近30年皖西大别山土壤侵蚀时空变化及其对景观格局的响应

Temporal and Spatial Changes of Soil Erosion and Its Response to Landscape Pattern in Dabie Mountains of Western Anhui in Recent 30 Years

[目的]为明确安徽省内长江流域和淮河流域重要的生态过渡区皖西大别山区的景观格局与土壤侵蚀及其关系,为该区域的景观格局调控和水土流失治理提供参考。[方法]借助RULSE模型计算皖西大别山区近30年土壤侵蚀模数,借助景观指数对其景观格局的变化进行描述,并使用偏最小二乘回归(PLSR)探究该区域景观指数对土壤侵蚀的影响关系。[结果]近30年,土壤侵蚀模数呈先减少后增加趋势;土壤侵蚀较严重地区主要集中在中西部和南部山区;大部分地区土壤侵蚀强度主要为微度和轻度,且各类土地利用类型的侵蚀强度有明显差别,表现为草地>耕地>林地;土地利用类型及景观格局总体较稳定,景观格局变化主要表现为景观破碎化的降低、景观异质性和连接性的提高;香农多样性指数(SHDI)、边界密度指数(ED)、相似邻近百分比(PLADJ)、景观形状指数(LSI)对皖西大别山区具有显著解释意义,且表现为SHDI、ED、LSI对土壤侵蚀起显著正向作用,PLADJ对土壤侵蚀起显著负向作用。[结论]在皖西大别山区,景观破碎化的提高和景观连通度的降低显著促进土壤侵蚀。

[Objective]The Dabie Mountain area in western Anhui Province is an important ecological transition area between the Yangtze River Basin and the Huaihe River Basin in Anhui Province.The study on the landscape pattern and soil erosion and their relationship in this area is helpful to provide a reference for the regulation of landscape pattern and soil erosion control in this area.[Methods]The RULSE model was used to calculate the soil erosion modulus in the Dabie Mountains of western Anhui in the recent 30 years.The changes of landscape pattern were described by landscape index,and the influence of landscape index on soil erosion was explored by partial least squares regression(PLSR).[Results]In recent 30 years,the soil erosion modulus showed a trend of decreasing first and increasing later.The areas with serious soil erosion were mainly concentrated in the central and western regions and the southern mountainous areas.In most areas,the soil erosion intensity was mainly slight and mild,and the erosion intensity of different land use types had obvious difference,which was grassland>cultivated land>forest land.The land use type and landscape pattern were generally stable.The change of landscape pattern was mainly manifested in the reduction of landscape fragmentation and the improvement of landscape heterogeneity and connectivity.Shannon’s Diversity Index(SHDI),Edge Density Index(ED),Proportion of Like Adjacencies(PLADJ),and Landscape Shape Index(LSI)had significant explanatory significance for the Dabie Mountain area in west Anhui Province.Shannon’s Diversity Index(SHDI),Edge Density Index(ED),and Landscape Shape Index(LSI)had significant positive effects on soil erosion,while Proportion of Like Adjacencies(PLADJ)had significant negative effects on soil erosion.[Conclusion]In the Dabie Mountains of western Anhui,the increase of landscape fragmentation and the decrease of landscape connectivity will significantly promote soil erosion.