Document: GEN-3-82-11

Biodiversity: Aspen has the lead, but will non-native species take over?

CHONG, G.W.* ^1,2, T.J.STOHLGREN ^1,2 and S.SIMONSON ²

USGS, Fort Collins, CO 80525 USA ¹
Colorado State University, Fort Collins, CO 80523 USA ²

Abstract:
From 1995 through 1998, 104 Modified-Whittaker plots (20 m by 50 m) were established in Rocky Mountain National Park, Colorado. Of those plots, 32 were established in aspen stands identified from aerial photos (1987, color; 1:15840 scale). We identified 188 vascular plant species that were unique to aspen plots. The remaining 72 plots combined contained 264 unique species. The slope of the mean species-area curve for the aspen vegetation type was the steepest of the nine vegetation types sampled (number of species = 23.8(log(area)) - 10.8, R² = 0.92). Although aspen stands cover a small proportion of Rocky Mountain National Park (2% based on one Park map), they contribute a disproportionate amount to plant species richness. Aspen plots also contained the greatest number of butterfly species. However, aspen plots contained 38 of the 42 non-native species identified in all plots. Research throughout the Rocky Mountain Region has found a similar trend: Hot-spots of native plant diversity are being invaded by non-native plant species. Thus, resource managers must consider the effects of management choices on understory species composition as well as on the aspen stands themselves.

Keywords: biodiversity, non-native species, aspen, Rocky Mountain National Park

This abstract is being presented at: 8:15 AM in session:
Oral Session #2: Conservation Ecology.