放牧强度对短花针茅荒漠草原群落特征及空间分布的影响

发布时间：2018-04-08 09:17

本文选题：荒漠草原　切入点：放牧强度　出处：《内蒙古农业大学》2017年硕士论文

【摘要】：短花针茅(Stipa breviflora)建群的草原属于荒漠草原。它是内蒙古草原的重要部分。放牧是该地区的主要草地利用方式之一。本研究采用野外试验观测和室内数学分析相结合的方法,对不同放牧强度下草地生态系统中植物群落特征、空间异质性及物种多度格局进行研究,旨在探讨放牧干扰下荒漠草原植物的空间分布状况的变化,为草地可持续利用提供依据。主要研究结果如下:1.短花针茅荒漠草原植物群落地上生物量、高度、密度及盖度随年份和放牧强度变化而变化。不同年份生物量随放牧强度增加而逐渐降低,轻度放牧、中度放牧、重度放牧区分别比对照区降低27%、47%、62%(P0.05);群落高度分别比对照降低23%、59%、111%(P0.05);重度放牧区群落盖度显著低于对照、中度和轻度放牧区(P0.05);中度与重度放牧区的群落密度显著低于对照(P0.05)。2.放牧强度与年份均对群落α多样性产生影响,但放牧强度与年度互作效应对Pielou指数有影响。放牧强度的增加使得群落多样性显著下降(P0.05),且放牧强度对群落多样性的影响大于年份的影响。3.放牧强度对物种数的影响高于年份的影响,群落物种数随着放牧强度的增加减少,对照、轻度、中度与重度放牧区物种数分别为24、21、21和19种。不同种类在不同放牧强度下出现频率不同,短花针茅出现频率随着放牧强度的增加显著增加(P0.05),无芒隐子草与短花针茅变化趋势一致,冷蒿和阿氏旋花随着放牧强度的增加显著降低(P0.05)。4.拟合优度结果显示,几何级数模型可以较好地拟合荒漠草原物种格局,群落多度格局未随年份和放牧强度的改变而发生改变,短花针茅对群落多度格局起关键作用。5.群落的空间异质性在不同年份未发生改变,但不同放牧强度下群落整体比随机分布具有更大的空间异质性,随着放牧强度增加,群落异质性增加。短花针茅、无芒隐子草的异质性指数在不同放牧强度下均高于群落异质性。
[Abstract]:Stipa breviflora (Stipa breviflora) of the buildings belonging to the steppe desert steppe. It is an important part of the Inner Mongolia steppe. Grazing is one of the main grassland in the area by the way. This study uses analysis method of field observation and indoor mathematical combination, on plant community characteristics of grassland ecosystem under different grazing intensity, research spatial heterogeneity and species abundance pattern, aims to explore the changes of the distribution of desert steppe grazing space, provide the basis for the sustainable utilization of grassland. The main results are as follows: 1. in the Stipa breviflora desert steppe aboveground biomass, height, density and coverage varies with year and grazing intensity. Different year biomass decreased with the increase of grazing intensity, light grazing, moderate grazing and heavy grazing area were higher than the control area decreased by 27%, 47%, 62% (P0.05); community height Were decreased by 23%, 59%, 111% (P0.05); heavy grazing area coverage was significantly lower than the control, moderate and mild grazing area (P0.05); community density of moderate and heavy grazing area was significantly lower than the control (P0.05).2. grazing intensity and two years of community diversity have an impact, but with the grazing intensity the interaction effect on Pielou index. Grazing intensity increased the community diversity decreased significantly (P0.05). The effects of grazing intensity and grazing intensity effects of.3. effects on community diversity than the year of species is higher than that of year, the number of species decreased with the increase of grazing intensity, control, mild, moderate and heavy grazing species were 24,21,21 and 19 respectively. Different species under different grazing intensities have different frequency, stipabreviflora frequency with the increase of grazing intensity increased significantly (P0.05), smooth implicit Grassland and Stipa breviflora trends, Artemisia frigida and Agassiz. With the increase of grazing intensity significantly decreased (P0.05).4. fitting results show that the model can better fit the geometric pattern of desert steppe species, species abundance and grazing intensity with the year pattern did not change in stipabreviflora up the key role of.5. in spatial heterogeneity in different years has not changed the community abundance pattern, but the whole community under different grazing intensity has greater spatial heterogeneity than random distribution, with the increase of grazing intensity, community heterogeneity increased. The heterogeneity index of Stipa breviflora, Cleistogenes songorica were higher than that of the community heterogeneity in different grazing intensities.

【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812

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