梯度增温对高寒草甸物种多样性和生物量的影响

本研究以青藏高原高寒草甸为试验对象，利用开顶室增温装置（Open-Top-Chambers，OTCs），探讨4种增温幅度对物种多样性和生物量的影响。结果表明：群落盖度在高度增温下显著减少（P<0.05）；低度增温下的Simpson指数、Shannon指数和Pielou指数显著低于对照处理（P<0.05）；地上生物量与总生物量在高度增温下显著减少（P<0.05）；10~20 cm处地下生物量在高度增温下显著增加（P<0.05），0~10 cm处地下生物量在高度增温下下减幅最大，20~30 cm处地下生物量在低度增温下增幅最大。本研究表明，在研究周期内物种丰富度对梯度增温响应不敏感，高度增温减少地上生物量的积累，地下生物量在不同幅度的增温处理下没有显著的变化规律性，响应并不敏感。

Effects of Gradient Warming on Species Diversity and Biomass in Alpine Meadows

In this study,we took the alpine meadow on Qinghai-Tibet Plateau as the research object,and the effects of four gradient warming treatments on species diversity and biomass were investigated by using Open-Top-Chambers (OTCs).The results showed that:the community coverage decreased significantly under high temperature treatment (P<0.05). The Simpson index,Shannon index and Pielou index under low temperature treatment were significantly lower than those under control condition (P<0.05). Aboveground biomass and total biomass decreased significantly under high temperature treatment (P<0.05). The underground biomass at 10~20 cm soil layer increased significantly under high temperature treatment (P<0.05),at 0~10 cm decreased the most under high temperature treatment,at 20~30 cm increased the most under low temperature treatment. This study shows that species richness was not sensitive to gradient warming during the study period,high temperature treatment reduces the accumulation of aboveground biomass,and underground biomass has no significant change regularity under different gradient warming treatment,so the response of underground biomass to gradient warming was not sensitive.