摘要
[目的]为探究短期增温和降水减少对沙质草地植物群落物种多样性、功能性状及生产力的影响,进一步揭示沙质草地植物群落特征对气候变化的响应.[方法]以科尔沁沙质草地植物群落为研究对象,利用开顶式生长室(OTC)模拟增温,研究降水减少0％、20％、40％和60％与增温的交互作用对沙质草地群落组成、物种多样性和功能性状的影响及群落特征与环境因子关系.[结果](1)短期增温和降水减少使沙质草地植物群落组成和物种优势度发生变化,其中优势物种猪毛蒿和达乌里胡枝子重要值显著降低,植物群落盖度和地上生物量显著降低.(2)短期增温显著降低Margalef丰富度指数、Simpson优势度指数、Shannon多样性指数和Pielou均匀度指数;短期降水减少对沙质草地物种多样性指标均无显著影响.(3)短期增温显著提高植物群落高度和叶干物质含量,显著降低叶片厚度;短期降水减少显著提高叶干物质含量和叶片厚度,显著降低植株高度和比叶面积.(4)短期增温是影响沙质草地物种多样性和功能性状的主要环境因素.[结论]短期增温和降水减少改变沙质草地群落特征,而且温度是影响沙质草地群落特征的主要环境因子.
Abstract
[Objective]The aim of this study is to study the effects of short-term warming and precipitation reduction on the species diversity,functional traits,and productivity,and to reveal the response of com-munity characteristics to climate change in sandy grassland.[Methods]The authors investigated the com-bined effects of precipitation reduction(0％,20％,40％and 60％)and warming on plant community com-position,species diversity,and functional trait,as well as relationship between community characteristics and environmental factors using open-top chambers(OTCs)to investigate the characteristics in semi-aird sands grassland of Horqin.[Results](1)Short-term warming and precipitation reduction led to changes in the plant community composition,community coverage,and aboveground biomass were significantly re-duced and species dominance of sandy grassland,suchas dominant species of Artemisia scoparia,Lespede-za davurica.(2)Short-term warming reduced Margalef richness index,Simpson index,Shannon index,and Pielou index,but short-term precipitation reduction had no effect on species diversities.(3)Short-term warming increased the height and leaf dry matter content,and reduced leaf thickness,while short-term precipitation reduction increased leaf dry matter content and leaf thickness,and reduced the height,leaf area ratio of plant community.(4)Short-term warming was the main environmental factor affecting the species diversity and functional traits in sandy grassland.[Conclusion]Short-term warming and precipitation reduction change community characteristics,but the temperature is the main environmental factor affect-ing community characteristics in sandy grassland.
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维普
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