The changes of plant communities and the landscape heterogeneity in Shule River Basin

The vegetation communities and landscape types in Shule River basin were classified and refined based on 231 plant-square survey combined with remote sensing data and existing vegetation data to reveal the characteristics of spatial distribution and other changes of vegetation types with the terrain and other elements. The vegetation landscape heterogeneity was analyzed using the grid line relative frequency from linear sampling method. The results showed that Alhagi sparsifolia, Nitraria tangutorum, Lycium ruthenicum, Tamarix sp., Kalidium foliatum, Sympegma regelii were the main vegetation types in the study area which occupied an absolutely dominant position. These vegetation characteristics of staggered distribution and mutual influence were the important factors influencing the structure, function and dynamics of ecosystems to form unique vegetation communities and landscape system of Shule River. Along with different altitude, the vegetation types were richer and the distribution was more complex with the relative frequency less than 50%. For the different gradient performance of landscape heterogeneity, the relative frequency of dominant populations in different vegetation types were not high and vegetation communities and landscape heterogeneity were lower. Along the vegetation of latitudinal direction, horizontal cross-sectional distribution was single with a large area which had domain population advantages.