| Poacynum hendersonii is one type of the common kendir. Apocynum is a wild perennial semi-erect shrub which belongs to the genus of Apocynum and section of Apocynaceae. It distributes mainly in Northwest and North of China, and Xinjiang Uygur Autonomous region is the main area where Poacynum hendersonii distributes. This study chose 5 main area (Bachu county, Xayar county, Yuli county, Layi lake, Aibi lake)where the Poacynum hendersonii mostly distributed in Xinjiang, we did the research about the average annual precipitation, average annual temperature, ground water level, pH value of the soil, soil salt content, SOC, TN of soil and the C/N ration of soil respectively, and also analyzed the relationship between all the ecological indexes and biomass. Besides, I did the research about the individual structure of Poacynum hendersonii, I also worked out a binary linear regression model between the biomass and the height and crown area of Poacynum hendersonii. According to the ecological adaptation features of Poacynum hendersonii, this study also gave some suggestion according to the situation as well as the ecological adaptation features. The main conclusions are listed as following:(1) There are three main habitat types of Poacynum hendersonii in Xinjiang Uygur Autonomous region:a. Saline soil type with deep ground water level. The total nitrogen content and SOC of soil is high, the ground water level is deep as 4m to 5.5m. Poacynum hendersonii here has plexiform growth with high biomass and thick rootstock. b. Saline soil type with mediate ground water level. It has high soil salt content as well as high SOC and pH value, the ground water level is between 2.5m and 4m, the height and biomass of Poacynum hendersonii which grows here is not as high as the last ecological type we mentioned above, c. Wet saline soil type with shallow ground water level. It has higher average annual precipitation compared to other types; it also has high soil salt content, and low pH value as well as low total nitrogen content of soil. The ground water level is between 2m and 3m, the distribution of Poacynum hendersonii here is very sparse with low biomass.(2) Through CCA rank analysis, we found that the distribution and biomss of Poacynum hendersonii was mainly influenced by precipitation,altitude, temperature,soil C/N,groundwater level and TN, which is to say that the distribution and biomass of Poacynum hendersonii is mainly determined by climate factor, soil fertility and ground water level.(3) The individual form of Poacynum hendersonii has significant difference in different sites. The stem ration which is the main determinant of the plant productivity is mainly influenced by the hydrographic condition of the habitat; in the meanwhile, it has low correlation with other environment factors. The study also worked out the regression model between biomass of Poacynum hendersonii and its height and crown area: B=0.046543H2+0.110536A-0.010206(B is the biomass after drying, H is the height, A represents the crown area).(4) We should enhance the protection of Poacynum hendersonii through the following 5 dimentions:"popularize the consciousness of protecting wild Poacynum hendersonii, enhance the force of transporting ecological water to the lower reaches of the Tarim River, irregrate and apply fertilizer to regain the vegetation, choose the quality variety to build the artificial field of Poacynum hendersonii, restrict massive manual harvest". |
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