毛竹入侵阔叶林对土壤真菌群落的影响

为揭示天目山毛竹入侵原始阔叶林后土壤真菌群落特征的变化，采用T-RFLP以及荧光定量PCR技术，分析毛竹纯林、竹阔混交林及原始阔叶林土壤真菌群落结构和数量特征.结果表明： 土壤真菌群落结构差异在毛竹纯林和阔叶林之间最为明显，其次为竹阔混交林和阔叶林；竹阔混交林土壤具有最高的真菌Shannon指数、均匀度指数及最低的Simpson指数.硝态氮含量和pH显著影响了真菌群落结构的变异，毛竹林土壤真菌群落结构受pH和铵态氮影响较大，而阔叶林主要受硝态氮影响.阔叶林土壤真菌数量显著高于毛竹纯林和竹阔混交林，真菌数量分别与土壤pH和硝态氮呈现显著负相关和正相关.表明真菌在阔叶林土壤中介导了异养硝化作用，毛竹入侵可能对此过程产生了显著影响.

Effects of Phyllostachys edulis invasion of native broadleaf forest on soil fungal community.

To investigate variation of soil fungal community in response to invasion of Phyllostachys edulis into native broadleaf forest, we characterized the community structure and the abundance of fungi in soil under bamboo (BB), mixture forest of bamboo and broadleaf (MF) and broadleaf forest (BL) using terminal restriction fragment length polymorphism (T-RFLP) and real time quantitative PCR. The results showed that the most obvious difference in the soil fungal community structure was observed between the BB and BF stands, followed by that between the MF and BL. Shannon index and evenness index of soil fungi were higher in the MF than in the BB and BL. pH and NH₄⁺-N content were the most important environmental gradients on the distribution of fungal community under BB, while NO₃^--N content significantly affected the distribution of the fungal community under BL. The abundance of fungi in BL was significantly higher than that in BB and MF, and the fungi abundance showed a negative correlation with soil pH but a positive correlation with NO₃^--N content. These results implied that heterotrophic nitrification driven by fungi could occur in soil of BL, and this process might be changed by the bamboo invasion.