Classification and Ordination of Alpine Plant Communities, Sheep Mountain, LemhiCountry, Idaho

摘要

The alpine vegetation in the immediate vicinity of Sheep Mountain, Lemhi Range,Lemhi County, Idaho, was investigated using data from field observations analyzed by the programs TWINSPAN and CANOCO (CCA). Percent cover of vegetation and environmental data were recorded for 77 plots. By computer analysis, eight communities were identified and then described with respect to apparent habitat preferences. The predominant communities are characterized by (1) Carex rupestris, (2) Carex elynoides, and (3) Calamagrostis purpurascens-Carex elynoides. An exposure gradient showed the strongest correlation with the community distribution, but substrate, elevation, and slope were also found to be important. In general, the study area communities present a uniformly dry turf-like physiognomy, with some early snowbed and Dryas or Salix mat communities occasionally present.