Abstract: Environment changes have a profound influence on biological diversity and ecosystem function of alpine grasslands on Qinghai-Tibet Plateau, by altering the spatial patterns of plant communities. Plant communities generally change over space with changing environment conditions. However, our understanding about what factors drive such a variation remains controversial. Here, we investigated the importance of different soil factors to plant community characteristics from west to east on the eastern Qinghai-Tibet Plateau and the sensitivity of plant communities to these factors, as well as the effects of key soil factors on ecosystem multifunctionality. The results showed that there are differences in the importance and sensitivity of soil factors to plant communities. Compared with other soil factors, soil moisture was more important in affecting all the measured plant community indices (P<0.05). Plant community indices showed a strong sensitivity to soil moisture (P<0.05). There was a significant nonlinear positive relationship between soil moisture and ecosystem multifunctionality (P<0.05). Our results indicate that soil moisture may play a pivotal role in governing spatial variation of plant communities and consequently has a large effect on grassland ecosystem functions on Qinghai-Tibet Plateau.

Key words: plant community, spatial distribution, multifunctionality, Qinghai-Tibet Plateau