# 79 FR 11053: Endangered and Threatened Wildlife and Plants; Removing Oenothera avita ssp. eurekensis and Swallenia alexandrae From the Federal List of Endangered and Threatened Plants

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URL: https://www.frixlaw.com/law-library/statutes/FR_PRORULE_2014-04232

## Section

- **Citation:** 79 FR 11053
- **Heading:** Endangered and Threatened Wildlife and Plants; Removing Oenothera avita ssp. eurekensis and Swallenia alexandrae From the Federal List of Endangered and Threatened Plants
- **Jurisdiction:** Federal
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** August 14, 2026
- **Source:** Compiled text
- **Location:** Federal Register / Vol. 79 / 79 FR 11053

## Text

DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R8-ES-2013-0131; FXES11130900000-145-FF09E42000] RIN 1018-AW04 Endangered and Threatened Wildlife and Plants; Removing Oenothera avita ssp. eurekensis and Swallenia alexandrae From the Federal List of Endangered and Threatened Plants AGENCY:
Fish and Wildlife Service, Interior.

ACTION:
Proposed rule and 12-month petition finding.

SUMMARY:
We, the U.S. Fish and Wildlife Service (Service), propose to remove Oenothera avita ssp. eurekensis (now accepted as Oenothera californica subsp. eurekensis, with a common name of Eureka Valley evening-primrose, Eureka evening-primrose, or Eureka Dunes evening-primrose) and Swallenia alexandrae (with a common name of Eureka dune grass or Eureka Valley dune grass) from the Federal List of Endangered and Threatened Plants. This action is based on a review of the best available scientific and commercial information, which indicates that both species no longer meet the definition of an endangered species, and further do not meet the definition of a threatened species, under the Endangered Species Act of 1973, as amended (Act). This proposed rule, if made final, would remove these plants from the List of Endangered and Threatened Plants. This document also constitutes our 12-month finding on a petition to remove both species from the List of Endangered and Threatened Plants. We are seeking information and comments from the public regarding this proposed rule.

DATES:
We will accept comments received or postmarked on or before April 28, 2014. We must receive requests for public hearings, in writing, at the address shown in the FOR FURTHER INFORMATION CONTACT section by April 14, 2014.

ADDRESSES:
Comment submission: You may submit comments by one of the following methods:
information and comments from the public regarding this proposed rule.

DATES:
We will accept comments received or postmarked on or before April 28, 2014. We must receive requests for public hearings, in writing, at the address shown in the FOR FURTHER INFORMATION CONTACT section by April 14, 2014.

ADDRESSES:
Comment submission: You may submit comments by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Search box, enter Docket No. FWS-R8-ES-2013-0131, which is the docket number for this rulemaking. Then, in the Search panel on the left side of the screen, under the Document Type heading, click on the Proposed Rules link to locate this document. You may submit a comment by clicking on “Comment Now!”
(2) By hard copy: Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS-R8-ES-2013-0131; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042-PDM; Arlington, VA 22203.
We request that you send comments only by the methods described above. We will post all comments on http://www.regulations.gov. This generally means that we will post any personal information you provide us (see the Information Requested section below for more information).
Document availability: You may obtain copies of the proposed rule and related documents (including a copy of the Background Information document (Service 2014, entire) referenced throughout this proposed rule) at http://www.regulations.gov under Docket No. FWS-R8-ES-2013-0131, or at the Ventura Fish and Wildlife Office's Web site at http://www.fws.gov/ventura/.
FOR FURTHER INFORMATION CONTACT:
Stephen P. Henry, Deputy Field Supervisor, Ventura Fish and Wildlife Office, 2493 Portola Road, Suite B, Ventura, CA 93003; telephone 805-644-1766; facsimile 805-644-3958. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339
ish and Wildlife Office's Web site at http://www.fws.gov/ventura/.
FOR FURTHER INFORMATION CONTACT:
Stephen P. Henry, Deputy Field Supervisor, Ventura Fish and Wildlife Office, 2493 Portola Road, Suite B, Ventura, CA 93003; telephone 805-644-1766; facsimile 805-644-3958. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary
Species addressed. Oenothera avita ssp. eurekensis (now accepted as Oenothera californica subsp. eurekensis; Eureka Valley evening-primrose) and Swallenia alexandrae (Eureka dune grass) are endemic to three dune systems in the Eureka Valley, Inyo County, California. Eureka Valley falls within federally designated wilderness within Death Valley National Park, and is managed accordingly by the National Park Service (Park Service).
Purpose of the Regulatory Action. This document constitutes our 12-month finding in response to a petition to delist Eureka Valley evening-primrose and Eureka dune grass, and we are proposing to remove both plants from the Federal List of Endangered and Threatened Plants.
Basis for the Regulatory Action. Under the Endangered Species Act of 1973, we may be petitioned to list, delist, or reclassify a species. Under the Act, a species may be determined to be an endangered species or threatened species because of any of five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) Overutilization for commercial, recreational, scientific, or educational purposes; (C) Disease or predation; (D) The inadequacy of existing regulatory mechanisms; or (E) Other natural or manmade factors affecting its continued existence. We must consider the same factors in delisting a species
ors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) Overutilization for commercial, recreational, scientific, or educational purposes; (C) Disease or predation; (D) The inadequacy of existing regulatory mechanisms; or (E) Other natural or manmade factors affecting its continued existence. We must consider the same factors in delisting a species. We may delist a species if the best scientific and commercial data indicate the species is neither threatened nor endangered for one or more of the following reasons: (1) The species is extinct, (2) The species has recovered and is no longer endangered or threatened, or (3) The original scientific data used at the time the species was classified were in error.
The primary threat to Eureka Valley evening-primrose and Eureka dune grass at the time of listing was off-highway vehicle (OHV) activity at Eureka Dunes (43 FR 17910; April 26, 1978); although not specifically stated in the final listing rule, this also presumes a lesser degree of impacts from camping that were associated with OHV activity on and around the dunes. Habitat protections and ongoing management by the Bureau of Land Management (BLM; up until
Information Requested
We intend any final action resulting from this proposal will be based on the best scientific and commercial information available, and be as accurate and as effective as possible. Therefore, we request comments or information from other governmental agencies, tribes, the scientific community, industry, or other interested parties concerning this proposed rule. We particularly seek comments concerning:
(1) Reasons why we should or should not delist Eureka Valley evening-primrose and Eureka dune grass under the Act (16 U.S.C. 1531 et seq. ).
(2) New biological or other relevant data concerning any threat (or lack thereof) to these plants.
agencies, tribes, the scientific community, industry, or other interested parties concerning this proposed rule. We particularly seek comments concerning:
(1) Reasons why we should or should not delist Eureka Valley evening-primrose and Eureka dune grass under the Act (16 U.S.C. 1531 et seq. ).
(2) New biological or other relevant data concerning any threat (or lack thereof) to these plants.
(3) New information concerning the range, distribution, and population size of both Eureka Valley evening-primrose and Eureka dune grass. Additionally, we are seeking information to aid in determining trends for both species, particularly in light of varying methodologies employed since listing (e.g., transects, photopoints, grid systems), the need to extrapolate anticipated future rangewide trends, and the need to utilize the best methodologies possible for future monitoring, including post-delisting monitoring.
(4) New information on the effects of other potential threat factors, including changes in the distribution and abundance of populations, disease, predation by small mammals, or negative effects resulting from the presence of invasive, nonnative species (particularly Salsola spp. (Russian thistle)).
(5) New information and data on the current or planned activities within the ranges of Eureka Valley evening-primrose and Eureka dune grass that may adversely affect or benefit the plants.
(6) New information or data on the projected and reasonably likely impacts to Eureka Valley evening-primrose and Eureka dune grass associated with climate change.
rticularly Salsola spp. (Russian thistle)).
(5) New information and data on the current or planned activities within the ranges of Eureka Valley evening-primrose and Eureka dune grass that may adversely affect or benefit the plants.
(6) New information or data on the projected and reasonably likely impacts to Eureka Valley evening-primrose and Eureka dune grass associated with climate change.
(7) What should be included in a post-delisting monitoring plan for the species, including length of monitoring period, monitoring intervals, what monitoring techniques are appropriate, triggers and thresholds for additional monitoring or initiating status reviews, and so forth.
Please include sufficient information with your submission (such as scientific journal articles or other publications) to allow us to verify any scientific or commercial information you include. Please note that submissions merely stating support for or opposition to the action under consideration without providing supporting information, although noted, will not be considered in making a determination, as section 4(b)(1)(A) of the Act directs that determinations as to whether any species is an endangered or threatened species must be made “solely on the basis of the best scientific and commercial data available.”
You may submit your comments and materials concerning this proposed rule by one of the methods listed in the ADDRESSES section. We request that you send comments only by the methods described in the ADDRESSES section. If you submit information via http://www.regulations.gov, your entire submission—including any personal identifying information—will be posted on the Web site. If your submission is made via a hardcopy that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy submissions on http://www.regulations.gov
ssion—including any personal identifying information—will be posted on the Web site. If your submission is made via a hardcopy that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy submissions on http://www.regulations.gov.
Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on http://www.regulations.gov, or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Ventura Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT ).
Public Hearings
Section 4(b)(5) of the Act provides for one or more public hearings on this proposal, if requested. Requests must be received no later than April 14, 2014. Send your request to the address shown in FOR FURTHER INFORMATION CONTACT . We will schedule public hearings on this proposal, if any are requested, and announce the dates, times, and places of those hearings, as well as how to obtain reasonable accommodations, in the Federal Register and local newspapers at least 15 days before the hearing.
Peer Review
In accordance with our joint policy on peer review published in the Federal Register on July 1, 1994 (59 FR 34270), we will seek the expert opinions of at least three appropriate and independent specialists regarding this proposed rule. A discussion of additional information related to this proposed rule—including (but not limited to) information on life history, taxonomy, genetics, seed bank ecology, survivorship and demography, rangewide distribution, and abundance surveys—is presented in the Background Information document (Service 2014) available at http://www.regulations.gov (Docket No. FWS-R8-ES-2013-0131). The purpose of peer review is to ensure that decisions are based on scientifically sound data, assumptions, and analyses
rmation on life history, taxonomy, genetics, seed bank ecology, survivorship and demography, rangewide distribution, and abundance surveys—is presented in the Background Information document (Service 2014) available at http://www.regulations.gov (Docket No. FWS-R8-ES-2013-0131). The purpose of peer review is to ensure that decisions are based on scientifically sound data, assumptions, and analyses. The peer reviewers will conduct assessments of the proposed rule, and the specific assumptions and conclusions regarding the proposed delisting. These assessments will be completed during the public comment period.
We will consider all comments and information we receive during the comment period on this proposed rule as we prepare the final determination. Accordingly, the final decision may differ from this proposal.
Previous Federal Actions
Consideration of Federal protection for Eureka Valley evening-primrose and Eureka dune grass began when the Secretary of the Smithsonian Institution, as directed by section 12 of the Act, prepared a report on native plants considered to be endangered, threatened, or extinct in the United States. This report (House Doc. No. 94-51) was presented to Congress on January 9, 1975, and included Eureka Valley evening-primrose and Eureka dune grass as endangered. On July 1, 1975, we published a notice in the Federal Register (40 FR 27823) accepting the report as a petition within the context of section 4(c)(2) (now section 4(b)(3)) of the Act and of our intention to review the status of the plant taxa (groups of distinct populations considered separate from other such groups, such as species and subspecies) named therein
nd Eureka dune grass as endangered. On July 1, 1975, we published a notice in the Federal Register (40 FR 27823) accepting the report as a petition within the context of section 4(c)(2) (now section 4(b)(3)) of the Act and of our intention to review the status of the plant taxa (groups of distinct populations considered separate from other such groups, such as species and subspecies) named therein. On June 16, 1976, we published a proposed rule in the Federal Register (41 FR 24523) to determine approximately 1,700 vascular
On July 7, 2005, we published a notice indicating our intent to initiate 5-year status reviews for 31 species, including Eureka Valley evening-primrose and Eureka dune grass (70 FR 39327), and requested that the public provide us information within 60 days. On November 3, 2005, we published a notice extending the comment period to January 3, 2006 (70 FR 66842). We did not receive any information from the public regarding Eureka Valley evening-primrose or Eureka dune grass during either comment period. Five-year reviews were completed for both taxa on September 24, 2007 (Service 2007a, b). Based on the best available information at that time, we concluded that both taxa no longer met the definition of an endangered species, and further do not meet the definition of a threatened species, under the Act, and we recommended their removal from the List of Endangered and Threatened Plants.
On May 18, 2010, we received a petition dated May 13, 2010, from the Pacific Legal Foundation requesting that the Service delist Eureka Valley evening-primrose and Eureka dune grass. The petition was based on the analysis and recommendations contained in our 2007 5-year status reviews for these taxa
nder the Act, and we recommended their removal from the List of Endangered and Threatened Plants.
On May 18, 2010, we received a petition dated May 13, 2010, from the Pacific Legal Foundation requesting that the Service delist Eureka Valley evening-primrose and Eureka dune grass. The petition was based on the analysis and recommendations contained in our 2007 5-year status reviews for these taxa. On January 19, 2011, we published a 90-day finding (76 FR 3069) in which we concluded that the petition and information in our files provided substantial information indicating that delisting may be warranted, announced that we were initiating status reviews for these taxa, and requested scientific and commercial data and other information regarding these taxa from governmental agencies, Native American Tribes, the scientific community, industry, and any other interested parties. We received one letter from the public that provided additional information relevant to Eureka dune grass (Bell 2011).
On March 27, 2013, the Pacific Legal Foundation filed a lawsuit challenging our failure to issue the required 12-month findings in response to their petition. Pursuant to a settlement agreement approved by the court on August 5, 2013, and revised by a court order on December 19, 2013, we must deliver 12-month findings for the Eureka Valley evening-primrose and Eureka dune grass to the Federal Register by February 21, 2014.
This document constitutes our 12-month finding on the petition to delist Eureka Valley evening-primrose and Eureka dune grass, and we are proposing to delist the two taxa, which would remove them from the List of Endangered and Threatened Plants.
Background
For this proposal, we conducted a scientific analysis as presented in this document and supplemented with additional information presented in the Background Information document (Service 2014, entire; available at http://www.regulations.gov , Docket No. FWS-R8-ES-2013-0131)
e proposing to delist the two taxa, which would remove them from the List of Endangered and Threatened Plants.
Background
For this proposal, we conducted a scientific analysis as presented in this document and supplemented with additional information presented in the Background Information document (Service 2014, entire; available at http://www.regulations.gov , Docket No. FWS-R8-ES-2013-0131). The Background Information document was prepared by Service biologists to provide additional discussion of the environmental setting for the Eureka Valley, and other background information of Eureka Valley evening-primrose's and Eureka dune grass's life history, taxonomy, genetics, seed bank ecology, survivorship and demography, rangewide distribution, and abundance surveys, as well as additional information on the threats that may be impacting both species.
Eureka Valley evening-primrose and Eureka dune grass are endemic (unique to a geographic area) to the sand dunes of Eureka Valley (Figure 1), which occurs within Death Valley National Park, Inyo County, California. Three dune systems occur in Eureka Valley and are located between the Last Chance Mountains to the east, the Saline Mountains to the south, and the Inyo Mountains to the west and north (Rowlands 1982, p. 2). The Eureka Dunes parallel the Last Chance Mountains (Service 1982, p. 12) and are the largest of the three dunes, covering a total area of about 2,003 acres (ac) (811 hectares (ha)) (Service 2013a based on Shovik 2010). The Saline Spur and Marble Canyon Dunes, two smaller dune systems, cover an area of about 238 ac (96 ha) and 610 ac (247 ha), respectively (Service 2013a based on Shovik 2010). Saline Spur Dunes and Marble Canyon Dunes, including a southern extension of Marble Canyon Dunes known as the unnamed site, are located approximately 4 miles (mi) (6.4 kilometers (km)) and 9 mi (14.4 km) west of Eureka Dunes (Bagley 1986, p. 4)
arble Canyon Dunes, two smaller dune systems, cover an area of about 238 ac (96 ha) and 610 ac (247 ha), respectively (Service 2013a based on Shovik 2010). Saline Spur Dunes and Marble Canyon Dunes, including a southern extension of Marble Canyon Dunes known as the unnamed site, are located approximately 4 miles (mi) (6.4 kilometers (km)) and 9 mi (14.4 km) west of Eureka Dunes (Bagley 1986, p. 4). The southern extension of Marble Canyon Dunes (the unnamed site) was previously treated as a separate dune system, but we refer to this area and the rest of the dune system as the Marble Canyon Dunes. See additional discussion in Service 2014 (pp. 4-7).
EP27FE14.026
Eureka Valley Evening-Primrose
Species Description, Taxonomy, and Life History
Eureka Valley evening-primrose is a short-lived perennial in the evening-primrose family (Onagraceae). It forms rosettes for the first 1 or 2 years, then develops decumbent or ascending stems up to 8 decimeters (31.5 inches (in)) high. Plants produce clusters of white fading-to-pink flowers, which continue to be produced as long as conditions are favorable.
The taxon was listed as Oenothera avita (W.M. Klein) W.M. Klein subsp. eurekensis (Munz and J.C. Roos) W.M. Klein (Klein 1965, p. 116). However, since that time, the accepted scientific name (Wagner 1993, p. 803; Wagner 2002, p. 395; Wagner et al. 2007, p. 180; Wagner 2012, p. 952; CNPS 2013) has been and will be treated in this document as O. californica subsp. eurekensis, and referred to as Eureka Valley evening-primrose throughout the remainder of this document.
The plant spends most of the year as a small rosette of leaves (Pavlik 1979a, pp. 47-49, 52; 1979b, pp. 87-88). In April and May, plants undergo rapid stem elongation and bloom between April and July. Under optimal conditions, recruits (first-year plants) can bloom in the year in which they germinate (Pavlik 1979a, p. 66). In general, evening-primrose species are pollinated by hawkmoths, butterflies, and bees (Gregory 1963, pp
ear as a small rosette of leaves (Pavlik 1979a, pp. 47-49, 52; 1979b, pp. 87-88). In April and May, plants undergo rapid stem elongation and bloom between April and July. Under optimal conditions, recruits (first-year plants) can bloom in the year in which they germinate (Pavlik 1979a, p. 66). In general, evening-primrose species are pollinated by hawkmoths, butterflies, and bees (Gregory 1963, pp. 387, 398, 403, 407; Moldenke 1976, pp. 322, 346, 358). Following the blooming period, the elongated stems die back and are buried by shifting sands. Plants sometimes bloom again in the fall with additional summer or fall rains (Pavlik 1979a, p. 53; 1979b, p. 89). Eureka Valley evening-primrose also has the ability to reproduce clonally (produce new individuals through vegetative growth rather than by seed), which provides a vegetative means for reproduction (Pavlik 1979a, p. 68; Pavlik and Barbour 1986, p. 84; Pavlik and Barbour 1988, p. 240).
Abundance and timing of rainfall appear to be important not only for germination, but for successful recruitment of individuals into the population; sufficient rainfall for germination in the fall months needs to be followed by additional rainfall events during the winter months for recruitment to occur. After several consecutive years of favorable conditions, a parent rosette may become ringed with smaller rosettes. In years with unfavorable climatic conditions, established plants may remain dormant and persist underground by their fleshy roots. Therefore, the number of above-ground plants observed in any year represents only a portion of the population.
Pavlik and Barbour (1985, pp. 15, 21) note that Eureka Valley evening-primrose is capable of abundant and precocious seed production. Eureka Valley evening-primrose has seed characteristics that provide mechanisms to ensure some seeds remain near the parent plant and some seeds disperse far from the parent plant
bove-ground plants observed in any year represents only a portion of the population.
Pavlik and Barbour (1985, pp. 15, 21) note that Eureka Valley evening-primrose is capable of abundant and precocious seed production. Eureka Valley evening-primrose has seed characteristics that provide mechanisms to ensure some seeds remain near the parent plant and some seeds disperse far from the parent plant. These characteristics ensure that there is a potential source of seed to supplement existing populations or establish new populations. Under laboratory conditions, seeds may remain viable at least 8 years (Pavlik and Barbour 1986, pp. 31, 36, 81). However, seed age or exposure to unfavorable conditions (such as heat and moisture) can reduce seed viability (Pavlik and Barbour (1986, p. 31). Some seeds may also be lost and unavailable for future recruitment. This may occur if wind
Age-class distribution, survival, and mortality of Eureka Valley evening-primrose were examined by Pavlik and Barbour (1985, 1986). Research results indicate that despite the observed high mortality of young plants, short-lived cohorts (plants produced from a given year's reproduction that do not survive to the following year) produced large amounts of seed when compared to cohorts with high survivorship (plants produced from a given year's reproduction that have a high rate of survival to the following year), which produced relatively smaller amounts of seed (Pavlik and Barbour 1986, p. 10). Consequently, years with low plant survival potentially produce seed numbers equal to or better than years with high survival. Coupled with the contribution of vegetative reproduction (i.e., production of rosettes from branched rootstock), this copious seed production may compensate for short lifespans and high mortality observed by Pavlik and Barbour (1986, p. 14)
Pavlik and Barbour 1986, p. 10). Consequently, years with low plant survival potentially produce seed numbers equal to or better than years with high survival. Coupled with the contribution of vegetative reproduction (i.e., production of rosettes from branched rootstock), this copious seed production may compensate for short lifespans and high mortality observed by Pavlik and Barbour (1986, p. 14).
Monitoring efforts were initiated by the Park Service in the Eureka Valley in 2007, but this level of monitoring is not expected to continue if the species is delisted (Cipra and Fuhrmann 2013). Between 2010 and 2013, a combined effort by the U.S. Geological Survey (USGS) and Chow (Chow and Klinger 2013, entire) implemented an additional monitoring protocol for Eureka Valley evening-primrose. These monitoring efforts provided information on Eureka Valley evening-primrose's population structure (life-history stages), spatial distribution, and abundance. However, due to differences in methods for life stage classification and estimating spatial extent, and because neither the Park Service or USGS tracked the survivorship of individual plants, we cannot make a direct comparison between these monitoring efforts and the study conducted by Pavlik and Barbour (1986, entire) in the 1980s. Consequently, we cannot determine if current populations of Eureka Valley evening-primrose exhibit similar survival rates observed by Pavlik and Barbour (1986). However, assuming Eureka Valley evening-primrose populations continue to experience high mortality among recruits, recruitment from one year to the next is likely low.
Rangewide Distribution
As stated above in the Background section, all known, extant populations of Eureka Valley evening-primrose occur within Eureka Valley in Death Valley National Park (see Figure 1, above). The first known distribution map of this species is from 1976 (BLM 1976, p. 16)
continue to experience high mortality among recruits, recruitment from one year to the next is likely low.
Rangewide Distribution
As stated above in the Background section, all known, extant populations of Eureka Valley evening-primrose occur within Eureka Valley in Death Valley National Park (see Figure 1, above). The first known distribution map of this species is from 1976 (BLM 1976, p. 16). However, the most recent distribution maps generated in 2007 and 2008 (Park Service 2008a) and between 2011-2013 (Park Service 2011a, 2012a, 2013a) are the most detailed and accurate.
Eureka Valley evening-primrose occupies the stabilized, gentle dune slopes extending out onto the shallower sand fields bordering the dune systems of Eureka Valley (Bagley 1986, p. 10; Service 1982, p. 7). We have previously described in our 5-year status review (Service 2007a, Appendix A) the spatial distribution of Eureka Valley evening-primrose and the surveys that occurred following listing of the species and up to the late 1990s. Therefore, we are limiting our discussion in this proposed rule to the new information collected from the Park Service's monitoring program from 2007 to 2013, which was not available at the time of the 5-year status review.
Since 2007, new information on the species distribution (specifically, the above-ground expression of rosettes and flowering individuals) has been provided by the Park Service (Park Service 2008a, 2010a; 2011a; 2011b; 2012a; 2013a). As part of its survey efforts, the Park Service has mapped the extent of Eureka Valley evening-primrose at the southern end of Marble Canyon Dunes (i.e., the unnamed site), which had not been fully documented previously. In summary, the above-ground distribution of Eureka Valley evening-primrose may vary significantly from year to year (such as comparisons of data between 2007 and 2013, the latter of which captured a mass germination event that occurred on the sand flats of Eureka Dunes in March 2013 (Park Service 2013a, pp. 5, 8))
yon Dunes (i.e., the unnamed site), which had not been fully documented previously. In summary, the above-ground distribution of Eureka Valley evening-primrose may vary significantly from year to year (such as comparisons of data between 2007 and 2013, the latter of which captured a mass germination event that occurred on the sand flats of Eureka Dunes in March 2013 (Park Service 2013a, pp. 5, 8)). These variations require us to rely on more than a single survey event (i.e., we rely on a composite over time of its general habitat and distribution) to determine how much habitat the species occupies. Additionally, Eureka Valley evening-primrose's distribution may vary geographically within the same year, as observed at the Saline Spur and Marble Canyon Dunes in 2008 and 2013 (Park Service 2013a, pp. 4, 5, 12, 14).
Quantifying changes in the distribution of Eureka Valley evening-primrose since listing by comparing historical and current distribution maps is challenging due to the varying methods used to collect data, the level of detail that was achieved with those methods, and survey intensity. However, comparing historical and current distribution maps can indicate, over a long time period, if the population has persisted in certain locations. Overall, the presence and absence maps generated between 2007 and 2013 are more precise than any previously generated maps because the Park Service implemented a standardized survey method and created a grid system that allowed them to note specific changes in the distribution of the Eureka Valley evening-primrose. On a small scale, the usefulness of comparing recent maps with historical maps is limited because the 2007-2013 maps only reflect the above-ground expression, which shows extreme annual variation of the species for those particular years. On a large scale, however, these recent maps indicate that the populations are still present in the same general locations that they were known from at the time of listing and at the time of our 2007 5-year status review
ith historical maps is limited because the 2007-2013 maps only reflect the above-ground expression, which shows extreme annual variation of the species for those particular years. On a large scale, however, these recent maps indicate that the populations are still present in the same general locations that they were known from at the time of listing and at the time of our 2007 5-year status review.
Abundance Surveys and Population Estimates
Abundance data for Eureka Valley evening-primrose have been collected by various parties and entities between 1974 and 2013. However, it is difficult to compare older and newer data sets due to the annual fluctuation in the above-ground distribution of Eureka Valley evening-primrose, as well as differences in methodology and scale. Consequently, estimating total population size is difficult at best. Additionally, we have no information regarding population size of Eureka Valley evening-primrose at the time of listing; abundance surveys (which could be used to estimate population size) prior to listing were limited to the north end of Eureka Dunes. Therefore, we cannot determine how populations may have changed over time and across the range of the species since listing.
Our evaluation of the Park Service's 2011 data set (which is the only year of data collected that allows a comparison across three different survey methods) indicates the estimated number of Eureka Valley evening-primrose individuals (i.e., above-ground expression) is within the range of 8,409 to 15,357 (see “Abundance Surveys and Population Estimates—Eureka Valley evening-primrose” section of the Background Information document (Service 2014, pp. 26-30)). The Park Service also estimated the total population size in 2011 to be 8,028 individuals (which included a slight recalculation from the previous estimate), and in 2013 to be 21,286 individuals (Park Service 2013a, p
e range of 8,409 to 15,357 (see “Abundance Surveys and Population Estimates—Eureka Valley evening-primrose” section of the Background Information document (Service 2014, pp. 26-30)). The Park Service also estimated the total population size in 2011 to be 8,028 individuals (which included a slight recalculation from the previous estimate), and in 2013 to be 21,286 individuals (Park Service 2013a, p. 7), the latter of which documents a substantial increase in the above-ground expression of plants following a mass germination event observed on the sand
Although information on abundance and long-term population trends are limited in spatial extent, the best available data indicate (as stated above) that the Eureka Valley evening-primrose population is estimated to be in the thousands. However, it also is important to note that actual population sizes may vary greatly from the estimates described above for the following reasons:
(1) The size of the area on which densities were calculated is small (i.e., 1-ha monitoring plots or line transects) in comparison to the size of the area to which the densities are being extrapolated (i.e., the dune systems).
(2) Because Eureka Valley evening-primrose is clonal and exhibits a somewhat clumped distribution, it is often difficult to count individuals, and in general it is difficult to estimate the true population size (i.e., individuals can be both underestimated and overestimated).
(3) Different survey methods will result in different estimates of abundance.
(4) The density data used to estimate the 2011 population size only reflect the above-ground distribution of the species for that particular year.
(5) The Eureka Valley evening-primrose exhibits high annual variation, so the estimated population size will vary depending on the data collected within a given year.
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(3) Different survey methods will result in different estimates of abundance.
(4) The density data used to estimate the 2011 population size only reflect the above-ground distribution of the species for that particular year.
(5) The Eureka Valley evening-primrose exhibits high annual variation, so the estimated population size will vary depending on the data collected within a given year.
(6) These population estimates include both reproductive and nonreproductive individuals; we do not know how many nonreproductive individuals survive to flower and set seed.
Eureka Dune Grass
Species Description, Taxonomy, and Life History
Eureka dune grass is a perennial, hummock-forming (development of mounds of windblown soil at the base of plants on dune landscapes) grass comprising a monotypic genus (genus containing only one single species) of the grass family (Poaceae). The coarse, stiff stems reach 20 in (50 cm) in height, and the lanceolate leaves are tipped with a sharp point (DeDecker 1987, p. 2). Flowers are clustered in spike-like panicles and produce seeds that are 0.16 in (4 millimeter (mm)) long and 0.08 in (2 mm) wide (Bell and Smith 2012, p. 1496). The root system becomes fibrous and extensive over time and can give rise to adventitious stems. Based on its morphological characteristics and taxonomic affinities, the species is thought to be a relictual species, which exists as a remnant of a formerly widely distributed group in an environment that is now different from where it originated.
Eureka dune grass is dormant during the winter and begins to produce new shoot growth around February. Growth accelerates in May, with flowering from April to June and seed dispersal between May and July (Pavlik 1979a, pp. 47-49; Pavlik 1979b, p. 87; Service 1982, pp. 4-6). Like all grass taxa, the flowers of Eureka dune grass are wind-pollinated and therefore do not rely on insect pollinators. Eureka dune grass does not appear to propagate asexually (Pavlik and Barbour 1985, p
wth around February. Growth accelerates in May, with flowering from April to June and seed dispersal between May and July (Pavlik 1979a, pp. 47-49; Pavlik 1979b, p. 87; Service 1982, pp. 4-6). Like all grass taxa, the flowers of Eureka dune grass are wind-pollinated and therefore do not rely on insect pollinators. Eureka dune grass does not appear to propagate asexually (Pavlik and Barbour 1985, p. 4); therefore, sexual reproduction is considered to be the dominant form of reproduction for this species.
Individuals have been observed to continue growing for at least 12 years with no signs of senescence (Henry n.d., pers. comm. in Pavlik and Barbour 1986, p. 11), and likely can grow for decades; older individuals form large hummocks that can reach on the order of 2,500 cubic decimeters (88 cubic feet; extrapolated from Pavlik and Barbour (1988, p. 229)). Germination of new individuals appears to occur infrequently, typically in response to rainfall during the summer months (Pavlik and Barbour 1986, pp. 47-59).
The following information on Eureka dune grass seedbank ecology is available related to seed production, dispersal, seed fate (based on wind dispersal and seed predation), viability, and germination:
• The amount of Eureka dune grass seed produced per individual increases with canopy size, which means that larger individuals may contribute more seed to the seed bank (Pavlik and Barbour 1985, p. 14). Compared to other perennial grass species, Eureka dune grass produces low numbers of seeds per individual (Pavlik and Barbour 1986, p. 30); this low seed production could be due to the inefficiency of wind pollination and the low density of individuals across the dunes (Pavlik and Barbour 1985, p. 17).
• Eureka dune grass seeds with floral bracts may disperse long distances whereas seeds without floral bracts may remain near the parent plant (Pavlik and Barbour 1985, pp. 40-41)
seeds per individual (Pavlik and Barbour 1986, p. 30); this low seed production could be due to the inefficiency of wind pollination and the low density of individuals across the dunes (Pavlik and Barbour 1985, p. 17).
• Eureka dune grass seeds with floral bracts may disperse long distances whereas seeds without floral bracts may remain near the parent plant (Pavlik and Barbour 1985, pp. 40-41). Long-distance seed dispersal is important in forming new or supplementing existing populations (although wind dispersal could send seeds outside of suitable habitat and thus make them unavailable for future recruitment). In contrast, seeds remaining near the parent plant are important in supplementing existing populations.
• Seed predation may occur from insects and rodents. The amount of predation by scale insects and rodents was first studied by Pavlik and Barbour (1985, 1986). Pavlik and Barbour's (1985, p. 59) preliminary observations in 1985 indicated a small percentage (less than 2 percent) of pre-dispersal seed predation occurred by scale insects, whereas in 1986, they (Pavlik and Barbour 1986, p. 32; 1988, pp. 233-234) found that 14 percent of Eureka dune grass seeds (without floral bracts) and 6 percent of disseminules (seeds with floral bracts) were removed overnight by rodents. However, these data were only collected from the north end of Eureka Dunes. Therefore, we cannot determine if the level of insect and rodent predation observed by Pavlik and Barbour (1985, 1986) on seeds occurs across the range of the species or how it may affect the population due to the limited scope and duration of the study. However, given the species continues to occupy the same general distribution, it does not appear that the level of seed predation is causing population-level declines.
• Under laboratory conditions, seeds may remain viable for at least 8 years (Pavlik and Barbour 1986, pp
ccurs across the range of the species or how it may affect the population due to the limited scope and duration of the study. However, given the species continues to occupy the same general distribution, it does not appear that the level of seed predation is causing population-level declines.
• Under laboratory conditions, seeds may remain viable for at least 8 years (Pavlik and Barbour 1986, pp. 31-32;
• An important factor in the persistence of Eureka dune grass may be the mass germination and establishment of Eureka dune grass seedlings (Pavlik and Barbour 1986, p. 55), particularly from seeds in the seed bank. These mass germination events are likely dependent on rare, above-average rainfall during the summer months (Pavlik and Barbour 1986, p. 51). For instance, the extremely wet conditions in July 1984 led to the mass germination and establishment of Eureka dune grass seedlings in 1984 and 1985; these favorable climatic conditions occurred only once in the previous 90 years (Pavlik and Barbour 1986, p. 54). More frequent climatic events that occur every 11 to 15 years may result in smaller germination and establishment events, which may serve to supply new individuals and replace those individuals that are lost through senescence (Pavlik and Barbour 1986, p. 54).
A demographic study was initiated in 1985 (Pavlik and Barbour 1985, entire; 1986, entire) to better understand how population attributes affected local abundance and persistence of Eureka dune grass; the study tracked the fate of seedlings established in 1984 (1984 cohort), as well as mature and senescent individuals. However, we note two constraints to these data: (1) The study was spatially restricted to the north slope of the Eureka Dunes and thus is not representative of the entire range of the species; and (2) The study was carried out over a 2-year period that included a year with very high rainfall that triggered a mass germination event followed by a year with very low rainfall
nd senescent individuals. However, we note two constraints to these data: (1) The study was spatially restricted to the north slope of the Eureka Dunes and thus is not representative of the entire range of the species; and (2) The study was carried out over a 2-year period that included a year with very high rainfall that triggered a mass germination event followed by a year with very low rainfall. Thus, the conclusions generated from this study may not be representative of the population's response over a longer period of time. Given these constraints, results indicate that 24 percent of the 1984 cohort survived to develop into hummocks and 92 percent of the mature and senescent plants survived (Pavlik and Barbour 1986, pp. 9-10; 1988, p. 225). The cause of mortality among recruits was attributed to uprooting and damage from windstorms (Pavlik and Barbour 1986, p. 9; 1988, p. 225). A follow-up survey in 1987 found more than 90 percent of the 1984 cohort alive and growing (Pavlik and Barbour 1988, p. 225). This information indicates that once young plants become established, survival rates may be equal to that of mature and senescent plants.
Using survivorship data from the demographic study described above, Pavlik and Barbour (1986, p. 11) attempted to compare potential persistence of Eureka dune grass with other perennial grass species and two other Eureka Valley endemic plants (i.e., Eureka Valley evening-primrose and Astragalus lentiginosus var. micans (shining milk-vetch)). Although the comparisons were limited in scope and duration, Pavlik and Barbour (1986, p. 11) estimate that the established population of Eureka dune grass might persist for 88 years in the absence of recruitment. However, based on study limitations, including use of data collected following a rare mass germination event, this number may be an overestimate.
Similar to Eureka Valley evening-primrose (see Eureka Valley Evening-primrose section, above), monitoring of Eureka dune grass was initiated in 2007 (Park Service 2008a, entire)
ureka dune grass might persist for 88 years in the absence of recruitment. However, based on study limitations, including use of data collected following a rare mass germination event, this number may be an overestimate.
Similar to Eureka Valley evening-primrose (see Eureka Valley Evening-primrose section, above), monitoring of Eureka dune grass was initiated in 2007 (Park Service 2008a, entire). These monitoring efforts have provided information on Eureka dune grass population structure (life-history stages), spatial distribution, and abundance. Results indicate that the majority of the Eureka dune grass population was in its reproductive stage (33 to 66 percent) and a very small percent (0 to 3 percent) was in the nonreproductive seedling stage (Park Service 2008a, p. 13). Due to differences in how life stage classifications were made and in spatial extent of study areas, we cannot make a direct comparison between the study conducted by Pavlik and Barbour (1985, 1986) and Bagley (1986) and the information collected by the Park Service (Park Service 2008a). Additionally, the Park Service did not track the survivorship of individual plants; therefore, we cannot determine if current populations of Eureka dune grass exhibit similar survival rates observed by Pavlik and Barbour (1986, pp. 9-10; 1988, p. 225) in the 1980s. Even so, information collected by Pavlik and Barbour (1985, 1986), Bagley (1986), and the Park Service (2008a) indicate that: (1) Though the age-distribution within the population varies depending on the time of data collection, adult plants typically make up the majority of the population; and (2) Recruitment from year to year is likely low, but high recruitment each year is probably not necessary for the population to persist because of the long lifespan and high survivorship of the plants once they are established. Ultimately, population persistence will depend on the replacement of adult and senescent plants with new recruits
ants typically make up the majority of the population; and (2) Recruitment from year to year is likely low, but high recruitment each year is probably not necessary for the population to persist because of the long lifespan and high survivorship of the plants once they are established. Ultimately, population persistence will depend on the replacement of adult and senescent plants with new recruits.
Rangewide Distribution
As stated above in the Background section, all known, extant populations of Eureka dune grass occur within Eureka Valley in Death Valley National Park (see Figure 1, above). The first known distribution map of this species is from 1976 (BLM 1976, p. 16). However, the most recent maps generated in 2007 and 2008 (Park Service 2008a) and between 2011 and 2013 (Park Service 2011a, 2012a, 2013a) are the most detailed and accurate.
Eureka dune grass occupies the gentle to relatively steep slopes of the Eureka Dunes, and variable terrain of Saline Spur and Marble Canyon Dunes (Pavlik 1979a, pp. 35-36; Pavlik 1979b, p. 47; Service 1982, p. 4). At the time of listing, there were three known populations of Eureka dune grass within Eureka Valley, with the majority of the distribution on the Eureka Dunes (43 FR 17910; April 26, 1978). As mentioned above, although additional plants were subsequently discovered and described at the southern end of Marble Canyon Dunes, these are considered and described within this document as part of the Marble Canyon Dunes population.
We have previously described in our 2007 5-year status review the spatial distribution of Eureka dune grass and the surveys that occurred following listing of the species and up to the 1990s (Service 2007b, Appendix A). Therefore, we are limiting our discussion in this proposed rule to the new information collected from the Park Service's monitoring program from 2007 to 2013, which was not available at the time of the 5-year status review
-year status review the spatial distribution of Eureka dune grass and the surveys that occurred following listing of the species and up to the 1990s (Service 2007b, Appendix A). Therefore, we are limiting our discussion in this proposed rule to the new information collected from the Park Service's monitoring program from 2007 to 2013, which was not available at the time of the 5-year status review.
Quantifying changes in the distribution of Eureka dune grass since listing by comparing historical and current distribution maps is challenging due to the varying methods used to collect data, the level of detail that was achieved with those methods, and survey intensity. However, comparing historical and current distribution maps can indicate, over a long time period, if the population has declined or increased in certain locations. Overall, the presence and absence maps generated between 2007 and 2013 are more precise than any previously generated maps because the Park Service implemented a standardized survey method and created a grid system that allowed them to note specific changes in the distribution of the Eureka dune grass. Additionally, as part of its survey efforts, the Park Service has mapped the extent of Eureka dune grass at the southern end of Marble Canyon Dunes (i.e., the
Based on the life history of Eureka dune grass (see “Eureka Dune Grass Biology” section of the Background Information document, Service 2014, pp. 13-14), there is likely minimal annual variation in the distribution of Eureka dune grass because this species is long-lived, and mortality of young plants (once they become established) is relatively low and decreases with age. Consequently, to quantify changes in the distribution of Eureka dune grass that have occurred since listing, we compared the Park Service's 2013 distribution map to older maps (i.e., maps from the BLM (1976) and DeDecker (1979))
istribution of Eureka dune grass because this species is long-lived, and mortality of young plants (once they become established) is relatively low and decreases with age. Consequently, to quantify changes in the distribution of Eureka dune grass that have occurred since listing, we compared the Park Service's 2013 distribution map to older maps (i.e., maps from the BLM (1976) and DeDecker (1979)). Again, those caveats mentioned previously (i.e., differences in survey methods, level of detail, survey intensity) make comparing distribution maps spanning a 37-year period difficult; however, these comparisons yield information regarding areas where the changes in the distribution of the population may have occurred. Based on our evaluation of current and historical distribution maps, the distribution of Eureka dune grass at Eureka Dunes appears relatively unchanged, and it continues to occupy habitat across the entire dune system, including habitat at the southern end of Marble Canyon Dunes (i.e., the unnamed site), which had not been fully documented previously.
Because the current Eureka dune grass distribution maps may not capture what is occurring on a small scale (such as localized declines in the density of plants) or the area occupied by the species, three additional analyses were conducted.
(1) Using distribution data between 2007 and 2013, the Park Service (2013a, entire) calculated changes in the number of 1-ha grid cells occupied by Eureka dune grass. Results showed a decrease in the number of grid cells occupied at Eureka Dunes, and no change at Marble Canyon and Saline Spur Dunes (Park Service 2013a, pp. 4, 5). Specifically at Eureka Dunes in 2012, Eureka dune grass was present at 397 cells as compared to 446 cells in in 2007; in 2013, Eureka dune grass was present at 390 cells (Park Service 2013a, p. 4). Thus, a change in Eureka dune grass distribution is evident at one location, but not represented across the range of the species at this time.
nyon and Saline Spur Dunes (Park Service 2013a, pp. 4, 5). Specifically at Eureka Dunes in 2012, Eureka dune grass was present at 397 cells as compared to 446 cells in in 2007; in 2013, Eureka dune grass was present at 390 cells (Park Service 2013a, p. 4). Thus, a change in Eureka dune grass distribution is evident at one location, but not represented across the range of the species at this time.
(2) In 2012 and 2013, the Park Service mapped individual clumps of Eureka dune grass on Eureka Dunes to help track the fate of individual clumps over time and to further ground-truth the 1-ha plot GPS-referenced grid system study employed between 2007 and 2013 (Park Service 2012a, 2013a). In 2013, the Park Service (2013a, p. 4) noted dead and dying hummocks on the northeast and southwest side of Eureka Dunes, which is consistent with the change in distribution observed in the Park Service's (2013a, p. 4) analysis at Eureka Dunes. Based on the Park Service's 2013 map, we calculated that 86 ac (35 ha) of the surface of the 2,003-ac (811-ha) Eureka Dunes (less than 4.3 percent) is occupied by Eureka dune grass (Service 2013b, unpublished data). While this new mapping effort will help refine existing monitoring, this information is limited in use because (to date) it only represents 2 years of data at two locations on one of three dunes where the species occurs. If the Park Service conducts additional mapping surveys in the future, new data could be more useful to help determine how the distribution of Eureka dune grass is changing over time.
this new mapping effort will help refine existing monitoring, this information is limited in use because (to date) it only represents 2 years of data at two locations on one of three dunes where the species occurs. If the Park Service conducts additional mapping surveys in the future, new data could be more useful to help determine how the distribution of Eureka dune grass is changing over time.
(3) We inspected photopoints taken at Eureka Dunes as early 1974 to those in 2013 in an attempt to observe possible changes in Eureka dune grass abundance and distribution over time. Our visual inspection indicates a reduction, or in some cases a loss, in the visible Eureka dune grass individuals (especially in the number of large reproductive plants) at the north and southwest end of Eureka Dunes, and portion of Marble Canyon Dunes. We also calculated what proportion of the dunes were represented by the “viewshed” in the photopoints to determine to what extent the observed reduction represented conditions for the species dunewide. Results indicate that approximately 670 ac (271 ha), or 33.4 percent of the Eureka Dunes was visible in the photopoints taken from the north and south end of the dune (Service 2013c, unpublished data). Repeat photopoints were also made at a portion of Marble Canyon Dunes. The photopoints captured 130 ac (53 ha) out of a total 610 ac (247 ha) of the Marble Canyon Dunes, which constituted 21 percent of the dune and showed a similar visible reduction in the Eureka dune grass individuals over time. While our “viewshed” analysis likely overestimates the area visible from these photopoints, it represents our best estimate of the area covered by these repeat photopoints. The observation that a portion of the population at the north and southwest end of Eureka Dunes and part of Marble Canyon Dunes may be experiencing a decline in the abundance and distribution of large, reproductive individuals may be important if these individuals are not replaced
area visible from these photopoints, it represents our best estimate of the area covered by these repeat photopoints. The observation that a portion of the population at the north and southwest end of Eureka Dunes and part of Marble Canyon Dunes may be experiencing a decline in the abundance and distribution of large, reproductive individuals may be important if these individuals are not replaced. However, while a reduction in visible Eureka dune grass individuals is clearly noticeable from a visual inspection, it is difficult to quantify this reduction in terms of estimating changes in population distribution, densities, or abundance. Additionally, without other quantitative data to assist in interpretation, it is difficult to distinguish whether visual changes represent local shifts in distribution and density or rangewide changes in the population. Because our analysis is limited to only a portion of the range of the species, we cannot determine what changes in distribution and abundance have occurred over this same time period across the rest of the species' range within Eureka Valley.
On a small scale, the usefulness of comparing recent maps with historical maps is limited because of the higher precision that was possible in the 2007 to 2013 surveys. Overall and on a large scale, however, the most recent maps indicate that Eureka dune grass populations are still present in the same general locations that they were known from at the time of our 2007 5-year status review.
Abundance Surveys and Population Estimates
Developing population estimates for Eureka dune grass is challenging. We have no information regarding population size at the time of listing, and abundance surveys (which could be used to estimate population size) prior to listing were limited to the northern end of Eureka Dunes. Data collected since listing that could be used to estimate the abundance or population size of Eureka dune grass vary in methods, study areas, timing, and environmental conditions
enging. We have no information regarding population size at the time of listing, and abundance surveys (which could be used to estimate population size) prior to listing were limited to the northern end of Eureka Dunes. Data collected since listing that could be used to estimate the abundance or population size of Eureka dune grass vary in methods, study areas, timing, and environmental conditions. Abundance data have been collected by various parties and entities between 1974 and 2013 (e.g., Henry 1976; Bagley 1986; Park Service 2008a, 2010a, 2011a, 2011b, 2012a, 2013a). It is difficult to compare these data sets primarily due to the use of different methodologies used and because the earlier efforts were limited in spatial extent. Therefore, we cannot determine how Eureka dune grass populations may have changed over time and across the range of the species since listing. Nevertheless, as discussed above for Eureka Valley evening-primrose, there is some usefulness to calculating these estimations as they provide an approximation of the size of each of the populations over time.
Park Service (2008a) data (e.g., resurveys of Henry (1976) and Bagley (1986) transects) provide the most site-specific comparison at this point in time, identifying statistically significant
Because of the limitations identified above, as well as the fact that previous studies documenting the abundance of Eureka dune grass were limited to the north end of Eureka Dunes (and thus may not be representative of the species' abundance at Eureka Dunes or at the other dunes), we are only using data from the monitoring plots established by the Park Service (Cipra in litt. 2011) at all three dunes (i.e., survey data from 2011 and 2013) to provide a population estimate for Eureka dune grass
g the abundance of Eureka dune grass were limited to the north end of Eureka Dunes (and thus may not be representative of the species' abundance at Eureka Dunes or at the other dunes), we are only using data from the monitoring plots established by the Park Service (Cipra in litt. 2011) at all three dunes (i.e., survey data from 2011 and 2013) to provide a population estimate for Eureka dune grass. For the same reasons as presented above for Eureka Valley evening-primrose, in order to compare survey methods across years prior to 2013, we only used 2011 data (i.e., the most complete data set prior to 2013 that included habitat-wide surveys of all three dunes in the same year). The Park Service estimated the total population size to be 8,014 individuals in 2011, and 8,176 individuals in 2013 (Park Service 2013a, p. 7). Based on this information, thousands of Eureka Dune grass individuals exist, and the number was relatively stable across the 2 years compared.
Finally, it is important to note that these population estimates are extrapolations; therefore, the true population size may vary greatly for the following reasons:
(1) The size of the area on which abundance counts were calculated is small (i.e., 1-ha monitoring plots or estimates of relative density within the grid system) in comparison to the size of the area to which the densities are being extrapolated (i.e., the dune systems).
(2) Because Eureka dune grass exhibits a somewhat clumped distribution, it is often difficult to count individuals, and in general it is difficult to estimate the true population size (i.e., individuals can be both underestimated and overestimated).
ative density within the grid system) in comparison to the size of the area to which the densities are being extrapolated (i.e., the dune systems).
(2) Because Eureka dune grass exhibits a somewhat clumped distribution, it is often difficult to count individuals, and in general it is difficult to estimate the true population size (i.e., individuals can be both underestimated and overestimated).
(3) These population estimates include both reproductive and nonreproductive individuals; we do not know the abundance of reproductive individuals within the population.
Regardless of these limitations in extrapolating population estimates for Eureka Dune grass, the best available data indicate the species continues to persist within Eureka Valley across its range (and as stated above, we have no information regarding population size at the time of listing for comparison, with population surveys prior to listing being limited to the northern end of Eureka Dunes). Currently, Eureka Dune grass is known to persist at all three dunes and is represented by thousands of individuals at each of these locations per the best data available from the Park Service.
Recovery and Recovery Plan Implementation
Section 4(f) of the Act directs us to develop and implement recovery plans for the conservation and survival of endangered and threatened species unless we determine that such a plan will not promote the conservation of the species. Under section 4(f)(1)(B)(ii), recovery plans must, to the maximum extent practicable, include: “Objective, measurable criteria which, when met, would result in a determination, in accordance with the provisions of [section 4 of the Act], that the species be removed from the list.” However, revisions to the list (adding, removing, or reclassifying a species) must reflect determinations made in accordance with sections 4(a)(1) and 4(b) of the Act
t, to the maximum extent practicable, include: “Objective, measurable criteria which, when met, would result in a determination, in accordance with the provisions of [section 4 of the Act], that the species be removed from the list.” However, revisions to the list (adding, removing, or reclassifying a species) must reflect determinations made in accordance with sections 4(a)(1) and 4(b) of the Act. Section 4(a)(1) requires that the Secretary determine whether a species is endangered or threatened (or not) because of one or more of five threat factors. Section 4(b) of the Act requires that the determination be made “solely on the basis of the best scientific and commercial data available.” Therefore, recovery criteria should help indicate when we would anticipate an analysis of the five threat factors under section 4(a)(1) would result in a determination that a species is no longer an endangered species or threatened species because of any of the five statutory factors.
Thus, while recovery plans provide important guidance to the Service, States, and other partners on methods of minimizing threats to listed species and measurable objectives against which to measure progress towards recovery, they are not regulatory documents and cannot substitute for the determinations and promulgation of regulations required under section 4(a)(1) of the Act. A decision to revise the status of or remove a species from the Federal List of Endangered and Threatened Plants (50 CFR 17.12) is ultimately based on an analysis of the best scientific and commercial data then available to determine whether a species is no longer an endangered species or a threatened species, regardless of whether that information differs from the recovery plan.
In 1982, we finalized the Eureka Valley Dunes Recovery Plan, which included both Eureka Valley evening-primrose and Eureka dune grass (Recovery Plan; Service 1982)
on an analysis of the best scientific and commercial data then available to determine whether a species is no longer an endangered species or a threatened species, regardless of whether that information differs from the recovery plan.
In 1982, we finalized the Eureka Valley Dunes Recovery Plan, which included both Eureka Valley evening-primrose and Eureka dune grass (Recovery Plan; Service 1982). Following guidance in effect at that time, the Recovery Plan did not include criteria that specifically addressed the point at which threats identified for each species would be removed or sufficiently ameliorated. Instead, the Recovery Plan identified two objectives, each with specific recovery tasks, to consider Eureka Valley evening-primrose and Eureka dune grass for downlisting to threatened status, and eventually, delisting (Service 1982, pp. 26-41). These two objectives are:
(1) Restore the Eureka dune grass and the Eureka Valley evening-primrose to threatened status by protecting extant populations from existing (i.e., in 1982) and potential human threats.
(2) Determine the number of individuals, populations, and acres of habitat necessary for each species to maintain itself without intensive management, in a vigorous, self-sustaining manner within their natural historical dune habitat (estimated 6,000 ac (2,428 ha)) and implement recovery tasks to attain these objectives.
Objective 1: Restore the Eureka dune grass and the Eureka Valley evening-primrose to threatened status by protecting extant populations from existing (i.e., in 1982) and potential human threats Objective 1 is intended to remove existing human threats to populations of Eureka Valley evening-primrose and Eureka dune grass through enforcement of existing laws and regulations, and management of human access to Eureka Valley (Service 1982, p. 26). At the time of listing, the primary threat to both species was off-highway vehicle (OHV) activity, and a lesser threat was camping on and around the dunes (43 FR 17910; April 26, 1978)
sting human threats to populations of Eureka Valley evening-primrose and Eureka dune grass through enforcement of existing laws and regulations, and management of human access to Eureka Valley (Service 1982, p. 26). At the time of listing, the primary threat to both species was off-highway vehicle (OHV) activity, and a lesser threat was camping on and around the dunes (43 FR 17910; April 26, 1978). Since listing, potential human threats have included other recreational activities such as sandboarding and horseback riding.
Various land management activities have been implemented by the BLM (prior to Park Service acquisition of the Eureka Valley area in 1994) and the Park Service (since 1994). All of the dune systems within Eureka Valley have also been designated as Federal wilderness areas. A number of management activities have been implemented to support the long-term protection of Eureka Valley evening-primrose and Eureka dune grass within the Federal wilderness area, including (but not limited to): making OHV activity illegal; conducting patrols to enforce laws, regulations, and restrictions; closing and restoring unauthorized roads; installing interpretative signs, barriers, and wilderness boundary signs; and delineating and maintaining campsites (Park Service 2008b, 2009, 2010b).
Additionally, various education and public outreach (e.g., public awareness program, interpretive displays) has been conducted to reduce overall impacts to the species. Because all three populations occur within Federal wilderness areas that are now protected against the threats identified as imminent at the time of listing and in the Recovery Plan, we conclude that this recovery objective has been met
ionally, various education and public outreach (e.g., public awareness program, interpretive displays) has been conducted to reduce overall impacts to the species. Because all three populations occur within Federal wilderness areas that are now protected against the threats identified as imminent at the time of listing and in the Recovery Plan, we conclude that this recovery objective has been met.
Objective 2: Determine the number of individuals, populations, and acres of habitat necessary for each species to maintain itself without intensive management, in a vigorous, self-sustaining manner within their natural historical dune habitat (estimated 6,000 ac (2,428 ha)) and implement recovery tasks to attain these objectives Although this objective in the 1982 recovery plan is not the clearest example of a measurable and objective criterion, the intent is to evaluate the status of both species with regards to demographic characteristics to determine whether they could be considered recovered as opposed to meeting either the definition of an endangered species or the definition of a threatened species, and more importantly to attain the desired demographic levels necessary for recovery. While we have not yet developed precise values for all of the various demographic characteristics that help us determine whether the removal of threats have the desired effect (e.g., stable populations, positive growth), both species still occupy all three dune systems, and the best available monitoring data indicate thousands of plants are present at each dune system. Additionally, the best available information indicates that the BLM and Park Service have sufficiently minimized OHV and other recreation activities that were previously impacting the populations and their habitat
able populations, positive growth), both species still occupy all three dune systems, and the best available monitoring data indicate thousands of plants are present at each dune system. Additionally, the best available information indicates that the BLM and Park Service have sufficiently minimized OHV and other recreation activities that were previously impacting the populations and their habitat. Even though the precise values of all demographic characteristics are not known, we note that many research and monitoring efforts have occurred for both species since the time of listing (unless otherwise noted), which have provided information on the life-history needs of both Eureka Valley evening-primrose and Eureka dune grass, as well as potential impacts to both species, including (but not limited to) the following studies:
(1) Conducting a series of studies on both species to investigate effects of pollination on seed set, seed ecology, species' demography, and plant and animal interactions (herbivory, seed predation, and dispersal) (Pavlik and Barbour 1985, 1986).
(2) Establishing baseline conditions for monitoring trends of both species across all three dune systems (Bagley 1986).
(3) Studying the genetic diversity of all Eureka dune grass populations (Bell 2003).
(4) Conducting partial distribution surveys of both species on portions of various dunes (Beymer in litt. 1997a; Peterson in litt. 1998), as well as documenting the distribution and abundance of Russian thistle, a potential competitor, across all three dune systems (Park Service 2011b).
(5) Documenting distribution, abundance, and demography of both species (Park Service 2008a, 2008c, 2010a, 2011a, 2011b, 2012a, 2013a).
(6) Determining if vegetation succession at the northern end of Eureka Dunes (Eureka dune grass habitat) is associated with changes in subsurface hydrology (Park Service 2008c, p. 4).
a potential competitor, across all three dune systems (Park Service 2011b).
(5) Documenting distribution, abundance, and demography of both species (Park Service 2008a, 2008c, 2010a, 2011a, 2011b, 2012a, 2013a).
(6) Determining if vegetation succession at the northern end of Eureka Dunes (Eureka dune grass habitat) is associated with changes in subsurface hydrology (Park Service 2008c, p. 4).
(7) Investigating potential competition between Russian thistle and Eureka Valley evening-primrose, and the effects of herbivory on Eureka Valley evening-primrose (Chow and Klinger 2013; Chow in litt. 2011).
(8) Monitoring photopoint stations over time, starting in 1985, and retaken at various intervals (Park Service 2008c, 2011b).
As a result of the considerable work that has been undertaken to understand the population dynamics and life histories of these two species, we consider the intent of Objective 2 has been partially met. Based on our review of the Recovery Plan and the information obtained from the various surveys and research activities that have occurred to date, we conclude that the status of the habitat for Eureka Valley evening-primrose and Eureka dune grass has improved due to activities that have been implemented by BLM and the Park Service. The effects of these activities on the status of the two taxa are discussed in further detail below.
Summary of Factors Affecting the Species
Section 4 of the Act and its implementing regulations (50 CFR part 424) set forth the procedures for listing species, reclassifying species, or removing species from listed status. “Species” is defined by the Act as including any species or subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature (16 U.S.C. 1532(16))
e Act and its implementing regulations (50 CFR part 424) set forth the procedures for listing species, reclassifying species, or removing species from listed status. “Species” is defined by the Act as including any species or subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature (16 U.S.C. 1532(16)). A species may be determined to be an endangered or threatened species because of any one or a combination of the five factors described in section 4(a)(1) of the Act: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or human made factors affecting its continued existence. A species may be reclassified or removed from the Federal List of Endangered and Threatened Plants (50 CFR 17.12) on the same basis.
Determining whether the status of a species has improved to the point that it can be downlisted or delisted requires consideration of whether the species is endangered or threatened because of the same five categories of threats specified in section 4(a)(1) of the Act. For species that are already listed as endangered or threatened, this analysis of threats is an evaluation of both the threats currently facing the species and the threats that are reasonably likely to affect the species in the foreseeable future
A species is an “endangered species” for purposes of the Act if it is in danger of extinction throughout all or a significant portion of its range and is a “threatened species” if it is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range
and the threats that are reasonably likely to affect the species in the foreseeable future
A species is an “endangered species” for purposes of the Act if it is in danger of extinction throughout all or a significant portion of its range and is a “threatened species” if it is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. The word “range” in the significant portion of its range phrase refers to the range in which the species currently exists, and the word “significant” refers to the value of that portion of the range being considered to the conservation of the species. The “foreseeable future” is the period of time over which events or effects reasonably can or should be anticipated, or trends extrapolated. For the purposes of this analysis, we first evaluate the status of the species throughout all its range, then consider whether the species is in danger of extinction or likely to become so in any significant portion of its range.
Brief History of Threats Analysis
At the time of listing, the primary threat to Eureka Valley evening-primrose and Eureka dune grass was OHV activity at Eureka Dunes (43 FR 17910; April 26, 1978); although not specifically stated in the final listing rule, this also presumes a lesser degree of impacts from camping that were associated with OHV activity on and around the dunes. By the time the Recovery Plan was developed in 1982 (Service 1982, entire), threats to both plants from these activities had been substantially ameliorated. Subsequently, we conducted a 5-year status review (which included an analysis of threats that affect the species) in 2007 (Service 2007a, 2007b, entire). By this point in time, the primary threat at the time of listing (OHV activity at Eureka Dunes) had been addressed with closure of Eureka Dunes by BLM, subsequent land use designations, and management measures undertaken by BLM and later by the Park Service (Service 2007a, pp. 8-10, 11-12, 13; Service 2007b, pp. 5-7, 9, 11)
f threats that affect the species) in 2007 (Service 2007a, 2007b, entire). By this point in time, the primary threat at the time of listing (OHV activity at Eureka Dunes) had been addressed with closure of Eureka Dunes by BLM, subsequent land use designations, and management measures undertaken by BLM and later by the Park Service (Service 2007a, pp. 8-10, 11-12, 13; Service 2007b, pp. 5-7, 9, 11). We also identified camping, horseback riding, and sandboarding as potential threats since the time of listing; however, we determined that these activities no longer posed a threat to the two species because of successful management implemented by the Park Service (Service 2007a, pp. 10-12, 13; Service 2007b, pp. 7-8, 11). Finally, we identified potential threats to Eureka Valley evening-primrose and Eureka dune grass in our 2007 5-year status reviews, including: Russian thistle, predation, and stochastic events; we determined that we did not have sufficient information to conclude that these impacts were a threat to the continued existence of both species (Service 2007a, pp. 11, 12-13; Service 2007b, pp. 9, 10-11).
For a detailed discussion of the current status review initiated with our 2011 90-day finding (76 FR 3069), please see the Background Information document (Service 2014, pp. 38-65). The following sections provide analyses of the potential current or future impacts to Eureka Valley evening-primrose and Eureka Dune grass, including: OHV activity (Factors A and E); other recreational activities (i.e., horseback riding, sandboarding, camping, and associated access routes) (Factors A and E); overutilization for commercial, recreational, scientific, or educational purposes (Factor B); herbivory and seed predation (Factor C); inadequacy of existing regulatory mechanisms (Factor D); competition with Russian thistle (Factor E); climate change (Factor E); and stochastic events (Factor E).
A
s (i.e., horseback riding, sandboarding, camping, and associated access routes) (Factors A and E); overutilization for commercial, recreational, scientific, or educational purposes (Factor B); herbivory and seed predation (Factor C); inadequacy of existing regulatory mechanisms (Factor D); competition with Russian thistle (Factor E); climate change (Factor E); and stochastic events (Factor E).
A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range
OHV Activity
OHV activity generally includes 4-wheel drive vehicular use of roads and trails, predominantly on public lands, for the purpose of touring, hunting, fishing, or other public land use. Within the Eureka Valley, OHV activity was an authorized use until 1976, when BLM closed Eureka Dunes and some of the surrounding area to OHVs following publication of the proposed rule to list Eureka Valley evening-primrose and Eureka dune grass. Subsequently in 1980, BLM designated Eureka Dunes and some of the surrounding area as an Area of Critical Environmental Concern (ACEC) and began compliance monitoring and management (BLM 1982, pp. 3-5). BLM's efforts resulted in few observed violations of the OHV closures between 1979 and 1994 (Service 1982, p. 24; DeDecker 1994, Harris 1994, and Stormo 1994 in Noell 1994, p. 9).
In general, the impacts to Eureka Valley evening-primrose and Eureka dune grass associated with OHV activity have essentially been ameliorated, in large part due to the designation of Federal wilderness areas throughout both species' ranges. First, the management of Eureka Valley was transferred from BLM to the Park Service in 1994. Subsequently in 1994, all of the dune systems within Eureka Valley were designated as Federal wilderness areas. Under the authority of the Wilderness Act of 1964 (16 U.S.C. 1131 et seq. ), use of mechanized vehicles were no longer allowed throughout the entire ranges of both species
t both species' ranges. First, the management of Eureka Valley was transferred from BLM to the Park Service in 1994. Subsequently in 1994, all of the dune systems within Eureka Valley were designated as Federal wilderness areas. Under the authority of the Wilderness Act of 1964 (16 U.S.C. 1131 et seq. ), use of mechanized vehicles were no longer allowed throughout the entire ranges of both species. This OHV prohibition throughout the range of both species, along with the benefits associated with the prohibition of other activities in Federal wilderness areas (e.g., development of new roads or structures, use of motorized equipment), all of which must be implemented by the Park Service (per various laws, directives, and plans specific to the Park Service and Death Valley National Park), have essentially ameliorated the threat of OHV activity and other ground disturbance activities to both species.
Since 1994, the Park Service has documented occasional illegal OHV activity in Federal wilderness areas and has proposed additional measures to further reduce this activity; however, the Park Service acknowledges that the remote location of the dunes and limited resources make enforcing restrictions difficult (Park Service 2011b, p. 17).
OHV activity could affect Eureka Valley evening-primrose and Eureka dune grass habitat in multiple ways, as evidenced from many studies that have occurred within dune ecosystems (such as Wilshire and Nakata 1976, Webb and Wilshire 1983). Physical impacts on dunes can include compaction or erosion of sandy substrates, acceleration of wind erosion (Gillette and Adams 1983, pp. 97-109), and acceleration of dune drift (Gilberston 1983, pp. 362-365). OHV activity can also change the unique hydrologic conditions of dunes. Because dunes have the capacity to hold moisture for long periods of time, disturbance of the surface sands resulting in exposure of moist sands underneath can increase moisture loss from the dunes (Geological Society of America 1977, p. 4)
Adams 1983, pp. 97-109), and acceleration of dune drift (Gilberston 1983, pp. 362-365). OHV activity can also change the unique hydrologic conditions of dunes. Because dunes have the capacity to hold moisture for long periods of time, disturbance of the surface sands resulting in exposure of moist sands underneath can increase moisture loss from the dunes (Geological Society of America 1977, p. 4). Changes in physical and hydrologic properties of the dunes from heavy OHV activity could in turn affect the suitability of the dune habitat for germination and recruitment of seedlings, clonal expansion of existing individuals, and dispersal of seeds to favorable microsites.
The same potential OHV impacts that affect dune habitat can also affect Eureka Valley evening-primrose and Eureka dune grass individual plants. Normally, these types of impacts would be discussed under Factor E (Other Natural or Manmade Factors Affecting Its Continued Existence), but are included here in the Factor A discussion for ease of analysis. OHV impacts to individual plants within
Although unauthorized OHV activity has occasionally occurred on the Eureka Dunes, it has not approached the levels seen prior to listing Eureka Valley evening-primrose and Eureka dune grass as endangered species. Management actions initially taken by BLM prior to listing (i.e., closure to OHV recreation) and following listing of these species (e.g., vehicle route closures, control of visitor use, visitor education, enforcement of wilderness closures) have continued and increased under Park Service management, and all populations of both species are now within designated wilderness area where OHVs are prohibited. The management of OHV activity through land use designations (i.e., ACEC, Federal wilderness areas) has resulted in the near elimination of OHV activity on Eureka Dunes at the current time
education, enforcement of wilderness closures) have continued and increased under Park Service management, and all populations of both species are now within designated wilderness area where OHVs are prohibited. The management of OHV activity through land use designations (i.e., ACEC, Federal wilderness areas) has resulted in the near elimination of OHV activity on Eureka Dunes at the current time. We anticipate this will continue into the future because we expect Federal wilderness areas to remain in place indefinitely, and we expect the Park Service's current management to be implemented over the next 20 years, as well as modified periodically into the future with adaptive management strategies (as demonstrated by the Park Service's natural resource management strategies to date and anticipated in the future per Park Service policies and regulations (see Factor D)). Additionally, the remote location, inaccessibility, and wilderness status of the Saline Spur and Marble Canyon Dunes appear to be providing sufficient protection for dune habitats and plants at these locations both currently and in the future. Although the Park Service has documented sporadic occurrences of unauthorized OHV activity, these occurrences are almost entirely localized to areas on and adjacent to the northern end of Eureka Dunes (Beymer 1996; Beymer in litt. 1997b,d,g; Beymer 1997c,e,f; Anderson 1998; Dellingers 1998a-c; Peterson in litt. 1998b,c; Rods 1998; Park Service circa 2000; Rods 2000; Park Service 2011b). Therefore, we conclude, based on the best available information, that the Wilderness Area designation, coupled with Park Service management of OHV activity and other visitor uses, have significantly reduced these impacts to Eureka Valley evening-primrose and Eureka dune grass and their habitat currently and into the future
998b,c; Rods 1998; Park Service circa 2000; Rods 2000; Park Service 2011b). Therefore, we conclude, based on the best available information, that the Wilderness Area designation, coupled with Park Service management of OHV activity and other visitor uses, have significantly reduced these impacts to Eureka Valley evening-primrose and Eureka dune grass and their habitat currently and into the future.
Other Recreational Activities
In addition to unauthorized OHV activity that may occur currently (as described above), other recreational activities have been known historically and currently occur (occasionally) within the Eureka Dunes, including horseback riding, sandboarding, camping outside of designated areas, and creation of access routes.
Camping and associated access routes were identified as a minor threat in the Recovery Plan because their proximity to Eureka Dunes facilitated unauthorized OHV activity (Service 1982, pg. 22, 23). Horseback riding and sandboarding were potential threats to Eureka Valley evening-primrose and Eureka dune grass identified after listing, and were discussed in the 5-year status reviews published in 2007 (Service 2007a, p. 10; Service 2007b, pp. 78). All of these activities were discussed in our 5-year review under Factor A because, like OHV activity, they have the ability to have physical impacts on the dune habitat (such as destabilization and displacement of sands); however, these same activities have the potential for damaging individual plants through crushing, trampling, and uprooting. Although impacts to individual plants are more appropriately discussed under Factor E, for ease of analysis we also discuss impacts to individual plants here.
Although horseback riding was first identified by the Park Service as a potential concern in the late 1990s, there is no information regarding the extent of an impact to Eureka Valley evening-primrose and Eureka dune grass during this period, nor is there specific evidence related to the adverse effects of trampling by horses
or ease of analysis we also discuss impacts to individual plants here.
Although horseback riding was first identified by the Park Service as a potential concern in the late 1990s, there is no information regarding the extent of an impact to Eureka Valley evening-primrose and Eureka dune grass during this period, nor is there specific evidence related to the adverse effects of trampling by horses. Regardless, the Park Service considered potential adverse effects from horseback riding to be similar to those of light to moderate OHV activity (as described by Pavlik (1979a) as one to multiple tire passes over individual plants), which in turn could trample or crush (Factor E) Eureka Valley evening-primrose or Eureka dune grass plants.
Sandboarding became popular in the late 1990s, and this activity increased within Eureka Valley specifically following an October 1997 article in Esquire Magazine that identified Eureka Dunes as a location to pursue this activity (Warren 1997, p. 143). There is no information regarding the extent of the adverse effects that this activity had on Eureka Valley evening-primrose or Eureka dune grass, but crushing (Factor E) of individual Eureka dune grass plants was observed in 1997 (Beymer 1997h).
Camping and access routes were first identified as a concern to Eureka Valley evening-primrose and Eureka dune grass habitat and plants as a result of observed OHV activity concentrating near the northwest corner of Eureka Dunes (BLM 1982, p. 4; Service 1982, pp. 22-23). The Recovery Plan discusses camping and associated access routes as facilitating unauthorized OHV activity, which in turn caused adverse effects to habitat for both species (Service 1982, p. 24); although the plan does not specify, we assume these activities were identified as threats because the concentration of activity could result in trampling of individual plants (Factor E) or alteration of habitat due to compaction or erosion (Factor A)
ated access routes as facilitating unauthorized OHV activity, which in turn caused adverse effects to habitat for both species (Service 1982, p. 24); although the plan does not specify, we assume these activities were identified as threats because the concentration of activity could result in trampling of individual plants (Factor E) or alteration of habitat due to compaction or erosion (Factor A).
Since the time of listing, a number of actions have been implemented to reduce and eliminate impacts associated with horseback riding, sandboarding, camping, and establishment of associated access points within and around Eureka Valley evening-primrose and Eureka dune grass habitat (e.g., establishing designated wilderness areas throughout the Eureka Valley, with attendant restrictions on the development of new roads and structures, and not allowing the use of motorized vehicles off designated roads). The BLM and Park Service have implemented recommendations from the Recovery Plan (e.g., establishment of defined camping areas away from the dunes, transforming the northwest access point into a day-use-only area) (Park Service 2000, p. 11; Park Service 2006, pp. 6-7), and horseback riding and sandboarding have been prohibited since 2002 (Park Service 2002, p. 3; 2006, p. 10). The Park Service enforces the restrictions, including the wilderness area designation that prohibits OHV activity (and thus potential unauthorized camping and access routes) on the dunes. Beginning in 2007, the Park Service also expanded a program to further increase visitor compliance with the rules and regulations that outline authorized activities in the Eureka Dunes, which includes: Conducting patrols; closing and restoring illegal roads; installing interpretative signs, barriers, and wilderness boundary signs; and delineating and maintaining campsites (Park Service 2008b, 2009, 2010b). While the NPS has documented some in litt. 1997b,d,g; Beymer 1997c,e,f; Anderson 1998; Dellingers 1998a-c; Peterson in litt
t outline authorized activities in the Eureka Dunes, which includes: Conducting patrols; closing and restoring illegal roads; installing interpretative signs, barriers, and wilderness boundary signs; and delineating and maintaining campsites (Park Service 2008b, 2009, 2010b). While the NPS has documented some in litt. 1997b,d,g; Beymer 1997c,e,f; Anderson 1998; Dellingers 1998a-c; Peterson in litt. 1998b,c; Rods 1998; Park Service circa 2000; Rods 2000; Park Service 2011b). Therefore, the best available information at this time indicates that unauthorized OHV and other recreational activities, if they occur, are not causing population-level effects (as compared to pre-listing levels) for either species currently, nor are they expected to do so in the future, in large part due to the extensive protections and management provided by the Park Service.
B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
Utilization for commercial, recreational, scientific, or educational purposes was not identified as a threat to Eureka Valley evening-primrose or Eureka dune grass in the listing rule. Both taxa have no known commercial or recreational value that we consider consumptive (that is, based on physical use or removal of the plants). Educational groups frequently visit Eureka Dunes, but we are unaware of any activities that would be considered consumptive use. Since listing, there have been three section 10(a)(1)(A) permits issued for studies involving the removal of plants, seeds, or plant parts. These studies usually involve collection of seeds or leaves for laboratory experiments or collection of voucher specimens for herbaria; in each case we analyzed potential impacts during the permitting process and determined that the collection activities would not jeopardize the continued existence of the species
A) permits issued for studies involving the removal of plants, seeds, or plant parts. These studies usually involve collection of seeds or leaves for laboratory experiments or collection of voucher specimens for herbaria; in each case we analyzed potential impacts during the permitting process and determined that the collection activities would not jeopardize the continued existence of the species. Additionally, Eureka dune grass seeds were collected in 2007, as part of a joint project between the Park Service and the Center for Plant Conservation to preserve germplasm (a collection of genetic resources) of federally listed species (Fraga 2007). We do not consider this level of research and collection to pose any potential threat of overutilization for either of the species. Furthermore, the State of California and Park Service have regulatory mechanisms in place to control any potential utilization in the future (see also Factor D below). Any collection of plants would require permits from the State of California and the Park Service. We conclude that overutilization for commercial, recreational, scientific, or educational purposes is not a short-term or long-term threat to the continued existence of Eureka Valley evening-primrose or Eureka dune grass.
C. Disease or Predation
At the time of listing, disease and predation were not identified as potential threats to Eureka Valley evening-primrose or Eureka dune grass. Since then, studies on both species imply that herbivory and seed predation are potential threats for both species.
hort-term or long-term threat to the continued existence of Eureka Valley evening-primrose or Eureka dune grass.
C. Disease or Predation
At the time of listing, disease and predation were not identified as potential threats to Eureka Valley evening-primrose or Eureka dune grass. Since then, studies on both species imply that herbivory and seed predation are potential threats for both species.
(1) Pavlik and Barbour (1985, pp. 62-63) concluded that jackrabbit pruning of Eureka dune grass would seldom lead to the death of mature plants; however, in contrast, pruning could remove branches of Eureka Valley evening-primrose or jackrabbits may cause mortality of individual plants by uprooting them. Additionally, the pruning could have a negative effect on seed production if it occurs prior to ripening and dispersal (Pavlik and Barbour 1985, pp. 60, 62-63. Pavlik and Barbour (1985, pp. 62-63) suggested that herbivory of Eureka Valley evening-primrose could result in a substantial loss of seeds entering the seed bank if peak herbivory coincided with peak seed production in a given season, though they noted that most seed production occurred prior to the start of intense herbivory.
(2) Chow ( in litt. 2011) hypothesized that herbivory of Eureka Valley evening-primrose may affect the size, survivability, and fecundity of individual plants. Chow ( in litt. 2011) collected preliminary information on the effects of herbivory at all three dunes in 2011. This information indicates that the level of herbivory varies at each dune, ranging from either no evidence of herbivory to the complete loss of individuals (although we note this information was limited to one season).
adapted to withstand some level of herbivory and seed predation. Given that both species have persisted since listing (and since the studies in 1985 and 1986), and continue to occupy the same general distribution, it does not appear that herbivory and seed predation by themselves are occurring at such a level to cause population-level declines or other adverse effects to either species as a whole. Based on the best available information at this time (i.e., a single season of herbivory/seed predation study; the expectation that these species have evolved with some level of herbivory/seed predation; and that herbivory/seed predation is naturally occurring, and some level of herbivory/seed predation is expected for both species), we conclude that the observed impacts are not causing population-level effects for either species currently, nor are they expected to do so in the future.
D. The Inadequacy of Existing Regulatory Mechanisms
Because the ranges of both Eureka Valley evening-primrose and Eureka dune grass now occur entirely on Park Service land, any potential for impacts to the two species would be those from Park Service activities or from activities under their jurisdiction. Regulatory mechanisms (as they relate to OHV and other recreational activities) that protect the Eureka Valley evening-primrose and Eureka dune grass habitat were discussed under Factor A above (i.e., protections afforded currently and into the future as a result of the congressionally designated wilderness). These protections, taken together, would provide adequate regulatory mechanisms to prevent the Eureka Valley evening-primrose and Eureka dune grass from becoming endangered or threatened after they are removed from the Federal List of Endangered and Threatened Plants. Additional regulatory mechanisms (not discussed above under Factor A) as they relate to Factors A, B, C, and E include the following:
se protections, taken together, would provide adequate regulatory mechanisms to prevent the Eureka Valley evening-primrose and Eureka dune grass from becoming endangered or threatened after they are removed from the Federal List of Endangered and Threatened Plants. Additional regulatory mechanisms (not discussed above under Factor A) as they relate to Factors A, B, C, and E include the following:
(1) Organic Act of 1916 (16 U.S.C. 1, as amended ). This Act promotes and regulates the use of National Parks to conserve scenery, national and historical objects, and wildlife to
(2) General Management Plan (2002). The Park Service manages the Eureka Valley under a broad general management plan, which identified the need for development of site-specific management for Eureka Valley (Park Service 2002, p. 7); however, such a plan has not yet been developed. Despite the lack of a site-specific management plan for the Eureka Valley, the general management plan must be consistent with the legal and stewardship mandates outlined in national and Park Service-wide laws and policies (Park Service 2002; Park Service 2006).
(3) Wilderness and Backcountry Stewardship Plan (2013). In 2013, the Park Service finalized its Wilderness and Backcountry Stewardship Plan and environmental assessment, which is considered an implementation plan tiered from the 2002 General Management Plan. The Park Service selected a modification of one of the alternatives (i.e., Alternative D) that would provide benefits to Eureka Valley evening-primrose and Eureka dune grass, and their habitat, by delineating existing campsites and designating additional campsites at Eureka Dunes, prohibiting camping and sandboarding on Eureka Dunes, upgrading or replacing the existing vault toilet and installing a second low maintenance toilet on the east side of the dunes, supporting a campground host during heavy visitor use periods, and increasing visitor education on- and off-site (Park Service 2013b, pp. 4, 5, 10, 16)
ing campsites and designating additional campsites at Eureka Dunes, prohibiting camping and sandboarding on Eureka Dunes, upgrading or replacing the existing vault toilet and installing a second low maintenance toilet on the east side of the dunes, supporting a campground host during heavy visitor use periods, and increasing visitor education on- and off-site (Park Service 2013b, pp. 4, 5, 10, 16). This plan also discusses the Park Service's methods for managing nonnative plant species including (but not limited to) Russian thistle.
Removing Eureka Valley evening-primrose and Eureka dune grass from the Federal List of Endangered or Threatened Plants would not significantly change the protections afforded these species. At the time of listing, the existing regulatory mechanisms were a concern because we determined they were inadequate to address the threat to the habitat posed by OHV recreation. Currently, because the ranges of both Eureka Valley evening-primrose and Eureka dune grass occur entirely on Park Service land, any potential for impacts to the two species would be those from Park Service activities or from activities under their jurisdiction. All areas containing populations of both species are within congressionally designated wilderness (Park Service 2002). The Park Service has also prohibited other activities, such as sandboarding and horseback riding, that have potential adverse effects to populations of these species (Croissant in litt. 2005), and the Park Service implements extensive public outreach, promotes research, and ensures enforcement of its laws and regulations (either through patrols or potentially the future use of a campground host) to ensure impacts to both species are minimized to the maximum extent practicable (Park Service 2002, 2006, 2013b)
tial adverse effects to populations of these species (Croissant in litt. 2005), and the Park Service implements extensive public outreach, promotes research, and ensures enforcement of its laws and regulations (either through patrols or potentially the future use of a campground host) to ensure impacts to both species are minimized to the maximum extent practicable (Park Service 2002, 2006, 2013b).
While most of these laws, regulations, and policies are not specifically directed toward protection of Eureka Valley evening-primrose and Eureka dune grass, they mandate consideration, management, and protection of resources that benefit these species. Additionally, these laws contribute to and provide mechanisms for agency planning and implementation directed specifically toward management of Eureka Valley evening-primrose and Eureka dune grass and their habitat. Because most of these laws and regulations are national in scope and are not conditional on the listed status of the plants, we expect these laws and regulatory mechanisms to remain in place after Eureka Valley evening-primrose and Eureka dune grass are delisted. Therefore, the inadequacy of existing regulatory mechanisms is not a threat to Eureka Valley evening-primrose and Eureka dune grass now or in the future. Additionally, although some factors described in this document may continue to cause stress to either one or both species, the existing regulatory mechanisms are sufficient to manage the continued existence of Eureka Valley evening-primrose and Eureka dune grass currently and in the future.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
OHV Activity and Other Recreational Activities
See the “OHV Activity” and “Other Recreational Activities” sections, above under Factor A, for a complete discussion of realized and potential impacts since the time of listing. As stated there, we included a complete discussion of potential impacts to both habitat and individual plants under Factor A for ease of analysis
g Its Continued Existence
OHV Activity and Other Recreational Activities
See the “OHV Activity” and “Other Recreational Activities” sections, above under Factor A, for a complete discussion of realized and potential impacts since the time of listing. As stated there, we included a complete discussion of potential impacts to both habitat and individual plants under Factor A for ease of analysis. We conclude, based on the best available information, that the Wilderness Area designation, coupled with Park Service management of OHV activity and other recreational activity, have significantly reduced potential impacts to Eureka Valley evening-primrose and Eureka dune grass individuals currently and into the future. See additional discussion above under Factors A and D.
Competition With Russian Thistle
Invasive, nonnative plants can potentially impact the long-term persistence of endemic species. Salsola spp. (Russian thistle) is the only invasive, nonnative species that has spread onto the dunes in the Eureka Valley. Previous information (available at the time of our 2007 5-year reviews) was generally limited to personal observations and collections with no specific information regarding the density or distribution of Russian thistle. However, due to continuing concerns expressed by the Park Service and other parties since 2007, we conducted a more thorough review of the life-history characteristics of Russian thistle and the potential impacts it could have on both species, particularly the potential for Russian thistle to compete with Eureka Valley evening-primrose and Eureka dune grass for resources such as water and nutrients.
Russian thistle is known to spread in areas where soil has been disturbed, and is commonly found along road margins, rail lines, feed lots, and abandoned agricultural fields, and in grain seed
tential impacts it could have on both species, particularly the potential for Russian thistle to compete with Eureka Valley evening-primrose and Eureka dune grass for resources such as water and nutrients.
Russian thistle is known to spread in areas where soil has been disturbed, and is commonly found along road margins, rail lines, feed lots, and abandoned agricultural fields, and in grain seed. Although the source of spread is unknown for the Eureka Valley, it was first noted there in the 1970s; agricultural activities (grazing and farming) still occur in the northern portion of Eureka Valley to the north of Death Valley National Park, likely serving as a continuing seed source.
At the time of our 2007 5-year status reviews, we briefly discussed potential competition with Russian thistle as a threat to Eureka Valley evening-primrose and Eureka dune grass. We concluded that Russian thistle was not a substantial threat to Eureka Valley evening-primrose because the latter continued to occupy areas containing Russian thistle, and there was no information regarding the effects of Russian thistle on the stability of the population (Service 2007a, p. 12). For Eureka dune grass, we also concluded that Russian thistle was not a substantial threat because there was no information to support a competitive relationship between it and Russian
In 2011, the distribution and density pattern of Russian thistle and Eureka Valley evening-primrose was mapped by the Park Service across all three dunes over several years (Park Service 2011a, pp. 18-21). In addition, the USGS noted an inverse relationship in the spatial distribution and abundance of the two species along a series of transects. Both of these studies suggested that there may be a competitive relationship for resources (for instance, water or light) between Russian thistle and Eureka Valley evening-primrose (Chow and Klinger 2013, p. 15)
several years (Park Service 2011a, pp. 18-21). In addition, the USGS noted an inverse relationship in the spatial distribution and abundance of the two species along a series of transects. Both of these studies suggested that there may be a competitive relationship for resources (for instance, water or light) between Russian thistle and Eureka Valley evening-primrose (Chow and Klinger 2013, p. 15). Therefore, in 2012, USGS initiated an ex situ pilot study to determine if there is a potential competitive relationship between Russian thistle and Eureka Valley evening-primrose (Chow and Klinger 2013, pp. 15-18). Preliminary information provided by Chow and Klinger (2013, pp. 17-18) indicates that intraspecific competition (competition between individuals of the same species) had a greater effect on Eureka Valley evening-primrose than interspecific competition (competition between individuals of different species) with Russian thistle. However, we note that the results of this study are preliminary and limited to a short time period (i.e., 10 weeks). Based on past and current Park Service management practices, we reasonably anticipate that the Park Service would incorporate new information received from future management and research studies into their future management plans for Eureka Valley.
Limited information is available on the effects of Russian thistle to native plant species and ecosystems, likely because Russian thistle tends to invade disturbed areas; thus, almost all available literature is based on its effects to agricultural crops and grazing lands. Regardless, general impacts to native flora, including Eureka Valley evening-primrose or Eureka dune grass, from Russian thistle could include increased competition when water is limited (Allen 1982, p. 739), or potentially reduced recruitment (such as exhibited by other invasive, nonnative plants that occur in high abundance) (Thomson 2005, pp. 615-624; Barrows et al. 2009, pp. 679, 683)
g lands. Regardless, general impacts to native flora, including Eureka Valley evening-primrose or Eureka dune grass, from Russian thistle could include increased competition when water is limited (Allen 1982, p. 739), or potentially reduced recruitment (such as exhibited by other invasive, nonnative plants that occur in high abundance) (Thomson 2005, pp. 615-624; Barrows et al. 2009, pp. 679, 683).
To better understand the overlap in distribution of Russian thistle and Eureka Valley evening-primrose, we examined the Park Service's best available data layers for each species (i.e., 2010 data for Russian thistle and 2011 data for Eureka Valley evening-primrose, which were the years in which each species had the greatest above-ground expression). Based on our analysis, the distribution of Russian thistle overlaps the Eureka Valley evening-primrose distribution over all three dunes by 84 percent (Service 2013a). However, the extent of overlap does not necessarily indicate that competition is occurring. Since 2010, there have been years with very little to virtually no germination of Russian thistle (Park Service 2011a, p. 18; 2012a, p. 4; 2013a p. 4). It is unclear whether the conditions that stimulate germination of Eureka Valley evening-primrose are the same conditions that would stimulate the germination of Russian thistle. For instance, in 2013, there was mass germination of Eureka Valley evening-primrose in the sand flats to the east of Eureka Dunes, but there was little germination of Russian thistle (Park Service 2013a, p. 4), indicating that different environmental factors are needed to trigger mass germination events in these two species. It is possible that, during years when Russian thistle is abundant, this plant may compete with Eureka Valley evening-primrose for resources such as water and nutrients. However, the best available information does not indicate that Russian thistle may outcompete Eureka Valley evening-primrose for these resources either currently or in the future
igger mass germination events in these two species. It is possible that, during years when Russian thistle is abundant, this plant may compete with Eureka Valley evening-primrose for resources such as water and nutrients. However, the best available information does not indicate that Russian thistle may outcompete Eureka Valley evening-primrose for these resources either currently or in the future.
At this time, competition with Russian thistle does not appear to be impacting the Eureka Valley evening-primrose at a level that would cause population-level or species-level effects. We have reached this conclusion for the following reasons:
(1) Russian thistle abundance, like that of Eureka Valley evening-primrose, varies annually; therefore, the degree to which these species overlap will vary annually.
(2) The best available information does not indicate that the same conditions that stimulate the germination of Eureka Valley evening-primrose also stimulate germination of Russian thistle, which in turn reduces the likelihood of a competitive relationship between these species either in the short term or long term. The mass germination of Eureka Valley evening-primrose individuals in 2013 implies different environmental factors are needed to get a similar mass germination of Russian thistle to potentially impact Eureka Valley evening-primrose seedlings or established plants. Therefore, this reduces the likelihood of a competitive relationship between these species either in the short-term or long-term.
With regard to Eureka dune grass, we have already noted above that the distribution of Russian thistle occurs across all three dunes. However, the best available data indicate that the potential for Russian thistle to impact Eureka dune grass is unlikely because:
(1) Eureka dune grass typically occurs on the steeper, unstable slopes of the dunes, which appears to limit the establishment of Russian thistle; and
ureka dune grass, we have already noted above that the distribution of Russian thistle occurs across all three dunes. However, the best available data indicate that the potential for Russian thistle to impact Eureka dune grass is unlikely because:
(1) Eureka dune grass typically occurs on the steeper, unstable slopes of the dunes, which appears to limit the establishment of Russian thistle; and
(2) Russian thistle roots are more shallow than those of Eureka dune grass, which reduces the likelihood of potential competition between the two species.
Additionally, based on our analysis of the Park Service's data on Russian thistle presence/absence in 1-ha grid cells, the extent of overlap between these two species at all three dunes combined is 36 percent, ranging from 19 to 91 percent among the three dunes (Service 2013b). Because the Park Service's data is limited to the presence of both species within the same 1-ha grid, these data alone do not indicate that these two species are in close proximity to each other on a smaller spatial scale (which could indicate they are competing for the same resources). However, because the abundance of Eureka dune grass is sparse (i.e., covers 4.3 percent of the entire dune habitat on Eureka Dunes), and Russian thistle is unable to colonize the steeper, unstable slopes where Eureka dune grass occurs, it is unlikely that there is much overlap between these two species at a small spatial scale, even when they both are present in the same 1-ha grid cell. Therefore, based on the best available information, we conclude that competition with Russian thistle does not pose a threat to Eureka dune grass at this time, nor is it expected to become a threat in the future.
Climate Change
Our analyses under the Act include consideration of ongoing and projected changes in climate. The terms “climate” and “climate change” are defined by the Intergovernmental Panel on Climate Change (IPCC)
able information, we conclude that competition with Russian thistle does not pose a threat to Eureka dune grass at this time, nor is it expected to become a threat in the future.
Climate Change
Our analyses under the Act include consideration of ongoing and projected changes in climate. The terms “climate” and “climate change” are defined by the Intergovernmental Panel on Climate Change (IPCC). “Climate” refers to the mean an

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