三峡库区植被不同演替阶段的土壤养分特征

Soil Nutrient Characteristics in Different Vegetation Successional Stages of Three Gorges Reservoir Area

用空间替代时间的方法分析三峡库区植被在不同演替阶段的土壤养分特征。结果表明:随着植被正向演替,土壤pH值逐步降低;土壤有机质和速效磷含量表现为常绿阔叶林>针阔混交林>落叶阔叶林>灌丛>针叶林,水解性氮含量表现为针叶林>灌丛>针阔混交林>落叶阔叶林>常绿阔叶林;有机质、水解氮和速效磷含量在植被演替过程中表现出较强的表聚性;相关分析表明有机质含量、水解性氮含量和速效磷含量3者之间存在极显著正相关,且都与土层极显著负相关;植被演替进程与土壤pH值极显著负相关、与水解性氮含量显著负相关、与速效磷含量极显著正相关。

We analyzed the soil nutrient dynamics at different vegetation successional stages of Three Gorges reservoir area by space-time substitution.The results showed that the soil pH decreased with the development of positive vegetation succession and presented acidic property.The contents of soil organic matters and available phosphorus increased with the progress of positive vegetation succession.The change of soil organic matters was evergreen broad-leaved forest coniferous forest deciduous broadleaved forest shrub coniferous forest,while the change of hydrolyable nitrogen was coniferous forest shrub coniferous forest deciduous broadleaved forest evergreen broad-leaved forest.The contents of organic matters,hydrolytic nitrogen and available phosphorus appeared obvious accumulation in the surface layers of the soil at different vegetation successional stages.Correlation analysis indicated that there were extremely significant correlation between organic matter,hydrolytic nitrogen and available phosphorus which had extremely significantly negative correlative with soil layers.The different vegetation stages had extremely significantly negative correlation with soil pH and hydrolytic nitrogen,but had significantly positive correlative with available phosphorus.