FWS refuses to delist the Peirson's milk-vetch, and ORV litigation looms once again
73 Fed. Reg. 41007 (Thursday, July 17, 2008)(DEPARTMENT OF THE INTERIOR; Fish and Wildlife Service; 50 CFR Part 17; Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To Delist Astragalus magdalenae var. peirsonii (Peirson’s milk-vetch); Notice of 12-month petition finding.)
Astragalus magdalenae var. peirsonii (Peirson’s milk-vetch) is an erect to spreading, herbaceous, short-lived perennial in the Fabaceae (Pea family). Plants may reach 8 to 27 inches (in) (20 to 70 centimeters (cm)) in height and develop taproots that penetrate to the deeper, moister sand. Photo from Bureau of Land Management.
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 12-month finding on a petition to remove Astragalus magdalenae var. peirsonii (Peirson’s milk-vetch) from the Federal List of Threatened and Endangered Plants under the Endangered Species Act. After reviewing the best scientific and commercial information available, we find that the petitioned action is not warranted. We ask the public to submit to us any new information that becomes available concerning the status of, or threats to, the species. This information will help us monitor and encourage the conservation of this species.
EXCERPT: For many years controversy has focused on the abundance of Astragalus magdalenae var. peirsonii in any given year and the implications of abundance figures for the long-term persistence of the species. For a species that fluctuates widely in numbers from year to year, an assessment of abundance may not be the most meaningful measure of the likelihood of persistence. Characterizing the population trend, resilience, and long-term viability of A. magdalenae var. peirsonii would be more relevant but has not been done in a rigorous and meaningful manner to date. In addition, we agree with the updated petition (ASA 2005) that understanding the soil seed bank is important to understanding the long-term viability of A. magdalenae var. peirsonii. However, we do not agree that the nature, extent, and dynamics of the seed bank for A. magdalenae var. peirsonii have been characterized to the point that we fully understand the seed bank’s contribution to the long-term persistence of A. magdalenae var.
peirsonii. In addition, we do not agree that the available data provide evidence that A. magdalenae var. peirsonii will continue to persist because of the extent and nature of its seed bank. In short, we have an incomplete understanding of the relationship of abundance data and seed bank data to the long-term persistence of A. magdalenae var. peirsonii. Therefore, we cannot conclude that high numbers of aboveground plants and the purported large numbers of seeds in the seed bank ensure the long-term persistence of the species.
We continue to consider OHV activity the primary threat to Astragalus magdalenae var. peirsonii. Documentation available attests to historical and ongoing OHV impacts to the species ... Areas within the dunes subject to intensive OHV use (e.g., staging areas) have a lower abundance of A. magdalenae var. peirsonii. Longer-term monitoring indicates that plants exposed to OHV activity have a reduced likelihood of survival... Available
information suggests that within the foreseeable future OHV use will continue to increase and pose a threat to the survival of A. magdalenae var.
KEITHINKING: In February 2008, FWS revised the critical habitat for the Peirson's milk-vetch. See prior ESA blawg. At the time, in recognition of the potential future controversy over the species and the potential impacts on recreational off road vehicle use, FWS even excluded one previously identified unit of critical habitat "based on the disproportionate economic and social impacts associated with the designation of this unit relative to the other units designated as critical habitat." This finding addresses a delisting petition that had been pending before the FWS; predictably, the petitioners included: the American Sand Association, the Off-Road Business Association, the San Diego Off-Road Coalition, the California Off-Road Vehicle Association, and the American Motorcycle Association. In addition to its rejection of the "abundance" arguments, as quoted above, FWS also included an interesting discussion of the specialized plant genetics of the species, and in particular, genetic traits that absolutely necessitate large species populations to facilite reproduction:
"experiments in the field and under greenhouse conditions indicate that A. magdalenae var. peirsonii plants are not capable of self-pollination, and thus require pollinators for outcrossing. Moreover, Porter et al. (2005, p. 34) reported from microscopic examination of hand-pollinated flowers that pollen from the same flowers did not adhere to the stigmatic surface, while pollen from another plant did adhere. Unless pollen grains adhere, fertilization cannot occur. These results indicate that A. magdalenae var. peirsonii exhibits traits consistent with self-incompatibility (Porter and Prince 2007, pp. 10–11). Self-incompatibility (SI) is a genetic mechanism in plants that prevents selffertilization, or fertilization by pollen from plants that share the same SI allele. This means that inbreeding depression is avoided because only pollen from plants that do not share SI alleles with the maternal plant will be able to successfully fertilize eggs (Frankham et al. 2002, pp. 37–38; Castric and Vekemans 2004, p. 2873). This observation is a significant consideration for assessing the adequacy of population size, structure, and function. Large populations of standing individuals, with high SI allele diversity, are likely necessary to provide adequate numbers of individuals that can potentially fertilize the available eggs and ensure that seed is produced." 73 Fed. Reg. at 41021-41022.
Still doubting the inevitable notice of intent to sue? Check out the AP and Arizona Star article, reproduced by the CitizenReviewOnline: "Small plant blocks off-roaders - Milkvetch protected by Endangered Species Act, keeps dune riders out of area 3-1/2 times the size of Manhattan"