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Species Diversity and the Effect (?) Entironment of Manas River Valley

Author: WuYingXiang
Tutor: ZhangFengHua
School: Shihezi University
Course: Crop Cultivation and Farming System
Keywords: Manas River Basin Oasis Stress Physiology Soil environment Plant diversity
CLC: Q948
Type: Master's thesis
Year: 2010
Downloads: 50
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Abstract

With the impact of human activities on the arid oasis, desert oasis ecosystem stability become an issue of concern. Understand oasis of natural vegetation diversity and its influencing factors, the main problem of the vegetation community ecology of desert ecosystems. In this study, the Manas River Basin, Shihezi oasis region, for example, through field investigation, laboratory analysis and testing, analysis of the regional climate and soil physical and chemical properties of differentiation law, the Total species resistant physiological study of natural vegetation to clarify oasis area of ??natural vegetation Species Diversity Characteristics and its influencing factors, and quantitative analysis of the major population in the community niche response to changes in the soil environment, designed to provide a theoretical basis and reference for the conservation and restoration of natural vegetation. The results are as follows: 1. Study area plant growing season average temperature, effective accumulated temperature and precipitation are presented as landforms different parts of regional changes in soil physical and chemical indicators and biological indicators of regional change. (2) The diversity of natural vegetation in the transition area, species richness index (R2), Simpson index (D), the Shannon-Wianer index (H), the Pielou evenly the index (Jsw) were 2.19,0.88, 0.96,0.96. In the high salt content of the alluvial fan edge region, R2, D, H minimum, respectively 1.57,0.79,0.81. Correlation analysis showed that: soil moisture and plant diversity index D was significantly related to the soil conductivity diversity index R2 D significantly related. Soil salt and water is the key factor to affect the plant diversity of the region. 3 Total species the Tamarix, pod quinoa, Salsola niche width larger (gt; 0.5) are the dominant species, the remaining non-dominant species. Tamarix pod quinoa and Salsola between any two niche similarity ratio greater the very similar Tamarix, of Salsola and pod quinoa resources. Niche similarity between the proportion of the species on a single ecological factor analysis showed that niche proportional similarity between species in soil salinity gradient, natural plant species in the salt gradient of resources on a smaller ecological differentiation of species have a strong Salt. The same habitat, the Tamarix body proline (Pro) and malondialdehyde (MDA) content much larger than caspica the Salsola, indicating that the the Tamarix cells sensitive to salt stress, in addition to the salt secretion can also be produced by the body proline to regulate cell infiltration, and then reach the salt-tolerant, drought effects. The Salsola body Pro and MDA content minimum, indicating the Salsola strongest ability to adapt to the environment, may be a salt-repellent plants. Pro and MDA content caspica body and soil water content was significantly negatively correlated, indicating that water is affect caspica the key factor. In the saline-alkali soil conductivity and plant diversity index correlation was not significant. Species diversity decreases first and then increasing trend with increasing soil salinity, plant communities toward the development of salinity ecotypes direction. Plant species richness index R2 and the evenness index Jsw their soil bacteria characterized the number of colonies was significantly related 0.989 * 0.990 * Alkali Region, plant diversity and soil bacterial diversity are affected. Alkali Region screened three to promote seed germination of soil bacteria and a bacterial inhibition of seed germination. Which salt solution growth-promoting bacteria on seed germination role in the initial stage of germination strongest, compared to 368% -136% germination rate of the salt treatment, but in the late germination role will be reduced to 19.5% -12.9%. The above study shows that the vegetation of the study area are salt-tolerant plants, the ability to adapt to salt, to the development of salt-tolerant ecotypes. The vegetation changes gradually adapt to changes in the soil environment, from another point of view that human activities led to the oasis region towards the development of saline environment.

Species Diversity and the Effect (?) Entironment of Manas River Valley

Abstract

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