Impact of Ecoenvironment on Vegetation Community Pattern in Gurbantunggut Desert
古尔班通古特沙漠生境对植物群落格局的影响

Vegetation investigation and soil sampling of 14 sites, across the Gurbantunggut Desert along the range of 87o37'09"-88o24'04"E and in the range of 44o14'04"-45o41'52"N, were carried out. Eight species of low tree and shrubs, 5 of perennial herbs, 8 of annual plants, 48 of ephemeral and ephemeroid plants were recorded. These species of the plants occupy 1/3 species of Gurbantunggut Desert plant indices and their communities form vast patches of desert vegetation with great landscape significance. In the investigation we found that the vegetation communities are accordingly succeeded with the spacial variation of macro-ecoenvironment. On the basis of counting the frequency and important values, we chose Sinpson dominance index (C) and Herlbert diversity index (PIE) to describe the composition and structure characteristics of tree-shrub and herb synusiae. Using Principal Component Analysis (PCA) and Correlation Analysis (CA) we found that the micro-ecoenvironment heterogeneity of aeolian soil physio-chemical properties, such as soil nutrient, soil moisture, soil salt, pH, etc., only exerts significant impact on the diversity of herb synusia (PIEherb), with a negative correlation. Meanwhile, the micro-ecoenvironments, which take a form of antagonistic interaction, have composed a fragile equilibrium of the desert environment. In case this equilibrium is disturbed by artificial and natural factors, the ecological distribution pattern of Gurbantunggut Desert would change.