青藏高原北部戈壁区植物多样性及其环境解释

Plant diversity and its environmental explaination in gobi district of northern Qinghai-Tibet Plateau,northwestern China

为了揭示青藏高原北部戈壁区植物多样性与环境因子的关系,用38个青藏高原北部戈壁区的群落样方调查数据和环境数据,通过单因素方差分析、CCA分析和方差分解等方法研究了青藏高原北部戈壁区植物多样性及其与环境因子的关系。结果表明:1)共记录植物12科29属36种,以藜科、柽柳科、禾本科和菊科植物为主,红砂分布频率最大,该地区植物生活型主要为灌木和草本;2)该区域不同优势群落外貌特征不同,在植株密度上存在极显著差异(P<0.01),在植被盖度上存在显著差异(P<0.05),但各群落的物种丰富度和香农指数无明显差异;3)经过CCA分析,年平均降水量显著影响该区域植物物种分布;4)该地区群落结构主要受土壤因子、气候因子、生物因子共同影响,三者的解释率达到51.68%,其中土壤因子的单独解释率最高,达到25.36%,剩余48.91%未解释部分说明还有其他因素影响着该区域植物群落结构。总而言之,青藏高原北部戈壁区植物多样性水平低,群落结构简单,其植物多样性主要受土壤条件的影响。

In order to explore the relationship between plant diversity and environmental factors in gobi district of northern Qinghai-Tibet Plateau of northwestern China, the sampling data and environmental data of 38 plant communities in the gobi area of northern Qinghai-Tibet Plateau were used to study the relationship between plant diversity and environmental factors in this area by one-way ANOVA, CCA analysis, variance decomposition. The results showed that：1） there were 36 species of 29 genera in 12 families, the main species were Chenopodiaceae, Tamaricaceae, Gramineae and Compositae plants, and the distribution frequency of Reaumuria songarica was the largest. The plant forms grew in this area are mostly shrubs and herbs; 2 ） The characteristics of different dominant communities in the region were different. There were very significant differences in plant density （P 〈0. 01） and there were significant differences in vegetation coverage （ P 〈0. 05 ） , but there were not significant differences in species richness and Shannon diversity index in each community. 3） By CCA analysis, the annual precipitation significantly affected the distribution pattern of plant species in the area;4 ） The community structure of the area was mainly affected by soil factors, climatic factors and biological factors and the explanatory rate of the above three reached 51. 68%, among which, the individual explanatory rate of soil factor was the maximum, reached 25. 36%. Since the remaining 48. 91% was not explained, it can be presumed that there were other factors affecting the plant community structure in the region. In conclusion, the plant diversity level in the gobi area of the northern Qinghai-Tibet Plateau is low and the community structure is simple. Soil condition is the most important factor influencing plant diversity.