Abstract: Avian species diversities during their breeding seasons are investigated in secon dary mountain forests in Zuojia natural reserve, Songhua lake natural reserve, Tiangang natural reserve of Jilin province and Xianfeng forest farm of Heilongjiang province. The species composition, density and consuming biomass in the deseribed sites are similar, the diversities of foraging, foraging deight, foliage height and physioghomic coverage are also similar. It indicated the homogeneity of forest phase, avian composition and its diversity in secondary mountain forests is Northeast China. Because of the seasonal and annual variations of resources, birds can coexist by sharing natural resources.

Key words: ecological frangibility, natural hazard, dynamic change, Qingping