Abstract:

The species diversity of higher plants and coniferous bark beetles in hilly cultivated land (community Ⅰ).Pinus tabulaeformis-P. armandi-Quercus aliena var.acuteserrata (communityⅡ),P. tabulaeformis-P. armand-Q. variabilis (community Ⅲ),P. tabulaeformis-P. armandi-Q. liaotungensis (community Ⅳ),Abies fargesii-Larix potaninii (community Ⅴ) and Betula albosinensis-B. utilis-A. fargesii (communityⅥ ) in Niubeiliang Nature Reserve were studied. The result showed that from shrub communities to mixed coniferous and broad-leaved forest communities,the Shannon-Wiener's diversity index,Pielou's evenness index and species richness presented an increasing trend; but from mixed coniferous and broad-leaved forest communities to alpine coniferous forest communities and alpine meadow communities,the Shannon_Wiener's diversity index,Pielou's evenness index and species richness presented an decreasing trend. View the situation as a whole,the diversity of forest communities is higher than that of shrubs and meadow communities,the diversity of the deciduous broad-leaved forest is higher than that of coniferous forest. However,the Berger-Parker's dominance index presented a trend just on the contrary compared to Shannon-Wiener's diversity index,Pielou's evenness index and species richness. The result of species diversity of bark beetles in different forest communities showed that the species diversity and evenness indices decreased in the following sequence: community Ⅱ,community Ⅲ,community Ⅳ,community Ⅴ,community Ⅵ and community Ⅰ. However,the dominance index presented a trend just on the contrary compared to diversity index and evenness index. On the basis of natural geography and vegetation,the plant communities and coniferous bark beetles communities diversity were compared in Niubeiliang Nature Reserve,the results indicated that: in different forest plant communities,the diversity of bark beetles had much difference. The result also showed that in the mixed coniferous and broad-leaved forest communities which had complex ecological condition and abundant vegetation,the Shannon-Wiener's diversity index,Pielou's evenness index and species richness of bark beetles were higher than those in other communities. Because the dominance index was lower than those in other communities,so it was hard to found a breakout of bark beetle in the mixed coniferous and broad-leaved forest communities. These indicated that the ecological management measures which promote the diversity and stability of forest ecosystem were of far reaching importance in improving automatic control of pest population.

Key words: bark beetles, community, species diversity