广西喀斯特地区植被演替对土壤质量的影响

以植被演替空间序列代替时间序列的方法,在野外选取广西喀斯特地区4个主要植物群落演替阶段即草地、灌草地、灌丛、乔林的典型样地,对土壤物理、化学和生物学性状进行了比较研究,以探讨植被演替对土壤质量的影响。结果表明:不同的植被演替导致了土壤物理、化学和生物学性质的显著差异。随演替的正向进行,土壤综合肥力指标值(Q I)呈增长趋势,其土壤质量综合指数分别为:草地(0.09)、灌草地(0.16)、灌丛(0.61)、乔林(0.89)。自然植被的正向演替是提高土壤质量的有效途径。导致草地和灌草地土壤质量相对较低的主要因素是植物生产力较低,土壤养分积累较少,土壤有机质等养分含量较低,土壤微生物数量较少,土壤酶活较低。土壤微生物数量结合土壤酶是反映土壤生物学活性和土壤质量的较好指标。

Effects of Vegetation Succession on Soil Quality in Karst Region of Guangxi, China

The space list method was used to replace the time list in selecting four plots in their different stages of vegetation succession as grass stage,grass-shrub stage,shrub stage and forest stage in the open karst region of Guangxi,reports were based on the responses of the soils physical,chemical and biological properties to the four vegetation succession.This study indicate that the different vegetation succession led to significant differences in the soils physico-chemical and biological properties.The soil quality increased with progressive succession,the indices of soil quality for grass stage,grass-shrub stage,shrub stage and forest stage were 0.09,0.16,0.61 and 0.89,respectively,vegetation succession was an effective approach to improving soil quality.The factors that led to the poor soil quality of the grass and grass-shrub plantations were lower plant productivity,lower accumulation soil nutrients,lower soil nutrient especially organic matter,lower soil microbes and lower soil enzyme.Soil microbial amount combined with enzyme was the better indicator for reflecting soil biological activity and soil quality.