Abstract:

Evergreen broadleaved forest in Tianmu Mountain National Nature Reserve of Zhejiang Province as an example, a digital elevation model (DEM) was used to analyze the difference of community biodiversity and basal area under different terrain. The results showed: From the single terrain factor, in evergreen broadleaved forest community, under higher or lower slope angle, biodiversity and basal area were reduced, and the highest biodiversity and basal area occurred in middle slope angle; Changes of basal area had higher sensitivity than biodiversity's with the variation of slope aspect; Basal area showed decreasing tendency from east along south to west; The highest biodiversity and basal area is the east direction, the lowest is the south-west direction; Both biodiversity and basal area reduces by earth surface roughness increasing. Based on the compound factor analysis, slope aspect and slope angle had little effect on biodiversity, but they had great relation with basal area, in each slope angle class, the basal area of south-west slope is the lowest; Combination of slope direction and roughness influences biodiversity a little, but it has certain relation with basal area. In every roughness class, the south-west slope has the lowest basal area; Combination of slope angle and roughness affects biodiversity and basal area greatly, in the same roughness class, tree species count changes by slope angle class: slope angle class 2> slope angle class 3> slope angle 1, in all slope class except slope class 1, the basal area has increasing tendency by slope angle.

Key words: digital elevation model (DEM), evergreen broadleaved forest, biodiversity, basal area, difference