HR: 0800h
AN: GC41A-0120    [Abstracts]
TI: Alpine Plant Monitoring for Global Climate Change; Analysis of the Four California GLORIA Target Regions
AU: Dennis, A
EM: adennis@calflora.org
AF: CalFlora, 1700 Shattuck Ave. #198, Berkeley, CA 94709, United States
AU: Westfall, R D
EM: bwestfall@fs.fed.us
AF: USDA Forest Service, PSW Research Station, Sierra Nevada Research Center, 800 Buchanan St., Albany, CA 94710, United States
AU: * Millar, C I
EM: cmillar@fs.fed.us
AF: USDA Forest Service, PSW Research Station, Sierra Nevada Research Center, 800 Buchanan St., Albany, CA 94710, United States
AB: The Global Observation Research Initiative in Alpine Environments (GLORIA) is an international research project with the goal to assess climate-change impacts on vegetation in alpine environments worldwide. Standardized protocols direct selection of each node in the network, called a Target Region (TR), which consists of a set of four geographically proximal mountain summits at elevations extending from treeline to the nival zone. For each summit, GLORIA specifies a rigorous mapping and sampling design for data collection, with re-measurement intervals of five years. Whereas TRs have been installed in six continents, prior to 2004 none was completed in North America. In cooperation with the Consortium for Integrated Climate Research in Western Mountains (CIRMOUNT), California Native Plant Society, and the White Mountain Research Station, four TRs have been installed in California: two in the Sierra Nevada and two in the White Mountains. We present comparative results from analyses of baseline data across these four TRs. The number of species occurring in the northern Sierra (Tahoe) TR was 35 (16 not found in other TRs); in the central Sierra (Dunderberg) TR 65 species were found. In the White Mountains, 54 species were found on the granitic/volcanic soils TR and 46 (19 not found in other TRs) on the dolomitic soils TR. In all, we observed 83 species in the Sierra Nevada range TRs and 75 in the White Mountain TRs. Using a mixed model ANOVA of percent cover from summit-area-sections and quadrat data, we found primary differences to be among mountain ranges. Major soil differences (dolomite versus non-dolomite) also contribute to floristic differentiation. Aspect did not seem to contribute significantly to diversity either among or within target regions. Summit floras in each target region comprised groups of two distinct types of species: those with notably broad elevational ranges and those with narrow elevational ranges. The former we propose to be species that retain importance in vegetation structure across elevation and the latter to be more sensitive to climate change. In general, we find common species in the Sierra Nevada to be rare in the White Mountains, that the northern Sierra Nevada TR (Tahoe area) to be distinct in many vegetation features, and that distinct substrate differences in the White Mountains delineate significant species diversities. With four target regions, we document patterns of species composition, distribution, and diversity with respect to elevation, aspect, and geographic distance. This provides new information about summit floras in the White Mountains and Sierra Nevada, and documents baseline conditions against which we will measure response to climate change.
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1632 Land cover change
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting