森林演替过程中优势树种凋落叶对土壤微生物组成的影响  

Effects of leaf litter from dominant tree species during forest succession on the composition of soil microbial communities

作　　者：梁健[1] 王孝安[1] 陶树兴[1] 何文莹[1] 王慧敏[1] 

机构地区：[1]陕西师范大学生命科学学院,西安710062

出　　处：《生态学杂志》2008年第7期1127-1133,共7页Chinese Journal of Ecology

基　　金：国家重点基础研究发展规划资助项目(2002CB111505)

摘　　要：为了进一步认识森林群落演替机理,研究了黄土高原马栏林区处于不同演替阶段的森林土壤微生物组成,以及优势树种凋落叶对土壤微生物组成的影响。采用凋落叶浸提液处理不同类型的土壤,利用土壤浸提液固体培养基测定微生物数量,以系统聚类和主成分分析等方法进行数据分析。结果表明:微生物总数量及土壤细菌数量按白桦(Betulaplatyphylla)林→油松(Pinus tabulaeformis)林→辽东栎(Quercus liaotungensis)林递增;在先锋森林群落向顶极群落演替过程中,微生物组成的综合性指标Shannon-Wiener指数呈下降趋势;土壤微生物3大类群中,数量较少者对Shannon-Wiener指数的大小变化起着较大作用;依据可培养微生物组成,8种土样可划分为3个类群,辽东栎及油松凋落叶对土壤微生物组成的影响不同,辽东栎凋落叶对土壤微生物学性质的作用更强;马栏林区森林土壤微生物组成与植被类型及演替阶段关系密切;演替高级阶段森林优势树种凋落叶可能通过其对土壤微生物组成的改造优势,逐渐改变土壤的微生物学性质,进而促进植被演替。In order to further understand the mechanisms of forest succession, the composition of soil microbes under forests at different succession stages in the Malan forest region of Loess Plateau and the effects of leaf litter from dominant tree species on the composition of soil microbial communities were investigated. The extracts of leaf litter were imposed to different types of soil samples. The number of soil microbes was determined by using solid medium added with the extracts of soil, and cluster and principal component analyses were applied to process the obtained data. The results showed that the total number of soil microbes and the number of bacteria increased in the order of Betula platyphylla forest→Pinus tabulaeformis forest→Quercus liaotungensis forest. From the pioneer community to the climax community, Shannon-Wiener index, a comprehensive indicator used to describe the microbial composition, showed a downward trend. Of three soil microbial groups, the group with a smaller number played a more important role in the changes of Shannon-Wiener index. According to the composition of cuhurable soil microbes, the test eight soil samples were divided into three groups. Compared with that from P. tabulaeformis, the leaf litter from Q. liaotungensis played a greater role on the composition of soil microbial communities. It was suggested that the composition of soil microbes in Malan forest region was closely related to the forest vegetation type and its succession stage. Through its specific dominance, the leaf litter from the dominant tree species at advanced succession stage could change the soil microbial composition gradually, and thereby, promote the occurrence of vegetation succession.

关 键 词：马栏林区 凋落叶 土壤微生物 植被演替 

分 类 号：S714[农业科学—林学]