Vertical Spatial Variability of Species Richness for Different Vegetation Types in Karst Mountains Area

To reveal altitudinal vertical spatial variability for different layers species richness of plant community in Karst mountains area,the variability were analyzed with geostatistics in Bijie region,Guizhou province,where is in the centre of Yunnan,Guizhou,Guangxi Karst area with large altitudinal variation.The results showed that optimal semivariogram theoretical model for arbor layer species richness is spherical model while shrub layer,herb layer are linear with sill model.The arbor layer species richness showed strong spatial relativity to vertical gradient.The rate of nugget to sill is 0.52%,the shrub layer,herb layer showed very weak spatial relativity to vertical gradient.The rate of nugget to sill are 314.70%,3455.09% respectively.The range of arbor layer,shrub layer,herb layer are 177.37m,73.02m,49.97m.Moran's I of species richness of shrub layer,herb layer and altitudinal variation showed similarity trends,but arbor layer was much different.