Study On Vegetation Classification And Community Biodiversity Of The Reaumuria Desert In China

Reaumuria L.belongs to Tamaricaceae,is a shrub or subshrub.It is the most important forage grass in the desert area,and also the main plant for windbreak and sand fixation.Reaumuria songarica desert is the most widely distributed zonal desert community in China.Systematic study on the community types,geographical distribution and community biodiversity of Reaumuria songarica can provide important reference and data for the compilation of the desert volume of Vegetation of China,and also provide reference for biodiversity protection and ecological construction in desert areas.This paper used systematic field surveys,combined with relevant literature data,to classify China's Reaumuria soongarica deserts,classified 3 Alliance,9 Association Group and 44 Association,and analyzed the composition,structure and diversity of the Reaumuria L.desert communities feature.The main results and conclusions are as follows:1.According to the statistical analysis of 46 sites and 138 samples,a total of 97 species of vascular plants have been recorded in the Reaumuria L.desert in China.The main life forms were shrubs,subshrubs and perennial herbs,accounting for 77.6% of the total species,while the rest were annual and biennial herbs.According to the taxonomic classification of Raunkiaer life forms,20 species of phanerophytes and 20 species of chamaephytes accounted for 41.2% of the total species.There were 30 species of hemicryptophytes,accounting for 30.9% of the total species and 8 species of cryptophytes,accounting for 8.2% of the total species.Among the water ecological types,80 species were mainly xerophytes(super-xerophytes,xerophytes and mesoxerophytes),16 species were mesophytes(mesophytes and meso-xerophytes),accounting for 82.5% of the total species,and 1 species was hygrophyte plant.The composition of life forms and water ecological types reflects the adaptation of the desert communities to drought environment.2.The Reaumuria L.desert can be classified into 3 Alliance,9 Association Group and 44 Association.They are Reaumuria soongarica Desert Alliance,Reaumuria trigpna Desert Alliance,Reaumuria kaschgarica Desert Alliance.The nine groups were Reaumuria songarica-Herb Shrub and Herb Desert,Reaumuria soongarica-Shrubs Shrub Desert,Reaumuria soongarica-Shrub-Herbs Shrub and Herb Desert,Reaumuria soongarica-Semi-Shrub – Herbs Shrub-Semi-Shrub and herb Desert,Reaumuria soongarica-Semi-Shrub Shrub and Semi-Shrub Desert,Reaumuria trigpna-Herb Shrub and herb Desert,Reaumuria trigpna-Semi-Shrub Shrub and Semi-Shrub Desert,Reaumuria kaschgarica-Shrubs-Herbs desert,Reaumuria kaschgarica-Shrub-Herbs Semi-Shrub-Shrub and Herb Desert,Reaumuria kaschgarica-Shrub SemiShrub-Shrub Desert?3.For species ? diversity in Reaumuria L.desert,Shannon Wiener diversity index,Simpson's diversity index,and Pielou evenness index are significantly negatively correlated with precipitation and altitude.The results of partial correlation analysis show that the ? diversity(Bray-curtis)of community species based on the important value and the ? diversity(S?rense)based on binary data,the presence or absence of species,were significantly positively correlated with climatic factors and geographical distance(P < 0.01).4.According to the analysis of 35 associations with quadrant data,14 associations are convergence and 6 associations are diverged.The phylogenetic structure of the rest of the association is stochastic diffusion.The results of partial correlation analysis showed that the phylogenetic structure based on importance value was positively correlated with geographical distance.The phylogenetic structure based on binary data was positively correlated with climate factors(P < 0.01).