (I) essential to the conservation of the species and (II) which may require special management considerations or protections; and (ii) specific areas outside the geographic area occupied by the species at the time it is listed, upon a determination by the Secretary that such areas are essential for the conservation of the species. Section 4(b)(2) of the Act states that the Secretary must make the designation on the basis of the best scientific data available and after taking into consideration the economic impact, the impact on national security, and any other relevant impacts of specifying any particular area as critical habitat. Also, under section 4(b)(2) of the Act, the Secretary may exclude an area from critical habitat if she determines that the benefits of such an exclusion outweigh the benefits of specifying such areas as part of critical habitat, unless she determines, based on the best scientific data available, that the failure to designate such area as critical habitat will result in the extinction of the species.

The critical habitat we are designating in this rule, consisting of four units and seven subunits comprising 31,569 ha (78,009 ac) for slickspot peppergrass, constitutes our current best assessment of the areas that meet the definition of critical habitat for the species.

Economic analysis.
In order to consider economic impacts, we previously prepared an analysis of the economic impacts of the proposed critical habitat designation and related factors. The final economic analysis, completed March 12, 2012, was based on the 2011 proposed critical habitat and concluded that critical habitat designation would not likely affect levels of economic activity or conservation measures being implemented within the proposed critical habitat area. The final economic analysis is available at
https://www.regulations.gov
under the docket number for this rulemaking, which is FWS-R1-ES-2010-0071.

Previous Federal Actions

On December 7, 2009, slickspot peppergrass was listed as a threatened species throughout its range (74 FR 52014, October 8, 2009). On May 10, 2011, we published a proposed rule to designate critical habitat for slickspot peppergrass (76 FR 27184). On August 8, 2012, the District Court of Idaho vacated the final rule listing slickspot peppergrass as a threatened species under the Act and remanded the rule to the Service for further consideration consistent with the Court's opinion (
Gov. C.L. “Butch” Otter, et al.
v.
Ken Salazar, et al.,
Case No. 1:11-cv-00358-CWD [D. Idaho]). On February 12, 2014, we concurrently proposed reinstatement of threatened status for the species and a revised proposed designation of critical habitat (79 FR 8416 and 79 FR 8402, respectively). On August 17, 2016, we published a final rule reinstating threatened status for the species under the Act (81 FR 55058). On July 23, 2020, we published an updated revised proposed rule to designate critical habitat (85 FR 44584).

Summary of Changes From the Proposed Rule

Our July 23, 2020, revised proposed critical habitat rule (85 FR 44584) detailed changes from the previous

proposed and revised critical habitat rules (76 FR 27184, May 10, 2011; 79 FR 8402, February 12, 2014). Here, we summarize changes from our July 23, 2020, proposed rule (85 FR 44584) to this final rule resulting from the comments we received during the public comment period, as discussed below under Summary of Comments and Recommendations.

1. We added six new Element Occurrences (EOs) (recorded species locations) that were occupied at the time of listing but had not been evaluated in our proposed rule for physical or biological features (PBFs) essential to the conservation of the species. For this final rule, we determined that these six EOs contained one or more PBFs. See the Criteria and Methodology Used To Identify Critical Habitat section, below, for details.

2. In our proposed rule, we did not include E.O. 57 based on surveys that indicated it did not meet our PBF criteria. However, we re-evaluated the PBFs for E.O. 57 and determined that it contained one or more PBFs; therefore, we are including it in our final critical habitat designation. See the Criteria and Methodology Used to Identify Critical Habitat section, below, for details.

3. We included D-ranked EOs, which represent the lowest ranked occupied EOs. The E.O. alphabetical ranking system measures viability of a species or ecological integrity of the community and was developed by NatureServe (2002, 2020
b
). The Idaho Department of Fish and Game (IDFG) uses this system, and we relied on IDFG rankings to determine if EOs contained one or more PBFs. Our rationale for including D-ranked EOs is provided in the section Criteria and Methodology Used to Identify Critical Habitat, below.

4. We increased the buffer around EOs from 250 meters (m) (820 feet (ft)) to 500 m (1,640 ft). This increase is based on foraging distances of most of the important pollinators of slickspot peppergrass instead of using the foraging distance of a single pollinator (solitary bee), which was how we determined the buffer size in our proposed rule. We provided additional citations on foraging distances of the other pollinator species to support this increase in the section Physical or Biological Features Essential to the Conservation of the Species, below.

5. We excluded approximately 2,736 ha (6,761 ac) of State of Idaho land and 4,508 ha (11,141 ac) of private and municipal (county and city) land from our critical habitat designation under section 4(b)(2) of the Act, as detailed in Considerations of Impacts under Section 4(b)(2) of the Act, below.

6. We clarified our description of the PBFs to provide more context but did not change their meaning. A description of PBFs is in the section Physical or Biological Features Essential to the Conservation of the Species with additional discussion provided under Criteria and Methodology Used to Identify Critical Habitat, below.

7. We deleted “honeybees” from our description of PBF 4 under the
Summary of Essential Physical or Biological Features
and from paragraph (2)(iv) of the rule. Please see Physical or Biological Features Essential to the Conservation of the Species for additional information and citations.

8. We made small, nonsubstantive clarifications and corrections throughout this final rule to ensure consistency, clarify information, reduce redundancy, update scientific names of plants, and update or add new references.

The combined effect of the changes we have made from our July 23, 2020, proposed rule (85 FR 44584) to this final rule result in an increase from a proposed designation of critical habitat of 17,049 ha (42,129 ac) to a final designation of critical habitat of approximately 31,569 ha (78,009 ac). The reasons for this increase are mentioned in the list above and explained more thoroughly in the following sections of the preamble.

Supporting Documents

In 2011, we sought comments from five independent specialists to ensure that our proposed critical habitat designation was based on scientifically sound data and analyses regarding the 2011 proposed rule. We received responses from three of the individuals. In 2020, we completed a species status assessment (SSA) report for slickspot peppergrass. 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.

In accordance with our joint policy on peer review published in the
Federal Register
on July 1, 1994 (59 FR 34270), and our August 22, 2016, memorandum updating and clarifying the role of peer review of listing actions under the Act, we sought peer review of the SSA report. In August 2018, we solicited expert opinion and received responses from four independent specialists with scientific expertise on slickspot peppergrass and its habitat regarding our draft SSA report. The purpose of peer review is to ensure that our critical habitat designations are based on scientifically sound data, assumptions, and analyses. The peer reviewers generally concurred with our methods and conclusions, and provided additional information, clarifications, and suggestions to improve the SSA report. That information was incorporated into the final SSA that informed our proposed and final designation of critical habitat. We also considered all comments and information we received from the public during comment periods for previous proposals (76 FR 27184, May 10, 2011; 79 FR 8402, February 12, 2014; 85 FR 44584, July 23, 2020).

The final economic analysis (dated March 12, 2012), which documents the potential economic effects of the designation, considered all public comments and any new information as of 2011 (IEc 2012).

The final SSA report (USFWS 2020) and final economic analysis (IEc 2012) are available at
https://www.regulations.gov
under Docket No. FWS-R1-ES-2010-0071.

Summary of Comments and Recommendations

In our revised proposed rule published on July 23, 2020 (85 FR 44584), we requested that all interested parties submit written comments on the proposal by September 21, 2020. We also stated in the July 23, 2020, revised proposed rule (85 FR 44584) that comments submitted during the previous comment periods for the May 10, 2011, proposed rule (76 FR 27184) and the February 12, 2014, revised proposed rule (79 FR 8402) would be considered. For all comment periods, we reached out to appropriate Federal and State agencies, Tribes, scientific experts and organizations, and other interested parties and inviting them to comment on the proposal. Newspaper legal notices requesting public comments were published in the Idaho Statesman. We did not receive any requests for a public hearing during any of our comment periods.

During the first comment period (76 FR 27184, May 10, 2011), we received 16 comment letters addressing the proposed critical habitat designation for slickspot peppergrass. Of these comments, 3 were from peer reviewers and 13 were from public organizations or individuals. During the second comment period (79 FR 8402, February 12, 2014), we received 17 comment letters addressing the proposed critical habitat designation or the draft economic analysis. For the most recent comment period (85 FR 44584, July 23, 2020), we received 23 comment letters on the proposed rule to designate

critical habitat for slickspot peppergrass; the majority of commenters supported the designation of critical habitat. All substantive information provided during these comment periods was either incorporated directly into this final rule or is addressed below. Comments that we incorporated as changes in our revised proposed rules (79 FR 8402, February 12, 2014; 85 FR 44584, July 23, 2020) or into this final rule are not presented here or are addressed briefly. In addition, we received comments outside the scope of this rulemaking action such as comments related to threats (
e.g.,
livestock grazing, wildfire, Owyhee harvester ants, nonnative invasive plants, inadequate management practices, pesticides, and off-road vehicle use), conservation measures identified in conservation plans (CCA, State of Idaho et al. 2006; CA, BLM 2014; INRMP, U.S. Air Force 2017), and management actions, or the lack thereof, that commenters believed were a threat to the conservation of slickspot peppergrass; we did not respond to comments that were outside the scope of this rulemaking. Comments regarding threats have been addressed in the slickspot peppergrass final listing rule (74 FR 52014, October 8, 2009), the reinstatement of the listing rule (81 FR 55058, August 17, 2016), and the SSA (USFWS 2020). We consolidated the comments by topic and provide a brief response, below.

Peer Reviewer Comments

We solicited expert opinion in 2011 from five appropriate and independent specialists regarding the May 10, 2011, proposed rule (76 FR 27184). We received input from three of the individuals. Since that time, we have implemented a standard practice of developing an SSA as the scientific foundation to inform our section 4 rulemaking (
e.g.,
listing determinations and recovery plans). In 2018, we initiated the development of an SSA for slickspot peppergrass, and in August 2018, we solicited expert opinion from four independent specialists with scientific expertise on slickspot peppergrass and its habitat regarding our draft SSA report. These four individuals generally concurred with the information and conclusions in the draft SSA report, including our use of data from the Idaho Department of Fish and Game (IDFG) (Kinter and Miller 2016, entire). These data were used extensively in the development of the SSA and in our proposed and final critical habitat rules. Peer review comments are incorporated into the SSA report and this final rule as appropriate.

Comment 1:
One peer reviewer and several commenters expressed concern that the proposed designation of critical habitat did not include D-ranked EOs, (representing the lowest quality extant slickspot peppergrass EOs). The reviewer stated that higher ranked EOs are likely more important to the conservation of slickspot peppergrass; however, the omission of the smaller EOs (which could be ranked lower) from the designation fails to recognize that these populations may harbor genetic variation important to the overall genetic variability of the species. This peer reviewer added that given the prospect of climate change and the continued deterioration of slickspot peppergrass habitat, maintaining and protecting the highest possible levels of genetic diversity may prove important to the long-term survival of the species. Another peer reviewer agreed that several EOs should be added to critical habitat.

Our Response:
After careful consideration of the comments, we are adding D-ranked EOs to our critical habitat designation for this final rule. We present our rationale for adding D-ranked EOs in the Criteria and Methodology Used to Identify Critical Habitat section, below.

Comment 2:
One peer reviewer recommended that we include at least a 250-m (820-ft) area surrounding slickspot peppergrass habitat to ensure that pollinators are able to maintain their populations. In addition, multiple commenters disagreed with information in the proposed rule (85 FR 44584, July 23, 2020) regarding using a 250-m (820-ft) pollinator buffer to reflect a “reasonable mid-point” for the foraging range of a solitary bee when the actual mid-point of the range cited in the proposed rule was 375 m (1,230 ft). Several commenters indicated that a larger buffer (
e.g.,
600-m buffer) would be necessary to include all potential pollinators that might benefit slickspot peppergrass. Conversely, one commenter stated that we should use the shortest flight distance (150 m (492 ft)) of a solitary bee cited in the proposed rule. Another commenter questioned our use of scientific literature (
i.e.,
Steffan-Dewenter et al. 2002; Gathmann and Tscharntke 2002) that used research on solitary bees from study plots in Germany to extrapolate to solitary bees in southern Idaho. They went on to say that these cited works are not proven to be relevant to the sagebrush steppe where slickspot peppergrass is found and, therefore, not the “best science” relevant to the species.

Our Response:
After considering comments and reviewing additional literature, we determined that increasing the buffer around occupied EOs is appropriate. To ensure habitat of sufficient quantity and quality is available to support nesting and egg laying, feeding, and reproduction of slickspot peppergrass's pollinators, we increased the buffer around each EO from 250 m (820 ft) to 500 m (1,640 ft) based on our consideration of the foraging ranges of all important pollinators of slickspot peppergrass and not solely on the foraging range of a medium-sized solitary bee. Additional information and citations to support this increase in the buffer can be found in the section, Physical or Biological Features Essential to the Conservation of the Species, below.

Regarding our use of peer-reviewed literature based on research conducted in Germany, we used the best available scientific information on pollinator foraging ranges. Although the studies were conducted in Germany and not in sagebrush-steppe habitat, the information pertained to flight distances based on bee body size, which we can extrapolate to similarly sized bees occurring in sagebrush-steppe habitat.

Comment 3:
One peer reviewer commented that the 250-m (820-ft) area around EOs may not adequately protect adjacent suitable slick spots to allow slickspot peppergrass populations to shift or expand as conditions allow within current EOs and recommended increasing the buffer to 500 m (1,640 ft). In addition, this reviewer and several commenters recommended including unoccupied slick spots that border proposed critical habitat areas. Another peer reviewer proposed including more of the identified slickspot peppergrass habitat (slick spots present) in the Mountain Home Area in Idaho as critical habitat. This same reviewer also stated their opinion that more habitat needs to be designated to address fragmentation, ensure pollination, and maintain genetic diversity.

Our Response:
Based on the best scientific information available, we are designating EOs that are currently occupied by slickspot peppergrass (
i.e.,
EOs B-D) as well as increasing the buffer around each occupied EO. The increased buffer will ensure habitat of sufficient quantity and quality is available to support the nesting, feeding, and reproduction for pollinators of slickspot peppergrass in occupied slick spots. We are not designating any areas outside the geographical area occupied by the species at the time of listing because we did not identify any

unoccupied areas that were essential for the conservation of the species.

Comment 4:
One peer reviewer recommended we include two recently discovered EOs as critical habitat to allow for more connectivity. In addition, several commenters requested that new EOs found during surveys from 2017-2020 and reported by the Bureau of Land Management (BLM) be included in our critical habitat designation.

Our Response:
After receiving several comments on newly identified EOs that were discovered during surveys by the BLM between 2016 and 2018, we identified nine EOs in IDFG's Idaho Fish and Wildlife Information System (IFWIS) database that were unranked. At our request, the IDFG reviewed all nine of the EOs. Six of the EOs (EOs 122 (Unit 3a), and 123, 124, 727, 728, 729 (Unit 4)) had enough associated information for the IDFG to conduct their ranking process. All six met our criteria for critical habitat as defined by the PBFs essential to the conservation of the species. EO 122 was occupied at the time of listing (2016). The other five EOs were found in 2017 and were likely occupied at the time of listing because these slick spots had not been surveyed prior to 2017, and slickspot peppergrass is not likely to colonize new areas to the extent to which these EOs were populated (number of plants ranged from 13 to 766 per EO) within a year. Therefore, all six EOs are included in our final critical habitat designation. We did not include the remaining three EOs (EOs 730, 731, and 732) in Unit 4 because they lacked enough information to be ranked according to IDFG's criteria, which we rely on to determine if an EO has one or more PBFs.

State Comments

Comment 5:
The State of Idaho commented that in 2019 the IDFG relocated slickspot peppergrass at EO 114 and mapped additional plants about 3 kilometers (km) (1.9 miles (mi)) to the southeast based on a 1911 herbarium collection. Another commenter stated that the proposed critical habitat polygons imply that slickspot peppergrass populations do not exist in significant numbers outside the defined area. They went on to cite examples where additional occupied slick spots were found during IDFG surveys (Miller and Kinter 2018, pp. 5, 7; Miller and Kinter 2019, p. 5). The commenter further stated that unless we use supporting research to delineate critical habitat boundaries, any boundaries we designate would be arbitrary.

Our Response:
For this final rule, we used the most current EO data from the IDFG (IFWIS July 2021). As discussed above in our response to
Comment 4
and in Criteria and Methodology Used To Identify Critical Habitat, we also added six new EOs to our critical habitat designation that were in the IDFG database but had not been ranked by IDFG biologists. And while some uncertainty will always exist, the information used in this final rule represents the best available scientific information upon which to make a critical habitat designation for slickspot peppergrass. Further, survey and monitoring work for this species and its habitat will continue into the future and is not limited to critical habitat boundaries. Additional occupied habitat identified during future surveys would be considered during section 7 consultations if there is a Federal nexus (
i.e.,
any action funded, authorized (permitted), or carried out by a Federal agency) and in our recovery efforts for the species. Please refer to the Background section, below, for further discussion.

Comment 6:
The State and one other commenter remarked that the proposed rule (85 FR 44584, July 23, 2020) states that for an EO to fulfill the criteria described in PBF 1, both the slick spot geological feature needs to be present (PBF 1(a)), and the site needs to contain sparse vegetation with absent, or limited to low to moderate, invasive nonnative plant cover (PBF 1(b)). The commenters stated that based on the habitat description associated with EOs ranked C and below, we are proposing to include some EOs that do not meet PBF 1(b). Without both of these features, the EO does not meet PBF 1 in its entirety and, therefore, does not meet our definition of an ecologically functional slick spot. In addition, the commenters stated that providing “one” PBF is not sufficient and if, for example, the slick spot is ecologically functional (PBF 1a and 1b) but is not surrounded by relatively intact sagebrush (PBF 2), then the interdependent habitat requirements are also not met.

Our Response:
The IDFG EO rankings do not necessarily correlate directly to the PBFs. For example, as described in the
Summary of Essential Physical or Biological Features,
below, PBF 1(b) states that ecologically functional microsites or “slick spots” are characterized by sparse vegetation, with introduced, invasive, nonnative plant species cover absent or limited to low to moderate levels. However, the IDFG EO rankings do not directly measure invasive, nonnative plant cover within the actual slick spot. The assessments of condition were based mostly on the EO habitat surrounding the slick spots, which tended to be more invaded than the slick spots. So, even if a habitat ranking was characterized as being moderately to highly invaded, the slick spots themselves often had very low amounts of invasive species (Kinter 2020, pers. comm.). Therefore, we used the IDFG EO rankings, which constitute the best available information that we have, as surrogates to help us determine which EOs provide the PBFs essential to the conservation of the species that may require special management considerations or protections. In addition, although some of the EOs with lower ranks (CD- and D-ranked EOs) often have PBFs with degraded conditions and may require special management considerations or protection, we determined that including these lower ranked EOs is essential to the conservation of the species. The Criteria and Methodology Used To Identify Critical Habitat section, below, of this final rule has been revised to reflect these clarifications.

As stated in the proposed rule (85 FR 44584, July 23, 2020), and in this final rule, areas are included in critical habitat if they contain one or more of the PBFs; PBFs do not have to occur simultaneously to constitute critical habitat for slickspot peppergrass.

Comment 7:
The State and two commenters (Owyhee County Commissioners and a private landowner) stated that all EOs and sub-EOs that were assigned a condition or landscape factor rank of C, CD, or D based on either Miller and Kinter's Snake River Plain and Adjacent Foothills 2018 report or Miller and Kinter's Jarbidge Geographic Area 2019 report should not be designated as critical habitat. They added that the EO assessments in the 2018 and 2019 reports provide context to the 2016 rankings in many EOs and that these assessments should be used to determine whether an EO meets the PBF criteria. They further state that the 2018 and 2019 documents support the need to eliminate more areas of proposed critical habitat as not meeting PBFs. They also state that population size is not described as a PBF but is still one of three factors determining an EO rank in the IDFG assessment with some EOs most likely having a higher rating due to the population size, and not because of the quality of the habitat itself. The State of Idaho questioned if these habitats are essential for the conservation of the species, noting that the occupied status of these EOs is not in question, but whether the habitat truly meets the PBF criteria based on site conditions detailed in the 2018 and

2019 reports (Miller and Kinter 2018 and 2019, entire).

Our Response:
For our July 23, 2020, revised proposed rule (85 FR 44584) for slickspot peppergrass, we relied on information provided by the IDFG that provided their most up-to-date assessments for slickspot EOs, including updated EO ranks (Kinter and Miller 2016, entire). Information contained in the 2016 report was from field surveys conducted from 2012 through 2016. Miller and Kinter's 2018 report includes the details of their field surveys from 2012 through 2016 for the Foothills and Snake River Plain Geographic Areas. Miller and Kinter's 2019 report also includes the details of their field surveys during the period 2014-2015 for the Jarbidge Geographic Area. The 2016 report was a summary of all field surveys and contained the updated EO ranks that were derived from data collected during the above-mentioned survey periods. While supplemental information was considered, the EO ranks reported in the 2016 report represent the best available scientific data from which we made our final critical habitat determination.

As the commenters noted, a portion of the EO ranking score was based on the EO/sub-EO size. While EO size is not identified as a specific PBF, population size does contribute to the resiliency of a species; therefore, we clarified in the Criteria and Methodology Used To Identify Critical Habitat section, below, that we used the IDFG rankings as surrogates to help us determine which EOs provide the PBFs essential to the conservation of the species that may need special management. Also, please see our response to
Comment 7.

With respect to the State's comment regarding which EOs meet our definition of critical habitat, based on comments received during the public comment period on our revised proposed critical habitat rule (85 FR 44584, July 23, 2020), we reevaluated our criteria for determining which EOs contain PBFs and meet our definition of critical habitat. The proposed rule did not include EOs ranked D or lower; however, in this final rule we included all areas that were occupied at the time of listing that are ranked B-D (there are currently no EOs ranked A or AB). Our rationale for including D-ranked EOs is provided in the Criteria and Methodology Used To Identify Critical Habitat section, below.

Comment 8:
The State of Idaho commented that, because private lands cannot be subject to management actions and conservation measures through the Endangered Species Act unless there is a Federal nexus resulting in section 7 consultation, the proposed critical habitat rule (85 FR 44584, July 23, 2020) provides no new conservation measures across any of the sites, whether Federal, State, or privately owned. They also stated that management actions through section 7 consultation will not effectively address the threats of wildfires and invasive species on private lands. Lastly, they commented that designation of critical habitat on private land can lead to decreased land values and possibly expose slickspot peppergrass to threats that cannot be addressed by a section 7 consultation. Given these reasons, the State believes that the benefits of exclusion (from critical habitat designation) outweigh the benefits of inclusion on private land.

Our Response:
As detailed in the Considerations of Impacts Under Section 4(b)(2) of the Act section of this document, below, based on our evaluation of the available information, we determined that the benefits of excluding private lands outweighed the benefits of including them in our critical habitat designation; therefore, we excluded private land from the final designation. Activities with a Federal nexus that may affect slickspot peppergrass plants on private land will still require section 7 consultation under the Act. Actions that may affect slickspot peppergrass plants on private lands without a Federal nexus do not require section 7 consultation with the Service.

As a conservation tool, a critical habitat designation ensures that when actions with a Federal nexus are proposed within critical habitat, the Federal action agency reviews the proposed action and, if needed, consults with the Service to determine if the action will adversely modify critical habitat. Critical habitat does not require a Federal agency or a private landowner proposing an action with a Federal nexus to perform any conservation actions, although the Service and the Federal action agency may identify conservation recommendations that can be voluntarily implemented.

Comment 9:
The State of Idaho and multiple commenters stated that there are additional administrative costs of section 7 consultation that are incurred under critical habitat designation, including land-value depreciation. In addition, the State commented that the economic analysis did not consider economic impacts to livestock permittees from delaying the spring grazing season, indirectly eliminating grazing by lowering turnout and, therefore, opportunity costs to private and State endowment lands. Several other commenters urged the Service to undertake an in-depth consideration of the potential impacts of the critical habitat designation on the economy of the affected areas. One commenter expressed concern that the economic analysis did not capture the potential significant impacts on affected livestock permittees of the implementation of existing livestock-grazing conservation measures.

Our Response:
According to section 4(b)(1)(A) of the Act, the listing of a species as threatened or endangered is a decision made based “solely on the basis of the best scientific and commercial data available.” However, in the case of designating critical habitat, the Act requires additional considerations under section 4(b)(2) including the economic, national security, and other impacts of designating a particular area as critical habitat. Because of this distinction, we must analyze the effects of a critical habitat designation separate from any effects that may result from the listing of a species. To do so, our guidelines for economic analyses of proposed critical habitat designations, developed in accordance with the recommendations set forth in Executive Order 12866 (“Regulatory Planning and Review”), describe the need to measure the benefits and costs of a rule against a baseline.

The analysis of economic impacts of a critical habitat designation involves evaluating the baseline condition under two scenarios: one with critical habitat and one without critical habitat. The impacts of critical habitat equal the difference, or “increment,” between these two scenarios. This is known as an “incremental analysis.” Measured differences may include changes in land or resource use, environmental quality, or time and effort expended on administrative and other activities by Federal landowners, Federal action agencies, State and local governments, or private third parties. Any differences that are attributable solely to critical habitat are considered an incremental impact of the designation. Most of the examples of impacts offered by commenters were effects attributable to other conservation measures for slickspot peppergrass that are already in place because of the listing of the species (
e.g.,
delaying turnout of cattle when soils are saturated) and not due to critical habitat; such effects cannot be considered an impact of critical habitat.

Currently, and as described in our final economic analysis, we do not foresee a circumstance in which designation of critical habitat will change the outcome or alter the timing

of future Federal agency section 7 consultations. Any conservation measures implemented to minimize impacts to the species would likely be sufficient to also minimize impacts to critical habitat.

Comment 10:
The State of Idaho commented that the Idaho Department of Lands (IDL) was part of the 2006 Candidate Conservation Agreement (CCA) for slickspot peppergrass ensuring habitat is protected on Idaho endowment lands, which negates the need for critical habitat designation. In addition, the State commented that even though the CCA has expired, the IDL continues to implement conservation measures outlined in the 2006 CCA.

Our Response:
As described in our response to
Comment 9,
above, we have a statutory obligation to designate critical habitat for listed species, based on the identification of those areas occupied by the species at the time of listing, that provide the PBFs essential to the conservation of the species, and that may require special management considerations or protection. However, the Act additionally provides the Secretary discretion to exclude areas from the final designation if the benefits of excluding those areas outweigh those of including them (and if such exclusion will not result in the extinction of the species). As detailed in Considerations of Impacts Under Section 4(b)(2) of the Act below, following our review and evaluation of the best available information, including the new 2021 conservation agreement between the Service and the State of Idaho, we agree that the benefits of excluding areas on State of Idaho lands outweigh the benefits of including those areas in critical habitat, and we have excluded all State-owned lands from this final designation of critical habitat. This includes the State of Idaho endowment trust lands, management of which is entrusted to the State Board of Land Commissioners. The IDL is the administrative arm of the Board and carries out the executive directives of the Board to meet the constitutional trust mandate under article IX section 8 of the Idaho Constitution to use the trust lands for the support of State institutions.

Comment 11:
The State of Idaho commented that several areas along Idaho Department of Transportation rights-of-way (ROWs) are critical to reduce the potential for fire starts from Interstate 84. They further stated that the proposed designated critical habitat within these ROWs puts large areas that have slickspot peppergrass outside of the ROW at risk by potentially affecting the ability to implement mowing and other preventative measures needed to halt fire starts from the Interstate.

Our Response:
Rights-of-way (ROW) on Federal lands are not excluded from critical habitat designation if they contain one or more of the PBFs described within the final rule and are part of an EO ranked B, BC, C, CD, or D or are within 500 m (1,640 ft) of those EOs. If an area is designated as critical habitat, and there is a Federal nexus associated with an ROW project, a section 7 consultation in this area would evaluate the presence of any PBFs and note whether there are effects from the action that may affect critical habitat. During emergency events, the primary objective of the responding agency must be to protect human life and property, and this objective takes precedence over normal consultation requirements. In such events, agencies can engage in emergency section 7 consultation with the Service to expedite recommendations for minimizing adverse effects to listed species and designated critical habitat areas that may be adversely affected by emergency response activities.

Tribal Comments

Comment 12:
The Shoshone-Bannock Tribes asked that the Service consider ecological range characteristics, rather than simply presence of slickspot peppergrass, when designating critical habitat and cited examples (
e.g.,
climate, elevation, soil characteristics, solar irradiance, and community species composition characteristics), as drivers for potential and occupied habitat. They indicated that this type of scientific analysis would not result in the small and highly fragmented critical habitat unit maps being proposed, and the analysis may help the Service identify new EOs. They added that slickspot peppergrass needs additional critical habitat outside the proposed critical habitat units to facilitate spread and colonization. Further, the Tribes and one additional commenter stated that surveys for additional habitat should continue, as well as high-quality and experimentally designed monitoring programs.

Our Response:
Please see our responses to
Comments 1-3.
In response to the comment regarding more survey, monitoring, and analysis being needed, 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. We must make this designation on the basis of the information available at this time, and we may not delay our decision until more information about the species and its habitat is available. This final rule expands on the proposed critical habitat by including areas with D-ranked EOs, which represent the lowest ranked occupied EOs, and increasing the buffer around EOs from 250 meters (m) (820 feet (ft)) to 500 m (1,640 ft) in order to provide habitat for all of the important pollinators of slickspot peppergrass.

While some uncertainty will always exist, the information used in this final rule represents the best available information upon which to make a critical habitat designation for slickspot peppergrass. It also does not preclude future survey, monitoring, and analyses for this species and its habitat, and it is not limited to critical habitat boundaries. We will be developing a recovery plan with input from stakeholders and partners that will establish priorities and measures to recover the species, and which will consider ecological range characteristics and address habitat fragmentation. During the recovery planning process, a range of conservation tools, data, and analyses will be used to determine how best to recover the species.

Comment 13:
The Shoshone-Bannock Tribes commented that grazing should not be allowed within occupied habitat if necessary to protect the species from extinction. They stated that the best way to manage grazing use on public lands is to implement strong management goals and objectives that maintain high-quality biological soil crust communities and enhance degraded biological soil crust communities where they have been impacted from grazing and surface disturbances.

Our Response:
We will be developing a recovery plan with input from stakeholders and partners that will establish priorities and measures to recover the species. These priorities will include measures to prevent or reduce habitat degradation and will set goals to facilitate the recovery of the species. Furthermore, the BLM's conservation agreement (BLM 2014) outlines conservation measures for ongoing actions authorized by the BLM including livestock grazing, rights-of-way activities, and military training. These conservation measures currently apply to slickspot peppergrass EOs and the surrounding area out to 805 m (2,641 ft).

Public Comments

Comment 14:
One commenter stated that the Service failed to describe how many plants are present in each EO.

Our Response:
We did not include the number of plants in the proposed rule (85 FR 44584, July 23, 2020) because we

did not rely solely on the number of plants in an EO. Instead, we followed an EO ranking method developed by NatureServe (NatureServe 2020
b,
entire) and used by the IDFG to rank EOs that combined measures of population size and habitat quality; therefore, we did not provide the number of plants in the EO descriptions.

Comment 15:
One commenter expressed concern that designating slickspot peppergrass critical habitat for those EOs with rankings of CD or better continues to set the stage for additional habitat loss in future assessments. They followed with this example, “if an EO with a C ranking now is found to have a D rank in 3-5 years, it is not clear whether the USFWS would strip the critical habitat designation from the particular EO.”

Our Response:
In this final rule, we are designating all occupied EOs ranked B-D as critical habitat. If, in subsequent years, an EO is no longer found to be occupied, and it no longer contains the essential PBFs, it would still be part of the critical habitat designation. A future section 7 consultation in this area would evaluate the presence of any PBFs and note whether or not there are effects from the action that may affect the critical habitat. If we revise the critical habitat designation in the future, we would take into consideration where the species is present (occupied habitat) and whether any PBFs are present in any area at the time of that revision.

Comment 16:
One commenter stated that the 250-m (820-ft) area be a guideline rather than a fixed rule so that it could be reduced when it would include unsuitable habitat, such as roads, cropland, or ecological sites without slick spots. The commenter also remarked that crossing allotment boundaries when slick spots are not present in adjacent allotments needlessly complicates the management of the adjacent allotment.

Our Response:
As described in this final rule, the designation of critical habitat does not include roads or other developed sites such as cropland, airports, and buildings. When determining critical habitat boundaries within this final rule, we made every effort to avoid including these types of developed areas because such lands lack the PBFs for slickspot peppergrass. The scale of the maps we prepared under the parameters for publication within the Code of Federal Regulations may not perfectly reflect the exclusion of such developed lands. However, any such lands inadvertently left inside critical habitat boundaries shown on the maps of this final rule have been excluded by text in the rule and are not designated as critical habitat.

In reference to grazing allotment management, areas are included in critical habitat if they are occupied by slickspot peppergrass (
i.e.,
EOs B-D) or are within the additional 500-m (1,640-ft) pollinator buffer area of those EOs. Furthermore, we do not anticipate or foresee any changes to conservation measures currently in place for livestock use. When projects proposed on BLM lands may affect listed species or critical habitat, consultation with us is required under section 7(a)(2) of the Act. Currently, we do not foresee a circumstance in which critical habitat will change the outcome of future section 7 consultations as all areas designated as critical habitat are also included in BLM section 7 consultations addressing the effects of actions on the species.

Comment 17:
One commenter stated that the polygons associated with Unit 2, Subunit 2a in Ada County are widely dispersed, covering multiple Sections, Townships, and Ranges and that designating the entire subunit as critical habitat made little sense considering the wide distribution of plant EOs and the significant amount of residential and commercial development that occupied the spaces between populations.

Our Response:
The critical habitat units are based on geographically clustered EOs that meet our definition of critical habitat. Only occupied EOs and their associated buffers are being designated as critical habitat. In our proposed rules, we displayed critical habitat surrounded by rectangular polygons on our unit and subunit maps, which led to confusion about what was actually the designated critical habitat. In our final rule, we updated our maps by eliminating the rectangular polygons so that only critical habitat is displayed.

Comment 18:
One commenter responded that the Service recently issued a proposed rule on defining habitat due, in part, to a decision by the U.S. Supreme Court in
Weyerhaeuser Co.
v.
U.S. FWS,
139 S. Ct. 361 (2018) and was concerned that this proposed definition of habitat was not included in our July 23, 2020, revised proposed rule (85 FR 44584) for slickspot peppergrass.

Our Response:
As stated in the revised regulations regarding the definition of habitat (85 FR 81411, December 16, 2020), these regulations apply only to critical habitat rulemakings for which a proposed rule is published after January 15, 2021. We published our revised proposed critical habitat rule for slickspot peppergrass on July 23, 2020 (85 FR 44584). Therefore, the revised regulations regarding the definition of habitat do not apply to this final critical habitat rule for slickspot peppergrass. Furthermore, we rescinded the habitat definition on June 24, 2022 (87 FR 37757) with an effective date of July 25, 2022.

Comment 19:
One commenter stated that critical habitat should not be designated for slickspot peppergrass because any “official designation” is meaningless for the preservation of the species in the face of its primary threats: fire and invasive species. The commenter added that slickspot peppergrass is a BLM- and State of Idaho-sensitive species and that areas containing slickspot peppergrass already receive priority status for fire-fighting activities; therefore, the designation of critical habitat will not increase BLM's (and others') ability or willingness to extinguish fires. The commenter concluded that because there would be no change in how the primary threats are managed, section 7 consultation is meaningless.

Our Response:
We designate critical habitat by identifying the areas that are essential to the conservation of the species based on our understanding of the range of the species and the species' essential PBFs. If an area meets those criteria for designating critical habitat, we develop proposed critical habitat unit designations. In addition, even if the designation of critical habitat will not increase an action agency's ability to conserve the species, the designation itself is still prudent because the areas meet the definition of critical habitat and there are habitat-based threats within the critical habitat boundaries.

Comment 20:
One commenter stated that the rulemaking should include a provision, to the extent permitted by the Act, that any EOs that are burned by wildfire, so that they no longer contain the necessary combinations of habitat PBFs, are automatically not considered to be critical habitat from the date of the fire and continuing until further rulemaking on the subject.

Our Response:
Section 3 of the Act defines critical habitat, in part, as having PBFs that are essential to the conservation of the species, which may require special management considerations or protection. If an area is designated as critical habitat and is subsequently burned by wildfire such that it no longer contains the essential PBFs, it would still be part of the critical habitat designation but may need special management to restore some of the PBFs.

Comment 21:
One commenter stated that there is no science demonstrating that any management considerations or methods of protections will significantly

affect the survivability of slickspot peppergrass populations. They stated that we lack information on the essential features to support slickspot peppergrass, and, without knowledge of the soil chemistry at a specific location, designation of critical habitat will be arbitrary since that area (
i.e.,
slick spot) may or may not contain the essential features.

The commenter also questioned what science there is to demonstrate that slickspot peppergrass pollination and seed production is different between adjacent sagebrush habitat and non-sagebrush habitat and requested information that substantiates the necessity to include adjacent sagebrush habitat in the critical habitat designation.

Our Response:
As required by section 4(b)(2) of the Act, we used the best scientific data available in determining those specific areas within the geographic area occupied at the time of listing that contain the features essential to the conservation of slickspot peppergrass and that may require special management considerations or protection. We have reviewed and considered scientific and commercial data contained in numerous technical reports, peer-reviewed published journal articles, and other documents and based our determination of slickspot peppergrass PBFs (including ecologically functioning microsites) on the best available data regarding the plant's currently known habitat requirements (See Physical or Biological Features Essential to the Conservation of the Species, below, for more information). We acknowledge that not all slick spots contain slickspot peppergrass. Therefore, based on the best scientific information available to us at this time, we limited the critical habitat designation to areas known to be occupied by the species (including some adjacent sagebrush-steppe habitat to provide for ecosystem function). While we also acknowledge that slickspot peppergrass has been infrequently documented outside of slick spots, the vast majority of plants documented over the past 25 years of surveys and monitoring for the species are documented within slick spot microsite habitats. For more information on slick spot microsites, please see the 2009 listing rule (74 FR 52014, October 8, 2009) and the slickspot peppergrass SSA report (USFWS 2020, pp. 4, 6).

Comment 22:
One commenter stated that the Service has not adequately considered a broad body of current data (including GIS data for native and nonnative vegetation, soils, development, etc.) available on the degree and severity of habitat degradation that currently exists (citing information used by the BLM in their Land Use Plans), or used site-specific information on the current road, livestock, energy, or other infrastructure and management schemes that are being applied within the critical habitat designation. The commenter stated that the proposed rule designates “bits and pieces” of critical habitat, which the commenter states will promote additional fragmentation, make management of critical habitat difficult and less economically feasible, and encourage more harmful fences and other developments.

Our Response:
Regarding the ecological setting of slickspot peppergrass, the species' habitat is inherently fragmented because it relies on isolated and non-contiguous slick spot habitats. We identified areas within the geographic range of slickspot peppergrass that were occupied at the time of listing and contain the PBFs essential to the conservation of the species that may require special management considerations or protection. Please see Criteria and Methodology Used to Identify Critical Habitat, below, for more details on how critical habitat was determined. Regarding the comment that we did not use site-specific information on the current road, livestock, energy, or other infrastructure and management schemes that are being applied within the critical habitat designation, and the commenter's statements regarding the BLM Land Use Plans, we will work with the BLM to avoid or minimize these potential impacts during future section 7 consultations, as appropriate, and recommend the BLM take these potential impacts into consideration when developing their management plans.

On Federal land, it is the responsibility of the appropriate land management agency to develop and implement resource management plans. Projects with a Federal nexus would require section 7 consultation under the adverse modification standard if they affected designated critical habitat (see the
Section 7 Consultation
section, below, for more discussion of this process). However, if project-related effects may occur, areas occupied by slickspot peppergrass would require section 7 consultation whether the area is designated as critical habitat or not. In addition, as part of developing and implementing a recovery strategy for a listed species, we consider site-specific management strategies important to the conservation of the species, and we also work with landowners, managers, researchers, and others to develop and implement them, as appropriate, as part of the recovery process.

Comment 23:
One commenter stated that projected and reasonably likely impacts of climate change on slickspot peppergrass are unknown, as is the response to climate change by slickspot peppergrass. The commenter added that future climate change is only a hypothesis based on non-validated models, which cannot be proven. Conversely, two other commenters stated that climate change is expected to exacerbate several of the primary threats to slickspot peppergrass, and it is essential that a much greater area (including occupied and unoccupied habitat and areas located at the highest elevations available) be protected to ensure the species' viability and aid efforts to buffer the species from adverse climate change impacts. They also stated that it is hypothesized that slick spots were created during the Pleistocene and are no longer being formed and, therefore, all remaining slick spots should be protected. The commenter also noted that climate change is not mentioned in the body of the July 23, 2020, revised proposed critical habitat rule (85 FR 44584).

Our Response:
As described in our February 2020 slickspot peppergrass SSA report (USFWS 2020, pp. 79-83), it is possible that climate change has contributed to the downward trend in slickspot peppergrass population numbers observed over the past decade and the projected consequences of climate change could act to further exacerbate the primary threats of frequent wildfire and invasive, nonnative annual grasses on slickspot peppergrass throughout its range. After considering the best available information as well as the comments received, we are now including all occupied EOs ranked B-D and extending the buffer around EOs from 250 m (820 ft) to 500 m (1,640 ft)). In addition, we are including six newly ranked EOs; five are located in the Jarbidge geographic area, which contains the highest elevation habitat. In Criteria and Methodology Used to Identify Critical Habitat, below, we provide our rationale for making these changes.

Regarding the comment about climate change not being addressed in our July 23, 2020, revised proposed rule (85 FR 44584), we have included a brief discussion in our Criteria and Methodology Used to Identify Critical Habitat section, below. Information identified in the SSA indicates that climate change has already amplified the effects of wildfire and invasive,

nonnative plants on slickspot peppergrass and may have been a factor in the continuing downward trend in slickspot peppergrass population numbers observed over the past decade. Habitat is often dynamic and species may move from one area to another over time, but most plant species cannot naturally shift their geographic ranges fast enough to keep up with predicted high projected rates of climate change. The Intergovernmental Panel on Climate Change (IPCC) projects changes to the global climate system in the 21st century will likely be greater than those observed in the 20th century (IPCC 2007, p. 45; IPCC 2014, pp. 10, 60). However, by designating critical habitat in all three geographic areas (Foothills, Snake River Plain, and Jarbidge) where the species occurs, including all B-D ranked EOs as well as the 500-m (1,640-ft) pollinator buffer around designated EOs, we determined that these areas will help support slickspot peppergrass under potential climate change scenarios in the future. A complete description of the potential effects from climate change and our evaluation of this threat is found in the October 8, 2009, final listing rule (74 FR 52014), the August 17, 2016, listing reinstatement rule (81 FR 55058), and our February 2020 slickspot peppergrass SSA report (USFWS 2020, pp. 79-83).

In addition, 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 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 required for recovery of the species. Areas that are important to the conservation of slickspot peppergrass, both inside and outside a critical habitat designation, would 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 of section 9 of the Act if actions occurring in these areas may affect the species.

Comment 24:
Two commenters did not support the section 4(a)(3)(B)(i) exemptions for the Mountain Home Air Force Base Juniper Butte Range and the Idaho National Guard Army OCTC due to the growing presence of military activity in southern Idaho, increasing threats from military uses, and potential spread of weeds from personnel accessing sites. One of the commenters stated that the OCTC and the Juniper Butte Range should be included in the critical habitat designation.

Our Response:
The National Defense Authorization Act for Fiscal Year 2004 (Pub. L. 108-136, 117 Stat. 1392) amended the Act, specifically, section 4(a)(3)(B)(i) (16 U.S.C. 1533(a)(3)(B)(i)) to provide that: “The Secretary shall not designate as critical habitat any lands or other geographic areas owned or controlled by the Department of Defense (DoD), or designated for its use, that are subject to an integrated natural resources management plan prepared under section 101 of the Sikes Act (16 U.S.C. 670a), if the Secretary determines in writing that such plan provides a benefit to the species for which critical habitat is proposed for designation.” Both the Mountain Home Air Force Base Juniper Butte Range (and associated emitter sites and rights-of-way) and the Idaho Army National Guard OCTC facilities have INRMPs prepared under section 101 of the Sikes Act. We determined that conservation efforts identified in these INRMPs are being implemented, are effective, and will provide a conservation benefit to slickspot peppergrass occurring in habitats within or adjacent to the identified lands. Examples of slickspot peppergrass conservation benefit within these INRMPs can be found in the Exemptions,
Application of Section 4(a)(3) of the Act
section below. Therefore, lands within these two installations are exempt from critical habitat designation under section 4(a)(3)(B)(i) of the Act, and we do not have the discretion to include them as the commenter recommends.

Comment 25:
One commenter stated that the monetary and security costs to the Idaho Army National Guard and U.S. Air Force from designating slickspot peppergrass critical habitat in their training ranges is not captured in the 2012 final economic analysis.

Our Response:
We exempted, under section 4(a)(3)(B)(i) of the Act, the Idaho Army National Guard's Orchard Combat Training Center (OCTC) and U.S. Air Force's Juniper Butte Range from the critical habitat designation based on development and implementation of approved INRMPs. Given these areas are exempt from critical habitat designation, there are no associated incremental costs of critical habitat designation to consider in the economic analysis. Therefore, any costs to the Idaho Army National Guard and U.S. Air Force are due to the listing of slickspot peppergrass, not designation of critical habitat, and thus will not be discussed in this final rule. Please see the Exemptions,
Application of Section 4(a)(3) of the Act,
section of this final rule for further information.

Comment 26:
One commenter stated that the economic analysis completed in March 2012 does not reflect accurate, timely, or most recently available data. The commenter recommended that we conduct a current economic analysis that takes a growing population, increased development, climate change, and the economics of restricting livestock grazing in and around critical habitat EOs into consideration.
Our Response:
In the 2020 revised proposed critical habitat rule and in the
Exclusions Based on Economic Impacts
section of this rule, we articulate the reason why the incremental economic impacts of our current revised proposed designation of critical habitat for slickspot peppergrass will be similar to levels described in the 2012 final economic analysis. The BLM indicated that any increase in cost associated with critical habitat section 7 compliance would be limited to increases in BLM staff costs, which have been minimal since 2012 when the economic analysis was completed, but not an increase in time needed to conduct section 7 compliance (Kershaw 2020, pers. comm.). Unless unforeseen changes occur to existing conservation measures or the management of land-use activities, the incremental impacts of critical habitat designation described in the 2012 final economic analysis would continue to be limited to additional administrative costs of section 7 consultations for Federal agencies, primarily BLM, associated with considering the potential for adverse modification of critical habitat.

In this final rule, we are also excluding State and private lands from designation of critical habitat. Therefore, there are no section 7 critical habitat consultation requirements on those lands, although they will still be subject to section 7 consultation on the species if there is a Federal nexus. Therefore, we still find that the conclusion of the 2012 final economic analysis applies to this final rule.

Comment 27:
One commenter stated that Federal oversight is required to conserve slickspot peppergrass, and that State of Idaho or private lands should not be excluded given that the agreements typically relied upon are voluntary and unenforceable. This commenter also said that reluctance by private landowners to allow access to slickspot peppergrass habitat will only further ensure that no oversight is possible.

Our Response:
The Act provides the Secretary with discretion to exclude

areas from the final designation if the benefits of excluding those areas outweigh those of including them (and if such exclusion will not result in the extinction of the species). As detailed in the Considerations of Impacts Under Section 4(b)(2) of the Act section, below, based on our review and evaluation of the best available information, we conclude that the benefits of excluding areas on State of Idaho and private lands outweigh the benefits of including those areas in critical habitat. We therefore excluded all State and private lands from the final critical habitat designation.

Comment 28:
Two commenters stated that our revised proposed rule cited several documents (
e.g.,
Gathmann and Tscharntke 2002; Steffan-Dewenter et al. 2002; Kinter and Miller 2016) to support our findings, but our document did not provide a list of references. They recommended that these references be added when the revised proposed rule is finalized.

Our Response:
All references cited in our revised proposed rules and our final rule are available on the internet at
https://www.regulations.gov
in Docket No. FWS-R1-ES-2010-0071 and upon request from the Idaho Fish and Wildlife Office. All references for our July 23, 2020, revised proposed rule (85 FR 44584), including the three references cited as examples in the comment above, can be found by going to
https://www.regulations.gov/document/FWS-R1-ES-2010-0071-0065
and downloading the “Download File”. However, Gathmann and Tscharntke (2002) was incorrectly cited as “Achim Gathmann, A. and T. Tscharntke” and, therefore, was out of alphabetical order in our list of references. We corrected this mistake in our final rule references list.

Comment 29:
Several commenters questioned whether the Service was following its own Information Quality Act procedures.

Our Response:
We have reviewed and considered scientific and commercial data contained in numerous technical reports, published journal articles, and other documents. We must base our critical habitat designation for slickspot peppergrass on the best available scientific data. We acknowledge that uncertainties exist; however, section 4 of the Act mandates that we make our designation based on the best scientific information available at the time of our determination. We have designated critical habitat for slickspot peppergrass consistent with 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, to ensure that our decision is based on the best scientific data available.

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 under section 3 of the Act, means to use and 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. Such methods and procedures include, but 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 also 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 PBFs that are essential to the conservation of the species (such as space, food, cover, and protected habitat).

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.

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, or other species conservation planning efforts if new information available at the time of these planning efforts calls for a different outcome.

Physical or Biological Features Essential to the Conservation of the Species

In accordance with section 3(5)(A)(i) of the Act and regulations at 50 CFR 424.12(b), in determining which areas we will designate as critical habitat from within the geographical area occupied by the species at the time of listing, we consider the PBFs that are essential to the conservation of the species and that may require special management considerations or protection. The regulations at 50 CFR 424.02 define “physical or biological features essential to the conservation of the species” as the features that occur in specific areas and that are essential to support the life-history needs of the species, including, but not limited to, water characteristics, soil type, geological features, sites, 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. For example, physical features essential to the conservation of the species might include gravel of a particular size required for spawning, alkaline soil for seed germination, protective cover for migration, or susceptibility to flooding or fire that maintains necessary early-successional habitat characteristics. Biological features might include prey species, forage grasses, specific kinds or ages of trees for roosting or nesting, symbiotic fungi, or a particular level of nonnative species consistent with conservation needs of the listed species. The features may also be combinations of habitat characteristics and may encompass the relationship between characteristics or the necessary amount of a characteristic essential to support the life history of the species.

In considering whether features are essential to the conservation of the species, we may consider an appropriate quality, quantity, and spatial and temporal arrangement of habitat characteristics in the context of the life-history needs, condition, and status of the species. These characteristics include, but are not limited to, space for individual and population growth and for normal behavior; food, water, air, light, minerals, or other nutritional or physiological requirements; cover or shelter; sites for breeding, reproduction, or rearing (or development) of offspring; and habitats that are protected from disturbance.

With rare exception, slickspot peppergrass occurs only in slick spot microsites scattered within the greater, semiarid, sagebrush-steppe ecosystem of southwestern Idaho. Slick spots provide habitats that are representative of the historical, geographical, and ecological distribution of slickspot peppergrass, and provide nutrients and water for reproduction, germination, and seed dispersal. The restricted distribution of slickspot peppergrass is likely due to its adaptation to the specific conditions within these slick spot habitats. Slick spots are distinguished from the surrounding sagebrush habitat as having the following characteristics: microsites where water pools when rain falls (Fisher et al. 1996, pp. 2, 4); sparse native vegetation; distinct soil layers with a columnar or prismatic structure, higher alkalinity and clay content, and natric (sodic, high sodium) properties (Fisher et al. 1996, pp. 15-16; Meyer and Allen 2005, pp. 3-5, 8; Palazzo et al. 2008, p. 378); and reduced levels of organic matter and nutrients due to lower biomass production (Meyer and Quinney 1993, pp. 3, 6; Fisher et al. 1996, p. 4). Although the low permeability of slick spots appears to help hold moisture (Moseley 1994, p. 8), once the thin crust dries out, the survival of slickspot peppergrass seedlings depends on the ability of the plant to extend the taproot into the argillic horizon (soil layer with high clay content) to extract moisture from the deeper natric zone (Fisher et al. 1996, p. 13).

Ecologically functional slick spots have the following three primary layers: the surface silt layer, the middle restrictive layer, and an underlying moist clay layer. Although slick spots can appear homogeneous on the surface, the actual depth of the silt and restrictive layer can vary throughout the slick spot (Meyer and Allen 2005, Tables 9, 10, and 11). The top two layers (surface silt and restrictive) of slick spots are normally very thin; the surface silt layer varies in thickness from a 0.25 to 3 centimeters (cm) (0.1 to 1.2 inches (in)) in slick spots known to support slickspot peppergrass, and the restrictive layer varies in thickness from 1 to 3 cm (0.4 to 1.2 in) (Meyer and Allen 2005, p. 3). Fisher et al. (1996, p. 4) describe the smooth surface layer of slick spots as crustlike, with prominent vesicular pores. Below the surface layer, the soil clay content increases abruptly and creates a strongly structured, finely textured boundary (horizon) formed by the concentration of silicate clay materials, known as an argillic horizon.

Slick spot soil profiles are distinctive and distinguished from the surrounding

soil matrix by very thin surface layers that form prominently vesicular crusts, natric-like argillic horizons that occur just below the soil surface, and by increasingly saline and sodic conditions with depth (Fisher et al. 1996, pp. 11, 16). Disturbances that alter the physical properties of slick spot soil layers, such as deep disturbance and the addition of organic matter, may lead to destruction and permanent loss of slick spots. Slick spot soils are especially susceptible to mechanical disturbances when wet (Rengasamy et al. 1984, p. 63; Seronko 2004, in litt., entire). Such disturbances disrupt the soil layers important to slickspot peppergrass seed germination and seedling growth and alter hydrological function.

The biological soil crust, also known as a microbiotic crust or cryptogamic crust, is another component of quality habitat for slickspot peppergrass. Such crusts are commonly found in semiarid and arid ecosystems, and are formed by living organisms, primarily bryophytes (mosses), lichens, algae, and cyanobacteria (blue-green algae), that bind together surface soil particles (Moseley 1994, p. 9; Johnston 1997, p. 4). Microbiotic crusts play an important role in stabilizing the soil and preventing erosion, increasing the availability of nitrogen and other nutrients in the soil, and regulating water infiltration and evaporation levels (Johnston 1997, pp. 8-10). In addition, an intact crust appears to aid in preventing the establishment of invasive plants (Brooks and Pyke 2001, p. 4; Serpe et al. 2006, pp. 174, 176). These crusts are sensitive to disturbances that disrupt crust integrity, such as compression due to livestock trampling or off-road vehicle use and are also vulnerable to damage by fire. Recovery from disturbance is possible but occurs very slowly (Johnston 1997, pp. 10-11).

The native, semiarid sagebrush-steppe habitat of southwestern Idaho where slickspot peppergrass is found can be divided into two plant associations, each dominated by the shrub Wyoming big sagebrush (
Artemisia tridentata
ssp.
wyomingensis
): (1) Wyoming big sagebrush—Thurber's needlegrass
(Achnatherum thurberianum
); and (2) Wyoming big sagebrush—bluebunch wheatgrass
(Pseudoroegneria spicatum
) habitat types. The perennial bunchgrasses Sandberg's bluegrass (
Poa secunda
) and bottlebrush squirreltail (
Elymus elymoides
) are commonly found in the understory of these habitats, and basin big sagebrush
(Artemisia tridentata
ssp.
tridentata
), gray or rubber rabbitbrush (
Ericameria nauseosus
), yellow rabbitbrush (
Chrysothamnus viscidiflorus
), strict buckwheat (
Eriogonum strictum
), bitterbrush (
Purshia tridentata
), and little-leafed horsebrush (
Tetradymia glabrata
) form a lesser component of the shrub community. Under relatively undisturbed conditions, the understory is populated by a diversity of perennial bunchgrasses and forbs, including species such as Indian ricegrass (
Achnatherum hymenoides
), common yarrow (
Achillea millefolium
), varileaf phacelia (
Phacelia heterophylla
), Pursh's milkvetch (
Astragalus purshii
), longleaf phlox (
Phlox longifolia
), and purple threeawn (
Aristida purpurea
var.
longiseta
).

Slickspot peppergrass is primarily an outcrossing species requiring pollen from separate plants for more successful fruit production; it exhibits low seed set in the absence of insect pollinators (Robertson 2003, p. 9; Robertson and Klemash 2003, p. 338; Robertson and Ulappa 2004, p. 1707; Billinge 2006, p. 40; Robertson et al. 2006, p. 40; Billinge and Robertson 2008, pp. 1005-1006). Insects from 25 families have been observed on slickspot peppergrass flowers (Robertson and Klemash, 2003, pp. 335-336). Of those 25 insect families, the primary slickspot peppergrass pollinators include several families of bees (Anthophoridae, Apidae, Colletidae, Halictidae, Sphecidae, and Vespidae), flies (Bombyliidae, Syrphidae, Calliphoridae, and Tachinidae), beetles (Cerambycidae, Dermestidae, Melyridae), and moths (Gelechiidae) (Robertson and Hannon 2003, p. 6; Robertson and Klemash 2003, p. 336; Robertson and Leavitt 2011, p. 384).

Pollinators need a diversity of native plants with overlapping bloom times to provide flowers for foraging throughout their active season; nesting and egg-laying sites (
e.g.,
bare ground, hollow stems, bunchgrasses); sheltered, undisturbed places for overwintering; and connected habitat patches (The Xerces Society 2018, pp. 15-17). In our proposed rule, we used a 250-meter (m) (820-foot (ft)) pollinator use area around each E.O. based on a foraging range of the solitary bee. However, we received several comments supporting an expansion of the pollinator-use buffer area to 500-m (1,640 ft) to account for the foraging range of all the associated pollinators noted in the above paragraph. After a thorough review of all the pollinator species for slickspot peppergrass, we agreed that each E.O. should be surrounded by a 500-m (1,640-ft) pollinator-use area to ensure that sufficient habitat and a diversity of native flowering plants are available to support the pollinator community required for the viability of slickspot peppergrass populations.

To determine the size of the pollinator-use area or buffer, we evaluated the pollinators of slickspot peppergrass and the distance that those pollinators were likely to fly in search of food. Although slickspot peppergrass is pollinated by a variety of insects, its primary pollinators are composed of families of small- to medium-sized solitary bees and flies, and larger, thread-waisted sphecid wasps (Sphecidae), meloid beetles, moths, and butterflies (Robertson and Leavitt 2011, pp. 384-385; Robertson 2020, pers. comm.). Flight distances are generally correlated with body size in bees; larger bees can fly farther than smaller bees (Gathmann and Tscharntke 2002, entire; Greenleaf et al. 2007, pp. 592-594; Kendall et al. 2022, p. 4). While researchers have reported that some solitary bee species, particularly larger bodied ones, are capable of foraging greater than 1 kilometer (km) (0.6 mile (mi)) (Zurbuchen et al. 2010, pp. 671-672), the majority of these species are central-place foragers (
i.e.,
remain close to their nest), thus foraging distances tend to be 500 m (1,640 ft) or less (Steffan-Dewenter 2003, p. 1041; BLM 2012, p. 19; Danforth et al. 2019, p. 207; O'Neill 2019, pp. 108-109; Antoine and Forrest 2021, p. 152). Syrphid flies, which are not central-place foragers, have been documented carrying pollen up to 400 m (1,312 ft) (Rader et al. 2011, pp. 522-525). Other noncentral-place foragers like moths and butterflies are capable of foraging over larger areas and could use areas within EOs and their associated buffers and beyond. Therefore, we find that a 500-m (1,640-ft) buffer is adequate for flies, moths, and butterflies, as well as the solitary bee pollinators of slickspot peppergrass.

In addition, honeybees were identified as a pollinator of slickspot peppergrass in our 2020 proposed rule (85 FR 44584). However, they are a nonnative species and compete for floral resources with native insect pollinators and spread diseases to native bees (Cane and Tepedino 2017, entire; Wojcik et al. 2018, pp. 827-829; Alger et al. 2019, pp. 5-7; Iwasaki and Hogendoorn 2022, pp. 7-8). Because of the potential negative impact they may have on the diverse native pollinator community associated with slickspot peppergrass, we do not consider them essential to the conservation of the species in this final rule.

The areas designated as critical habitat will ensure maintenance and continuity of foraging and nesting habitats for insect pollinators adjacent to occupied slick spots, thus promoting

a healthy pollinator community. This healthy pollinator community, in turn, helps to increase seed viability and production of slickspot peppergrass and is essential for maintaining genetic diversity in the species over the long term. In addition, the provision of sufficient native sagebrush-steppe habitat protects slickspot peppergrass from wildfire, nonnative plant invasions, and colonization by Owyhee harvester ants (see our final listing rule (74 FR 52014, October 8, 2009), the reinstatement of the listing rule (81 FR 55058, August 17, 2016), and the SSA (USFWS 2020) for a description of these threats), and it helps to maintain local ecosystem characteristics within the larger landscape, which are crucial for protecting the species and its persistent seed bank. The seed bank is an essential feature of slickspot peppergrass's biology because it provides the species with resilience in the face of stochastic impacts and variation in environmental conditions.

Summary of Essential Physical or Biological Features

Based on our current knowledge of habitat characteristics required to sustain the species' life-history processes, we determine that the PBFs essential to the conservation of slickspot peppergrass are:

(1) Ecologically functional microsites or “slick spots” that are characterized by:

(a) A high sodium and clay content, and a three-layer soil profile, which allows for successful seed germination, seedling growth, and maintenance of the seed bank. The surface horizon consists of a thin, silty, vesicular, pored (small cavity) layer that forms a physical crust (the silt layer). The subsoil horizon is a restrictive clay layer with an abruptic (referring to an abrupt change in texture) boundary with the surface layer, that is natric or natric-like in properties (a type of argillic (clay-based) horizon with distinct structural and chemical features) (the restrictive layer). The second argillic subsoil layer (that is less distinct than the upper argillic horizon) retains moisture through part of the year (the moist clay layer); and

(b) Sparse vegetation with invasive, nonnative plant species cover absent or limited to low to moderate levels.

(2) Relatively intact, native Wyoming big sagebrush (
Artemisia tridentata
ssp.
wyomingensis
) vegetation assemblages, represented by native bunchgrasses, shrubs, and forbs, within 500 m (1,640 ft) of slickspot peppergrass element occurrences to protect slick spots and slickspot peppergrass from disturbance from wildfire, slow the invasion of slick spots by nonnative plant species and native harvester ants, and provide the habitats needed by slickspot peppergrass' pollinators.

(3) A diversity of native plants whose blooming times overlap to provide pollinator species with flowers for foraging throughout the seasons and to provide nesting and egg-laying sites; appropriate nesting materials; and sheltered, undisturbed places for hibernation and overwintering of pollinator species. In order for genetic exchange of slickspot peppergrass to occur, pollinators must be able to move freely between slick spots. Alternative pollen and nectar sources (other plant species within the surrounding sagebrush vegetation) are needed to support pollinators during times when slickspot peppergrass is not flowering, when distances between slick spots are long, and in years when slickspot peppergrass is not a prolific flowerer.

(4) Sufficient pollinators for successful fruit and seed production, particularly pollinator species of the sphecid and vespid wasp families, species of the bombyliid and tachnid fly families, and halictid bee species, most of which are solitary insects that nest outside of slick spots in the surrounding sagebrush-steppe vegetation, both in the ground and within the vegetation.

Special Management Considerations or Protections

When designating critical habitat, we assess whether the specific areas within the geographical area occupied by the species at the time of listing contain features which are essential to the conservation of the species and which may require special management considerations or protection. A detailed discussion of the threats affecting the PBFs essential to the conservation of slickspot peppergrass, and that may require special management consideration or protection, can be found in the final listing rule published in the
Federal Register
on October 8, 2009 (74 FR 52014), the 2016 final rule reinstating threatened status for the species under the Act (81 FR 55058, August 17, 2016), in the recently completed SSA report (USFWS 2020, pp. 59-83, 85-103), and in the latest 5-year review (USFWS 2021).

The primary threats to the PBFs for slickspot peppergrass include the following direct and indirect effects: the current wildfire regime (
i.e.,
increasing frequency, size, and duration), invasive, nonnative plant species (
e.g.,
cheatgrass), and habitat loss and fragmentation due to agricultural and urban development. One of the indirect threats experienced by slickspot peppergrass is the negative impact on insect pollinators caused by conversion and fragmentation of native habitats due to invasive, nonnative plant species and various forms of development. Another indirect threat is the potential increase in seed predation by Owyhee harvester ants resulting from the conversion of sagebrush-steppe to grasslands. Livestock pose a threat to slickspot peppergrass, primarily through mechanical damage to individual plants and slick spot habitats; however, current livestock management conditions and associated conservation measures address this potential threat such that it does not pose a significant risk to the viability of the species as a whole.

In the 2009 listing rule (74 FR 52014, October 8, 2009), climate change in and of itself was not considered to represent a significant range-wide threat to slickspot peppergrass; however, it was acknowledged that climate change potentially plays an important supporting role in intensifying the primary threats to the species. Information identified in the SSA (USFWS 2020, pp. 79-82) indicated that climate change has already amplified the effects of wildfire and invasive, nonnative plants on slickspot peppergrass, and through its influence on invasive, nonnative annual grass spread, climate change may have been a factor in the continuing downward trend in slickspot peppergrass population numbers observed over the past decade. Other, less significant factors that have the potential to impact the species include the effects from rangeland revegetation projects, wildfire management practices, recreation, and military use.

All areas of critical habitat may require some level of management to address current and future threats to slickspot peppergrass and to maintain or restore the PBFs. Special management to protect the features essential to the conservation of slickspot peppergrass from the effects of the current wildfire regime may include preventing or restricting the establishment of invasive, nonnative plant species, post-wildfire restoration with native plant species, and reducing the likelihood of wildfires affecting the nearby plant community components. Rapid response to wildfires from local and government fire agencies can potentially limit the size of wildfires and the spread of wildfire into slickspot peppergrass habitat. For fires that do occur in critical habitat, post-fire restoration plans can identify ways to limit invasive, nonnative vegetation and restore habitat using native plants.

Special management to protect the features essential to the conservation of

slickspot peppergrass from the effects of invasive, nonnative unseeded plant species and seeded nonnative plants (also referred to as “highly competitive nonnative seeded plants” (USFWS 2020, p. 68)) may include the following: (1) protecting remnant blocks of native vegetation, (2) educating the public about invasive, nonnative species, (3) supporting research and funding for nonnative plant species control and native species restoration, (4) preventing or restricting the establishment of nonnative plant species, (5) washing vehicles prior to travel into areas containing slickspot peppergrass, and (6) reducing the likelihood of wildfires.

Special management to protect the features essential to the conservation of slickspot peppergrass from the effects of livestock use may include conservation measures and actions to minimize the effects of livestock use on these lands. Existing conservation plans and land use plans contain numerous measures to avoid, mitigate, and monitor the effects of livestock use on slickspot peppergrass. For example, livestock-grazing conservation measures are implemented through the conservation agreement between the Bureau of Land Management (BLM) and the Service (BLM 2014, pp. 8-12) and the Mountain Home Air Force Base Integrated Natural Resources Management Plan (INRMP; U.S. Air Force 2017, p. 192). Existing conservation measures include prescribing a minimum distance for the placement of salt and water troughs, identifying livestock use restrictions to reduce trampling of slick spots during wet periods, constructing fences, or potentially modifying current livestock use. We recognize the potential for negative impacts to slickspot peppergrass populations and slick spots that may result from seasonal, localized trampling events. However, under current management conditions, we do not consider livestock use to pose a significant threat to slickspot peppergrass. We encourage the continued implementation of conservation measures and associated monitoring to ensure potential impacts of livestock trampling to slickspot peppergrass are avoided or minimized.

Special management to protect the features essential to the conservation of slickspot peppergrass from the effects of residential and agricultural development may include the following: (1) creating managed plant reserves and open spaces, (2) limiting disturbances to and within suitable habitats, (3) increasing compliance inspections with livestock grazing permit holders, (4) requiring project fencing with adjacent construction activities, (5) disallowing new roads, and (6) evaluating the need for, and conducting, restoration efforts or revegetation of native plants in open spaces, plant preserves, or disturbed areas.

Special management to protect the features essential to the conservation of slickspot peppergrass from the effects of Owyhee harvester ant seed predation are addressed under the special management considerations for the current wildfire regime and invasive nonnative plants.

Finally, the protection of pollinators and their habitat is essential to the conservation of slickspot peppergrass. General pollinator management practices include: (1) maintaining a diversity of native plants with overlapping bloom times to provide flowers for foraging throughout the pollinators' active season, (2) nesting and egg-laying sites (
e.g.,
bare ground, hollow stems, bunchgrasses, and larval host plants), (3) sheltered, undisturbed places for overwintering, (4) a landscape free of pesticides and high levels of pathogens, and (5) connected habitat patches (The Xerces Society 2018, pp. 15-17).

The designation of critical habitat does not imply that lands outside of critical habitat do not play an important role in the conservation of slickspot peppergrass. Activities with a Federal nexus that may affect those areas outside of critical habitat, such as development, agricultural, or road construction activities, are still subject to review under section 7 of the Act if they may affect slickspot peppergrass.

Criteria and Methodology Used To Identify Critical Habitat

As required by section 4(b)(2) of the Act, we use the best scientific data available to designate critical habitat. In accordance with the Act and our implementing regulations at 50 CFR 424.12(b), we review available information pertaining to the habitat requirements of the species and identify specific areas within the geographical area occupied by the species at the time of listing and any specific areas outside the geographical area occupied by the species to be considered for designation as critical habitat. We are not designating any areas outside the geographical area occupied by the species at the time of listing because we did not identify any unoccupied areas that were essential for the conservation of the species and, therefore, met the definition of critical habitat.

We delineated critical habitat units within the three geographic areas where slickspot peppergrass occurs in order to represent genetic variability across the species' range. These areas include the Foothills, the Snake River Plain, and the Jarbidge (USFWS 2020, p. 5). Each critical habitat unit contains polygons of critical habitat consisting of slickspot peppergrass populations known as Element Occurrences (EO) and associated pollinator buffers that extend 500 m (1,640 ft) from the outer edge of the EOs. EOs are based on the standards and methods developed by NatureServe (NatureServe 2002, entire; NatureServe 2020
a,
entire; NatureServe 2020
b,
entire) and adopted by the Idaho Department of Fish and Game (IDFG). Slickspot peppergrass EOs are groups of plants that occur within 1 km (0.6 mi) of each other. Therefore, an EO can consist of one occupied slick spot or several occupied slick spots aggregated into one EO providing they are within the 1-km (0.6 mi) distance of one another. IDFG botanists track EOs and enter them into the Idaho Fish and Wildlife Information System (IFWIS), which is managed by the IDFG. The IDFG uses NatureServe guidance (NatureServe 2020
b
) to rank slickspot peppergrass EOs. Information used to inform the rankings was based on a systematic assessment of field data collected from summer 2012 through spring 2016 (Kinter and Miller 2016), plus data provided to the IDFG by the BLM for surveys from 2016 to 2018.

As per the NatureServe guidance, IDFG botanists ranked slickspot peppergrass EOs based on three factors: size, condition, and landscape context (Kinter and Miller 2016, p. 3). Possible EO ranks include A, B, C, D, E, F, H, or X; higher rankings (the highest rank is A) indicate sites with greater habitat quality and larger population sizes, which we infer are more likely to persist and sustain the species. Rankings of B, BC, C, CD, and D refer to states of decreased abundance and quality of detectable plants, native plant community, habitat condition, and overall landscape context within 1 km (0.6 mi) of occupied slick spots. Areas ranked E are those records with confirmed slickspot peppergrass presence but for which no additional habitat information is available. Rankings of F indicate areas where slickspot peppergrass was previously found, but no individuals were found when last visited by a qualified surveyor. Areas ranked H indicate historical occurrences where old location information is too vague to allow the EO to be found again. Rankings of X denote extirpated occurrences due to habitat destruction associated with development or agricultural conversion.

We based our criteria for the identification of critical habitat on IDFG's EO rankings. EO rankings are used for assessing estimated viability or probability of persistence as well as for prioritizing conservation planning or actions (NatureServe 2020
b,
p. 2, 12). IDFG botanists ranked each EO and sub-EO (a smaller, distinct area within the EO that is delineated for localized management) based on measures of habitat quality (EO and sub-EO condition and surrounding landscape context) and species abundance. Weighted calculations used by the IDFG to determine the ranking of each EO and sub-EO were as follows:

• 33 percent of the EO ranking score was based on the EO/sub-EO size (highest number of plants observed in at least 1 of up to the past 6 years of available IDFG data);

• 45 percent of the EO ranking score was based on habitat condition within EOs/sub-EOs as documented during IDFG recent field reviews; and

• 22 percent of the EO ranking score was based on habitat condition of the landscape within 1 km (0.6 mi) of EOs/sub-EOs as documented during IDFG recent field reviews.

These IDFG rankings do not necessarily correlate directly to the PBFs. For example, as described above in
Summary of Essential Physical or Biological Features,
PBF 1(b) states that ecologically functional microsites or “slick spots” are characterized by sparse vegetation, with introduced, invasive, nonnative plant species cover absent or limited to low to moderate levels. However, the IDFG rankings do not directly measure invasive, nonnative plant cover within the actual slick spot. The assessments of condition were based mostly on the EO habitat surrounding the slick spots, which tended to be more invaded than the slick spots. So, even if a habitat ranking was characterized as moderately to highly invaded, the slick spots themselves often had very low amounts of invasive species (Kinter 2020, pers. comm.). Therefore, we used the IDFG rankings, which constitute the best available information, as surrogates to help us determine which EOs provided the PBFs essential to the conservation of the species (
i.e.,
the EOs most likely to provide for populations of slickspot peppergrass that will contribute to the conservation and recovery of the species).

Based on comments received during the public comment period on our revised proposed critical habitat rule (85 FR 44584, July 23, 2020), we reevaluated our criteria for determining which EOs contain PBFs and meet our definition of critical habitat. The proposed rule included slickspot peppergrass EOs with IDFG rankings of B, BC, C, and CD as designated critical habitat. However, in this final rule, we also included all areas that were occupied at the time of listing that are ranked D. Although some of the EOs with D rankings often have PBFs with degraded conditions and may need special management, we determined that including these lower ranked EOs is essential to the conservation of the species in part because we no longer have any excellent (A-ranked) or excellent to good (AB ranked) EOs, and we need these lower ranked EOs to increase the redundancy of populations across the species' range. Since 2006, there have been no A- or AB-ranked EOs of slickspot peppergrass (Kinter and Miller 2016, p. 8; Colket et al. 2006, p. 11; IFWIS database (IDFG Database 2021)). Ultimately, we conclude that every EO included in critical habitat was occupied at the time of listing and has one or more of the PBFs sufficient to justify designation.

Slickspot peppergrass is a species endemic to southwest Idaho with a relatively small geographic range and limited, finite habitat. Slick spot microsites are believed to have formed during the Pleistocene, and current climate conditions may not allow for the formation of new slick spots; therefore, the loss of slick spot microsites within the range of slickspot peppergrass seems to be permanent (USFWS 2020, pp. 6-7). A statistical analysis of 11 years of range-wide monitoring data demonstrated that across all three geographic areas, slickspot peppergrass is declining (Bond 2017, p. 11), and without new tools and management to reduce or ameliorate the primary threats (increased wildfire and invasive plants) to the species, slickspot peppergrass is predicted to continue to decline into the future (USFWS 2020, pp. 121, 124-130).

In addition, we expect climate change to magnify the severity and scope of the primary threats of changing wildfire regimes and invasive nonnative plants to slickspot peppergrass, thereby reducing resiliency, representation, and redundancy of slickspot peppergrass populations rangewide (USFWS 2020, pp. 79-82). In the 2009 listing rule (74 FR 52014, October 8, 2009), we did not consider climate change to represent a significant range-wide threat to slickspot peppergrass. However, information identified in the SSA indicates that climate change has already amplified the effects of wildfire and invasive, nonnative plants on slickspot peppergrass. Through its influence on the spread of invasive, nonnative annual grasses, climate change may have been a factor in the continuing downward trend in slickspot peppergrass population numbers observed over the past decade.

Elevations for slickspot peppergrass populations range from a low of 756 m (2,480 ft) at EO 68 south of New Plymouth, Idaho, in the Foothills geographic area to a high of 1,654 m (5,425 ft) at EO 97 south of the Juniper Butte Range in the Jarbidge geographic area. Both extremes of low- and high-elevation areas contain slickspot peppergrass populations assessed by IDFG as having good population viability (B-ranked), although the lower elevation populations of the Foothills geographic area are smaller in area and more isolated, likely due to more fragmented habitats. The current higher fragmentation levels and projected future increased risk for wildfire and invasive, nonnative plants (particularly cheatgrass) make lower elevation populations more vulnerable to the effects of climate change than the higher elevation populations in the Jarbidge geographic area because these threats are likely to be amplified in lower elevation areas as temperatures increase. Most plant species cannot naturally shift their geographic ranges fast enough to keep up with predicted high projected rates of climate change in most landscapes. However, by designating critical habitat in all three geographic areas (Foothills, Snake River Plain, and Jarbidge) where the species occurs, including all B-D ranked EOs as well as the 500-m (1,640-ft) pollinator buffer around designated EOs, we have determined that these areas will help support slickspot peppergrass under potential climate change scenarios in the future.

We also continue to include areas that may have been partially degraded in the past by threats such as wildfire. The Act defines critical habitat as the specific areas within the geographical area occupied by the species, at the time it is listed, on which are found those physical or biological features essential to the conservation of the species and which may require special management considerations or protections. A combination of special management activities such as habitat enhancement or threat-reduction actions may be appropriate to maintain (and possibly increase) slickspot-peppergrass population resiliency and species persistence over time. Including lower ranked EOs (CD and D) will help ensure we retain the flexibility to consider various paths to recovery. In summary, after considering the best available information, we determined that all

occupied slickspot peppergrass EOs ranked B-D contain one or more of the physical or biological features essential to the conservation of the species and, therefore, meet our definition of critical habitat.

We have determined that 113 EOs (42 B-ranked, 2 BC-ranked, 33 C-ranked, 7 CD-ranked, and 29 D-ranked) meet our criteria for critical habitat designation. These 113 EOs reflect the merging of 2 C-ranked EOs (EOs 19 and 41) into B-ranked EO 18, the addition of CD-ranked EOs 23 and 57 that were not included in the proposed rule (85 FR 44584, July 23, 2020), and the addition of 6 new EOs. These six EOs include EO 122 (Unit 3a; C rank) and EOs 123, 124, 727, 728, and 729 (Unit 4, B rank). These EOs were ranked by the IDFG after publication of our July 23, 2020, revised proposed rule (85 FR 44584) and meet our definition of critical habitat. EO 122 was occupied at the time of listing (2016). The other five EOs were found in 2017 and were likely occupied at the time of listing because these slick spots had not been surveyed prior to 2017, and slickspot peppergrass is not likely to colonize new areas to the extent to which these EOs were populated (number of plants ranged from 13 to 766 per EO) within a year. Therefore, all six EOs are included in our final critical habitat designation.

In the 2009 final listing rule (74 FR 52014, October 8, 2009), we described the total area of known EOs (that is, area covered by the EOs themselves) as being approximately 6,500 hectares (ha) (16,000 acres (ac)). This area reflected only the known locations of individuals of the plant, as recognized in the IDFG IFWIS database as of 2009, and is a small portion of the overall geographic range of the species. In the May 10, 2011, proposed critical habitat rule (76 FR 27184), we described in detail the criteria used to identify critical habitat, including a 250-m (820-ft) buffer around EO polygons to provide areas for pollinator support and to minimize disturbance to the plant's habitat. We have since reassessed the size of the pollinator buffer and, in this final rule, we are increasing the buffer around EOs to 500 m (1,640 ft) (see the section Physical or Biological Features Essential to the Conservation of the Species, above, for details).

In this final rule, we used Geographic Information System (GIS) software (ESRI ArcGIS 10.7.1) to more precisely map areas that meet the definition of critical habitat rather than the mapping methodology we used in our 2011 and 2014 proposed rules (76 FR 27184, May 10, 2011; 79 FR 8402, February 12, 2014), which used the Public Land Survey System Quarter-Quarter section method. The GIS-based method involves delineation of B- through D-ranked slickspot peppergrass EOs surrounded by 500-m (1,640-ft) pollinator buffers to create polygons of slickspot peppergrass critical habitat. In contrast, critical habitat maps in 2011 and 2014 were created by selecting all Quarter-Quarter sections that intersected with B- through CD-ranked EOs or their surrounding 250-m (820-ft) pollinator buffers. The use of Quarter-Quarter sections, which represent land survey boundaries rather than biologically based boundaries, resulted in large areas outside of the GIS-generated polygons being included as proposed critical habitat in the 2011 proposed critical habitat rule (76 FR 27184, May 10, 2011) and the 2014 revised proposed critical habitat rule (79 FR 8402, Feb. 12, 2014). Use of GIS-based information represents a more precise method of delineating critical habitat that does not include extraneous areas.

The use of B- through D-ranked EO polygons and their surrounding 500-m (1,640-ft) pollinator buffers to create a more biologically sound critical habitat designation method is feasible, and is consistent with current Service regulations (77 FR 25611, May 1, 2012; 81 FR 7414, Feb. 11, 2016; 84 FR 45020, August 27, 2019) as well as with other Service critical habitat rules (
e.g.,
White Bluffs bladderpod (78 FR 76995, December 20, 2013), Webber's ivesia (79 FR 32126, June 3, 2014), beardless chinchweed (86 FR 31830, June 15, 2021)).

When determining final critical habitat boundaries, we made every effort to avoid including developed areas such as lands covered by buildings, pavement, and other structures because such lands lack PBFs necessary for slickspot peppergrass. These areas lacking PBFs were identified in GIS using aerial imagery from the ArcGIS World Imagery layer, aerial imagery from Google Earth Pro, and the 2019 National Agricultural Imagery Program (NAIP) Idaho layer, which has a spatial resolution of a 60-centimeter ground sample distance. Areas that lacked PBFs were then manually clipped out of our critical habitat polygons. The scale of the maps we prepared under the parameters for publication within the Code of Federal Regulations may not reflect the exclusion of such developed lands. Any such lands inadvertently left inside critical habitat boundaries shown on the maps of this final rule have been excluded by text in the final rule and are not designated as critical habitat. Therefore, a Federal action involving these lands will not trigger section 7 consultation with respect to critical habitat and the requirement of no adverse modification, unless the specific action will affect the PBFs in the adjacent critical habitat.

Therefore, we are designating as critical habitat lands that we determined were occupied at the time of listing (
i.e.,
currently occupied) and that contain one or more of the PBFs that are essential to support life-history processes of the species, and that may require special management considerations or protections. The four units each contain one or more of the physical or biological features that support multiple life-history processes for slickspot peppergrass.

The final critical habitat designation is defined by the map or maps, as modified by any accompanying regulatory text, and presented at the end of this document under Regulation Promulgation. We will make the coordinates or plot points or both on which each map is based available to the public on
https://www.regulations.gov
at Docket No. FWS-R1-ES-2010-0071, and on our internet site here:
https://www.fws.gov/species/slickspot-peppergrass-lepidium-papilliferum.

Final Critical Habitat Designation

We are designating approximately 31,569 ha (78,009 ac) of critical habitat in four units and seven subunits for slickspot peppergrass. The four units are the: (1) Payette and Gem Counties Unit, (2) Gem and Ada Counties Unit, (3) Ada and Elmore Counties Unit, and (4) Owyhee County Unit. Table 1 shows the critical habitat units and the approximate area of each unit. All units are considered occupied at the time of listing. The critical habitat areas we describe below constitute our current best assessment of areas that meet the definition of critical habitat for slickspot peppergrass.

Table 1—Critical Habitat Units for Slickspot Peppergrass
[Area estimates reflect all critical habitat within critical habitat unit or subunit boundaries.]

Unit
Subunit

Federal land in hectares
(acres)

Bureau of
Land Management

Bureau
of Reclamation

Total land in
hectares
(acres)

1-Payette and Gem Counties

695 (1,718)
9 (23)
704 (1,741)

2-Gem and Ada Counties
2a
874 (2,160)
0
87

[Text truncated at 120,000 characters. The full text is on the page linked above.]

---

Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2023-09219. Public record. Not legal advice.