川西高寒山地灌丛草甸土壤抗蚀性研究

Study on the Soil Erosion Resistance of Alpine Shrub Meadow in Western Sichuan

以康定折多山高寒山地灌丛草甸土壤为研究对象,采用野外调查与室内分析相结合的方法,运用主成分分析法对土壤抗蚀性进行综合评价,以期探讨不同海拔和坡向土壤理化性质及抗蚀性差异。结果表明:(1)淋溶层土壤理化性质的变化剧烈程度高于淀积层土壤,且这种变化不受海拔和坡向的影响,不同坡向间土壤的性质差异主要受气候因素主导;(2)土壤各理化性质指标之间以及土壤理化性质与抗蚀性之间有明显的相关性,其中土壤抗蚀性受团聚体含量及稳定性的影响最大;(3)研究区土壤抗蚀性的大小顺序为3800 m半阳坡>4200 m半阴坡>3800 m半阴坡>4200 m半阳坡>4000 m半阳坡>4000 m半阴坡。其中>0.25 mm风干团聚体含量、团聚体GMD值和团聚体分形维数D 3个指标为评价该地区土壤抗蚀性的最佳指标。可见,不同海拔和坡向间土壤抗蚀性有明显分异特征,提高土壤团聚体含量及稳定性是加强该区土壤抗蚀性的关键。

The alpine shrub meadow soils in Zheduo Mountain,Kangding,were studied by the combination of field investigation and indoor analysis,and the principal component analysis method was used to comprehensively evaluate the erosion durability of soil,in order to explore the differences of soil physical,chemical properties,and erosion durability of soil under different elevations and slope aspects.The results showed that:(1)The variations of soil physicochemical properties in leaching layer were more severe than that of the sedimentary layer,and this change was not affected by the elevation and slope direction.The difference in soil properties between different slopes aspects was mainly dominated by climatic factors.(2)There were significant correlation among soil physical,chemical properties,and erosion durability of soil,erosion durability of soil was mostly affected by agglomerate content and stability;(3)The erosion durability of soil followed the order:3800 m semi-sunny slope>4200 m semi-shady slope>3800 m semi-shady slope>4200 m semi-sunny slope>4000 m semi-sunny slope>4000 m semi-shady slope.The three indicators that>0.25 mm air-dried aggregate content,aggregate GMD value,and aggregate fractal dimension D were the best indicators for evaluating soil corrosion resistance in this area.It can be seen that there were obvious differentiation characteristics of soil erosion durability under different elevations and slope aspects.Increasing the content and stability of soil aggregates were the key processes in strengthening erosion durability of soil in this area.