Vegetation Analysis And Mapping Of Stipa Breviflora Desert Steppe In Ordos Plateau, Inner Mongolia

Ordos Plateau is located in transitional belt of Warm-temperated grassland and desert,which is characterized as complicated habitats and seriously damaged ecosystem.The Stipa breviflora Dsert Steppe is one of the main vegetation types in Ordos Plateau.It is of great importance and practical meaning for rational utilization and protection of vegetation resources to study the characteristics of Stipa breviflora communities,explain the relationships between vegetation and environments and protract the vegetation maps from the view of vegetation Ecology.Using the basic theories and methods of vegetation ecology and 3S technology, this paper analyzed the Stipa breviflora Dsert Steppe in Ordos Plateau of Inner Mongolia in detail from the aspects as follows:the ordination,classification,and interspecific relationships among species of vegetation community,the relationships between vegetation community and environments,and mapping the vegetation community distribution.1.Choosing the existence of species in quadrats as indicator for vegetation classification,we combined the traditional classification with DCA ordination,and divided the Stipa breviflora Dsert Steppe into seven community groups as follows:| Caragana stenophylla |—Stipa breviflora,Stipa breviflora—Thymus serpyllum,Stipa breviflora—Stipa klemenzii,Stipa breviflora—Cleistogenes songorica,Stipa breviflora—Stipa bungeana,Stipa breviflora—forbs and Stipa breviflora—Allium polyrhizum.2.The relationship between 18 main species of Stipa breviflora communities were studied usingχ~2 test for the 2×2 contingency table and Spearman's rank correlation analysis.The results indicated that:1) The pairs that present not significant correlation ware more than pairs that present significant and extremely significant correlation.In all of the species pairs,each of the Positive correlation coefficients and negative correlation coefficients were almost hold the half.2) The 18 main species could be divided into four ecological groups,viz.Stipa breviflora group,Heteropapus altaicus group,Artemisia xerophytica group,Caragana stenophylla group.3.The PCA is combined with correlation analysis in this paper to study the relationships between community distributions of Stipa breviflora communities and environmental factors.The cooperation of temperature gradient and water gradient is found to be the main factor controlling spatial distribution of Stipa breviflora communities in the study region.The research also finds out there is an affiliation between anthropological disturbance and differentiation of community type of Stipa breviflora.4.TM remote sensing digital image is used in this work to map the distribution of Stipa breviflora Dsert Steppe,hence to visualize the spatial distribution of different sorts of Stipa breviflora communities.