中亚热带地区米槠天然林土壤微生物群落结构的多样性

为了解土壤微生物群落的结构,采用磷脂脂肪酸方法对武夷山和建瓯的米槠(Castanopsis carlesii)天然林土壤微生物群落的结构多样性进行了研究。结果表明,两地米槠天然林的土壤微生物群落组成十分丰富,多样性指数、丰富度指数和均匀度指数分别为2.92~3.01、25.84~28.23 和0.88~0.90。0~10 cm土层的磷脂脂肪酸总量、细菌特征脂肪酸、真菌特征脂肪酸、放线菌特征脂肪酸、革兰氏阳性菌和阴性菌特征脂肪酸含量均高于10~20 cm土层的,且建瓯万木林自然保护区的高于武夷山国家级自然保护区。10~20 cm土层的革兰氏阳性菌/革兰氏阴性菌高于0~10 cm土层的;细菌特征脂肪酸含量显著高于真菌,表明细菌在土壤微生物群落结构中处于优势地位。主成分分析表明,土壤微生物群落结构的差异主要是由采样地点的不同引起。

Soil Microbial Community Structure Diversities of Castanopsis carlesii Nature Forests in the Mid-subtropics of China

In order to understand the soil microbial community structure, its diversities of Castanopsis carlesii forests in Wuyi Mountain and Jian'ou Wanmulin Nature Reserves at northern Fujian, eastern China were investigated by phospholipid fatty acid (PLFAs) method. The results showed that soil microbial community composition in C. carlesii forest was rich, the diversity index, richness index and evenness index of soil microbial communities for the two forests were 2.92-3.01, 25.84-28.23 and 0.88-0.90, respectively. The total PLFAs, bacterial PLFAs, fungal PLFAs, actinomycete PLFAs, gram-positive bacterial PLFAs, and gram-negative bacterial PLFAs at soil depth of 0-10 cm were higher than those of 10-20 cm, and those in Jian'ou were higher than those in Wuyi Mountain. The ratio of gram-positive bacterial PLFAs to gram-negative bacterial PLFAs at soil depth of 10-20 cm was higher than that of 0-10 cm. In each soil layer, the content of bacterial PLFAs was significantly higher than those of fungal PLFAs, accounting for 46.0%-50.2% and 10.0%-11.5%, respectively, indicating that bacteria were dominated in soil microbial community. Principal component analysis showed that the difference in soil microbial community structure came from the sampling site.