The Study On Community Ecology Of Rare And Endangered Pinus Bungeana Zucc.et Endl In Xiaolongshan Of Gansu Province

Pinus bungeana Zucc. et Endl is exclusive trifoliate pine in East Asia , it's the Chinese speciality and one of rare tree species. It ranges from Tianshui Maijishan to Liangdang county,Huixian county of xiaolong mountain forest .In this paper ,the valley of the Yongning River and Maiji mountain are two big sampling landses where we selected to study ecology feature of Pinus bungeana Zucc. et Endl community.In this paper, the quantitative characterics of Pinus bungeana Zucc. et Endl population including the size structure, spatial distribution pattern, growth dynamics, fractal dimension and species diversity were studied using methods of mathematics ecology from the angle of population and community ecology of Pinus bungeana Zucc. et Endl, then the present state and the endangering causes were analysed. This research offers gist to protecting and enlarging the crude resource of Pinus bungeana Zucc. et Endl population, afforesting plantation and sustainable utilize for us. The research can offer some important references to the population ecology of endangerous plant, too.Through the investigation on population structure of Pinus bungeana Zucc. et Endl in Mt.Xiaolong of Gansu Province, it's discovered that the size structure belongs to the shape of the reverse pyramid in Maijishan, and according to the life table ,it's concluded that the death rate of young tree is high and the survival curve has the trend to be the type of Deevey II, the population was stable in large size class and variable in small size class. High level frequency distribution has also explained that seedling young tree has insufficient obviously, this kind of structure is unfavourable for the long-term stability of population and community.The spatial distribution pattern of Pinus bungeana Zucc. et Endl was studied and the result shows that the population of Pinus bungeana Zucc. et Endl a pattern of clump. In one hand, this kind of distribution enhanced the ability to withstand the adverse environment condition, in another hand, this kind of distribution had no benefit to extend the population and had some effect on the endangered state of Pinus bungeana Zucc. et End. The fractal dimension reflected that there was a higher spatial occupational degree in Pinus bungeana Zucc. et Endl populations, The figure of corresponding inflection scale respectively shows individual congregate scale, and the data of 3 selected major quadrats are close relatively, shows Pinus bungeana Zucc. et Endl is constructive species and dominant species and have very high space occupies ability.Pinus bungeana Zucc. et Endl community tree layer species diversity index is higher than Lvliang Shan but lower than the other forest species diversity of north subtropical zone and temperate zone of our country. Through study of the disturb district and protection district shows that artificial factor has great damage for community biological diversity and after being broken , recovery is more difficult.In the end, some suggestion on the protection of Pinus bungeana Zucc. et Endl was proposedand in-situ conservation is considered to be important, at the sametime, ex-situ protection and the study on reproduction must be carried out and propagandizing the importance to protect Pinus bungeana Zucc. et Endl is necessary.