Changes of vegetation biomass, species diversity and NDVI across the ground temperature of permafrost in the Datong river source region on the northeastern edge of the Qinghai-Tibet plateau

A primary analysis was applied to analyze the effects of degradation of frozen soil on the alpine vegetation ecosystem based on the investigation data from 92 vegetation plots sampled in 2010 and 30m- normalized difference vegetation index (NDVI) data of these plots across the ground temperature of permafrost in the Datong river source region, on the northeastern edge of the Qinghai-Tibet plateau in China. The results show that: with the increase of the ground temperature, the species diversity index of plant communities had an ascendant trend and the succession of vegetation type had a change, like the wet plant species in communities decreased gradually and mesophyte plants expanded rapidly. When the permafrost type from sub-stable permafrost type to transitional type and then to unstable permafrost type, the phytomass had decrease trend; NDVI and soil moisture had the biggest value in the transitional permafrost region.