退化喀斯特植被恢复过程中土壤微生物生物量碳的变化

土壤微生物生物量是表征退化喀斯特植被恢复过程中土壤质量的重要特征之一。笔者以贵州花江喀斯特高原生态综合治理示范区内土壤为研究对象,分析了退化喀斯特植被恢复过程中不同生境、不同层次、根际和非根际土壤微生物生物量碳的变化特征。结果表明:退化喀斯特植被恢复过程中土壤中的微生物生物量碳存在较大差异。随着退化喀斯特植被的恢复,土壤微生物生物量碳明显上升,从大到小表现为乔木群落阶段、灌木群落阶段、草本群落阶段、裸地阶段,反映出土壤质量在逐渐恢复;土壤微生物生物量碳的变化特征在不同生境间从大到小主要表现为裸地和草本群落阶段为石沟、土面、石槽,灌木群落阶段和乔林阶段为石槽、土面、石沟;土壤剖面上均呈明显的垂直分布特征,即随土层深度的增加,呈递减趋势,根际和根外变化明显,表现为根际高于非根际。

Changes of soil microbial biomass carbon along successional processes of degraded Karst vegetation

The mechanism of degraded Karst vegetation restoration was a popular research topic in soil science and ecology for the last decade.Soil microbial biomass C was recommended as one of major characteristics of soil quality in the processes of degraded Karst vegetation restoration.The test soil was taken from the Karst plateau Ecological Synthesis Control Area in Huajiang of Guizhou.The changes of soil microbial biomass C with different microhabitats,different soil layer and Rhizospheric,Non-rhizospheric were studied during the process of degraded karst vegetation restoration.The results showed that soil microbial biomass C had obvious difference.With degraded Karst vegetation restoration,the soil microbial biomass C were ascending obviously,i.e.arboreal community stage>shrubby community stage>herbaceous community stage>bare land stage.It indicated that the soil quality has been restored gradually.The microhabitat characteristic of soil microbial biomass C was ascending as stone gully>soil surface>stone-groove in the bare land stage and herbaceous community stage.The shrubby community stage and arboreal stage were stone-groove>soil surface>stone gully.The characteristic of vertical distribution in the soil profile decreased with the increase of the soil depth.It presented as A>B.The soil microbial biomass C in rhizosphere was greater than that in non-rhizosphere.