不同植被类型条件下土壤抗蚀性变化特征及其影响因素

Changes and Influences of Soil Anti-erodibility Under Different Vegetation Types

采用野外调查与室内分析相结合的方法,开展山地森林-干旱河谷区不同植被条件下土壤抗蚀性及其影响因素研究。结果表明：退耕岷江柏林地土壤抗蚀性最好,岷江柏幼林和天然次生林地土壤抗蚀性次之,刺槐林地土壤抗蚀性最小。0-10cm土层土壤抗蚀性强于10-20cm,且在各土层间不同植被条件下土壤抗蚀性指数均达显著差异。0-10cm土层,土壤机械组成中砂粒与抗蚀指数、水稳性指数、团聚度呈显著或极显著负相关;中、细粉粒与水稳性指数和结构系数呈显著或极显著正相关,与分散系数均呈极显著负相关。微团聚体组成中,〈0.001mm颗粒与抗蚀指数呈显著负相关,与水稳性指数呈显著正相关。10-20cm土层,机械组成中砂粒与团聚度、分散系数呈极显著负相关;粗粉粒与团聚度、物理性粘粒与结构系数和团聚度呈极显著正相关。微团聚体组成中,1~0.05mm颗粒与团聚度呈显著负相关。0-10cm土层,抗蚀指数、水稳性指数、结构系数、团聚度与有机质、全氮含量之间呈显著正相关;水稳性指数、结构系数、团聚度与速效钾含量之间呈显著负相关;分散系数与有机质、全氮含量之间呈显著负相关,与速效钾含量之间呈显著正相关。10-20cm土层,抗蚀指数、水稳性指数与有机质含量之间呈显著正相关;水稳性指数、结构系数与速效钾含量之间呈显著负相关;分散系数与速效钾含量之间呈显著正相关。

By the method of field investigation and laboratory analysis,changes and influences of soil antierodibility under different vegetation types in dry valley of upper Minjiang River were studied.The results showed that soil anti-erodibility was the strongest for the conversion of farmland to Minjiang cypress,followed Minjiang young cypress and natural secondary forests.However,soil anti-erodibility was the poorest for the Robinia pseudoacacia.Soil anti-erodibility in 0-10cm layer was higher than that in 10-20 cm layer.At the same time,there were significant difference among the index of soil anti-erodibility in the 0-10cm and 10-20cm layer under the different vegetations types.There were significant negative correlations between sand fraction of mechanical composition and index of soil anti-erodibility,water stable index,aggregation degree in 0-10cm layer.However,there were significant positive correlations between physical clay and index of soil anti-erodibility,water stable index,structural granular index,aggregation degree.There were significant positive correlations between medium-fine dust and water stable index,structural granular index.However,there were significant negative correlations between medium-fine dust and soil dispersion coefficient.There were significant negative correlations between 0.001mm content of microaggregate composition and index of soil anti-erodibility,there were significant positive correlations between 0.001mm content of micro-aggregate composition and water stable index.In 10-20cm layer,there were very significant negative correlations between sand fraction of mechanical composition and aggregation degree,soil dispersion coefficient,however,there were very significant positive correlations between coarse dust of mechanical composition and aggregation degree.There were significant positive correlations between physical clay of mechanical composition and aggregation degree,structural granular index.There were significant negative correlations between content of at the size of 1~0.05mm in micro-aggregate composition and aggregation degree.There were significant positive correlations between index of soil anti-erodibility,water stable index,structural granular index,soil aggregation degree and soil organic matter,content of soil total N in 0-10cm layer,however,there were significant negative correlations between water stable index,structural granular index,soil aggregation degree and content of soil available K.There were significant negative correlations between soil dispersion coefficient and soil organic matter,content of total N,however,there were significant negative correlations between soil dispersion coefficient and content of soil available K.In 10-20cm layer,there were significant positive correlations between index of soil anti-erodibility,water stable index and soil organic matter.However,they were significant negative correlations between water stable index,soil structural granular index and content of soil available K.There were also significant positive correlations between soil dispersion coefficient and content of soil available K.