Assessment Of County-scale Water Containment And Soil Conservation Functions

Due to the uneven distribution of precipitation in Jiangxi Province during the year,the precipitation is more concentrated,and it is located in the southern red soil hilly area.Under the dual effect of regional natural geography and human interference,Jiangxi Province has become one of the provinces with the largest soil erosion area in China,and the large amount of soil erosion has caused great damage to the ecosystem.In order to clarify the soil and water conservation capacity at the county scale,this study took Wuning County,Jiangxi Province as the study area,selected 11 different woodland types,laid 26 sample sites throughout Wuning County,and measured the basic indexes of the litter layer and soil layer of different woodland types,and conducted a comprehensive water storage,indoor direct shear experiment method and RUSLE model to investigate the water connotation and soil conservation functions of different woodland types.The results show that.（1）The soil layer,as the dominant layer of water retention function in forest ecosystem,has 89.88%of the water retention capacity of the sum of litter layer and soil layer,among which the water retention capacity of tree and bamboo forests is the strongest,and after the vegetation reaches maturity,the soil water starts to be lost,so the mature and over-mature forests should be harvested appropriately and trees and bamboos should be planted in time to enhance the water retention function of forest land while making full use of the forest resources.the water-holding function of forest land.（2）The soil conservation capacity of 11 forest types ranges from 29.852(t·hm^-2·a^-1)to 52.362(t·hm^-2·a^-1),among which tree forests（water connotation forests）and tree forests（soil conservation forests）have the highest soil conservation capacity,and bamboo forests（water connotation forests）and bamboo forests（soil conservation forests）are second only to tree forests;in addition,tree forests,bamboo forests,citrus forests The soil has the best shear resistance.Extensive planting of tree,bamboo and citrus forests can help reduce the risk of soil erosion and improve the soil conservation function of the region.（3）The total water content of the selected 11 forest types in Wuning County,Jiangxi Province is 1.29×10⁷t in the deadfall layer and 1.15×10⁸t in the soil layer,accounting for 10.12%and 89.88%of the total respectively,and the water content capacity of the soil layer is much greater than that of the deadfall layer;the total soil erosion is 1118.608(t·hm^-2·a^-1)and the total amount of soil conservation is:442.886(t·hm^-2·a^-1).