The Study On Species Diversity And Dominant Populations Niche Of Gymnocarpos Przewalskii Maxim. Community In Hami Basin

In this paper, we take Gymnocarpos przewalskii Maxim. community as an research object, Gymnocarpos przewalskii Maxim. community species diversity and main plants niche were researched. On this basis, analyze the extinguish reason, and propose the corresponding protection measure.Researching district near the Hami Sandaoling, belongs to desert ecosystem. Representative scrub Gymnocarpos przewalskii Maxim., sarcozygium xanthoxylon Bunge., Atraphaxis furtescens Ewersm., Reaumuria soongorica Maxim., Haloxylon ammodendron Bunge., Ephedra przewalskii Stapf., Salsola arbuscula Pall.and so on,representative grass Zygophyllum rosovii Bunge., Halogeton glomeratus Mey., Alhagi sparsifolia Shap. and so on. There are 13 species in 39 samples, respectively belong to Paronychiaceae, Zygophyllaceae, Chenopodiaceae, Tamaricaceae, Polygonaceae, Ephedraceae, Solanaceae, Leguminosae.This paper systematically study the characteristic of species diversity of Gymnocarpos przewalskii Maxim. community, the results show that, species diversity of Gymnocarpos przewalskii Maxim. community is lower, as a whole, to compare with other temperate vegetation types. It ascribe to local arid ecological geographical environment. The range of Shannon-Wiener species diversity index was 0.6876 to1.5837,being lower than 1.8604-3.4142 of desert prairie and higher than 0.029-0.696 of sandy land, indict that the species diversity level is, as a result, adapt with the local ecological environment.Analyze the relation between species diversity and soil index by linear regression, revealed soil PH has significant effects on species diversity. Soil organic and nutrition mechanism on species diversity is uncertainty and has complex direction. Analyze the main plants niche in Gymnocarpos przewalskii Maxim. community, reveal Gymnocarpos przewalskii Maxim. and sarcozygium xanthoxylon Bunge. which occupy the bigger niche breadth are dominant species. The two species niche in soil Ph, soil salt and soil organic dimension overlapped greatly(0.9451,0.9704,0.9788) with each other, indicating similarity adapt to soil PH ,soil salt and soil organic. The two species with bigger niche breadth also with bigger niche overlaps with other species, suggesting wider niche species have bigger niche overlaps with other species. The niche similarity percentage of main species in Gymnocarpos przewalskii Maxim. community ranged from 0 to 0.5765,and below 0.3 account for 81.0%, niche similarity percentage is quite low, indicate desert plants community niche differentiation is remarkable.Conduct the Conservation Biology research to Gymnocarpos przewalskii Maxim., think that intrinsic factor and external poor surroundings together result in Gymnocarpos przewalskii Maxim. extinction. Among them, humanity activity is the dominant factor which aggravate the Gymnocarpos przewalskii Maxim. extinction. Not only make Gymnocarpos przewalskii Maxim. extinction directly, but also destroy Gymnocarpos przewalskii's Maxim. habitat environment to make Gymnocarpos przewalskii Maxim. extinction indirectly. Therefore, protect it habitat environment has the same significance compare with protect itself. In consideration of above reason, suggesting adopt below measures: in situ conservation, ex situ conservation, in vitro conservation, return to nature, earnestly carry out the laws and regulations, public education.