Distribution Of Plant Species Richness In The Desert Of Inner Mongolia

The desert region is widely distributed in northwest of Inner Mongolia,with a total area of more than 1.5×105km2.In order to reveal the distribution pattern of plant species richness in the region,we sampled 108 plots across the research area to examine the influence of the climate on plant species richness patterns in this study.Results show:(1)The general climate can be characterized as having a high evaporative demand,but low precipitation and simple plant composition in the region.103 kinds of plants,25 families and 65 genera,44 kinds of shrubs,58 species of herbs were recorded.Populus euphratica is the only kind of arbor,Chenopodiaceae,Compositae,Leguminosae,Gramineae and Zygophyllaceae are the dominant families,the several constitute about 70%of the species.Species distribution of high frequency among Reaumuria songarica,Nitraria tangutorum,Zygophyllum xanthoxylon,Stipa tianschanica,Allium mongolicum,Haloxylon ammodendron,Potaninia mongolica,Halogeton glomeratus,Calligonum mongolicum,Artemisia desertorum etc.(2)The families are mainly divided into 6 types and 3 subtypes,cosmopolitan has a maximum of 14 families,the dominant families were cosmopolitan and pantropic;65 genera belong to 12 types and 7 subtypes,the number of genera in the Mediterranea.W.Asia to C.Asia is up to 14.(3)The species richness of plant communities has obvious heterogeneity in spatial distribution in desert region of Inner Mongolia,which increases with the increase of longitude and altitude,and decreases with the increase of latitude.(4)Water and energy together dominate the distribution of plant species in desert of Inner Mongolia,hydrothermal dynamic hypothesis accounted for 54.8%of variation in total species richness with 45.2%explained by other undetermined factors.Furthermore 52.5%and 2.3%of total species variance was explained by energy and moisture factors.(5)There are significant differences for the species richness of different life forms.It does not apply to shrubs,but it has a better explanatory power to herb,accounted for 54.9%,not accounted for 45.1%,individual account of water factor is 21.2%,single interpretation of energy factor was 0.4%.The results showed that different life forms had different response strategies to climate.