98-22448. Endangered and Threatened Wildlife and Plants; Final Rule To Determine the Plant Pediocactus winkleri (Winkler Cactus) To Be a Threatened Species  

  • [Federal Register Volume 63, Number 161 (Thursday, August 20, 1998)]
    [Rules and Regulations]
    [Pages 44587-44595]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 98-22448]
    
    
    =======================================================================
    -----------------------------------------------------------------------
    
    DEPARTMENT OF THE INTERIOR
    
    Fish and Wildlife Service
    
    50 CFR Part 17
    
    RIN 1018-AC09
    
    
    Endangered and Threatened Wildlife and Plants; Final Rule To 
    Determine the Plant Pediocactus winkleri (Winkler Cactus) To Be a 
    Threatened Species
    
    AGENCY: Fish and Wildlife Service, Interior.
    
    ACTION: Final rule.
    
    -----------------------------------------------------------------------
    
    SUMMARY: The Fish and Wildlife Service (Service) determines the plant 
    species Pediocactus winkleri (Winkler cactus), to be a threatened 
    species. P. winkleri is endemic to lower elevations of the Colorado 
    Plateau in south-central Utah. Four populations of P. winkleri are 
    known. These populations total about 20,000 plants that grow on widely 
    separated parcels of habitat between 1 (2.4 acres (ac)) and 20 (48 ac) 
    hectares (ha) in size. This species is threatened by collection and by 
    habitat disturbances due to mining, recreation, and livestock. This 
    determination, that P. winkleri is a threatened species, implements 
    protection under the Endangered Species Act of 1973, as amended.
    
    DATES: This rule is effective September 21, 1998.
    
    ADDRESSES: The complete file for this rule is available for inspection, 
    by appointment, during normal business hours at the U.S. Fish and 
    Wildlife Service, Lincoln Plaza, Suite 404, 145 East 1300 South, Salt 
    Lake City, Utah 84115.
    
    FOR FURTHER INFORMATION CONTACT: John L. England at the above address 
    (telephone 801/524-5001).
    
    SUPPLEMENTARY INFORMATION:
    
    Background
    
        Pediocactus winkleri was discovered in the early 1960's and 
    described in scientific literature by Heil (1979). The plant genus 
    Pediocactus contains eight species, seven of these are rare endemics of 
    the Colorado Plateau region of Utah, Colorado, New Mexico, and Arizona 
    (Heil et al. 1981).
        Pediocactus winkleri is a small globose (globular) cactus with 
    stems 2.5 to 6.5 centimeters (cm) (1 to 2.5 inches (in)) tall and up to 
    5 cm (2 in) in diameter. It has clusters of 9 to 11 small radial spines 
    with dense fine woolly hairs at their base; erect central spines are 
    lacking. The flowers of P. winkleri are urn shaped, 1.8 to 2.5 cm (0.7 
    to 1 in) long and 1.8 to 3.8 cm (0.7 to 1.5 in) in diameter, and have a 
    peach-to-pink color. The fruit is barrel shaped, 0.7 to 1.0 cm (.3 to 
    .4 in) high and 0.8 to 1.1 cm (.31 to .43 in) wide, dehiscing (process 
    of opening) by a vertical slit along the ovary wall. The seeds are 
    shiny black, 3 millimeters (mm) (.12 in) long and 2 mm (.08 in) wide 
    (Heil 1979, Heil et al. 1981; Welsh et al. 1993).
        Based on the most recent surveys, the Service has determined that 
    Pediocactus winkleri occurs in four populations that total about 20,000 
    plants (Kass 1997; Fish and Wildlife Service 1994, 1997; D. Clark, 
    Torrey, Utah, personal communication 1998). The October 6, 1993, 
    proposed rule to list P. winkleri as endangered (58 FR 52059) stated 
    that P. winkleri occurred in 6 populations of about 3,500 plants. The 
    abundance estimate of 3,500 plants given in the proposed rule was 
    obtained from Heil (1984). Surveys through 1998, however, have 
    documented about 5,800 individual P. winkleri plants (Fish and Wildlife 
    Service 1997, Kass 1997, D. Clark, per. comm. 1998). Recent surveys in 
    1994 (Fish and Wildlife Service 1994), 1996 (T. Clark, Capitol Reef 
    National Park, pers. comm. 1996), 1997 (Fish and Wildlife Service 1997, 
    Kass 1997), and 1998 (D. Clark, per. comm. 1998) indicate that the 
    species total population could reasonably be estimated to be as many as 
    20,000 plants based on the amount of available habitat. Each of the 
    four populations contain a number of widely separated sites from 1 ha 
    (2.4 ac) to 20 ha (48 ac) in size. Since the proposed rule was 
    published, a survey conducted by the Bureau of Land Management (BLM) 
    discovered an additional population near the town of Ferron in 
    southwest Emery County, Utah (Fish and Wildlife Service 1994). The 
    Service and BLM conducted additional surveys of the species' entire 
    potential habitat on silty soils derived from the Dakota, Mancos, and 
    Morrison geologic formations. Additional sites were discovered within 
    existing population areas (Fish and Wildlife Service 1997; D. Clark 
    1998, pers. comm.). The Park Service also reports larger numbers of the 
    cactus within Capitol Reef National Park (K. Heil, pers. comm. 1993; 
    Tom Clark, Capitol Reef National Park, pers. comm. 1996, 1997; D. 
    Clark, pers. comm 1998). The BLM reports larger numbers of the species 
    from the Last Chance Desert population (Wayne Luddington, Bureau of 
    Land Management, Price, Utah, pers. comm. 1997; Fish and Wildlife 
    Service 1997). Service biologists visited these sites and subsequently 
    reviewed the status of all extant populations of P. winkleri (Fish and 
    Wildlife Service
    
    [[Page 44588]]
    
    1994, 1997). The Service consolidated the five P. winkleri populations 
    in Wayne County, Utah (Heil 1984 and Neese 1987) into two populations, 
    Notom and Hartnet, (Fish and Wildlife Service 1994) in an effort to be 
    consistent with the two, more recently discovered populations, Last 
    Chance and Ferron, in Emery County.
        Individual Pediocactus winkleri plants are usually situated on the 
    tops and sides of rocky hills or benches in Atriplex (saltbush) 
    dominated desert shrub communities (Heil 1984). The species grows in 
    alkaline silty loam or clay loam soils derived primarily from the 
    Dakota formation, the Brushy Basin member of the Morrison formation, 
    and the Emery sandstone member of the Mancos formation (Heil 1984, 
    Neese 1987, Fish and Wildlife Service 1997).
        Three of the four populations of Pediocactus winkleri form a narrow 
    arc extending from near Notom in central Wayne County to the vicinity 
    of Last Chance Creek in southwestern Emery County, Utah. The fourth is 
    a disjunct population occurring near Ferron, Utah, in western Emery 
    County. Most of these populations occur in widely scattered patches in 
    a range about 58 kilometers (km) (36 miles (mi)) long and about 0.5 km 
    (0.3 mi) wide. About two thirds of the population occurs on lands 
    managed by the BLM east and north of the Capitol Reef National Park 
    boundary. The remainder of the plants are found within the Park.
        The range of Pediocactus winkleri converges upon populations of the 
    listed endangered cactus P. despainii (San Rafael cactus). P. despainii 
    and P. winkleri are described as separate species in all taxonomic 
    treatments involving those species in regional floras (Welsh et al. 
    1993) and in monographs of the genus (Heil et al. 1981; K. Heil, San 
    Juan College, Farmington, New Mexico, pers. comm. 1994, 1998). Recent 
    cytotaxonomic research demonstrates that typical P. winkleri from the 
    Notom population is genetically different from typical P. despainii 
    from the San Rafael Swell (M. Porter, Rancho Santa Ana Botanic Garden, 
    Claremont, California, pers. comm. 1998). However, the two species are 
    phylogenetically related, and it has been suggested (Kass 1990) that 
    they be treated as varieties (i.e. subspecies) of P. winkleri, the 
    first of the two species to be described (Heil 1979; Welsh & Goodrich 
    1980). Occasional plants within the northern portion of the Last Chance 
    population bear characteristics intermediate between P. winkleri and P. 
    despainii. The two species are, however, morphologically distinct and 
    geographically separated. The Service recognizes P. winkleri as a 
    species distinct from P. despainii. If these species are later 
    recognized as subspecies, their designations as threatened and 
    endangered species will remain valid because section 3(15) of the Act 
    allows for the listing of subspecies.
    
    Previous Federal Action
    
        Federal actions relating to this species began when the Secretary 
    of the Smithsonian Institution prepared a report on those plants 
    considered to be endangered, threatened, or extinct. This report (House 
    Document No. 94-51) was then presented to Congress on January 9, 1975. 
    On July 1, 1975, the Service published a notice in the Federal Register 
    (40 FR 27823) formally accepting the report as a petition under section 
    4(c)(2) of the Act (petition acceptance is now governed by section 
    4(b)(3) of the Act), and acknowledging its intention to review the 
    status of those plants. Pediocactus winkleri was not included in the 
    1975 notice but was included as a new candidate species in the Federal 
    Register notice of December 15, 1980 (45 FR 82480). The 1980 notice 
    included P. winkleri as a Category 1 species. Category 1 species were 
    those taxa for which the Service had on file substantial information on 
    the biological vulnerability and threats to support proposing them as 
    endangered or threatened species.
        Section 4(b)(3)(B) of the 1982 amendments to the Act required the 
    Secretary of the Interior to make a finding within 1 year of receiving 
    a listing petition as to whether the listing is warranted, warranted 
    but precluded by other pending proposals of higher priority, or not 
    warranted. In this case a ``warranted but precluded'' finding was made. 
    This category requires a finding each year thereafter until the 
    petitioned taxa are either proposed for listing or a final ``not 
    warranted'' finding is made.
        Section 2(b)(1) of the 1982 amendments further required that all 
    petitions pending as of October 13, 1982, be treated as having been 
    newly submitted on that date. To facilitate making the necessary annual 
    ``warranted but precluded'' findings on several plant taxa, the Service 
    made an administrative decision to treat all the plant candidates in 
    Category 1 and Category 2 at that time as if their listings had been 
    petitioned on October 13, 1982. This included species such as 
    Pediocactus winkleri which was included as a candidate in the 1980 
    Notice of Review but was never the subject of a petition. As a result 
    of the administrative decision to treat these species as petitioned, P. 
    winkleri was included in the annual warranted but precluded findings, 
    first published on October 13, 1983.
        In the November 28, 1983, supplemental notice (48 FR 53640), the 
    Service changed the status of Pediocactus winkleri from Category 1 to 
    Category 2 as a result of a careful review of the status information. 
    Category 2 species were taxa for which the Service had information 
    indicating the appropriateness of a proposal to list the taxa as 
    endangered or threatened but for which more substantial data were 
    needed on biological vulnerability and threats. The Service 
    discontinued use of a category system in the February 28, 1996, Federal 
    Register notice (61 FR 7596).
        On September 27, 1985, the Service published a Notice of Review (50 
    FR 39526) replacing the 1980 notice and its 1983 supplement. This 
    Notice of Review included Pediocactus winkleri as a Category 1 species, 
    a change resulting from a status survey for P. winkleri (Heil 1984), 
    which documented the vulnerability and threats to this species. The 
    Service published Notices of Review on February 21, 1990 (55 FR 6184) 
    and September 27, 1993 (58 FR 51144), which retained P. winkleri as a 
    Category 1 species. The Service's proposal to list P. winkleri as 
    endangered on October 6, 1993 (58 FR 52059), constituted the warranted 
    12-month petition finding for this species. During the public comment 
    period on the 1993 proposal, the Service received substantive comments 
    on information contained in the proposal regarding the threats to and 
    population numbers of P. winkleri. Since that time, the Service has 
    made efforts through additional surveys to obtain the best available 
    scientific information in making the decision to list P. winkleri. The 
    Service believes this final rule is an accurate assessment of the 
    population numbers and threats faced by this species. In order to 
    obtain and incorporate any new scientific information into this final 
    determination for P. winkleri, and due to new information on the 
    species range and abundance obtained by the Service since the comment 
    period closed on December 6, 1993 (58 FR 52059), the Service reopened 
    the public comment period for 30 days on June 22, 1998 (63 FR 33901).
        The Service published Listing Priority Guidance for Fiscal Years 
    1998 and 1999 on May 8, 1998 (63 FR 25502). The guidance clarifies the 
    order in which the Service will process rulemakings giving highest 
    priority (Tier 1) to processing emergency rules to add species to the 
    Lists of Endangered and Threatened
    
    [[Page 44589]]
    
    Wildlife and Plants (Lists); second priority (Tier 2) to processing 
    final determinations on proposals to add species to the Lists, 
    processing new proposals to add species to the Lists, processing 
    administrative findings on petitions (to add species to the Lists, 
    delist species, or reclassify listed species), and processing a limited 
    number of proposed or final rules to delist or reclassify species; and 
    third priority (Tier 3) to processing proposed or final rules 
    designating critical habitat. Processing of this proposed rule is a 
    Tier 2 action.
    
    Summary of Comments and Recommendations
    
        In the October 6, 1993, proposed rule and associated notifications, 
    and the June 22, 1998, notice, all interested parties were requested to 
    submit factual reports or information that might contribute to the 
    development of a final rule. Appropriate Federal and State agencies, 
    county governments, scientific organizations, and other interested 
    parties were contacted and were requested to comment. Newspaper notices 
    requesting public comments were published in The Salt Lake Tribune and 
    the Deseret News on November 4, 1993, and the Emery County Progress on 
    November 2, 1993.
        In accordance with the Services' peer review policy published on 
    July 1, 1994 (59 FR 34270), the Service solicited the expert opinions 
    of three botanists regarding information contained in the proposed rule 
    and new information obtained following the proposal on the species 
    status. The three reviewers chosen are associated with colleges and 
    universities and are considered experts on the species. All three 
    reviewers responded and concurred with the Service's assessment of the 
    threats facing this species.
        During the comment period the Service received a total of twelve 
    comment letters which are addressed in the following summary. Pertinent 
    information received during the comment period has been incorporated 
    into this final rule.
        Issue 1: Botanical surveys by Neese (1987), Heil (1987), and Kass 
    (1990), while in or near the habitat of Pediocactus winkleri, had 
    objectives other than a specific inventory for P. winkleri. The 
    population of P. winkleri may be greater than 3,500 as stated in the 
    proposed rule, which was apparently based on the Heil (1984) status 
    report for P. winkleri. The Heil status report does not document how 
    the species population of 3,500 was arrived at. Additional inventory is 
    needed to establish a more accurate species population number.
        Service Response: From the close of the initial 1993 comment period 
    on December 6, 1993, several additional surveys and studies were 
    conducted (Fish and Wildlife Service 1994; 1997; Kass 1997; D. Clark, 
    pers. comm. 1998). As described above in the ``Background'' section, 
    these surveys documented a larger population than was known in 1993 and 
    give a better understanding of the natural and human caused impacts to 
    the species. Surveys through 1998 have documented actual numbers of 
    Pediocactus winkleri plants at about 5,800 (Fish and Wildlife Service 
    1997, Kass 1997, D. Clark, per. comm. 1998). Based on these most recent 
    surveys, the Service concurs with estimates by the BLM that P. winkleri 
    occurs in four populations with a total number of approximately 20,000 
    plants, which results from acceptable extrapolation of direct survey 
    counts (Kass 1997; Fish and Wildlife Service 1994, 1997; D. Clark, 
    pers. comm. 1998).
        Issue 2: The Service should resolve the taxonomic relationship 
    between Pediocactus despainii and P. winkleri before final listing. 
    Distinguishing between the two species in wild populations is 
    difficult.
        Service Response: Pediocactus despainii and P. winkleri are 
    currently considered separate species in all taxonomic treatments 
    involving those species in regional floras (Welsh et al. 1993) and in 
    monographic treatments of the genus (Heil et al. 1981; K. Heil, pers. 
    comm. 1994, 1998). However, the two species are phylogenetically 
    related, and it has been suggested (Kass 1990) that they be treated as 
    varieties of P. winkleri, the first of the two species to be described 
    (Heil 1979; Welsh & Goodrich 1980). Plant taxonomists working 
    specifically on this genus have no information, at this time, which 
    would warrant an alternative taxonomic treatment (Welsh et al. 1993; K. 
    Heil, pers. comm. 1994, 1998; M. Porter, pers. comm. 1994, 1998).
        The two species are morphologically distinct and geographically 
    separated as discussed above in the above ``Background'' section. 
    Pediocactus winkleri has uniformly smaller seeds than P. despainii. P. 
    winkleri areoles (the basal structure at the tip of stem tubercles 
    which forms the base from which the spines arise) are wooly with dense 
    villous hairs. P. despainii areoles are naked except for its spines. 
    These facts strongly suggest the current taxonomic classification is 
    accurate (K. Heil, pers. comm. 1993). Recent cytotaxonomic research 
    indicates that the P. winkleri and P. despainii are taxonomically 
    distinct (M. Porter, pers. comm. 1998).
        Issue 3: Recreational off-road vehicle (ORV) use is not affecting 
    all populations of Pediocactus winkleri. The heaviest ORV use in the 
    Notom area occurs outside the species' occupied habitat. The Hartnet 
    site is located within Capitol Reef National Park where no ORV use is 
    occurring. P. winkerli's characteristic of shrinking underground during 
    its vegetative stage naturally protects the species and it is only 
    vulnerable during its spring flowering period. The BLM has restricted 
    ORV use in the Price Resource Area within P. winkleri habitat.
        Service Response: ORV's are affecting all of the species' 
    populations to some degree, with the exception of the Last Chance 
    population where no ORV use occurs. Locally heavy use occurs with 
    observed adverse impacts in the Ferron population. Although ORV use 
    does not occur in that portion of the Harnet population contained 
    within Capitol Reef National Park, the remainder of this population 
    occurs on BLM land and is subject to ORV use. Occupied Pediocactus 
    winkleri habitat within the BLM portion of the Hartnet population 
    experiences frequent ORV spillover from the adjacent Dry Wash area 
    where heavy ORV use occurs. The Service agrees that the heaviest ORV 
    use occurs outside of occupied habitat in the Notom area, however, this 
    population also experiences frequent ORV spillover use (K. Heil, pers. 
    comm. 1993; Fish and Wildlife Service 1994, 1997; Wayne Luddington, 
    Bureau of Land Management, Price, Utah, pers. comm. 1996, 1997). The 
    BLM ORV restrictions in the Price Resource Area are for and within 
    populations of P. despainii, a listed endangered species, not P. 
    winkleri. Regarding the characterisic of the species to shrink 
    underground see discussion under Factor A.
        Issue 4: Livestock trampling is a minimal and decreasing threat to 
    Pediocactus winkleri. The BLM has reduced livestock grazing levels in 
    all P. winkleri habitat, in some cases to less than 20% of previous 
    levels.
        Service Response: The Service is aware of adverse impacts to this 
    cactus from livestock trampling. Recent survey and habitat monitoring 
    information show that livestock trampling continues to kill Pediocactus 
    winkleri plants (K. Heil, pers. comm. 1993; Fish and Wildlife Service 
    1994, 1997). This species is poorly adapted to the impacts of large, 
    sharp-hoofed ungulates, and plants are easily dislodged and killed by 
    domestic livestock herds moving through its habitat. This trampling 
    impact is most damaging during periods
    
    [[Page 44590]]
    
    when the soil surface is wet. These conditions occur most commonly 
    during mild winter and early spring days when livestock grazing is most 
    intense in the species' desert range habitat. Most of the reduction in 
    livestock grazing within Capitol Reef National Park occurred in the 
    southern portions of the Park outside the species' range. However, the 
    Service acknowledges that this threat is decreasing and is, at present 
    and by itself, a low level chronic threat, not a high level acute 
    threat.
        Issue 5: Mining and mining claim assessment work for gypsum and 
    uranium is a minimal and decreasing threat to Pediocactus winkleri. 
    Known occurrences of gypsum in the vicinity of P. winkleri populations 
    occur in the Carmel Formation which is not habitat for the species. 
    Development of known occurrences of uranium have only a slight 
    potential to affect the species. Current low prices for uranium ore are 
    expected to decrease interest in prospecting and mining claim 
    assessment work within the range of the species. Changes in regulations 
    affecting mining claim assessment activities are expected to decrease 
    surface disturbance associated with mining claim assessment work.
        Service Response: The Service has noted the above comment and has 
    revised the final rule appropriately. The recent development of a mine 
    for high quality, cosmetic grade bentonite clay is adversely affecting 
    the species in the Last Chance Desert (Fish and Wildlife Service 1994, 
    1997). Mining claims cover the entire Last Chance Desert population of 
    Pediocactus winkleri. Oil and gas activity is directly affecting the 
    Ferron population. A portion of this population was lost to a gas well. 
    A portion of the Hartnet population is in an oil and gas lease area.
        Issue 6: A commenter questioned whether or not the Notom 
    Pediocactus winkleri population has experienced an 80 percent loss of 
    its individuals to collectors. Another commenter questioned a statement 
    in the June 22, 1998, notice reopening the comment period that the FWS 
    estimation of the population size at Notom has declined from about 
    2,000 individuals in 1984 to an estimated 700 individuals in 1997.
        Service Response: In the 1993 proposal, the Service estimated that 
    about 80 percent of the plants in the Notom area were taken by plant 
    collectors over the last 10 years. The Service has revised this final 
    rule to indicate that only the portion of the Notom population in the 
    area of the monitoring transect has undergone a significant reduction 
    in numbers of plants primarily from collection. In 1984 the Service 
    established a monitoring transect in the Notom population of 
    Pediocactus winkleri in an easily accessible area that cactus 
    collectors frequent (Fish and Wildlife Service 1994, 1997). The Service 
    has periodically monitored this transect, usually at 2-year intervals. 
    The P. winkleri population along this transect declined from 53 plants 
    in 1984 to zero plants in 1997. Overall the population in the immediate 
    vicinity of the monitoring transect declined from 387 individuals in 
    1994 to 221 in 1997 (Fish and Wildlife Service 1997). The Service feels 
    that this loss of plants is primarily attributed to collection, 
    however, other factors including the characteristic of this species to 
    remain underground during dry years may have contributed to a higher 
    estimate of plant loss then has really occurred. The spring 1998 survey 
    estimated the entire Notom population at about 4,000 individuals.
        The Service, during its 1997 survey of the Notom population, 
    discovered 27 shovel marks within the occupied habitat of this species. 
    These marks were at the locations of plants last observed in 1994 and 
    missing in 1997, and are obviously the remains of an effort to exploit 
    this horticulturally desirable species. Most field collected cacti, 
    however, are collected using smaller garden trowels, and consequently 
    excavation scars are usually not noticeable after a few months.
        Issue 7: The BLM has the ability to manage for the conservation of 
    candidate species on lands under their jurisdiction and can control 
    collection of the species.
        Service Response: Collection of desirable small rare cacti is a 
    difficult action to detect and to control. The recognition and 
    protection offered a listed species under the Act focuses resources for 
    its preservation and recovery, and reinforces the actions of the BLM 
    and other Federal agencies through sections 7 and 9 of the Act for 
    conservation of the species. The listing of species under the Act 
    focuses the management actions of all Federal agencies to provide 
    active conservation and protection for listed species and provides 
    opportunities for States to assist in plant conservation under Section 
    6 of the Act.
        Issue 8: People living in an area where endangered species are 
    proposed for listing should be informed in time to be able to comment 
    and to hold public hearings.
        Service Response: One commenter requested a 2- to 3-year comment 
    period and also requested that a public hearing should be held. This 
    was the only request for a public hearing and the request was not 
    received during the specified open comment period.
        As stated previously, immediately after publication of the proposed 
    rule on October 6, 1993, the Service contacted all known interested 
    parties (i.e., Federal and State agencies, county governments, 
    scientific organizations, and others), and comments were solicited from 
    them. In addition, newspaper notices requesting public comments were 
    published (between November 2 and 4, 1993) in three newspapers that 
    cover the potentially affected area. Thus, the Service believes that 
    adequate time was given to receive requests for public hearings.
        The Service specified that public hearing requests must be received 
    by November 23, 1993, and no such request was received by that date. 
    However, at the request of Emery County, a representative of the 
    Service met with county officials to explain the Service's rationale 
    for proposing to list the species, and to receive the County's 
    comments. The Emery County commissioners were concerned that the 
    listing of Pediocactus winkleri would interfere with the economic 
    activities of grazing and mining within their County. These concerns 
    were also expressed in writing. The Service recognizes that potential 
    restrictions in land use to protect this cactus could limit some future 
    mining development plans and livestock grazing activities on Federal 
    lands within the species' range. P. winkleri has a limited distribution 
    and therefore widespread restrictions on these activities on public 
    lands in Emery and Wayne counties is not anticipated. The Service 
    reopened the public comment period again on June 22, 1998. The second 
    comment period closed on July 22, 1998. The Service received four 
    comments during the reopened comment period and has incorporated new 
    information provided during the comment period in this finding.
        Issue 9: The BLM believes that threats to the species have not been 
    adequately quantified, have lessened since the proposed rule was 
    published, and that species' protection under a conservation agreement 
    would be more appropriate than listing.
        Service Response: Threats to the species continue unabated since 
    the proposed rule was published in October 1993. Evidence of take was 
    documented not only at a specific transect which has been monitored 
    since 1984, but also from site visits where photographs of cattle 
    trampling, collecting, and ORV loss were documented. These losses are
    
    [[Page 44591]]
    
    not natural losses which could be expected to occur but losses which 
    could be prevented through stricter regulation and enforcement 
    activities.
        The Service commends the BLM for initiating the ``Pediocactus 
    winkleri and Pediocactus despainii Conservation Agreement and 
    Strategy'' and for its anticipated future implementation. The proposed 
    agreement contains strategies which, if implemented over time, would 
    assist in the recovery of both species of cactus. However, the 
    agreement is in draft form and is not signed. As such, the Service is 
    not able to consider the effectiveness of this agreement in reducing or 
    eliminating the threats to this species in the future as part of the 
    decision to list.
        Copies of the listing proposal were provided to three professional 
    botanists with research experience with rare flora including 
    Pediocactus winkleri. The supplemental population information provided 
    by BLM was also forwarded for their review. The three reviewers 
    continue to support listing due to continued threats to the species.
        The Service does not believe that the larger numbers of Pediocactus 
    winkleri found in BLM's most recent data is a function of reduced 
    threat, but instead is a function of the increased effort put forth to 
    find individual plants. Most surveys up until this year were conducted 
    by one or two individuals with limited resources. More recent BLM 
    surveys were conducted by four or more individuals over a period of 
    several weeks.
        Even though the increased surveys resulted in increased numbers of 
    Pediocactus winkleri, the threats to the species have not diminished to 
    the point that the species does not need protection under the Act. The 
    Service therefore believes listing as threatened is justified as 
    described in the following sections.
    
    Summary of Factors Affecting the Species
    
        After a thorough review of all available information, the Service 
    has determined that Pediocactus winkleri should be listed as a 
    threatened species. Procedures found in section 4(a)(1) of the Act and 
    regulations implementing the listing provisions of the Act (50 CFR part 
    424) were followed. A species may be determined to be an endangered or 
    threatened species due to one or more of the five factors described in 
    Section 4(a)(1). These factors and their application to P. winkleri are 
    as follows:
        A. The present or threatened destruction, modification, or 
    curtailment of its habitat or range. The small, restricted populations 
    of Pediocactus winkleri make the species highly vulnerable to human-
    caused habitat disturbances. ORV activity, mineral development, road 
    and utility corridor development, and livestock trampling have 
    adversely affected this species (Heil 1984, 1987; Heil, pers. comm. 
    1993; Neese 1987; Fish and Wildlife Service 1994, 1997). This species 
    is especially vulnerable during the spring flowering period when 
    seasonally moist soils make it susceptible to damage and mortality from 
    surface disturbance of its habitat. The species is easily dislodged by 
    domestic livestock and ORV's during periods when the soil is wet. ORV 
    use and livestock grazing are most intense during the mild spring 
    season when the species is most vulnerable to habitat disturbance. 
    During periods of drought, these cacti do not protrude above ground 
    level, thus rendering them less susceptible to livestock trampling and 
    damage by ORV activity. However, the species forms flower buds in the 
    autumn that persist over winter (Heil et al. 1981). These flowering 
    buds at the ground surface level are very vulnerable to surface 
    disturbance.
        A considerable portion of the habitat of this species, as well as 
    individual plants, are being damaged by ORV activity (Heil 1984, Neese 
    1987; Fish and Wildlife Service 1994, 1997). At the northern and 
    southern limits of the species' range, occupied Pediocactus winkleri 
    habitat, located on sparsely vegetated slopes in readily accessible 
    areas, is adjacent to heavily used ORV recreational areas, and is being 
    impacted by ORV activity. Except for habitat within Capitol Reef 
    National Park and the Last Chance population on BLM lands, the 
    remaining habitat of P. winkleri is experiencing similar but lesser 
    impacts from ORV activity (Fish and Wildlife Service 1997). Hard-tired 
    ORVs such as motorcycles and four wheel drive trucks and other highway 
    vehicles are most damaging to the species. These hard-tired vehicles 
    can cause damage and mortality even when the plant is dormant. 
    Increased erosion as a consequence of ORV's damaging the natural desert 
    pavement and cryptogamic crust potentially increases the species' 
    exposure to losses from extreme weather events which occur in the area.
        Livestock trampling has affected every population of this cactus 
    including those in Capitol Reef National Park (the Park is not closed 
    to livestock grazing). According to the BLM, livestock use in areas of 
    Pediocactus winkleri habitat has decreased in recent years, but the 
    impacts of trampling to some populations continue (Heil, pers. comm. 
    1993; Fish and Wildlife Service 1994, 1997). The Service believes 
    grazing and trampling impacts are, for the most part, more chronic than 
    acute and rarely impact more than one percent of the population each 
    year. Individuals lost due to livestock trampling probably could be 
    replaced by natural recruitment from the populations' seed bank. 
    However, cumulative impacts from collecting, localized ORV destruction, 
    and natural losses from disease and parasitism are at sufficient levels 
    in some portion of the species' range (i.e. Notom and Ferron 
    populations) that population viability is impaired.
        The habitat of Pediocactus winkleri contains bentonite clay, oil 
    and gas and some uranium ore deposits. The development of these mineral 
    and petroleum deposits and surface disturbance by annual assessment 
    work has directly affected the species. Currently, oil and gas field 
    development activities are impacting the Ferron population. This 
    activity has destroyed individual plants and occupied habitat. Over 
    eighty percent of the area occupied by the Ferron population is leased 
    for oil and gas (Fish and Wildlife Service 1997). In addition, 
    bentonite clay mining has impacted the Last Chance population by 
    destroying individual plants and occupied habitat (W. Luddington, pers. 
    comm. 1994, 1996, and 1997). Much of the Last Chance population is in 
    areas with registered mining claims (Fish and Wildlife Service 1997). 
    The transfer of mining claim patents from the Public domain to private 
    ownership is not affected by the Act. Unauthorized utility and road 
    development within the species' Notom population caused individual 
    plant mortality and habitat degradation in 1995 and remains a potential 
    threat to the species (Fish and Wildlife Service 1997).
        B. Over-utilization for commercial, recreational, scientific, or 
    educational purposes. Pediocactus winkleri is an attractive small 
    cactus, especially when it is in flower. Although difficult to 
    cultivate in most horticultural settings, this rare plant is highly 
    desired in cactus collections and gardens and has been sought by both 
    hobby and commercial cactus collectors (Hochstatter 1990, Heil 1984, 
    Heil, pers. comm. 1993, 1998). The fact that this species is difficult 
    to maintain in garden settings stimulates a continual demand for 
    replacement plants as cultivated garden and greenhouse plants die. 
    Cactus collectors are active in the Colorado Plateau, going from the 
    habitat of one species of Pediocactus to the next to collect a complete 
    set of the genus
    
    [[Page 44592]]
    
    (Heil, pers. comm. 1994; Fish and Wildlife Service 1994, 1997). A 
    portion of the Notom population of P. winkleri has been severely 
    reduced primarily from losses to plant collectors (Heil 1984 and U.S. 
    Fish and Wildlife Service 1997) (Also discussed under Issue 6). In 
    addition to the Notom population, the Hartnet and Ferron populations 
    are highly vulnerable to specimen collecting due to their ease of 
    access and their being known to cactus collectors (Heil 1984, and Fish 
    and Wildlife Service 1994, 1997).
        C. Disease or predation. Because of its small size and the 
    shortness of its spines, this species of cactus is less protected from 
    animals than other, more spiny species. The effects of livestock 
    grazing on desert vegetation may produce indirect impacts on 
    Pediocactus winkleri populations. The desert range of P. winkleri had 
    very sparse use by large, wild ungulates prior to the introduction of 
    domestic livestock. Livestock grazing has caused changes in the 
    floristic composition of the species' desert ecosystem with the 
    introduction of weeds. These introduced weeds have the potential to 
    outcompete over the long term, and to eventually reduce or displace 
    native species, including P. winkleri. The effects of livestock 
    trampling are discussed in Factor ``A'' above. This species is also 
    susceptible to natural infestations of beetle larvae which will kill an 
    individual within two years of initial infestation (Fish and Wildlife 
    Service 1994).
        D. The inadequacy of existing regulatory mechanisms. There are no 
    Federal or State laws or regulations directly protecting Pediocactus 
    winkleri or its habitat. The National Park Service (NPS) restricts, and 
    in most cases forbids, the collection of plants and plant materials 
    from National Parks. The BLM Manual 6840 (Special Status Species 
    Management) states that ``The BLM shall carry out management, 
    consistent with multiple use, for the conservation of candidate species 
    and their habitats and shall ensure that actions authorized, funded, or 
    carried out do not contribute to the need to list any of these species 
    as Threatened or Endangered.'' The BLM has the authority to control the 
    removal of vegetative materials from Federal lands under its management 
    and presently requires a permit to collect plant species. Current BLM 
    policy is to require a permit to collect any cactus from the habitat 
    area of P. winkleri. However, this species has populations that are 
    scattered over remote country, thus making protection from unauthorized 
    collecting difficult, even in Capitol Reef National Park. The Utah 
    Forest Products Act requires proof of ownership to harvest or transport 
    native vegetation from State, private, and Federal wildlands in Utah. 
    Listing of P. winkleri would also provide for greater statutory 
    protection and a more stringent penalty for take. Therefore, a greater 
    deterrent for taking the species would be established.
        The species is listed in Appendix I of The Convention of 
    International Trade in Endangered Species of Wild Fauna and Flora 
    (CITES). CITES import and export permits are generally required for 
    international trade in Appendix I species, and permits are not allowed 
    for commercial shipments. The small size of these species makes them 
    easy to hide and therefore hard to detect in international commerce.
        E. Other natural or manmade factors affecting its continued 
    existence. Pediocactus winkleri is restricted to a limited geographic 
    area with scattered, isolated occurrences and relatively low population 
    numbers per occurrence, which render this cactus vulnerable to human 
    disturbances. These additional stresses to the plant may exacerbate 
    natural disturbances to populations of this species.
        The Service has carefully assessed the best scientific and 
    commercial information available regarding the past, present, and 
    future threats faced by this species in determining to make this rule 
    final. As described under the Act, a species should be found to be 
    endangered if the species is in danger of becoming extinct throughout 
    all or a significant portion of its range. The term threatened is 
    defined as likely to become endangered within the foreseeable future 
    throughout all or a significant portion of its range. In the proposed 
    rule, Pediocactus winkleri was proposed to be listed as an endangered 
    species. With the new information collected on this species since the 
    proposed rule the Service has found that the population numbers are 
    larger than previously estimated. Based on a reevaluation of the 
    population numbers and threats, the preferred action is to list P. 
    winkleri as threatened. Collection has been documented in a portion of 
    the Notom population to significantly lower its numbers and is 
    considered a primary threat to the Hartnet and Ferron population. 
    Surface disturbances are impacting the ecosystem in which the species 
    occurs and may increase in the future, especially from recreational ORV 
    use. However, in an effort to eliminate soil compaction and plant 
    destruction, the draft BLM Conservation Agreement and Strategy will 
    restrict ORV use to existing roads and trails through the preparation 
    of a managment plan. Because of new information indicating a relatively 
    larger population of P. winkleri, and the expected implementation of a 
    Conservation Agreement and Strategy aimed at reducing and eliminating 
    threats to P. winkleri, threatened status is a more accurate assessment 
    of the current condition of this species. For the reasons given below, 
    it is not prudent to designate critical habitat at this time.
    
    Critical Habitat
    
        Critical habitat is defined in section 3(5)(A) of the Act as: (i) 
    the specific areas within the geographical area occupied by a species, 
    at the time it is listed in accordance with the Act, on which are found 
    those physical or biological features (I) essential to the conservation 
    of the species and (II) that may require special management 
    considerations or protection; and (ii) specific areas outside the 
    geographical area occupied by a species at the time it is listed, upon 
    a determination that such areas are essential for the conservation of 
    the species. ``Conservation'' means the use of all methods and 
    procedures that are necessary to bring the species to the point at 
    which the measures provided pursuant to the Act are no longer 
    necessary.
        Section 4(a)(3) of the Act, as amended, and implementing 
    regulations (50 CFR 424.12(a)) require that, to the maximum extent 
    prudent and determinable, the Secretary designate critical habitat 
    concurrently with determining a species to be endangered or threatened. 
    The Service finds that designation of critical habitat is not prudent 
    for this species at this time. Service regulations (50 CFR 
    424.12(a)(1)) state that designation of critical habitat is not prudent 
    when one or both of the following situations exist: (i) The species is 
    threatened by taking or other human activity, and identification of 
    critical habitat can be expected to increase the degree of such threat 
    to the species, or (ii) such designation of critical habitat would not 
    be beneficial to the species.
        As noted under Factor B in the ``Summary of Factors Affecting the 
    Species'', Pediocactus winkleri is threatened by collection, an 
    activity difficult to prevent. The listing of species as endangered or 
    threatened publicizes their rarity and may make them more susceptible 
    to collection. The publication of precise maps and descriptions of 
    critical habitat would make P. winkleri more vulnerable to collection. 
    Precise maps could also threaten more remote areas of P.
    
    [[Page 44593]]
    
    winkleri habitat, currently not subject to collection, by providing 
    specific location information to cactus collectors. The Service feels 
    that publication of precise maps for this species along with this final 
    listing rule would put this species at greater risk of collection by 
    cactus enthusiasts given the well documented history of previous 
    collections.
        Critical habitat designation, by definition, directly affects only 
    Federal agency actions. P. winkleri occurs entirely on lands under 
    Federal (BLM and NPS) management. Federal actions that might affect 
    this species and its habitat include activities such as mining, 
    grazing, and ORV use. Such activities would be subject to review under 
    section 7(a)(2) of the Act, whether or not critical habitat was 
    designated. Section 7(a)(2) requires Federal agencies to ensure that 
    activities they authorize, fund, or carry out are not likely to 
    jeopardize the continued existence of a listed species or to destroy or 
    adversely modify its critical habitat. Federal actions satisfying the 
    standard for adverse modification are nearly always found to also 
    jeopardize the species concerned, and the existence of critical habitat 
    designation does not materially affect the outcome of consultation. The 
    Service recognizes that there may be some benefit in designating 
    critical habitat for highly endangered species whose survival and 
    recovery depend upon expansion of range and numbers into currently 
    unoccupied habitat. However, this is not the case for P. winkleri which 
    is being listed as threatened and does not require unoccupied habitat 
    for its survival or recovery. Habitat protection for P. winkleri can be 
    accomplished through the section 7 jeopardy standard and there would be 
    no benefit from designating critical habitat for this species.
        Both the BLM and NPS are actively involved in the management and 
    monitoring of Pediocactus winkleri and are aware of the threats facing 
    this species. BLM has drafted a Conservation Agreement, with the 
    assistance of the NPS and other partners, aimed at reducing and 
    eliminating identified threats to P. winkleri. Designation of critical 
    habitat would not increase the commitment or management efforts of the 
    BLM or NPS. The Service believes that protection of P. winkleri will be 
    better addressed through the recovery process and through section 
    7(a)(2) of the Act, as amended.
        The Service finds that the designation of critical habitat is not 
    prudent because of the increase of threat from collection which far 
    outweighs any benefit that might be gained from identifying areas in 
    need of special protection. The Service feels that recovery of the 
    species will be accomplished more effectively with the current 
    coordination process that the Service has established with the BLM and 
    NPS.
    
    Available Conservation Measures
    
        Conservation measures provided to species listed as endangered or 
    threatened under the Act include recognition, recovery actions, 
    requirements for Federal protection, and prohibitions against certain 
    practices. Recognition through listing results in public awareness and 
    conservation actions by Federal, State, and local agencies, private 
    organizations, and individuals. The Act provides for possible land 
    acquisition and cooperation with the States and requires that recovery 
    actions be carried out for all listed species. The protection required 
    of Federal agencies and the prohibitions against certain activities 
    involving listed plants are discussed, in part, below.
        Section 7(a) of the Act, as amended, requires Federal agencies to 
    evaluate their actions with respect to any species that is proposed or 
    listed as endangered or threatened and with respect to its critical 
    habitat, if any is being designated. Regulations implementing this 
    interagency cooperation provision of the Act are codified at 50 CFR 
    part 402. Section 7(a)(2) requires Federal agencies to insure that 
    activities they authorize, fund, or carry out are not likely to 
    jeopardize the continued existence of the species or to destroy or 
    adversely modify its critical habitat. If a Federal action may affect a 
    listed species or its critical habitat, the responsible Federal agency 
    must enter into formal consultation with the Service.
        Pediocactus winkleri occurs on Federal lands managed by the BLM and 
    the NPS. Both of these Federal agencies are responsible for insuring 
    that all activities and actions on lands that they manage are not 
    likely to jeopardize the continued existence of P. winkleri.
        The Act and its implementing regulations set forth a series of 
    general prohibitions and exceptions that apply to all threatened 
    plants. All trade prohibitions of section 9(a)(2) of the Act, 
    implemented by 50 CFR 17.61 apply. These prohibitions, in part, make it 
    illegal for any person subject to the jurisdiction of the United States 
    to import or export, transport in interstate or foreign commerce in the 
    course of a commercial activity, sell or offer for sale this species in 
    interstate or foreign commerce, or to remove and reduce to possession 
    the species from areas under Federal jurisdiction. In addition, for 
    plants listed as endangered, the Act prohibits the malicious damage or 
    destruction on areas under Federal jurisdiction and the removal, 
    cutting, digging up, or damaging or destroying of such plants in 
    knowing violation of any State law or regulation, including State 
    criminal trespass law. Section 4(d) allows for the provision of such 
    protection to threatened species through regulation. This protection 
    may apply to this species in the future if regulations are promulgated. 
    Seeds from cultivated specimens of threatened plants are exempt from 
    these prohibitions provided that a statement of ``cultivated origin'' 
    appears on their containers. Certain exceptions to the prohibitions 
    apply to agents of the Service and State conservation agencies.
        The Act and 50 CFR 17.72 also provide for the issuance of permits 
    to carry out otherwise prohibited activities involving threatened 
    plants under certain circumstances. Such permits are available for 
    scientific purposes and to enhance the propagation or survival of the 
    species. For threatened plants, permits also are available for 
    botanical or horticultural exhibition, educational purposes, or special 
    purposes consistent with the purposes of the Act. It is anticipated 
    that permits will be sought for cultivated specimens, which are 
    currently available through domestic and international nurseries. 
    Requests for copies of the regulations regarding listed species and 
    inquiries about prohibitions and permits may be addressed to the 
    Regional Director, U.S. Fish and Wildlife Service, P.O. Box 25486, 
    Denver Federal Center, Denver, Colorado 80225; telephone number 303-
    236-7398; facsimile number 303-236-0027. Information collections 
    associated with these permits are approved under the Paperwork 
    Reduction Act, 44 U.S.C. 3501 et seq., and assigned Office of 
    Management and Budget clearance number 1018-6649. For additional 
    information concerning these permits and associated requirements, see 
    50 CFR 17.72.
        On July 29, 1983, Pediocactus winkleri was included in Appendix I 
    of CITES. Appendix I species generally require both an export and 
    import permit before international shipment of this species can occur. 
    Such shipment is strictly regulated by CITES party nations to prevent 
    effects that may be detrimental to the species' survival. Generally, 
    the import or export of an Appendix I species cannot be allowed if it 
    is for primarily commercial purposes. If plants are certified as 
    artificially propagated, however, international
    
    [[Page 44594]]
    
    shipment requires only export documents under CITES, and commercial 
    shipments may be allowed.
        It is the policy of the Service, published in the Federal Register 
    on July 1, 1994 (59 FR 34272), to identify to the maximum extent 
    practicable at the time a species is listed those activities that would 
    or would not constitute a violation of section 9 of the Act. The intent 
    of this policy is to increase public awareness of the effect of this 
    listing on proposed and ongoing activities within the species' range. 
    The Service believes the following actions would not be likely to 
    result in a violation of section 9:
        (1) Activities authorized, funded, or carried out by Federal 
    agencies (e.g., grazing, ORV activity, mining) when such activity is 
    conducted in accordance with any reasonable and prudent measures given 
    by the Service in a consultation conducted under section 7 of the Act;
        (2) Casual, dispersed human activities on foot (e.g., sight seeing, 
    photography, hiking).
        The Service believes that the following activities would likely 
    result in a violation of section 9:
        (1) Unauthorized collection and knowingly damaging Pediocactus 
    winkleri plants;
        (2) Interstate or foreign commerce and import/export without 
    previously obtaining an appropriate permit. Permits to conduct 
    activities are available for purposes of scientific research and 
    enhancement of propagation or survival of the species.
        (3) Use of herbicides or pesticides in violation of label 
    restrictions.
        Other activities not identified above will be reviewed on a case-
    by-case basis to determine if a violation of section 9 of the Act may 
    be likely to result from such activity. The Service does not consider 
    these lists to be exhaustive and provides them as information to the 
    public.
        Anyone interested in determining whether a particular activity 
    would constitute a prohibited act under section 9(a)(2) should contact 
    the Service's Field Supervisor in Salt Lake City (see ADDRESSES 
    section).
    
    National Environmental Policy Act
    
        The Service has determined that Environmental Assessments and 
    Environmental Impact Statements, as defined under the authority of the 
    National Environmental Policy Act of 1969, need not be prepared in 
    connection with regulations adopted pursuant to section 4(a) of the 
    Act. A notice outlining the Service's reasons for this determination 
    was published in the Federal Register on October 25, 1983 (49 FR 
    49244).
    
    Paperwork Reduction Act
    
        This rule does not contain any new collections of information other 
    than those already approved under the Paperwork Reduction Act, 44 
    U.S.C. 3501 et seq., and assigned Office of Management and Budget 
    clearance number 1018-0094. An agency may not conduct or sponsor, and a 
    person is not required to respond to a collection of information, 
    unless it displays a currently valid control number. For additional 
    information concerning permit and associated requirements for 
    threatened species, see 50 CFR 17.32.
    
    References Cited
    
        A complete list of all references cited herein is available upon 
    request from the Salt Lake City, Utah, Field Office (see ADDRESSES 
    section).
    
    Authors
    
        The primary author of this document is John L. England, botanist 
    (see ADDRESSES above).
    
    List of Subjects in 50 CFR Part 17
    
        Endangered and threatened species, Exports, Imports, Reporting and 
    recordkeeping requirements, Transportation.
    
    Regulation Promulgation
    
    PART 17--[AMENDED]
    
        Accordingly, the Service amends part 17, Subchapter B of Chapter I, 
    title 50 of the Code of Federal Regulations, as set forth below:
        1. The authority citation for Part 17 continues to read as follows:
    
        Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
    4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.
    
        2. Amend Sec. 17.12(h) by adding the following, in alphabetical 
    order under FLOWERING PLANTS, to the List of Endangered and Threatened 
    Plants to read as follows:
    
    
    Sec. 17.12  Endangered and threatened plants.
    
    * * * * *
        (h) * * *
    
    --------------------------------------------------------------------------------------------------------------------------------------------------------
                            Species                                                                                                                         
    --------------------------------------------------------    Historic range           Family            Status      When listed    Critical     Special  
             Scientific name                Common name                                                                               habitat       rules   
    --------------------------------------------------------------------------------------------------------------------------------------------------------
             Flowering Plants                                                                                                                               
                                                                                                                                                            
                       *                  *                  *                  *                  *                  *                  *                  
    Pediocactus winkleri.............  Winkler cactus......  U.S.A. (UT)........  Cactaceae..........  T                       641           NA           NA
                                                                                                                                                            
                       *                  *                  *                  *                  *                  *                  *                  
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    
    
    [[Page 44595]]
    
        Dated: August 13, 1998.
    Jamie Rappaport Clark,
    Director, Fish and Wildlife Service.
    [FR Doc. 98-22448 Filed 8-19-98; 8:45 am]
    BILLING CODE 4310-55-P
    
    
    

Document Information

Effective Date:
9/21/1998
Published:
08/20/1998
Department:
Fish and Wildlife Service
Entry Type:
Rule
Action:
Final rule.
Document Number:
98-22448
Dates:
This rule is effective September 21, 1998.
Pages:
44587-44595 (9 pages)
RINs:
1018-AC09
PDF File:
98-22448.pdf