格氏栲林土壤微生物结构的多样性特征研究

摘要

Phospholipid fatty acid (PLFA)method is used to study the soil microbial diversity in Castanopsis kawakamii forest.The results showed that 33 PLFA markers were detected with a total of 21 1.053μg/g.There had the biggest PLFA markers(26)party at the junction of natural and plantation forest(NPF),the next was natural mixed forest of C.kawakamii and Pinus massoniana(NF2)(23),monoculture plantations of Castanopsis kawakamii (CK)(19)and natural mixed forest of C.kawakamii and Schima superba (NF1)(18).The sort of total PLFA in these four sites was:NF2((72.71 ±14.76)μg/g)>CK((49.50 ±4.87)μg/g)>NF1((46.43 ±5.77)μg/g)>NPF((42.41 ±8.07)μg/g). Using dominant PLFAs to calculate the environmental adaptability indexes and getting the following results:Bacteria/fungi (B/F)was 4.942,gram positive bacteria/gram-negative (G+/G-)bacteria was 1.865,soil microbial pressure index (cy17∶0/16∶1ω7c)was 0.287.These indexes revealed that the soil circulation system had strong pressure feed-back ability.Principal component analysis (PCA)explains why the variation PLFA of was 87.43%.The results showed that the soil microbial community structure had strong regional distribution characteristics.%采用磷脂脂肪酸（PLFA）方法，探讨格氏栲林土壤微生物的多样性特征。结果表明，共检测出33种PLFA标记物，总量为211.053μg/g；天然林与林场交界处（NPF）的PLFA种类最多，为26种；格氏栲马尾松天然混交林（NF2）次之，为23种；格氏栲人工林（CK）为19种，格氏栲木荷天然混交林（NF1）的PLFA为18种，种类最少。各林型的PLFA含量大小排序为NF2（（72.71±14.76）μg/g）＞CK（（49.50±4.87）μg/g）＞NF1（（46.43±5.77）μg/g）＞NPF（（42.41±8.07）μg/g）。运用优势PLFA（含量大于1.9％）计算各林型的环境适应性指数，细菌/真菌（B/F）为4.942，革兰氏阳性细菌/革兰氏阴性细菌（G＋/G-）为1.865，土壤微生物压力指数（cy17∶0/16∶1ω7c）为0.287，表明格氏栲林对抗外界干扰能力强。主成分分析（PCA）解释了PLFA变异的87.43％。可见，格氏栲林土壤微生物群落结构有较强的区域分异特征。