Species Diversity in Overlapped Zones of Typical Secondary Forests in Guandishan Mountains

The overlapped zones of forests are highly rich in biological diversity.Shannon-Weiner's diversity index,Simpson's dominance index,Margalef's richness index and Pielou's evenness index were used to study the dynamic diversities of the community species in overlapped zones of secondary forests at different evolution stages in Guandishan Mountain,and comparatively analyze the species diversities of the communities in the overlapped zones and those in the regions in the neighborhood of the overlapped zones.The results showed that the overlapped zones of the forests at different evolution stages transformed from broadleaf forests and needle-leaf-broadleaf mixed forests into needle-leaf forests,their Shannon-Weiner's diversity indexes and Margalef's richness indexes varied in a single-peak pattern with their peaks appearing in needle-leaf-broadleaf mixed forests at the late evolution stage.the Simpson's dominance indexes,differing from the diversity and richness indexes,presented a concave-shaped change with their valley values appearing at the middle to late evolution stage.The Pielou's evenness indexes appeared to decline.The community species in the overlapped zones presented a higher Shannon Weiner's diversity index than those in the regions next to the overlapped zones,thereby having rich species diversity and presenting positive marginal effect.The Margalef's richness indexes varied inconsistently with the Shannon-Weiner 's diversity indexes,and this proved the influence of positive marginal effect,these two indexes both reflected that the overlapped zones under study had high species diversity.