内蒙古典型草原和荒漠草原群落的稳定性

发布时间：2018-05-04 06:45

本文选题：稳定性 + 变异性系数　；参考：《兰州大学》2016年硕士论文

【摘要】：在锡林郭勒草原两种不同类型草地上,分别选取处于不同演替阶段的植物群落,利用空间代替时间的研究方法,以植物群落生物量和土壤营养元素为变量,在时间序列上探讨不同类型草地群落特征及群落稳定机理,取得如下结论:1.锡林郭勒盟典型草原和荒漠草原均可分为5个植被演替阶段,各演替阶段联系紧密。其中克氏针茅和苔草群落是联接典型草原和荒漠草原过渡类型。2.不同类型草原的稳定性在植物个体水平中最低、功能群水平居中,群落水平的系统稳定性最高。不同类型草地群落中优势物种的变异系数较小,在群落系统中表现更稳定。群落功能群层次上,多年生草本对群落的贡献最大,也是最稳定的一类功能群。3.土壤营养元素的变异性和地上植被的变异性具有对应关系。土壤营养元素变异性从典型草原到荒漠草原逐渐变小,而稳定性呈现逐渐增强趋势。相比地上群落的变异性,土壤的变异性更小,表明土壤在生态系统中较植被更稳定。4.物种丰富度是草地群落稳定性的重要影响因子,随种群个体物种丰富度的增加,植物个体在群落中的稳定性也随之增加。
[Abstract]:The plant communities in different succession stages were selected on two different types of grasslands in Xilinguole grassland. The biomass of plant communities and soil nutrient elements were taken as variables by the method of space replacing time. In time series, the characteristics of different types of grassland community and the mechanism of community stability were discussed, and the following conclusion was obtained: 1. The typical steppe and desert steppe can be divided into 5 vegetation succession stages, each succession stage is closely related. Among them, the community of Stipa krjabini and Carex chinensis is the transitional type of the typical steppe and desert steppe. The stability of different types of steppe was the lowest at individual plant level, intermediate in functional group level, and the highest in system stability at community level. The coefficient of variation of dominant species in different types of grassland communities was smaller and more stable in community system. At the level of community functional group, perennial herbaceous plants contribute the most to the community and are the most stable functional group. 3. The variability of soil nutrient elements has a corresponding relationship with that of above-ground vegetation. The variability of soil nutrient elements gradually decreased from typical steppe to desert steppe, but the stability gradually increased. The variability of soil was smaller than that of aboveground community, indicating that soil was more stable than vegetation in ecosystem. Species richness is an important factor affecting the stability of grassland community. With the increase of individual species richness, plant individual stability in the community also increases.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S812

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