土壤水分影响青藏高原东部高寒草地植物群落特征及生态系统多功能性

Soil moisture affected plant community characteristics and ecosystem multifunctionality of alpine grasslands on the eastern Qinghai-Tibet Plateau

环境变化改变了草地植物群落空间格局的形成和演替,对青藏高原生物多样性和生态系统功能产生了深远影响。植物群落随环境变化在空间上呈现规律性变化,但植物群落特征在空间上主要受何种环境因素的驱动还存在较大争论。本研究在青藏高原东部自西向东调查了不同土壤因素在空间上对植物群落特征的重要性以及植物群落对这些因素的敏感性,并评估了影响生态系统多功能性的关键土壤因子。结果表明:土壤因子对植物群落的重要性及其敏感性存在差异,相比其他土壤因子,土壤水分对不同植物群落指标均具有显著的重要性(P<0.05),并且植物群落特征对土壤水分也有很强的敏感性(P<0.05);土壤水分与生态系统多功能性呈显著的非线性递增关系(P<0.05)。该研究表明,土壤水分对青藏高原东部植物群落具有重要的调控作用,并且这种作用最终可能影响草地生态系统功能。

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.