RESEARCH ON SOIL AND WATER CONSERVATION FUNCTION OF MAIN FOREST VEGETATION IN LUSHAN NATURE RESERVE IN JIANGXI PROVINCE

Along with the increasing environmental pressure and ecological crisis due to forest over-exploitation,studies on the quantitative relation between soil and water conservation function and forest ecological system,and on the water conservation mechanism of forest soil have been widely focused by ecologists,foresters,and expert of soil and water conservation all over the world.In order to evaluate the soil and water conservation function of different vegetation types,six widely distributed vegetation types in Lushan Nature Reserve of Jiangxi Province,including evergreen broadleaf forest,Yushan bamboo,evergreen-deciduous broad-leaved forest,deciduous forest,Huangshan pine,and Masson pine,were selected as study object.On the basis of the data of 15 indexes such as canopy density,richness,soil bulk density,capillary porosity,soil stable infiltration rate,litter reserves,litter decomposition intensity,elevation,and terrain slope obtained from field investigations and laboratory experiments,a multi-hierarchy and multi-index comprehensive evaluation system of soil and water conservations function was established,and the weights of various indexes were calculated and compared according to the total sorting of different index levels with the method of analytic hierarchy process(AHP).The results showed that the weights of vegetation factor,soil factor,ground litter factor,and terrain factors are 0.200 5,0.401 1,0.248 0,and 0.1504,respectively.It indicated that the soil factor of forest ecological system has great influence on soil and water conservation of forest land.The integrated assessment values of six vegetation types were obtained by linear scoring function,and the order of soil and water conservation capacity of six vegetation types are:evergreen broadleaf forest(0.701 3)Yushan bamboo(0.672 5)evergreen-deciduous broad-leaved forest(0.543 8)deciduous forest(0.494 7)Huangshan pine(0.418 1)Masson pine(0.316 4).The results indicated that the vegetation of evergreen broadleaf forest has the highest soil and water conservation capacity,while the Masson pine has the lowest capacity among the six vegetation types.The capacities of Yushan bamboo,evergreen-deciduous broad-leaved forest,deciduous forest,Huangshan pine are in between.The research results have certain reference significance to the Scholars of soil and water conservation.