不同林分类型土壤表层微生物群落变化特征

Variation Characteristics of Microbial Community in the Surface Soil of Different Stand Types

关键词:  毛竹林  常绿阔叶林  竹茶混交林  土壤微生物群落

Key words:  Phyllostachys edulisforest  evergreen broad-leaved forest  bamboo-tea mixed forest  soil microbial community

摘要:

近年来，高经济效益驱动着毛竹(Phyllostachys edulis)纯林经营方式向复合经营方式转变，而这种土地利用变化下土壤质量与土壤微生物群落的响应变化尚未得到充分认识，制约着毛竹林复合经营的可持续发展。为揭示这一响应变化特征，助力毛竹林复合经营，本研究采用时空互代法，研究常绿阔叶林转为毛竹纯林和毛竹纯林改造为竹茶混交林情况下土壤微生物群落的变化特征，解析影响土壤微生物群落变化的关键环境因素。结果表明：相较于常绿阔叶林，毛竹纯林土壤细菌与真菌群落组成发生显著改变，其中细菌Observed species指数提高9.08%，细菌与真菌群落网络的节点数下降、负相关关系连线数增加，同时土壤养分流失。毛竹纯林改造为竹茶混交林后，土壤养分、土壤细菌群落稳定性和协同作用均有一定的提升。冗余分析(Redundancy Analysis,RDA)显示，土壤有机碳(Soil Organic Carbon,SOC)和pH值是影响土壤微生物群落的主要因素。因此，相较于常绿阔叶林，需要改善毛竹纯林的经营管理以提升土壤微生物群落稳定性和土壤质量，而将毛竹纯林改造为竹茶混交林在一定程度上促进了土壤细菌群落稳定与土壤质量恢复。

Abstract:

In recent years,high economic benefits is driving the transformation of management mode of pure Moso bamboo (Phyllostachys edulis) forests to mixed forests.However,the variations of soil quality and soil microbial community in response to such land use changes have not been fully understood,which restricts the sustainable development of the composite management model of bamboo forests.The space-for-time substitution method was employed to study the variation characteristics of soil microbial community under the transformation of evergreen broad-leaved forest into pure Moso bamboo forest and the transformation of pure Moso bamboo forest into bamboo-tea mixed forest,which aimed to provide a theoretical basis for the composite management of Moso bamboo forests.Furthermore,the key environmental factors affecting the variations of soil microbial community were studied.The results showed that compared with the evergreen broad-leaved forest,the pure Moso bamboo forest demonstrated significant variations of soil bacterial and fungal community composition,in which the bacterial Observed species index increased by 9.08%,and the bacterial and fungal community networks presented decreased nodes and increased edges of negative correlations.At the same time,soil nutrients were reduced.After the pure Moso bamboo forest was transformed into the bamboo-tea mixed forest,the soil nutrients and the soil bacterial community stability and synergism were improved to a certain extent.Redundancy Analysis (RDA) showed that Soil Organic Carbon (SOC) and pH value were the main factors affecting the soil microbial community.Therefore,compared with the evergreen broad-leaved forest,the pure Moso bamboo forest needs more management efforts to improve soil microbial stability and soil quality.The transformation of pure Moso bamboo forest to bamboo-tea mixed forest improves the stability of soil bacterial community and promotes the restoration of soil quality to some extent.