全球变暖导致降水格局的变化，进而影响到土壤碳排放与土壤环境特征，土壤微生物群落结构是反映这一变化的有效早期响应指示。以南亚热带鼎湖山季风常绿阔叶林（季风林）土壤为对象，探讨降水变化对不同土壤层土壤微生物群落的影响，试验设置3种降水变化处理（年降水量不变但降水次数增加、减少50%降水量、自然降水），采用磷脂脂肪酸（PLFA）技术提取土壤微生物含量。结果表明：（1）不同降水处理对同一土层土壤微生物总PLFAs量、细菌PLFAs量、真菌PLFAs量、放线菌PLFAs量、丛枝菌根真菌PLFAs量影响不显著（P>0.05）；（2）0~10 cm土层中，土壤微生物细菌（革兰氏阳性菌和革兰氏阴性菌）、真菌、放线菌和丛枝菌根真菌的相对丰度值差异不明显，说明不同降水处理条件下，该层土壤微生物群落结构较为相似；（3）10~20 cm土层中，不同降水处理对细菌（革兰氏阳性菌和革兰氏阴性菌）的相对丰度产生明显的影响（P<0.05）；（4）在所有试验处理中，土壤pH作为一个重要的影响因子，与土壤微生物总PLFAs量成极显著负相关关系（P<0.01）。%Changes in precipitation patterns caused by global warming is a common phenomenon, which affects soil carbon respiration and soil environmental characteristics. Soil microbial community structure is an effective indicator to reflect this change. In this paper, we take the soil of the south subtropical monsoon evergreen broad-leaved forest in Dinghu mountain as research object. Our object explores the influence of precipitation changes on soil microbial communities in different soil layers. Three experimental treatments are included: The precipitation is constant but the times of precipitation increases, reduce the amount of precipitation by 50%, normal precipitation (control group). Soil microbial biomass was measured by the method of phospholipid fatty acid (PLFA). The experiment results show that: (1) The three precipitant treatments did not significantly affected the amounts of soil microbial total PLFAs, bacteria PLFAs, fungi PLFAs, actinomycetes PLFAs and arbuscular mycorrhizal fungi PLFAs of the same layer in the rainy premonsoon season. (2) In the layer 0~10 cm, the relative abundance of bacterial, gram-positive bacteria, gram-negative bacteria, fungi, actinomycetes, arbuscular mycorrhizal had not significant difference, which indicated the soil microbial community structures were similar under different treatment conditions. (3) In the layer 10~20 cm, the relative abundance of bacterial show obvious difference (P<0.05) in the soil microbial community structure. (4) There was the negative correlation between the soil pH value and the total PLFAs of soil microbial biomass (P<0.01) under different experimental treatment.
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