Environmental gradient analysis and species group division ofherb species distribution in alpine Meadow on Mt.Wutai

With the data of field work on vegetation investigation and habitat conditions survey, as well as solar radiation and soil wetness index simulation based on GIS technique, the relationship between herb species and ecological factors which directly act on species were analyzed by TWINSPAN and CCA ordination. The results showed that: 1) Temperature and solar direct radiation was the key factors that control the distribution of herb species in the study area of Mt.Wutai, where is covered by alpine meadow. 2) According to the distribution pattern of plant species along the habitat gradients, seven types of species can be distinguished, i.e., alpine colddry favoring species, alpine coldhumid favoring species, subalpine typical species, subalpine cooldry favoring species, subalpine coolhumid favoring species, montane warmdry favoring species, montane warmhumid favoring species. Those specie groups can be indicators as the habitat characteristics.3) The TWINSPAN results coincide with CCA ordination about the herb specie groups division.