不同森林恢复类型对土壤微生物群落的影响

为了评价不同森林恢复类型与方式对南方红壤丘陵区退化生态系统土壤微生物群落的影响，借助氯仿熏蒸法、平板涂抹法和BIOLOG检测法，比较研究了4种森林恢复类型土壤微生物的群落特征．结果表明，4种森林恢复类型土壤微生物生物量碳、细菌数量差异显著，2项指标均以天然次生林土壤最高，人工林次之，荒地最差；碳源平均颜色变化率(AWCD法)和微生物代谢多样性指数(丰富度和多样性)在5种植被类型的土壤中也有明显差异，其趋势与微生物量碳、细菌数量基本相同；天然次生林土壤微生物群落利用碳源的整体能力和功能多样性比人工林和荒地强．相关分析表明，0～20和20～40cm土壤微生物的代谢多样性与根系生物量紧密相关(r=0．933，P<0．05；r=0．925，P<0．05)．自然恢复更有利于改善土壤微生物的结构和功能．

Effects of forest restoration patterns on soil microbial communities

In this paper, soil microbial community properties of five vegetation patterns were measured by bacterial, microbial biomass carbon and metabolic diversity (BIOLOG) assays to evaluate the effects of different forest restoration patterns on soil microbial community. The results showed that among five sampling sites, soil microbial biomass carbon and bacterial amount were the highest under natural secondary forest, while those in CK were the least. In BIOLOG assays, the average well colour development (AWCD) and the richness and diversity indices indicated the differences of microbial metabolic diversity. The variation tendency of the indices was the same as that of microbial biomass and bacterial amount. It is suggested that under natural secondary forest, soil microbial community had a stronger ability of utilizing carbon source and a greater functional diversity than that in plantations and CK. The metabolic diversity of microbial communities in 0-20 and 20-40 cm soil layers showed a fairly good correlation with root biomass (r = 0.933, P < 0.05; r = 0.925, P < 0.05). In a word, soil microbial biomass, bacterial amount and metabolic diversity patterns were the highest under natural secondary forest, and natural restoration should be more propitious to improve the structure and function of soil microbial community.