Study On Ecological Niche Of The Forest Populations, Xiaolong Mountain National Nature Reserve

Niche theory of the relationship between the species, biodiversity, communitystructure and succession, and population evolution are widely used and achievedresults. So that niche theory become one of very active in the past two decades ofecological research fields. Exploring niche communities on plant populations andcommunities to clarify the theoretical issues of ecological significance, for forestcultivation and environmental management also has the value of practical guidance,but also for evaluating the effectiveness of protected areas, lay the foundation.With the ecological niche breadth and niche overlap index of Levins andShannon-Wiener, we research the ecological niche of the populations in the maincommunity of Pobulus davidiana,Quercus liaotungensis,Quercus aliena var.acuteserrata and Quercus variabilis Blume which is located in Xiaolongshan , GansuProvince. Based on the field survey, the results are showed in this paper. First,constructive species in the community there have the largest value of niche breadthand niche breadth index. The order of Bsw,BL has the same consistency. Second, thevalues of niche overlap in Quercus liaotungensis, Quercus aliena var. acuteserrataand Quercus variabilis Blume communities among populations are generally low,which show that in most populations have less competition, communities havesufficient environmental resources to share. But, the niche overlap values of thepopulations in the community of Pobulus davidiana are high, it is showed that in mostpopulations have more competition. Third, constructive populations and otherpopulations which have the large niche breadth values, they have a greater similarityin needing the habitat, reflects the trend of sharing resources. In Quercusliaotungensis, Quercus aliena var. acuteserrata and Quercus variabilis Blumecommunities the values of niche proportional similarity higher than 0.5, in average,only one-third, however, in the Pobulus davidiana community, the values of nicheproportional similarity are greater than 0.5. Which show that the similarity degree oftree species of resources utilization in the community is higher. Western QinlingMountains of China Xiaolongshan nature reserve is one of the Chinese warmtemperate oak forest distribution areas. Niche characteristics of community is warmtemperate broadleaf forest characterization of the niche.