ANTI-ERODIBILITY ANALYSIS IN FOREST SOIL OF TYPICAL FORESTS IN JINYUN MOUNTAIN IN CHONGQING CITY

Principal component analysis(PCA) was used to study the anti-erodibility of forest soil in 4 typical forests(mixed wood,broadleaf forest,bamboo forest and shrub forest),compared to arable land soil,in Jinyun mountain,Chongqing City,in Three Gorges Reservoir Areas.The result shows that the 13 anti-erodibility indexes can be scaled down to the 7 optimal indexes.PCA comprehensive exponent of anti-erodibility indexes shows that the order of anti-erodibility: shrub forest(45.51) mixed wood(41.94)broadleaf forest (32.65)bamboo forest(23.35),and that the anti-erobility of soil in Jinyun mountain is in decreasing trend from topsoil to bottom soil(49.32,41.86,32.03,27.11).The 19 soil samples in all soil layers in different land use types can be classified in to 3 sorts with different anti-erodibility on the basis of fuzzy-clustering analysis.