SOIL DEGRADATION AND ITS RELATION TO SOIL PROPERTIES IN SONGNEN PLAIN,NORTHEAST CHINA

摘要

Soil degradation is a major environmental issue posing threat to sustainable livehood of human in the semi-srid region of Songnen plain,northeast China.However,in a saline-sodic region,it remains unclear what relation between soil degradation index (SDI) and vegetation types,and which soil properties influence the SDI significantly.In this study,SDI of different vegetation types,and correlation between SDI and soil physico-chemical properties were investigated in a saline-sodic soil region in Northeast China,where the dominant grass during the 1960s,Leymus chinensis (Y) was replaced with the secondary successional order of Phragmites Australis (L),Puccinellia chinampoensis (M),Chloris virgate (H),and Suaeda salsa (P),together with bare lands (B).It was found that the SDI varied according to the vegetation types and had a highest value in the bare lands (SDI = 0.86),however,had a lowest value in Leymus chinensis (SDI = -0.76).And the soil electronical conductivity (EC) and total alkalization (TA) were factors that influence the SDI significantly compared to the other soil properties.