贵州乌江流域喀斯特生态系统土壤物理性质研究

分析研究了贵州乌江流域不同喀斯特生态系统的石灰土（岩性均腐土）土壤物理性质。结果表明：喀斯特生态系统（土壤利用方式和土壤侵蚀状况等）是影响土壤物理性质的主要因素。良好生态系统的土壤剖面发育良好，层次分异较明显，土层较深厚；土壤有机质含量较高；以粘壤土和粘土为主；土壤容重适宜，土壤孔隙性和结构性良好，土壤的抗蚀性和抗冲性强。退化生态系统（裸地）的土壤各种物理性状恶化，土壤的抗蚀性和抗冲性减弱。提出评价不同喀斯特生态系统的土壤抗蚀性的主要指标，并得出不同喀斯特生态系统的土壤抗蚀能力依次为：灌丛＋弱度侵蚀、森林＋轻微侵蚀〉荒草＋泥沙淤积、旱地＋中度侵蚀〉裸地＋强度侵蚀。

Study on Soil Physical Properties of Karst Ecosystems in Guizhou Wujiang River Basin

Based on the analysis and study on soil physical properties of different karst ecosystems in Guizhou Wujiang river basin,it is thought that the karst ecosystem is the main factor influencing the soil physical properties.In the good ecosystems,the soil profile develops very well and stratifies obviously and its layer is deep;the organic content is relatively high;the soil relies mainly on glueing loam and clay;its hole property is suitable,and structural property is good;the quality of resisting erosion and collapsing is strong.While in the degenerated ecosystems,its physical properties are worsened and the quality of resisting erosion and collapsing is weakened.Therefore,the main indices are made to evaluate the soil quality of resisting erosion in different karst ecosystems and its ability to anti-erosibility and collapsing is gotten as follows: shrub plus weak erosion and forest plus slight erosion> weeds plus silt and dry land plus middle erosion> infertile land plus strong erosion.