贵州花江退化喀斯特植被恢复过程中土壤微生物群落AWCD的变化

摘要

采用BIOLOG-ECO测试法研究了退化喀斯特植被恢复过程中根际和非根际、不同层次及不同生境土壤微生物群落的每孔颜色平均变化率(AWCD)的变化.结果表明,土壤微生物群落AWCD根际和根外变化明显,4个恢复阶段AWCD表现出R＞S的特点;在土壤剖面上,AWCD具有垂直的变化规律,4个恢复阶段A层土壤微生物群落A WCD表现出A＞B层的特点.植被恢复过程中不同生境、不同层次、根际及非根际的土壤微生物群落A WCD均随培养时间的延长而增大,土壤微生物利用单一碳源底物的能力表现出“弱—强—弱”的变化趋势,在培养时间48～144h时利用能力最强,且总体表现为石沟生境利用能力最强；同时,植被恢复过程中A WCD变化均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.%The average well color development (A WCD) of soil microorganism community in rhizosphere, non-rhizosphere, different microhabitats and different soil layers during the restoration of degraded karst vegetation was studied using the BI-OLOG-ECO test methods. AWCD of non-rhizosphere soil were significantly lower than that of rhizosphere soil in four recovery stages, which indicated that the number of microbial individual and population in rhizosphere soil of degraded karst forest during restoration was more. The metabolic function of soil microorganism community took on vertical change characteristic. AWCD of A layer soil were significantly higher than B layer soil in four recovery stages, which meant that the ability of soil microorganisms using single carbon substrate decreased with the increasing of soil depth. AWCD of soil microorganisms in rhizosphere, non-rhizosphere, different microhabitats and different soil layers increased with the prolonging of incubation time. The ability of soil microorganisms using single carbon substrate was weak at the beginning, then strong, weak at last, and was the strongest during 48 h to 144 h of incubation time. Moreover, the change of AWCD of soil microorganisms in different vegetation restoration stage was as follows, arboreal community stage > shrubby community stage > herbaceous community stage > bare land stage, indicating that the number of soil microbial species and individuals increased gradually with the vegetation restoration. The increase of soil microbial species and individuals could promote material cycling and energy flow of soil, improve soil quality, and was helpful for the restoration and reconstruction of degraded karst vegetation.