[Federal Register: July 27, 2007 (Volume 72, Number 144)] [Proposed Rules] [Page 41258-41284] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr27jy07-15] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 RIN 1018-AU98 Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Astragalus magdalenae var. peirsonii AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule; notice of availability of the draft economic analysis; notice of public hearings. ----------------------------------------------------------------------- SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to revise currently designated critical habitat for Astragalus magdalenae var. peirsonii (Peirson's milk-vetch) pursuant to the Endangered Species Act of 1973, as amended (Act). In total, approximately 16,108 acres (ac) (6,519 hectares (ha)) in Imperial County, California, fall within the boundaries of the proposed revised critical habitat designation. Lands being proposed as critical habitat are under Federal (15,857 ac (6,418 ha)), private (240 ac (97 ha)), and State (11 ac (4 ha)) ownership. Section 4 of the Act requires us to consider the economic and other relevant impacts of specifying any area as critical habitat. We have conducted an analysis of the economic impacts of designating the aforementioned areas as critical habitat for Astragalus magdalenae var. peirsonii, and are announcing the availability of the draft economic analysis for public review. We hereby solicit data and comments from the public on all aspects of this revised proposal, including data on the economic and other impacts of the designation. We are also announcing that public hearings will be held on both the proposed critical habitat rule and the draft economic analysis. DATES: We will accept comments from all interested parties until September 25, 2007. The public hearings will take place on August 23, 2007, from 1 p.m. to 3 p.m. and from 6 p.m. to 8 p.m. at the Carlsbad Fish and Wildlife Office in Carlsbad, California (see ADDRESSESS). ADDRESSES: Public Hearings. The public hearings will be held at the Carlsbad Fish and Wildlife Office, 6010 Hidden Valley Road, Carlsbad, California, 92011. Comments. If you wish to comment on the proposed rule and/or the draft economic analysis, you may submit your comments and materials, identified by RIN 1018-AU98, by any of the following methods: (1) You may send comments by electronic mail (e-mail) to fw8cfwocomments@fws.gov. Include ``RIN 1018-AU98'' in the subject line. (2) You may fax your comments to Jim Bartel, Field Supervisor, Carlsbad Fish and Wildlife Office at 760-431-5901. (3) You may mail or hand-deliver your written comments and information to Jim Bartel, Field Supervisor, Carlsbad Fish and Wildlife Office at the address above. (4) You may submit your comments at the Federal eRulemaking Portal, http://www.regulations.gov. Follow the instructions for submitting comments. Comments and materials received, as well as supporting documentation used in the preparation of this proposed rule, will be available for public inspection, by appointment, during normal business hours at the Carlsbad Fish and Wildlife Office at the above address (telephone 760-431-9440). Copies of the draft economic analysis are available for downloading from the Internet at http://www.fws.gov/carlsbad/ or by contacting the Carlsbad Fish and Wildlife Office directly at the above phone number or address. FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor, Carlsbad Fish and Wildlife Office, at the address listed under ADDRESSES (telephone 760-431-9440; facsimile 760-431-5901). Persons who use a telecommunications device for the deaf (TDD) may call the Federal Information Relay Service (FIRS) at 800-877-8339, 24 hours a day, 7 days a week. SUPPLEMENTARY INFORMATION: Public Comments Solicited We intend that any final action resulting from this proposal will be as accurate and as effective as possible. Therefore, comments or suggestions from the public, other concerned governmental agencies, the scientific community, industry, or any other interested party concerning this proposed critical habitat rule and its associated draft economic analysis are hereby solicited. On the basis of public comment, during the development of the final rule we may find that areas proposed are not essential or are appropriate for exclusion under section 4(b)(2) in which case they would be removed from the final critical habitat designation. Comments particularly are sought concerning: (1) The reasons any habitat should or should not be determined to be critical habitat as provided by section 4 of the Act, including whether the benefit of designation will outweigh any threats to the taxon caused by designation. (2) Specific information on the amount and distribution of Astragalus magdalenae var. peirsonii habitat, and what areas that were occupied at the time of listing that contain features essential for the conservation of the taxon should be included in the designation and why, and what areas that were not occupied at the time of listing are essential to the conservation of the taxon and why. (3) Additional information on the specific physical and biological features (primary constituent elements) that are essential to the conservation of Astragalus magdalenae var. peirsonii (see ``Primary Constituent Elements'' section of this proposed rule for more details). (4) Land use designations and current or planned activities in the subject areas [[Page 41259]] and their possible impacts on proposed critical habitat. (5) Information on how many of the State and local environmental protection measures referenced in the draft economic analysis were adopted largely as a result of the listing of Astragalus magdalenae var. peirsonii, and how many were either already in place or enacted for other reasons. (6) Whether the draft economic analysis identifies all State and local costs attributable to the revised proposed critical habitat designation, and information on any costs that have been inadvertently overlooked. (7) Whether the draft economic analysis makes appropriate assumptions regarding current practices and likely regulatory changes imposed as a result of the designation of critical habitat. (8) Whether the draft economic analysis correctly assesses the effect on regional costs associated with land use controls that derive from the designation of critical habitat. (9) Whether the economic analysis indicated potentially disproportionate impacts to any areas included in the proposed designation. Based on this information, we may consider excluding portions of these areas from the final designation per our discretion under section 4(b)(2) of the Act. (10) Whether the economic analysis appropriately identifies all costs that could result from the designation, in particular, any impacts on small entities or families; and whether it is appropriate that the analysis does not include the cost of project modifications that are the result of informal consultation only. (11) Whether the economic analysis appropriately identifies the benefits that could result from the designation. (12) Whether there is information about areas that could be used as substitutes for the economic activities planned in critical habitat areas that would offset the costs and allow for the conservation of critical habitat areas. (13) 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 accommodating public concerns and comments. If you wish to comment on the proposed rule and/or the draft economic analysis, you may submit your comments and materials by any one of several methods (see ADDRESSES section). Please submit e-mail comments to fw8cfwocomments@fws.gov. Please include ``Attn: RIN 1018- AU98'' in your e-mail subject line and your name and return address in the body of your message. If you do not receive a confirmation from the system that we have received your message, contact us directly by calling our Carlsbad Fish and Wildlife Office at phone number 760-431- 9440. Please note that comments must be received by the date specified in DATES in order to be considered. Before including your address, phone number, e-mail address, or other personal identifying information in your comment, you should be aware that your entire comment--including your personal identifying information--may be made publicly available at any time. While you can ask us in your comment to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so. Background This proposed rule addresses revised critical habitat for Astragalus magdalenae var. peirsonii. For additional information on the taxonomy, biology, and ecology of this taxon, refer to the final rule listing the taxon as threatened, published in the Federal Register on October 6, 1998 (63 FR 53596), or the proposed and final rules designating critical habitat for this taxon published in the Federal Register on August 5, 2003 (68 FR 46143), and on August 4, 2004 (69 FR 47330), respectively. It is our intention to discuss only those topics directly relevant to the revised designation of critical habitat in this proposed rule. Astragalus magdalenae var. peirsonii is an erect to spreading, herbaceous member of the Fabaceae (legume family) (Barneby 1959, p. 879; 1964, p. 862) that occurs on bowls, swales, and slopes of intact, active windblown sand dunes of the Algodones Dunes of Imperial County, California and the northeastern Estado de Baja California and Gran Desierto of northwestern Sonora, Mexico (Felger 2000, p. 300; Spellenberg 1993, p. 598; Willoughby 2005a, p. 2). Please refer to the ``Primary Constituent Elements'' section below for additional discussion on habitat requirements of this taxon. Plants may reach 8 to 27 inches (in) (20 to 70 centimeters (cm)) in height and develop tap roots (Barneby 1964, pp. 863-864) that penetrate deeply to the moister sand and that anchor plants in the shifting sand dunes. The root crown is often exposed by wind action moving the sand away from the base of the plants. Seeds are enclosed in fruits or pods and are either dispersed locally by falling out of partly opened fruits on the parent plant, ``salt-shaker'' style, or are dispersed further if blown across the sand after falling from the parent plant. Thus seeds can be transported from one favorable site to another, or remain near the parent plant, depending on winds (Phillips et al. 2001, p. 11). Seeds require no pre-treatment to induce germination, but germination success has been shown to improve dramatically when the outer seed coat is scarified (e.g., scratched, chipped) (Porter et al. 2005, p. 29). Germination appears to be more successful in the cooler months of the year when temperatures are less than 86 [deg]F (30 [deg]C) (Romspert and Burk 1979, pp. 45-46). Therefore, based on our current understanding of the taxon's life history, sufficient rain in conjunction with cool temperatures and wetter-than-average fall weather appears to trigger germination events. Depending upon conditions, Astragalus magdalenae var. peirsonii is capable of flowering before it is one year old (Barneby 1964, p. 862; Romspert and Burk 1979, p. 16; Phillips et. al 2001, p. 10; Phillips and Kennedy 2005, p. 22). Porter et al. (2005, pp. 31-32) hypothesized that if rains occur early in the growing season, then flowering can begin in as little as 3 months after germination. If, on the other hand, rains (and germination) do not occur until late February, then flowering is delayed until the next rainy season. In dry years, individuals die and are not replaced by new seedlings. This variability in annual abundance of above-ground plants has caused this taxon to be considered variously as an annual (completing its life cycle in a year or growing season) or a perennial (living for more than 2 years) (Munz 1932, p. 7; Munz 1974, p. 432; Barneby 1959, p. 879; Barneby 1964, p. 862; Spellenberg 1993, p. 598; Willoughby 2001, p. 21). Recent evidence has confirmed that this species is a short-lived perennial (Phillips et al. 2001, p. 10; Porter et al. 2005, pp. 31, 34). This taxon likely depends on the production of seeds in wetter years and the persistence of the seed bank from previous years to survive until appropriate conditions for germination occur again. Porter et al. (2005, p. 29) identified the primary dormancy mechanism in Astragalus magdalenae var. peirsonii as the impermeability of the seed coat to water and demonstrated little loss of viability in seeds stored for 5 years. This dormancy mechanism is consistent with species having a seed bank (Given 1994, p. 67). Dispersed seeds in a given year that do not germinate during the subsequent growing season become part of the soil seed bank (Given 1994, p. 67). [[Page 41260]] Species Distribution and Abundance In the United States, Astragalus magdalenae var. peirsonii is restricted to about 53,000 acres (ac) (21,500 hectares (ha)) in a narrow band running 40 miles (mi) (64 kilometers (km)) northwest to southeast along the western portion of the Algodones Dunes of eastern Imperial County, California, which is the largest sand dune field in North America. Astragalus magdalenae var. peirsonii has also been documented from the Gran Desierto of Sonora, Mexico (Felger 2000, p. 300) from an area south and southeast of the Sierra Pinacate lava field, but the Service has no additional information on the size of the population or extent of area occupied (63 FR 53599). The taxon was noted from the Borrego Valley, California, by Barneby (1959, p. 879) but no verified, reproducing population exists (Porter et al. 2005, pp. 9-10). Other observations from Yuma, Arizona, and San Felipe, Baja California, Mexico, were based on misidentified specimens (see Porter et al. 2005, pp. 9-10, and Phillips et al. 2001, p. 7, for detailed accounts). The Algodones Dunes are one of the largest sand dune fields in North America, extending about 40 mi (64 km), trending from northwest to southeast (Norris and Norris 1961, p. 608). Please refer to the 2003 proposed critical habitat rule for a more detailed discussion on the geomorphology of the Algodones Dunes (68 FR 46143). These dunes are often referred to as the Imperial Sand Dunes, a designation derived from their inclusion in the Imperial Sand Dunes Recreation Area (ISDRA) established by the Bureau of Land Management (BLM). The majority of the Algodones Dunes is managed by BLM within 8 management areas, of which 7 are occupied by Astragalus magdalenae var. peirsonii (Mammoth Wash, North Algodones Wilderness, Glamis, Gecko, Adaptive Management Area (AMA), Ogilby, and Buttercup). The State of California and private individuals own some small inholdings in the Mammoth Wash management area. The ISDRA is the most popular off-highway vehicle (OHV) area in the southwest United States, with a specified major focus to ensure that OHV recreation opportunities are continuously available while responding to increased need for protection of plant and animal species in the dunes (Willoughby 2003, pp. 1-3). As a result of a settlement agreement reached in 2000, the BLM agreed to establish 5 interim closure areas within the Algodones Dunes, temporarily closing these areas to OHV recreation (see Index Map in ``Rule Promulgation'' section). As a result of a June 3, 2005, lawsuit, these temporary closures are still in place (see ``Previous Federal Actions'' section below for more information about the 2005 lawsuit). The Algodones Dunes are in one of the driest and hottest regions in the United States. The rainfall is often described as scattered or patchy with amounts differing from place to place and from year to year, with areas to the northwest being generally dryer than those to the southeast (Willoughby 2001, p. 20). Romspert and Burk (1979, p. 11) reported average yearly rainfall during the period 1941-1970 was 2.6 in (66 millimeters (mm)). Average yearly rainfall between 1997 and 2002 at seven weather stations in the vicinity of the dunes ranged from a low of 0.1 in (3.3 mm) during the 2001-2002 growing season to a high of 6.1 in (155 mm) in the 1997-1998 growing season (Willoughby 2004, p.13). Average yearly rainfall between 2002 and 2006 at two weather stations on the dunes ranged from a low of 0.2 in (5.3 mm) during the 2005-2006 growing season to a high of 4.8 in (122 mm) during the 2004-2005 growing season (Willoughby 2006, p.18). The distribution and abundance of Astragalus magdalenae var. peirsonii has been recorded during several ongoing survey efforts. As discussed in the 2004 final critical habitat rule (69 FR 47330), the 1977 dunes-wide survey for A. m. var. peirsonii and four other rare psammophytic (sand-loving) scrub species (WESTEC 1977) was considered the most extensive survey of the Algodones Dunes conducted at that time. The BLM conducted rare plant surveys for 5 consecutive years from 1998 through 2002, generally repeating the methodology used by WESTEC in its 1977 survey (Willoughby 2001, p. iii). Raw data from the 2001 and 2002 surveys were provided by the BLM to the Service for use in the development of the 2004 final critical habitat rule. However, a written report of the 2001 and 2002 surveys (Willoughby 2004) was completed in October 2004, after the publication of the August 4, 2004, final critical habitat rule. As also discussed in the 2004 final critical habitat rule, Phillips and Kennedy (2002, 2003) conducted surveys for A. m. var. peirsonii from 2001 through 2003. Since publication of the 2004 final critical habitat rule, both the BLM (Willoughby 2005a, 2005b, 2006) and Phillips and Kennedy (2004, 2005, 2006) continued to conduct annual surveys for this species through 2006. Table 1 below summarizes all of the various survey efforts, including the number of sampling points or transects and the effective area surveyed by each effort as well as the estimated population by the survey methodology and the actual number of plants counted. Table 1.--Comparison of Survey Data Collected for Astragalus magdalenae var. peirsonii in the Algodones Dunes; Data Taken From 13 Unpublished Reports ---------------------------------------------------------------------------------------------------------------- Number of Estimated Number Year Surveyor plants counted population samples Effective area ---------------------------------------------------------------------------------------------------------------- 1977......................... WESTEC......... N/A N/A 542 53,000 ac 1998......................... BLM \1\........ 5,064 N/A 542 53,000 ac 1999......................... BLM \1\........ 942 N/A 542 53,000 ac 2000......................... BLM \1\........ 86 N/A 542 53,000 ac 2001......................... BLM \1\........ 5,930 N/A 542 53,000 ac 2002......................... BLM \1\........ 2,297 N/A 542 53,000 ac 2001......................... Phillips \2\... \3\ 71,926 N/A 127 ~35,000 ac 2001......................... Phillips \2\... 30,771 N/A 25 138 ac 2003......................... Phillips \2\... 33,202 N/A 25 138 ac 2005......................... Phillips \2\... 77,922 \4\ 173,328 25 138 ac 2006......................... Phillips \2\... 1,233 \4\ 2,035 25 138 ac 2004......................... BLM \1\........ 25,798 286,374 37,169 53,000 ac 2005......................... BLM \1\........ 739,805 1,831,076 123,488 53,000 ac [[Page 41261]] 2006......................... BLM \1\........ N/A 83,451 775 53,000 ac ---------------------------------------------------------------------------------------------------------------- (1) BLM reports cited as Willoughby; (2) Phillips reports cited as Phillips et al. or Phillips and Kennedy; (3) reconnaissance of unspecified area; (4) estimated population for 60 specific sample sites. Since different methodologies and survey effort were used by the BLM as compared to Phillips and Kennedy, it is difficult to compare the annual estimates of dunes-wide species abundance reported from the two different survey efforts. Early surveys conducted by WESTEC in 1977 (WESTEC 1977) and by BLM from 1998 through 2002 (Willoughby 2001, 2004) incorporated a methodology [whereby plants encountered along driving transects were qualitatively indexed to an abundance value] and represented in quadrants measuring 0.45 mi on each side. Analysis of these coarse, dune-wide surveys could only provide relative comparisons of mean abundance values between years. In 2004, the BLM embarked on a new sampling methodology that sampled a larger portion of the dunes in greater detail (Willoughby 2005a, pp. 1-5). Unlike previous surveys, the recent BLM surveys were scientifically and statistically designed to estimate the standing Astragalus magdalenae var. peirsonii population (Willoughby 2005a, 2005b, 2006). Data were compiled in adjacent 25 x 25-meter (m) cells along 4-5 km transects covering the full length of the dunes, and all micro-habitats were sampled along each transect (Willoughby 2005b, pp. 1-3). Within these 25 x 25-m cells, surveyors noted: The total number of plants; age class of plants; number of seedlings; number of flowering versus non-flowering plants; number of plants exhibiting damage from OHVs; and the number of plants showing damage from other sources (Willoughby 2005b, p. 3). The recent BLM surveys also increased the number of sample transects to 135 in 2004, and to 510 for the spring 2005 surveys; the increased transect numbers and more detailed survey methodology increased their overall sample count to 37,169 and 123,488, respectively (Willoughby 2005b). In 2006, the BLM used a randomized sample of 2005 known occupied cells during the very dry winter and spring of 2006 to yield a population estimate for the 2005-2006 survey year (Willoughby 2006, p. 6). Both the WESTEC and BLM surveys covered an effective area of about 53,000 ac (21,200 ha) and encompassed all management areas containing Astragalus magdalenae var. peirsonii (Willoughby 2005a, p. 2). By comparison, Phillips et al. (2001, p. 6) counted individual Astragalus magdalenae var. peirsonii from 127 specific locations covering an unspecified area of about 35,000 ac (14,165 ha) (Phillips and Kennedy 2002, Appendix A). Phillips and Kennedy (2002, 2003, 2004, 2005, 2006) then established 25 monitoring sites from these 127 locations for their multi-year survey effort, which had an effective area of about 138 ac (56 ha). The disparity between these three survey methods and the data collected makes it difficult to assess status and trends of the Astragalus magdalenae var. peirsonii population. However, we consider the surveys conducted by BLM to be the most extensive and precise effort to determine overall population abundance and distribution for this species, because this effort covered an effective area of about 53,000 ac (21,200 ha) and encompassed all management areas containing Astragalus magdalenae var. peirsonii. Also, the amount of data gathered in 2005 was the result of an exceptionally good rainfall year and extraordinary monitoring effort. We agree with the BLM that the 2005 survey effort represents the best estimate to date of distribution and abundance of the species on the Algodones Dunes (Willoughby 2006, p. v). The 2005-2006 survey year was an exceptionally dry year, with no A. m. var. peirsonii germination reported (Willoughby 2006, p. vi). While direct comparison of annual estimates of Astragalus magdalenae var. peirsonii abundance reported by BLM and Phillips and Kennedy is difficult due to differences in survey methodologies and effort used by the surveyors, some comparisons can be made which illustrate the wide variation in numbers of standing individuals found in any given year and in any given area of the dunes depending on abundance and distribution of rainfall. If we compare BLM data from 1998 with BLM 2000 data and compare Phillips and Kennedy's 2001 data with their 2003 data, we see the annual variation in species abundance at occupied sites. Along the same series of west to east transects, BLM counted a total of 5,064 plants in 1998, a heavy rainfall year, and 86 plants in 2000, a low rainfall year (Willoughby 2004, p. 36). The record of steep decline of the cohort counted by Phillips et al. in 2001 was tracked by Phillips and Kennedy (2002, p. 18), who reported that only 26 percent of the plants seen in spring of 2001 were present in late 2001. Phillips and Kennedy (2003, p. 12) also reported that only 0.26 percent of the plants counted in spring 2001 survived to spring 2003. This wide variation in numbers of standing individuals is also evident when comparing results of the BLM's dunes-wide surveys conducted in 2004, 2005, and 2006. In 2004, estimated dunes-wide abundance was 286,374 plants (5.5 plants/ac (13.5/ha)) (Willoughby 2005a, p. 37). In 2005, estimated dunes-wide abundance was 1,831,076 plants (39.8 plants/ac (86/ha)) (Willoughby 2005b, pp. 9-11). In 2006, estimated dunes-wide abundance was 83,451 plants (1.6 plants/ac (3.9/ ha)) (Willoughby 2006, p. vi). Differences in densities (plants per acre) are likely due to differences in rainfall between years. An above average amount of rainfall was recorded during the 2004-2005 growing season, resulting in the greatest abundance of plants to date, while the 2005-2006 growing season was considered an exceptionally dry year, resulting in zero reported germination. Density in 2004 may have also been decreased due to higher average monthly maximum temperatures recorded during the survey period, potentially impacting germination (Willoughby 2005a, p. 12). In any given year, Astragalus magdalenae var. peirsonii may be present as standing plants, as a ``soil seed bank'' in the sand dunes, or as plants persisting as perennial root crowns in the sand dunes. During any given year, the suitable habitat for A. m. var. peirsonii may be occupied by various combinations of these three life history phases. The dynamics of dune morphology, local rainfall patterns and amounts, and the spatial distribution of the soil seed bank contribute to the [[Page 41262]] patchy or mosaic nature of the distribution of standing plants of A. m. var. peirsonii. As discussed above, local rainfall patterns and amounts are likely to cause shifts in the proportions of these three life history phases. This species was federally listed as threatened due to threats of increasing habitat loss from OHV use and associated recreational development, destruction of plants, and lack of protection afforded the plant under State law (63 FR 53596). Impacts to individual plants and their habitat associated with OHV activities and recreation development continue to be the primary threat to this species in the United States. Please refer to the final listing rule (63 FR 53596) for a detailed discussion of the threats to the species and to the ``Special Management Considerations or Protection'' section of this proposed rule for a more detailed discussion on threats to this species' habitat. Previous Federal Actions For more information on previous Federal actions related to the designation of critical habitat for Astragalus magdalenae var. peirsonii, refer to the final listing rule published in the Federal Register on October 6, 1998 (63 FR 53596), and the proposed designation of critical habitat for this species published in the Federal Register on August 5, 2003 (68 FR 46143). On August 4, 2004 (69 FR 47330), we designated approximately 21,836 acres (ac) (8,848 hectares (ha)) of land in Imperial County, California, as critical habitat for this species. On June 3, 2005, the Center for Biological Diversity, Sierra Club, Public Employees for Environmental Responsibility, and Desert Survivors filed suit against the BLM and the Service alleging, among other violations related to the protection of Astragalus magdalenae var. peirsonii and desert tortoise (Gopherus agassizii), that the Service did not properly consider and weigh the benefits and costs associated with designating critical habitat for A. m. var. peirsonii. In a September 25, 2006, order and injunction regarding final relief, the court ordered the Service to submit a new final critical habitat rule to the Federal Register for publication no later than February 1, 2008. In addition, the Court ordered that the August 4, 2004 final critical habitat designation remain in full force and effect pending completion of the new final rule, and that the August 5, 2003 proposed designation of critical habitat be reinstated and remain effective pending completion of the new final rule or the issuance of a new proposed critical habitat rule for A. m. peirsonii. Therefore, under the Court's order, this proposed rule replaces the August 5, 2003 proposed critical habitat designation, and the August 5, 2003 proposed rule is no longer in effect. All areas currently designated under the August 4, 2004 final rule remain designated pending completion of the new final critical habitat rule. On November 30, 2005, we published a notice of 90-day finding on a petition to delist this species and an initiation of a status review in the Federal Register (70 FR 71795). Please see the notice of 90-day finding for a discussion of the previous Federal actions related to the delisting petition history of this species. We are currently completing a status review of Astragalus magdalenae var. peirsonii and will publish our 12-month finding on the delisting petition in the Federal Register later this year. Critical Habitat Critical habitat is defined in section 3 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, as defined under section 3 of the Act means to use and the use of all methods and procedures that are necessary to bring any endangered species or threatened species to the point at which the measures provided under the Act are no longer necessary. Critical habitat receives protection under section 7(a)(2) of the Act through the prohibition against destruction or adverse modification of critical habitat with regard to actions carried out, funded, or authorized by a Federal agency. Section 7(a)(2) of the Act requires consultation on Federal actions that are likely to result in the destruction or adverse modification of critical habitat. The designation of critical habitat does not affect land ownership or establish a refuge, wilderness, reserve, preserve, or other conservation area. Such designation does not allow government or public access to private lands. Section 7(a)(2) of the Act is a purely protective measure and does not require implementation of restoration, recovery, or enhancement measures. To be included in a critical habitat designation, the habitat within the area occupied by the species at the time of listing must first have features that are essential to the conservation of the species. Critical habitat designations identify, to the extent known using the best scientific data available, habitat areas that provide essential life cycle needs of the species (areas on which are found the primary constituent elements, as defined at 50 CFR 424.12(b)). Occupied habitat that contains the features essential to the conservation of the species meets the definition of critical habitat only if the essential features thereon may require special management considerations or protection. Thus, we do not include areas where existing management is sufficient to conserve the species. (As discussed below, such areas may also be excluded from critical habitat under section 4(b)(2) of the Act.) Unoccupied areas can be designated as critical habitat. However, when the best available scientific data do not demonstrate that the conservation needs of the species require additional areas, we will not designate critical habitat in areas outside the geographical area occupied by the species. Section 4 of the Act requires that we designate critical habitat on the basis of the best scientific data available. Further, the Service's Policy on Information Standards Under the Endangered Species Act, published in the Federal Register on July 1, 1994 (59 FR 34271); Section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658); and the associated Information Quality Guidelines issued by the Service provide criteria, establish procedures, and provide guidance to ensure that decisions made by the Service represent the best scientific data available. They require Service biologists, to the extent consistent with the Act and with the use of the best scientific data available, to use primary and original sources of information as the basis for recommendations to designate critical habitat. When determining which areas are critical habitat, a primary source of information is generally the listing package for the species. Additional information sources may include the recovery plan for the species, articles in peer-reviewed journals, conservation plans developed by States and counties, scientific status surveys and studies, biological assessments, or other unpublished materials and expert opinion or personal knowledge. All information is used in accordance with the provisions of Section 515 of the [[Page 41263]] Treasury and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658) and the associated Information Quality Guidelines issued by the Service. Habitat is often dynamic, and species may move from one area to another over time. Furthermore, we recognize that designation of critical habitat may not include all of the habitat areas that may eventually be determined to be necessary for the recovery of the species. For these reasons, critical habitat designations do not signal that habitat outside the designation is unimportant or may not be required for recovery. Areas that support populations, but are outside the critical habitat designation, will continue to be subject to conservation actions implemented under section 7(a)(1) of the Act and to the regulatory protections afforded by the section 7(a)(2) jeopardy standard, as determined on the basis of the best available information at the time of the action. Federally funded or permitted projects affecting listed species outside their designated critical habitat areas may still result in jeopardy findings in some cases. Similarly, critical habitat designations made on the basis of the best available information at the time of designation will not control the direction and substance of future recovery plans, habitat conservation plans, or other species conservation planning efforts if new information available to these planning efforts calls for a different outcome. Methods As required by section 4(b)(2) of the Act and regulations at 50 CFR 424.12, we used the best scientific and commercial information available in determining areas that contain the features essential to the conservation of Astragalus magdalenae var. peirsonii, areas that are essential to the conservation of A. m. var. peirsonii, or both. This included data from unpublished research and survey reports, such as WESTEC (1977); Porter et al. (2005); BLM surveys conducted from 1998 to 2006 (Willoughby 2001, 2004, 2005a, 2005b, 2006); peer-reviewed journal articles; site visits; and discussions with species experts. We are not including in this proposed critical habitat rule any areas outside the geographical area presently occupied by the species. Primary Constituent Elements In accordance with section 3(5)(A)(i) of the Act and regulations at 50 CFR 424.12, in determining which areas within the geographical area occupied by the species at the time of listing to propose as critical habitat, we consider those physical and biological features (primary constituent elements) that are essential to the conservation of the species, and that may require special management considerations or protection. These include, but are not limited to: (1) Space for individual and population growth and for normal behavior; (2) food, water, air, light, minerals, or other nutritional or physiological requirements; (3) cover or shelter; (4) sites for breeding, reproduction, and rearing (or development) of offspring; and (5) habitats that are protected from disturbance or are representative of the historic, geographical, and ecological distributions of a species. The specific primary constituent elements (PCEs) required for Astragalus magdalenae var. peirsonii are derived from the biological needs of A. m. var. peirsonii as described in the ``Background'' section of this proposed rule, and also in the final listing rule (63 FR 53596) and in the ``Background'' section of the 2003 proposed critical habitat rule (68 FR 46143). Space for Individual and Population Growth, Including Sites for Germination, Reproduction, Seed Dispersal, Seed Bank, and Pollination Astragalus magdalenae var. peirsonii is found on active sand dunes between active faces (so-called slip faces) of the dunes, in bowls, or on semi-stabilized shallow slopes, facing the slip-faces of active dunes (Porter et al. 2005, p. 14). Active sand dunes provide the space needed for individual and population growth, including sites for germination, reproduction, seed dispersal, seed bank, and pollination of A. m. var. peirsonii. Active sand dunes are characterized by bowls (hollows among the dunes), swales (low area), and slip faces (areas so steep that the loose sand naturally cascades downward) that run transverse to the primary ridge line. A. m. var. peirsonii generally occurs on west-facing slopes where there is relative substrate stability from the floor of the dune basin to beyond the ridge; the greatest concentrations are generally above the middle of the slope (WESTEC 1977, p. 75; Porter et al. 2001, pp. 12-13). Sand movement, dune-building, and dune migration are likely determined by the wind regime (Norris and Norris 1961, p. 609). Winds from the northwest are prevalent in the winter, while in the summer the winds are from the southeast (Romspert and Burk 1979, p. 11). Muhs et al. (1995, pp. 43-44) found, during a study of the sand source for the Algodones Dunes, that dominant sand-moving winds are as follows: Prevailing from the northwest all year at Indio, California; from the west or southwest all year at El Centro, California; and from the northwest in winter and from the southeast in summer at Yuma, Arizona. These winds are responsible for the local dispersal of seeds that either fall out of partly opened fruits or pods on the parent plant or that are released from fruits blown across the sand after falling from the parent plant (Phillips et al. 2001, p. 11). Seed germination patterns likely reflect the horizontal and vertical distribution of the seed bank in the shifting sand dunes (seeds will not effectively germinate if buried more than 3 in (8 cm) below the surface of the dune (Bowers 1996, p. 69)). As an adaptation to shifting sands and low soil moisture, this species has developed extremely long tap roots (Barneby 1964, p. 862) that penetrate deeply to the moister sand and that anchor the plants in the shifting dunes. According to Porter et al. (2005, p. 28), seedlings may have roots descending only 4 in (10 cm), whereas older plants (e.g., 4 years or older) are likely to have roots ``many meters deep.'' Seeds buried in the sand function as the seed bank and allow for growth when suitable conditions, such as adequate rainfall, scarification, and suitable sand depths, are met. Wind-driven sand appears to provide the primary mechanism for seed scarification (e.g., scratching or chipping of outer cover). While seeds require no pre-germination treatment to induce germination, scarification appears to significantly increase germination success. Porter et al. (2005, p. 29) conducted germination trials of Astragalus magdalenae var. peirsonii seeds collected from Algodones Dunes and found that, averaging over all germination trials, scarified seeds had 99.1 percent germination whereas unscarified seeds displayed 5.3 percent germination. In germination trials conducted by Romspert and Burk (1979, pp. 45-46), 92 percent or more seeds germinated within 29 days at temperatures of 77 [deg]F (25 [deg]C) or less, and no seeds germinated at temperatures of 86 [deg]F (30 [deg]C) or higher. This observation indicates that seeds on the dunes likely germinate in the cooler months of the year. Porter et al. (2005, p. 29) identified the primary dormancy mechanism in A. m. var. peirsonii as the impermeability of the seed coat to water and demonstrated little loss of viability in seeds stored for 5 years. Seedlings may be generally present in suitable habitat throughout the dunes, [[Page 41264]] especially during above-normal precipitation years. In intervening dry years, plant numbers decrease as individuals die and are not replaced by new seedlings. Porter (et al. 2005, p. 35) estimated that a total- or near-total failure of seedling recruitment occurs 20 percent of the time (1 of every 5 years). This species likely depends on the production of seeds in the wetter years and the persistence of the seed bank from previous years to survive until appropriate conditions for germination occur again. Astragalus magdalenae var. peirsonii occurs only in a vegetation community referred to as psammophytic (sand-loving) scrub, characterized by Croton wigginsii (Dunes croton), Eriogonum deserticola (Desert buckwheat), Helianthus niveus ssp. Tephrodes (Algodones Dunes sunflower), Palafoxia arida var. gigantean (Giant Spanish-needle), Pholisma sonorae, Tiquilia plicata (Plicate coldenia), Petalonyx thurberi (Thurber's sandpaper plant), and Panicum urvilleanum (Dunes panic grass) (WESTEC 1977, p. 58; Porter et al. 2005, p. 14). However, none of these species truly dominates the landscape (Porter et al. 2005, p. 14). In areas where the sand dunes are more stabilized (less sand dune building and movement), such as along the margins of the dune fields, the open canopy psammophytic scrub community is replaced by the sandier phases of the creosote bush scrub community. Astragalus magdalenae var. peirsonii is apparently excluded from the relatively more closed canopy, creosote bush scrub community. The presence of this associated co-adapted psammophytic scrub plant community is important for population growth of A. m. var. peirsonii, because it provides habitat for insect pollinators required by A. m. var. peirsonii for fruit production (Porter et al. 2005, p. 35). The white-faced digger bee (Habropoda pallida) has been found to be the most frequent visitor on and may be the primary pollinator for this taxon (Porter et al. 2005, p. 32). Intervening Areas for Gene Flow and Connectivity Within the Population The active sand dunes are continuous along the northwest-to- southeast axis. The continuity of the sand dunes provides connectivity and facilitates gene flow within the population by allowing the movement of pollinators and the wind dispersal of fruit and seeds. Therefore, areas of the sand dunes between bowls occupied by Astragalus magdalenae var. peirsonii are important for maintaining gene flow within the population. Areas That Provide the Basic Requirements for Growth (Such as Water, Light, and Minerals) A soil survey for the Imperial Valley area of Imperial County did not include the areas east of the Coachella Canal, but did depict a few adjacent portions of the Algodones Dunes as Rositas fine sand with 9 to 30 percent slopes (Zimmerman 1981, p. 32). Rositas fine sand is described as deep, somewhat excessively drained, sloping soils formed in wind-blown sands of diverse origin. Dean (1978, p. 65) describes the sand as quartz with a mean grain size of 0.006 in (0.17 mm). The dunes contain 60 to 70 percent quartz and 30 to 40 percent feldspar sand (Norris and Norris 1961, p. 610). Porter et al. 2005 (pp. 26-27) describes the sand as containing very little organic material (less than 1 percent). They also found that following rainfall, the dune surface held considerable moisture. Within two to three weeks of a rainfall event, moist sand was found 1 in (3 cm) below the dune surface and later in the season (e.g., April) moist sand was found 7 in (19 cm) below the surface (Porter et al. 2005, pp. 26-27). Therefore, Rositas fine sands are required by this species to provide the basic requirements for growth. Based on the best available information at this time, the primary constituent elements required by Astragalus magdalenae var. peirsonii are: (1) West and/or northwest-facing sides of bowls, swales, and slopes consisting of Rositas fine sands within intact, active sand dune systems (defined as sand areas that are subject to sand-moving winds) in the existing range of the species that provide space needed for individual and population growth, including sites for germination, reproduction, seed dispersal, seed bank, and pollination; (2) The associated co-adapted psammophytic scrub plant community characterized by Croton wigginsii, Eriogonum deserticola, Helianthus niveus ssp. tephrodes, Palafoxia arida var. gigantean, Pholisma sonorae, Tiquilia plicata, Petalonyx thurberi, and Panicum urvilleanum that provides habitat for insect pollinators, particularly the white- faced digger bee (Habropoda pallida), required for reproduction; and (3) Areas within intact, active sand dune systems between occupied bowls, swales, and slopes that allow for pollinator movement and wind dispersal of fruit and seeds. This proposed revision to the critical habitat designation is designed for the conservation of those areas containing PCEs necessary to support the life history functions that were the basis for the proposal and the areas containing those PCEs. Because not all life history functions require all the PCEs, not all proposed critical habitat units will contain all the PCEs. Units are designated based on sufficient PCEs being present to support at least one of the species' life history functions. Some units contain all PCEs and support multiple life processes, while some units contain only a portion of the PCEs necessary to support the species' particular use of that habitat. Special Management Considerations or Protection When designating critical habitat, we assess whether the areas determined to be occupied at the time of listing contain primary constituent elements that may require special management considerations or protection. We have also considered how revising the current designation highlights habitat that needs special management consideration or protection. Astragalus magdalenae var. peirsonii was listed due to destruction of plants and modification of habitat associated with OHV activity and associated recreational development (63 FR 53596). OHVs can impact habitat for A. m. var. peirsonii by: (1) Disrupting the natural processes that support dune formation, movement, and structure which could disrupt the available habitat needed for individual and population growth (PCE 1 and 3); (2) Causing the collapse of dune faces and ridges, which could result in burial of the seed bank (PCE 1); (3) Disturbing surface sand, thereby decreasing soil moisture needed for individual and population growth (PCE 1); and (4) Degrading the psammophytic scrub plant community that provides habitat for pollinators required for reproduction (PCE 2). In the 2004 final critical habitat rule, we stated that OHVs may also increase sand compaction (69 FR 47330). However, Porter et al. (2005, p. 27) measured soil compaction associated with undisturbed dunes, OHV-traversed sand dunes, and dunes disturbed by foot traffic, and found that soil compaction on the undisturbed dunes was significantly higher. They state that winds and rains cause the sand grains on the surface of the dune to sort and pack in undisturbed areas, thereby potentially reducing evaporative water loss from the dunes. They theorize that OHV activity or walking disturbs the surface and may result in increased [[Page 41265]] evaporative water loss in the dunes (Porter et al. 2005, p. 27). Special management considerations or protection may be required to minimize impacts to Astragalus magdalenae var. peirsonii habitat resulting from OHV recreation. The BLM (2003, Appendix 1 p. 13) listed the following possible management options to protect A. m. var. peirsonii and its habitat: (1) Use restrictions based on a permit system that would allow a specified level of use (high, medium, low, no use); (2) temporally based closures or limitations (open during some months or years, closed in others); (3) recognition and management of certain areas within a management area; and/or (4) increased education and outreach to OHV users to avoid certain areas. Special management considerations needed may also include additional enforcement to ensure visitor compliance with these management options. Criteria Used To Identify Critical Habitat All proposed revised critical habitat units are within areas that we have determined were occupied at the time of listing, and that contain sufficient primary constituent elements (PCEs) to support life history functions essential for the conservation of the species. Lands were proposed for designation based on sufficient PCEs being present to support the life processes. Some lands contain only a portion of the PCEs necessary to support the particular use of that habitat. We consider BLM's 2005 (Willoughby 2005b) survey data to be the best available information on the distribution and range of Astragalus magdalenae var. peirsonii on the Algodones Dunes. As discussed in the ``Background'' section of this proposed rule, an exceptional amount of rainfall was recorded during the 2004-2005 growing season, resulting in the highest recorded abundance of the species to date with an estimated 1,831,076 plants (39.8 plants/ac (86 plants/ha)) in the dunes (Willoughby 2005b, pp. 9-11). This rainfall event coincided with the start of BLM's revised survey methodology, which consisted of a more detailed survey approach, as previously described in the ``Background'' section, and covered a larger portion of the dunes (Willoughby 2005a, pp. 1-5). The 2005 survey contained 123,488 sample points covering an effective area of 53,000 acres. Because these surveys occurred under the best possible growth and germination conditions for the plant and covered the largest area and greatest number of sample point locations, we relied on BLM's raw 2005 survey data as the basis for our criteria and GIS model to delineate proposed critical habitat for A. m. var. peirsonii. As discussed in further detail below, we used the following criteria to delineate proposed critical habitat: (1) Areas occupied by the species at the time of listing; (2) areas occupied at a density greater than 100 plants per ha according to BLM's 2005 survey data (Willoughby 2005b); and (3) areas containing the features essential to the conservation of the species. As stated in the final listing rule (63 FR 53596), the Algodones Dunes was, and continues to be, the only area in the United States known to be occupied by Astragalus magdalenae var. peirsonii. We delineated the revised proposed critical habitat boundaries using the following GIS model: (1) We selected occupied cells (defined in Willoughby (2005b) as 25-m\2\ survey areas) with a plant density greater than 100 plants per ha (6 plants per cell) as core areas. About half of the plants observed in 2005 were in cells with a density more than or equal to 100 plants per ha. We used a density of 100 plants per ha since this captured the majority of the large clusters of standing plants. We believe these higher density core areas contain a larger extent of high quality habitat (e.g., suitable dune morphology and soil moisture) and therefore the PCEs required by this species. Also, since these core areas contain higher numbers of standing plants in proximity to each other, we believe that these areas likely support relatively large seed banks (a greater number of seeds being contributed by a greater number of standing plants). Therefore, based on our assumptions that these core areas contain a larger extent of high quality habitat and larger seed banks, we considered these areas most likely to contribute to the recovery of the species. (2) We expanded each core area to 1 ha then merged 1-ha core areas within 100-m distances of each other to form aggregated core areas. We expanded core areas to one ha to capture the entire population and seed bank in a dune bowl, based on our field observations that most occupied dune bowls are approximately one ha in size. We aggregated the 1-ha core areas within 100 m of each other to maintain space for wind dispersal of seeds between occupied dune bowls. This 100-m distance is a dunes-wide approximation of the average distance between aggregated core areas. (3) We then eliminated outlying or remote core areas greater than 400 meters (4 bowls) from adjacent core areas and core areas less than 400 m away but with a plant density less than approximately 370 plants (= 0.0005 of the total observed population of 739,805) within the aggregated core area. This step allowed us to remove core areas with low numbers of plants considered not essential to the conservation of the species. Since these areas are a greater distance from aggregated core areas and/or contain relatively fewer standing plants, we believe these areas either contain a smaller extent of high quality habitat (e.g., suitable dune morphology and soil moisture) and/or support relatively small seed banks. Since we were not able to determine the importance of these outlying or remote areas to the long-term conservation of the species, we did not include them in the proposed designation. (4) We then overlaid a 100-m\2\ grid onto the final core areas to define the legal boundaries of the proposed critical habitat. We removed remaining small polygons less than 400 m from the core habitat in which the plant density was low. Since these polygons contained a low number of standing plants, we believe these areas contain a smaller extent of high quality habitat (e.g., suitable dune morphology and soil moisture) and/or support relatively small seed banks. Since we are not able to determine the importance of these lower density areas to the long-term conservation of the species at this time, we did not include them in the proposed designation. This methodology captured approximately 92 percent of the 2005 observed population and includes areas we believe contain high density core populations, a large extent of high quality habitat, and a large seed bank and therefore important for the recovery of the species. Areas meeting the proposed critical habitat boundaries were then analyzed to determine if any existing conservation or management plans exist that benefit the taxon and its PCEs. As discussed in the 2004 final critical habitat rule (69 FR 47330), BLM released a proposed Recreation Area Management Plan (RAMP) for the ISDRA in 2003 (BLM 2003). The RAMP includes an intensive monitoring/study plan that the BLM has implemented (BLM 2003). As a result of the September 25, 2006, order and injunction regarding final relief, referenced in the ``Background'' section of this proposed rule, the Environmental Impact Statement associated with the 2003 RAMP was remanded back to the BLM for further consideration. [[Page 41266]] When determining proposed critical habitat boundaries within this proposed rule, we made every effort to avoid including developed areas such as buildings, paved areas, and other structures that lack PCEs for Astragalus magdalenae var. peirsonii. The scale of the maps prepared under the parameters for publication within the Code of Federal Regulations may not reflect the exclusion of such developed areas. Any such structures and the land under them inadvertently left inside critical habitat boundaries shown on the maps of this proposed rule have been excluded by text in the proposed rule and are not proposed for designation as critical habitat. Therefore, Federal actions limited to these areas would not trigger section 7 consultation, unless they affect the species or primary constituent elements in adjacent critical habitat. Summary of Changes From Previously Designated Critical Habitat The areas identified in this proposed rule constitute a proposed revision of the areas we proposed to designate as critical habitat for Astragalus magdalenae var. peirsonii on August 5, 2003 (68 FR 46143), and designated on August 4, 2004 (69 FR 47330). The main differences include the following: 1. This proposed revision includes 16,108 ac (6,519 ha) of land in Imperial County, California, a reduction of 36,672 acre (14,840 ha) from the 2003 proposed rule (68 FR 46143) and 5,728 ac (2,329 ha) from the 2004 final critical habitat rule (69 FR 47330). The differences in data and selection criteria between the currently designated critical habitat and this proposed revision are described further below. 2. The reduction in total acreage from the 2003 proposed critical habitat designation is primarily the result of a revised methodology to delineate critical habitat. The model used to delineate critical habitat boundaries in the 2003 proposed rule was based primarily on species survey data collected by the BLM from 1998 through 2002 along transects throughout the areas of the Algodones Dunes occupied by Astragalus magdalenae var. peirsonii. Each transect was composed of a series of grid squares measuring approximately 0.45 mi\2\. In order to create the model, we used the coarse scale BLM survey data to extrapolate the values for four variables: (1) The presence or absence of standing plants of A. m. var. peirsonii; (2) the abundance of A. m. var. peirsonii; (3) the frequency of occurrence of A. m. var. peirsonii over the survey years; and (4) the number of associated rare psammophytic plant taxa present. These variables were scored, then standardized, and finally compiled. Because of the dynamic nature of the distribution of this plant, the cyclic nature of suitable climatic regimes, and the presence of a seed bank for A. m. var. peirsonii, grid squares where this plant was not found were included in critical habitat if they were contiguous with occupied grid squares (68 FR 46143). The data used to create the 2003 model was considered the best available at that time and allowed us to identify areas known to be occupied by A. m. var. peirsonii as well as areas likely to be occupied based on the presence of suitable habitat (e.g. presence of associated psammophytic plant taxa). As discussed in the ``Background'' and ``Criteria Used to Identify Critical Habitat'' sections of this proposed rule, the model used to delineate revised critical habitat boundaries in this revised proposed rule is based on survey data collected by BLM in 2005 (Willoughby 2005b). A higher than average rainfall occurred during the 2004-2005 growing season, resulting in the highest Astragalus magdalenae var. peirsonii densities to date. Based on these survey data, our revised model uses occupancy and density to outline areas known to be occupied by the species. The model used to delineate the revised proposed critical habitat is based on data collected along a larger number of transects (510 versus 34) during a year of the highest recorded A. m. var. peirsonii abundance. Therefore, the data are more robust, relying primarily on occupancy documented over a larger area of the dunes and at a finer spatial resolution (25 m\2\ grid cells) during optimal environmental conditions instead of on the presence of suitable habitat (e.g., the presence of associated rare psammophytic plant taxa) as did the 2003 model. In summary, we consider the model used to delineate revised critical habitat boundaries in this proposed rule to more accurately depict the areas known to be occupied by the species than the model used to delineate the 2003 proposed critical habitat boundaries. We believe that the 2003 designation was more inclusive due to limited data and the rough spatial scale of the data, and the 2005 data now provide more specific and reliable information regarding abundance and distribution, allowing us to more precisely identify habitat essential to the conservation of the species associated with core population areas. Based on the new model, we determined that 36,535 ac (14,785 ha) previously proposed as critical habitat in 2003 are not essential to the conservation of the taxon, and therefore did not include these areas in the revised proposed critical habitat designation. 3. Of the 16,108 ac (6,519 ha) included in this proposed revision to critical habitat, 14 ac (6 ha) in Subunit 3B, 331 ac (134 ha) in Subunit 3C, and 75 ac (30 ha) in Unit 4 were not included in the 2003 proposed critical habitat rule. Also, 9,573 ac (3,874 ha) in Subunits 2A, 2B, 3A, 3B, 3C and all of Unit 4 (218 ac (88 ha)) were not included in the 2004 final rule (see Table 2 below). These 9,573 ac (3,874 ha) were excluded in the 2004 final rule under section 4(b)(2) of the Act as the Secretary determined that the economic benefits of excluding these lands outweighed the conservation benefits of including these lands in the designation due to the large potential economic and human costs of the designation (69 FR 47330). These lands are again under consideration for critical habitat in this proposed revision to critical habitat. All lands proposed for critical habitat have been re-evaluated in a revised economic analysis, consistent with the lawsuit discussed in the ``Previous Federal Actions'' section of this proposed rule. The new draft economic analysis is available for public review and comment concurrently with this rule (see ``Economic Analysis'' section below). Based on public comment and information in the economic analysis, habitat being proposed as critical habitat herein may be excluded from final critical habitat by the Secretary under the provisions of section 4(b)(2) of the Act and in our implementing regulations at 50 CFR 424.19. Table 2 below outlines the changes in Unit/Subunit number and area between the 2003 proposed critical habitat rule, the 2004 final critical habitat rule, and the 2007 revised proposed critical habitat rule for Astragalus magdalenae var. peirsonii. [[Page 41267]] Table 2.--Changes in Unit/Subunit Numbering and Area (in acres (ac) and Hectares (ha)) Between the 2003 Proposed Critical Habitat Rule, the 2004 Final Critical Habitat Rule, and the 2007 Revised Proposed Critical Habitat Rule for Astragalus magdalenae var. peirsonii -------------------------------------------------------------------------------------------------------------------------------------------------------- 2003 proposed rule (68 FR 46143) 2004 Final rule (69 FR 47330) 2007 revised proposed rule -------------------------------------------------------------------------------------------------------------------------------------------------------- Area (ac Unit/ Subunit Area (ac (ha)) Unit/ Subunit (ha)) Unit/ Subunit Area (ac (ha)) -------------------------------------------------------------------------------------------------------------------------------------------------------- 1A....................................... 16,510 (6,681) 1A........................... 16,509 (6,681) 1A, 1B, 1C, 1D.............. 4,675 (1,892) 1B....................................... 34,333 (13,894) 1B........................... \1\ 5,355 2A, 2B, 3A, 3B, 3C.......... \4\ 11,215 (2,167) (4,539) 1C....................................... 1,490 (603) 1C........................... \2\ 0 (0) 4........................... \5\ 218 (88) 1D....................................... 447 (181) 1D........................... \3\ 0 (0) (none)...................... (none) ----------------- ---------------- ---------------- Totals............................... 52,780 (21,359) ............................. 21,863 (8,848) ............................ 16,108 (6,519) -------------------------------------------------------------------------------------------------------------------------------------------------------- \1\ 28,978 ac (11,727 ha) excluded from final designation under section 4(b)(2) of the Act. \2\ Excluded from the final designation under section 4(b)(2) of the Act. \3\ Removed from the final designation; not essential to the conservation of the species. \4\ Includes 331 ac (134 ha) not included in the 2004 final designation. \5\ Includes 75 ac (30 ha) not designated in the 2004 final designation. Proposed Revisions to the Critical Habitat Designation We are proposing approximately 16,245 ac (6,574 ha) as critical habitat for Astragalus magdalenae var. peirsonii within 4 units further divided into 9 subunits. These lands are under Federal (15,995 ac (6,473 ha)), private (239 ac (97 ha)), and State (11 ac (4 ha)) ownership. The approximate area (ac (ha)) encompassed within each p