Study On Community Structure And Productivity Of Pinus Bungeana Forest

Pinus bungeana is a specie of pine genus of Pinaceae family. It's a endemic plant in china and the exclusive three needle leaves pine in eastasia. Pinus bungeana has beautiful slim and colors, is a kind of fine tree specie of forestation.Pinus bungeana has been widely distributed in china at one time, because of human activity and over cutting from strength to strength and the steep demand to the nature resources,the virgin forest of Pinus bungeana disappeared.Now the natural distribution covers of pinus bungeana forest form the north of Shanxi province, the east of Henan province, the piedmont of Qingling mountain of shannxi province,to the south of Gansu province, the north of Sichuan province and the west of Hubei province.The main purpose of this study is by doing a research of the structure,physiognomy, species and floristic composition of Pinus bungeana community. The suitable site conditions, biologicalcharacters, the growth function,etc,then analysising the productivity of different pinus bungeana forests in different areas, In this study, I also analysed the niche and distribution patterns of dominant species in Pinus Bungeana Communities,which could provide the scientific basis for decision-making on good protection and management in local area.Based on the datas of field investigation, then give some conclusions:The vertical structure of pinus bungeana community is simply and can be divided into three synusiums: the tree ,shrub and herbage layer. The commnuity is composed of 65 vascular plant species . Based on the analysis of the floristic elements at family, the result show that in the Pinus bungeana communithy the temperate elements dominates; some species belong to the cosmopolitan and old world genera , the most of these species have the characteristics of high latitude distribution.The comparative analyse on life form spectrum of pinus bungeana community showed that the Megaphanerophytes plants are the dominance elements in the community, its consistent in the composition of the community which developed in warm temperate forest climate condition. The phenomena reflect the climate characters of warm temperate monsoon climate area which has abundance rainfall summer and long cold winter. It also indicated that the plants in pinus bungeana communiuty hadn't used the environment and resources completely. The pinus bungeana's annual growth characteristics show: The grow order from fast to slow is the diameter at breast,the height,then the growth of volume.The Pinus bungeana forests can maintain existing structure of community in the future. The niche breadths of Pinus Bungeana Zucc and Quercus liaotungensis koidz ,the main dominant species in tree layer , and those of Viburnum shensianum Maxim, Ostryopsis davidana Decne, Sringa oblata Lindl. and Spiraea trilobaba L has been measured. The niche overlaps among the species with the same or similar environment requirements were great, while those between the species with broad niche breadth and other species were much greater. The natural resources were shared by populations in Pinus Bungeana community. The niche breadths of species in shurb layer are widely than tree layer, compared with the species in shurb layer, the species of tree layer had higher specialization ability to use resource and adapt environment. The spatial patterns of pinus bungeana population at different vertical layer , exhibits Negative binomial , Negative binomial and Poising dispersion, the other associated tree specices conform to aggregated distribution. It's related to the biological characteristics of pinus bungeana, structure of pinus bungeana community and heterogenicity of environment in plots.