Daily Rules, Proposed Rules, and Notices of the Federal Government
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The coordinates or plot points or both from which the critical habitat maps are generated are included in the administrative record for this rulemaking and are available at
We have determined that the Lemmon fleabane does no longer warrant listing. Through our five factor analysis, we have determined that the previously recognized threats to the Lemmon fleabane do not rise to a level of significance such that the species is in danger of extinction now or likely to become so in the foreseeable future.
We have determined that the following are threats to the acuña cactus:
• United States—Mexico border activities including inadequacy of regulatory mechanisms, and
• Predation by native insect and small mammal predators, in combination with other natural or manmade factors, including natural environmental variability and climate conditions such as drought.
We have determined that the following are threats to the Fickeisen plains cactus:
• Livestock grazing;
• Nonnative, invasive species; and
• Predation by native small mammal predators, in combination with other natural or manmade factors, including natural environmental variability and climate conditions such as drought.
We intend that any final action resulting from this proposed rule will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we request comments or information from other concerned governmental agencies, Native American tribes, the scientific community, industry, or any other interested parties concerning this proposed rule. We particularly seek comments concerning:
(1) These species' biology, range, and population trends, including:
(a) Habitat requirements for pollination, reproduction, and dispersal;
(b) Genetics and taxonomy;
(c) Historical and current range including distribution patterns;
(d) Historical and current population levels, and current and projected trends; and (e) Past and ongoing conservation measures for these species, their habitat or both.
(2) The factors that are the basis for making a listing determination for a species under section 4(a) of the Act (16 U.S.C. 1531
(a) The present or threatened destruction, modification, or curtailment of their 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 their continued existence.
(3) Biological, commercial trade, or other relevant data concerning any threats (or lack thereof) to these species and existing regulations that may be addressing those threats.
(4) Additional information concerning the historical and current status, range, distribution, and population size of these species, including the locations of any additional populations of these species.
(5) Any information on the biological or ecological requirements of the species, and ongoing conservation measures for the species and its habitat;
(6) The reasons why we should or should not designate habitat as “critical habitat” under section 4 of the Act (16 U.S.C. 1531
(7) Specific information on:
(a) The amount and distribution of these species and their habitat;
(b) What may constitute “physical or biological features essential to the conservation of these species,” within the geographical range currently occupied by these species;
(c) Where these features are currently found;
(d) Whether any of these features may require special management considerations or protection;
(e) What areas, that were occupied at the time of listing (or are currently occupied) and that contain features essential to the conservation of these species, should be included in the designation and why;
(f) What areas not occupied at the time of listing are essential for the conservation of these species and why.
(8) Land use designations and current or planned activities in the areas occupied by these species or proposed to be designated as critical habitat, and possible impacts of these activities on these species and proposed critical habitat.
(9) Information on the projected and reasonably likely impacts of climate change on these species and proposed critical habitat.
(10) Any foreseeable economic, national security, or other relevant impacts that may result from designating any area that may be included in the final designation. We are particularly interested in any impacts on small entities, and the benefits of including or excluding areas from the proposed designation that are subject to these impacts.
(11) Whether our approach to designating critical habitat could be improved or modified in any way to provide for greater public participation and understanding, or to assist us in
(12) The likelihood of adverse social reactions to the designation of critical habitat and how the consequences of such reactions, if likely to occur, would relate to the conservation and regulatory benefits of the proposed critical habitat designations.
(13) Information on certain populations of Fickeisen plains cactus. Specifically, there are eight populations where the Fickeisen plains cactus has been documented, but these areas have not been visited in over 18 years. Five populations are located on the Arizona Strip and are referred to as: Beanhole Well, Marble Canyon, Salaratus Draw, South Canyon, and Toquer Tank. The sixth population is located in proximity to Mays Wash that is south of the Town of Gray Mountain among Federal, State, and private lands. The last two populations are on the Navajo Nation. These eight areas are proposed as critical habitat for the Fickeisen plains cactus. We are seeking any information on specific population status of the Fickeisen plains cactus at these locations, whether these locations are currently occupied and contain the features essential to the conservation of the species, and the condition of the habitat.
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.”
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The layout of this rule is as follows: The 12-month not-warranted petition finding and candidate withdrawal for the Lemmon fleabane; the proposed listing of the acuña cactus and the Fickeisen plains cactus; the proposed critical habitat for the acuña cactus and the Fickeisen plains cactus.
This section summarizes the status and potential threats that we evaluated in order to determine that listing Lemmon fleabane is not-warranted and to remove it from candidate status. Additional material that we relied on is available in the Species Assessment and Listing Priority Assignment Form for Lemmon fleabane. This form is available on our national endangered species Web site:
On July 1, 1975 (40 FR 27824), the Lemmon fleabane was included among 3,000 plant species under status review. We first identified the Lemmon fleabane as a category 1 candidate species on September 30, 1993 (58 FR 51144). Candidates are those fish, wildlife, and plants for which we have on file sufficient information on biological vulnerability and threats to support preparation of a listing proposal, but for which development of a listing regulation is precluded by other higher priority listing activities. Candidate species were assigned a relative listing priority number in accordance with listing priority guidelines published on September 21, 1983 (48 FR 43098). On the basis of immediacy and magnitude of threats, as well as taxonomic status, we assigned the Lemmon fleabane a listing priority number (LPN) of 11, which is assigned when threats are of moderate to low magnitude and non-imminent. On October 25, 1999, we changed the LPN to a 5 to reflect threats that are of high magnitude but non-imminent, based on the threat of high severity fire and drought (64 FR 57534). Later, we decided a wildfire or drought would not adversely affect the entire population; therefore, on September 12, 2006, we changed the LPN to an 8, reflecting threats that are of moderate to low magnitude and imminence (71 FR 53756), and this LPN remained in effect until the last Candidate Notice of Review in 2011 (76 FR 66370, October 26, 2011). We now find that listing this species is not-warranted, and we are withdrawing this species from candidate status because the previously recognized threats to the Lemmon fleabane do not rise to the level of significance such that the species is in danger of extinction now or likely to become so in the foreseeable future. Our rationale is explained below.
The Lemmon fleabane is a tap-rooted perennial plant of the aster family (Nesom 2006, p. 342). The Lemmon fleabane occurs in crevices and ledges, on all aspects of tall, vertical-faced, and very cuspid (pointed) Escabrosa limestone cliffs of a single canyon, Scheelite Canyon, on Fort Huachuca on Department of Defense lands, in Cochise County, Arizona (Warren
The primary threat previously identified for the Lemmon fleabane was high severity wildfire, a phenomenon outside of the established fire history for the forests of the Huachuca Mountains. Scheelite Canyon is a narrow, shady, bedrock-laden cold-air-drainage, with higher humidity and cooler temperatures than surrounding areas; these factors aid in limiting the spread of severe fire within the canyon (Turner and Romme 1994, p. 59; Gebow and Hessil 2006, p. 21; Werth
Although Scheelite Canyon currently contains a woody fuel load, fire experts believe the Lemmon fleabane itself is relatively safe from fire (Gebow and Hessil 2006, p. 51; Leiendecker 2012, pers. comm.). Recent documentation of two other rare, cliff-dwelling
In summary, there is a very small probability that Scheelite Canyon will sustain a catastrophic fire in the future due to the southeast to northwest aspect of the canyon in the landscape; its humid, shady, and cool nature; and the presence of exposed rock outcroppings throughout the canyon lending to a discontinuous fuel load. Should such a fire occur, it would threaten individual plants exposed to flame and heat (Gebow and Hessil 2006, p. 85); however, due to the plants occurring in a variety of locations within the canyon, it is unlikely that all plants would be affected.
Recreational rappelling was noted as a minor threat to the Lemmon fleabane; however, we conclude that there is a very low probability of this type of activity taking place in Scheelite Canyon because recreational rappelling is not allowed by Fort Huachuca. Further, if unauthorized rappelling were to occur, the damage to Lemmon fleabane plants would be insignificant at the population level.
In addition to fire and rappelling posing less of a threat to the Lemmon fleabane than previously believed, several conservation measures have recently occurred or are being planned. Although we did not rely on these conservation measures to make our not-warranted finding, they are underway and will benefit the Lemmon fleabane now and into the future. In 2011, the Desert Botanical Garden collected hundreds of viable Lemmon fleabane seeds for long-term storage. This collection and future-planned seed collection by the Desert Botanical Garden may help offset impacts to the species in the event of a devastating wildfire and habitat loss. In addition, the U.S. Forest Service is currently working with Fort Huachuca to reduce fire potential at a landscape level throughout the district and on Fort Huachuca itself (Leiendecker 2012, pers. comm.). Finally, Fort Huachuca and the Service are drafting a conservation agreement which, once signed, will: (a) Ensure the continued monitoring of the Lemmon fleabane population and promote adaptive management based on monitoring results; (b) continue the restrictions on recreational activities in Lemmon fleabane habitat; and (c) encourage further research into the species' life history, population biology and demographics, and distribution.
Through our five-factor analysis, we have discounted any threats to the species and conclude there are no significant threats to the Lemmon fleabane. We, therefore, conclude that the previously recognized threats to the Lemmon fleabane do not rise to a level of significance such that the species is in danger of extinction now or in the foreseeable future. Additionally, we are not aware of any other potential stressors or threats that may impact the species or its habitat by itself or in combination, including the potential environmental effects that may result from climate change. Current and planned conservation measures will also benefit the Lemmon fleabane, although we are not relying on these conservation actions as the basis for our not-warranted finding. As a result, we have removed this species from the candidate list.
On July 1, 1975 (40 FR 27824), we published a Review of Status of Vascular Plants identifying the acuña cactus and the Fickeisen plains cactus as among 3,000 native plant taxa being reviewed for possible inclusion in the list of endangered and threatened species. On December 15, 1980, we published a Review of Plant Taxa for Listing as Endangered or Threatened Species and identified the Fickeisen plains cactus as category 1 species (45 FR 82480). Category 1 species were those taxa for which we had on file substantial information on biological vulnerability and threats to support proposing them as endangered or threatened species. The acuña cactus was not included in the 1980 notice. Both the acuña cactus and the Fickeisen plains cactus were included in the February 21, 1990, notice (55 FR 6184) as category 1 species.
In the September 30, 1993, notice (58 FR 51144) candidate species were assigned a status category indicating their status at that time. Each species was identified as increasing (I), stable (S), declining (D), or unknown (U). The 1993 notice identified the acuña cactus and the Fickeisen plains cactus as category 1-U: unknown, denoting species for which additional survey work is required to determine current trends.
We discontinued the use of a category system in the February 28, 1996, notice (61 FR 7596) and simply referred to category 1 species as candidate species. The acuña cactus and Fickeisen plains cactus were both assigned an LPN of 6, due to the high magnitude of threats which were non-imminent. We published four Candidate Notice of Reviews between 1997 and 2003, in which the acuña cactus and the Fickeisen plains cactus remained candidate species with an LPN of 6 (62 FR 49398, September 19, 1997; 64 FR 57534, October 25, 1999; 66 FR 54808, October 30, 2001; 67 FR 40657, June 13, 2002).
On October 30, 2002, we received a petition from the Center for Biological Diversity to list the acuña cactus as an endangered species under the provisions of the Act. On May 4, 2004, the Center for Biological Diversity petitioned the Service to list the acuña cactus and the Fickeisen plains cactus as an endangered species under the Act. Because these species were already candidates for listing, we did not issue findings on the petition. In the Candidate Notice of Review dated September 12, 2006 (71 FR 53756), we revised the LPN of the Fickeisen plains cactus from 6 to 3 based on direct mortality and reduced reproductive capacity resulting from off-road vehicle (ORV) use, trampling associated with livestock grazing, a continuing drought, and herbivory by rabbits and rodents. We also acknowledged that unauthorized collection of the Fickeisen plains cactus was a potential threat but we did not know at that time whether it was a continuing threat. In the notice of December 6, 2007 (72 FR 69034), we revised the LPN of the acuña cactus from 6 to 3 based on continued decline of the species caused by ongoing drought. An LPN of 3 reflects threats that are both imminent and high in magnitude, as well as the taxonomic classification as a subspecies. In plant classification generally, the use of the term variety, such as is used in the plants in this rule, is synonymous with the term subspecies. In the notice of October 26, 2011 (76 FR 66370), we retained an LPN of 3 for both species.
For each of the two cactus species, we provide a description of the species, its life history, its habitat, an evaluation of listing factors for that species, and our finding for the species.
It is our intent to discuss below only those topics directly relevant to the listing of the acuña cactus as an endangered species in this section of the proposed rule.
The acuña cactus is a small, spherical cactus, usually single-stemmed, that can be up to 40 centimeters (cm) (16 inches (in)) tall and 9 cm (3.5 in) wide (Arizona Rare Plant Guide Committee 2001, unpaginated; Zimmerman and Parfitt 2003, pp. 194-195). The acuña cactus has 11 to 15 radial spines up to 2.5 cm (1.0 in) long and 3 to 4 mauve-colored, up-turned central spines up to 3.5 cm (1.4 in) long (Arizona Rare Plant Guide Committee 2001, unpaginated; Zimmerman and Parfitt 2003, pp. 194-195). Rose, pink, or lavender flowers 3.6 to 6 by 4 to 9 cm (1.4 to 2.3 by 1.6 to 3.5 in) are produced in March (Arizona Rare Plant Guide Committee 2001, unpaginated; Zimmerman and Parfitt 2003, pp. 194-195). The fruits are pale green, are 1.25 cm (0.5 in) long, and contain small, nearly black seeds (Felger 2000, p. 208). The fruits ripen in April (Arizona Rare Plant Guide Committee 2001, unpaginated).
The acuña cactus relies solely on the production of seeds for reproduction, with pollination highly linked to survival, as the species cannot fertilize itself. Acuña cacti are pollinated by a suite of bees from the Andrenidae, Anthophoridae, Anthophorinae, Halictidae, and Megachilidae families; however, the leafcutter bee (
Although we do not know the lifespan of acuña cacti, there are individual plants that have been tracked at Organ Pipe Cactus National Monument (OPCNM) since 1977, and are still alive in 2012 (Holm 2012a, pers. comm.). The lifespan of seeds in the seedbank is unknown; however, in independent greenhouse tests of 6 and 4 year-old seed collected from two discrete populations, less than 19 percent and zero percent germination resulted, respectfully (Rutman 2007, p. 7). In tests of 1 and 2 year-old seed, germination ranged from 64 to 100 percent, and tests of seed collected 19 days previously resulted in 82 percent germination (Rutman 2007, p. 7). It is unknown if seed in its natural environment has the same short lifespan as has been demonstrated in these germination trials.
This species was originally described in 1953 by W.T. Marshall as
The acuña cactus occurs in valleys and on small knolls and gravel ridges of up to 30 percent slope in the Palo-Verde-Saguaro Association of the Arizona Upland subdivision of the Sonoran Desert scrub at 365 to 1,150 m (1,198 to 3,773 ft) in elevation (Phillips
The acuña cactus populations are known from Maricopa, Pima, and Pinal Counties in Arizona and from Sonora, Mexico (AGFD 2004, p. 2). In western Pima County, plants are known from the Puerto Blanco Mountains and adjacent Aguajita Wash and in the foothills of the Growler Mountains south of Dripping Spring on National Park Service (NPS) lands within OPCNM; from the Sauceda Mountains on Bureau of Land Management (BLM) lands; from Department of Defense military lands on the Barry M. Goldwater Gunnery Range (BMGR); and from private lands near Ajo. There is an unconfirmed report of acuña cactus individuals occurring on Tohono O'odham lands in the vicinity of known populations on BLM and BMGR lands; however this has not been verified (Howe 2012, pers. comm.). In Maricopa County, the acuña cactus is known from the Sand Tank Mountains on BLM lands within the Sonoran Desert National Monument. In Pinal County, plants are known from Mineral Mountain on BLM, State, and private lands. In Sonora, Mexico, the acuña cactus occurs on Reserva de la Biosfera El Pinacate y Gran Desierto de Altar (Pinacate Biosphere Reserve) and private ejido (ranch) lands. Available information indicates that the current range of this species does not differ from the historical range, with the exception that the current Ajo populations likely had been part of a larger population that
As the number of dead individuals documented within acuña cactus populations has increased greatly since study began in the 1970s (when tracking first began), it is important to track the number of healthy, unhealthy, and dead individuals. This not only allows us to document trends in total plant numbers, but can help in our understanding of the cause and extent of mortality.
There is one large area of approximately 1,326 ha (3,277 ac) within OPCNM that contains as many as 2,000 acuña cactus individuals (Rutman 2011, pers. comm.; AGFD 2011, entire). In 1981, this population was estimated to contain 10,000 individuals (Buskirk 1981, p. 3). Within this area, two 20-by 50-m (66-by 164-ft) permanent monitoring plots were established in 1977, with the aim of investigating growth, mortality, and recruitment of this species. Between 1977 and 1981, there was 31 percent mortality in the plots (Phillips and Buskirk 1982, p. 2). Two more plots were added in 1983, and two more in 1988. From 1988 through 1991, the population was thought to be stable or increasing (Johnson
In order to verify the identification and location of plants, specimens are collected, pressed, and placed on sheets that are stored in herbaria. A 1952 herbarium collection from a second location within OPCNM is evidence that a second disjunct population of the acuña cactus occurred historically within OPCNM. Current NPS staff were unaware of this herbarium collection, and the site, reported to be within 3 m (10 ft) of the U.S.-Mexico border, has not been revisited since 1952. Site visits in this area are currently considered dangerous, and therefore no efforts have been made to confirm the location of the population; we do not know if the population exists at this location.
In 1982, the BLM (Phoenix District) established three 20-by 50-m (66-by 164-ft) monitoring plots on Coffeepot Mountain. These plots were visited, and data were collected periodically between 1982 and 1992. In 1982, 157 living and 3 dead plants were found within plots. Over the years of study, many new recruits were found; however, there was also ongoing mortality with newly dead individuals documented each year. A census of individuals from both within and nearby the plots in 1987 found 310 living and 332 dead plants (Rutman
In 2006, a second population, estimated to be between 50 and 100 individuals, was located 1.2 kilometers (km) (0.75 miles (mi)) northwest of the Coffeepot Mountain monitoring plots in Ryans Canyon (Rutman 2006, p. 2). Rutman (2006, entire) did not mention size class or health of this population. This site has not been revisited.
A third population was discovered in 2006, 1.4 km (0.87 mi) to the northeast of the Coffeepot Mountain monitoring plots. Approximately 30 acuña cacti were noted there at the time; 25 percent mortality was reported one year later (Anderson 2011, p. 1). An October 2011 site visit by Service and BLM botanists revealed 23 adult and 2 juvenile living and 15 dead plants at this location (Service 2011a, p. 3). A fourth population was discovered by the BLM in March 2011, in a location near the third population; 10 plants were noted. No indications were given as to the age class structure or health of this population (Anderson 2011, entire).
At a site BLM calls Little Ajo Mountains, southeast of the New Cornelia Mine on less than 0.4 ha (1 ac), the population has fluctuated from 5 plants in 1997, to 7 plants in 2001, to 7 plants in 2006, to 11 plants in 2007, to 7 plants in 2008, and finally to 12 plants (including 5 very small plants) in 2011 (Rutman 2006, p. 2; Anderson 2011, entire; Service 2011a, p. 1).
In 1997, a single adult individual was reported from just north and outside of the populations in the Coffeepot ACEC (Geraghty
An isolated population near Darby Wells was first reported by Heil and Melton (1994, p. 14). Fewer than 10 plants were found at this site in 2007 (Rutman 2007, p. 4). There is no record if juveniles were among the plants found. The site has not been revisited.
On Indian Village Hill, there were 102 plants in 1996, when the population was first recorded (Rutman 1996b, pers. comm.). In 2006, 30 living and 33 dead plants were found; in 2007, a quick census noted fewer than 40 plants found (Rutman 2006, p. 1; Rutman 2007, p. 4). There is no record if juveniles were among the plants found in either year. In 2011, eight living and seven dead plants were recorded; no juveniles were found (Service 2011a, p. 1).
There were 16 live and 19 dead plants on Weather Tower Hill in 2006 (Rutman 2006, p. 1). There is no record if juveniles were among the plants found. The site has not been revisited.
There may be other locations on private lands unknown to Service or BLM botanists.
Felger (2000, p. 208) noted the occurrence of the acuña cactus between 3 and 18 km (2 and 11 mi) southwest of Sonoyta; no population estimates were made. Surveys of 7 groups of plants in this area from 2009 through 2010 revealed 659 living and 942 dead plants growing on approximately 1,700 ha (4,200 ac) (Pate 2011, pers. comm.; Pate 2011, map 1 and map 2). Pate (2012a, pers. comm.) noted seeing a few small seedlings among these plants.
Presented below is the total estimate of living, dead, and juvenile acuña cactus plants in populations visited over multiple years, including census results from 2011 and from previous years if sites have not been revisited or population estimates not updated. Notable trends are the large amount of mortality within the populations that have been visited more than once and the low numbers of juvenile plants in the populations.
• NPS—2,000 plants, or 58.9 percent of known individuals; estimated in 2011 by NPS staff. This population estimate is down from 10,000 individuals estimated at this location in 1981. Within the OPCNM plots, the number of recorded individuals peaked in 1991, with 446 plants found. In 2011, 49 total individuals including 10 juveniles were noted within these plots.
• Sonora, Mexico—659 plants or 19.4 percent of known individuals; estimated from 2009 to 2010 surveys. Nine hundred and forty-two dead individuals were also recorded during this survey period. There are no previous estimates from this population. A few juvenile plants were noted during the 2009 to 2010 survey period.
• BLM—655 plants, or 19.3 percent of known individuals; estimated from 2011 and other recent surveys. At Coffeepot mountain within the largest BLM population, 310 living and 332 dead individuals were recorded in 1987. This population was reduced to 150 individuals by 1992, and was reduced to approximately 75 individuals by 2006. No juveniles were noted since 2008, when a few were seen.
• Private Land—48 plants (37 near Ajo and 11 near Florence), or 1.4 percent of known individuals; estimated from 2011 and other recent surveys. A single population that was revisited on several occasions showed a total population of 102 individuals in 1996; in 2006, 30 living and 33 dead plants were found. In 2011, just 8 adult plants and no juveniles were recorded from this population.
• State Land—32 plants, or 0.9 percent of known individuals; estimated from 2011 surveys. At one location in the 1990s, the population was estimated to be 100 individuals; in 2008, only 20 living and many dead plants were found with no juveniles seen. In 2011, 30 living plants were recorded, including a new subpopulation previously not recorded. No juvenile plants were located in 2011. At a second location, in 1977, plants were considered common but localized, and the site supported many plants of various ages and sizes. Surveys of this area in 2008 resulted in the location of 45 adult plants with no juveniles found. In 2011, no living plants and two carcasses were located in this same area.
• Military BMGR—1 plant, or less than 0.1 percent of known individuals in 1997; the site has not been revisited.
Section 4 of the Act (16 U.S.C. 1533), and its implementing regulations at 50 CFR part 424, set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of the Act, we may list a species based on any of the following five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; and (E) other natural or manmade factors affecting its continued existence. Listing actions may be warranted based on any of the above threat factors, singly or in combination. Each of these factors is discussed below.
Based on the habitat characteristics described above, potential factors that may affect the habitat or range of the acuña cactus are: (1) Urban development and site degradation; (2) livestock grazing; (3) border activities; (4) nonnative, invasive plant species; (5) mining; and (6) drought and climate change.
The immediate threats from urban development include the direct loss of individuals and habitat. Indirect impacts of urban development include fragmentation of acuña cactus and associated pollinator populations, which can reduce genetic vigor of the cactus and result in degradation and fragmentation of habitat adjacent to development. When development occurs, there is also an increased use of habitat for recreational activity, which may also deplete habitat and result in mortality of individuals. The acuña cactus populations in OPCNM and the Sonoran Desert National Monument are protected from the immediate threats associated with urban development due to their National Monument status. National Monuments are lands set aside and managed to protect the natural and cultural resources within; development is minimal, though some site degradation may still occur.
To meet the country's energy demands, there has been a recent emphasis by the Federal Government to use BLM lands for development of renewable energy. Currently, there are no planned solar or wind energy projects on or near populations of the acuña cactus in the Sauceda, Sand Tank, or Mineral Mountains (Werner 2011, pers. comm.). In addition, most populations on BLM lands are remotely located and relatively inaccessible; therefore, we do not anticipate development in these areas.
As Arizona's population is expected to continue to grow in the future, both Pinal County and the State Land Department are promoting urban development in the vicinity of Florence (Pinal County 2009, pp. 4, 60, 94; Guthrie
Indirect urbanization effects to the areas that support the acuña cactus include ORV activity, which has been reported on BLM lands near both Ajo and Florence. These reports, however, showed no impact on the acuña cactus populations in 1994 (Heil and Melton 1994, pp. 15-16), although habitat degradation and direct loss of individuals is possible from this activity. In 1988, the BLM closed the Coffeepot ACEC to recreational ORV use (BLM 2011, p. 194) and, in 1990, prohibited ORV use outside of designated trails within the Sonoran Desert National Monument (BLM 2011, p. 181). In 2011, the BLM Lower Sonoran Field Office released a Draft Resource Management Plan and Environmental Impact Statement (Draft RMP/EIS) for review (BLM 2011, entire). This document supports the continued prohibition of ORVs outside of designated trails within the Sonoran Desert National Monument (BLM 2011, p. 181). Within the Coffeepot ACEC, alternatives for motorized travel range from no use to limited use on existing routes, but all alternatives restrict travel off of existing routes, thereby reducing the potential for impacts to the acuña cactus (BLM 2011, pp. 181, 185-188). Once finalized, the new RMP/EIS for the Lower Sonoran and the Sonoran Desert National Monument will remain in effect for the next 15 to 20 years (Foreman 2011, pers. comm.). The impacts of ORV activity on State or private lands are unknown; for ORV activity within the border region, see the discussion below of border activities.
In Sonora, Mexico, scattered populations of the acuña cactus occur within 10 km (6.2 mi) of the town of Sonoyta. Although the area is reported to be little-used and unoccupied except by drug and human smugglers (Pate 2011, pers. comm.), in recent decades and as a result of human demand, the Sonoyta region has been heavily impacted by
In addition, the actions of harvesting, burning, loading, and transporting wood and charcoal can result in running over individual acuña cactus and causing injury or mortality of plants, if such actions occur in areas supporting the acuña cactus. Also, human population growth and development in the border region between the United States and Mexico has risen in recent decades (Brown and Caldwell 2008, pp. 1-6); it is reasonable to conclude that the direct and indirect effects of urbanization are likely to increase threats to the acuña cactus populations in this region. The populations are currently split by a major highway, Interstate 8, and a power transmission line; many plants occur within 200 m (660 ft) of these corridors (Pate 2011, map 1 and map 2).
In summary, the direct and indirect effects of urbanization are threats to a portion of the known populations of the acuña cactus. However, these effects are currently limited to the acuña cactus populations in the vicinity of Ajo and Florence in the United States and in the immediate border region of Sonora, Mexico. These areas collectively make up less than 21 percent of known living acuña cactus individuals across the range of the acuña cactus. The majority of the range in the United States is protected from urban development because populations are on Federal lands, where little or no development will take place. In addition, most populations of the acuña cactus are relatively remote or otherwise protected from the effects of urbanization. We conclude that urban development and site degradation is not currently a threat to any entire population of the acuña cactus. As a result, based on our review of the available information, we conclude that the direct and indirect
In general, grazing practices can change vegetation composition and abundance and cause soil erosion and compaction, reduced water infiltration rates, and increased runoff (Klemmedson 1956, p. 137; Ellison 1960, p. 24; Arndt 1966, p. 170; Gifford and Hawkins 1978, p. 305; Waser and Price 1981, p. 407; Robinson and Bolen 1989, p. 186; Holechek
In 1970, a cattle tank named Conley Reservoir was established within the Coffeepot ACEC boundary prior to the ACEC designation and remains today (Foreman 2012, pers. comm.). A population of acuña cactus very near this tank was visited by the BLM botanist in 2010, who found abundant prickly pear (
The new BLM Draft RMP/EIS has implications for future livestock management within the Coffeepot ACEC and the Sonoran Desert National Monument (BLM 2011, entire). According to this document, under Alternative A (the no action alternative), livestock grazing within the ACEC would not change from the current regimes with no livestock facility development permitted (BLM 2011, pp. 32, 141). Under Alternative B, livestock grazing only in times of suitable forage production (ephemeral) would continue to be considered, but perennial stocking rates would be reduced by approximately 40 percent, and no livestock facilities would be developed that would increase livestock use within the area (BLM 2011, pp. 33, 196). Under Alternative C, grazing allotments designated as perennial/ephemeral would be reclassified as perennial only, with no supplemental ephemeral grazing applications considered (BLM 2011, p. 34). Under Alternative D, all allotments currently open to grazing would become unavailable as permits expire (BLM 2011, p. 35). Under Alternative E, the BLM's preferred alternative, current grazing levels and timing would remain the same, but livestock facilities could be developed with the aim of improving natural resource conditions through greater distribution of livestock (BLM 2011, p. 171). It is unclear if additional tanks would, as is implied, relieve pressure on the acuña cactus populations; it is also unclear if this would increase the overall number of cattle (or burros) in the area or the amount of land impacted, thus potentially impacting more acuña cactus populations. Whichever alternative is ultimately chosen, the finalized version of this management plan will remain in effect for 15 to 20 years after signing later in 2012 (Foreman 2011, pers. comm.).
In 2001, Presidential Proclamation 7397 (Clinton 2001, entire) created the Sonoran Desert National Monument; one population of acuña cactus containing 5.9 percent of known living acuña cacti occur in the Sand Tank Mountains. This area was designated for military purposes in 1941, and has had no livestock grazing for over 60 years (Clinton 2001, p. 2). During a site visit in 2006, no habitat impacts from livestock were reported from this location (Anderson 2011, p. 2). The current livestock management regime of no livestock being permitted within the Sonoran Desert National Monument Sand Tank Mountains acuña cactus population will be maintained for at least the next 15 to 20 years (BLM 2011, pp. 36-40; Foreman 2011, pers. comm.).