Meyer, Susan E. , Forbis, Tara .
Population viability analysis (PVA) for Arctomecon californica (Papaveraceae), an eastern Mojave Desert gypsophile perennial herb.
ARCTOMECON californica (golden bearpaw poppy) is a species of conservation concern because a significant portion of its range lies within Las Vegas Valley, an area undergoing rapid urban development. Habitat for this species lies within a region of low and unpredictable rainfall (100 mm annual mean). We used demographic data collected intermittently over thirty years to quantify life history attributes for this species and an eleven-year retrieval experiment to examine seed bank dynamics. Seedling recruitment occurred in early spring in years with unusually high winter precipitation, and plants, which are iteroparous, often reached reproductive maturity the following spring. If pollinators were not limiting, a mature plant, which had a mean lifespan of four years, could produce thousands of high quality seeds. The seeds form a long-lived seed bank, with probable longevity in the soil for an individual seed cohort of up to twenty years. The stochastic PVA model developed from these data showed that even large, intact populations are at considerable risk of local extinction due to environmental stochasticity alone, because of the relatively high probability of long runs of years too dry for successful recruitment or survival to maturity. Small, fragmented populations suffer from severe pollen limitation and therefore set little seed. Some of these populations seem to be extant solely as a consequence of seeds produced before fragmentation occurred. Such populations are predicted to have little chance of persistence. The best hope for preservation of this species over the long term lies in the protection of large tracts of occupied habitat, including adjacent non-gypsum habitat that can support pollinator populations during the frequently-occurring periods when A. californica is present only as a seed bank. Absence of actively-growing plants is a poor indicator of population status except in years immediately following a successful recruitment episode.[c.e.:srb]
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1 - USDA Forest Service, Rocky Mountain Research Station, Shrub Sciences Laboratory, 735 N 500 E, Provo, Utah, 84606, USA
2 - P.O. Box 150266, Ely, Nevada, 89315, USA
golden bearpaw poppy
Presentation Type: Oral Paper:Papers for Topics
Date: Tuesday, August 1st, 2006
Time: 2:15 PM