新疆木垒胡杨林区三种林分土壤真菌群落特征

Soil fungal community characteristics in three types of forest stand in Huyang forest region of Mulei,Xinjiang

采用T-RFLP、荧光定量PCR以及平板分离与鉴定等技术,分析了新疆木垒胡杨林区内胡杨过熟林、胡杨衰亡林及柽柳等植被下土壤真菌群落特征及其影响因素。结果表明:真菌群落结构差异在胡杨过熟林与柽柳之间最为明显,其次是胡杨过熟林与胡杨衰亡林;胡杨衰亡林、胡杨过熟林、柽柳分别具有最高的真菌丰富度指数、优势度指数和均匀度指数。3种林分土壤真菌数量在6.07×10~5~1.87×106copies·g^(-1)干土,胡杨过熟林土壤真菌数量显著高于胡杨衰亡林和柽柳。真菌丰富度、均匀度指数与pH呈正相关,优势度指数和真菌数量则与pH呈负相关。土壤pH显著影响了真菌的群落结构,其中胡杨衰亡林主要受pH和碳氮比的影响,而柽柳林受全氮的影响较大。上述结果表明:土壤真菌群落结构、多样性指数及数量在不同林分类型间存在明显差异,pH是影响真菌群落特征的关键因子。

In present study,we investigated the fungi community characteristics and influencing factors in soil under over-mature Populus euphratica（ OP）,effete P. euphratica（ EP） and Tamarix ramosissima（ TR） in Xinjiang Mulei Huyang forest region using terminal restriction fragment length polymorphism（ T-RFLP）,real-time quantitative PCR,and conventional separation and cultivation methods. The results showed that the most obvious difference in soil fungi community structure was observed between OP and TR stands,followed by that between OP and EP stands.The highest Shannon index,Simpson index and evenness index of soil fungi were detected in EP,OP and TR stands,respectively. The abundance of fungi ranged from 6.07×10^5to 1.87×10^6copies·g-1dry soil in the three forest soils,and the amount of fungi in OP stands was significantly higher than those in TR and EP stands. Soil pH was positively correlated with Shannon index and evenness index but negatively with Simpson index and fungi abundance. Soil pH significantly influenced fungi community structure,and pH and C / N ratio were the most important environmental factors affecting the distribution of fungi community under EP stands,while total N affected the distribution of fungi community under TR stands. These results showed that there were obvious differences in the community structure,diversity indices and abundance of soil fungi among OP,EP and TR stands,and soil pH was the key factor influencing fungi community characteristics.