干旱区生态环境知识资源中心(Arid): 放牧梯度上群落物种数与物种组成结构异质性的数量分析

Arid

	放牧梯度上群落物种数与物种组成结构异质性的数量分析
其他题名	Quantitative analysis of spatial heterogeneity in species richness and composition in grassland vegetation with different grazing intensities in the northeast Inner Mongolian steppe
	乌云娜 1; 张凤杰 1; 盐见正卫 2
来源期刊	干旱区地理
ISSN	1000-6060
出版年	2011
卷号	34 期号:6 页码:904-911
中文摘要	放牧干扰对草原的植物物种组成以及群落结构的影响过程是群落生态学的重要内容。在内蒙古呼伦贝尔草原轻牧、中牧、重牧3个样地上，设置100个0.25 m~2的小样方，通过调查种类组成，比较小尺度区分面积上的物种多样性及物种数目的空间分异性；采用Bray - Curtis相似性指数法研究了不同放牧梯度上物种组成结构异质性的变化趋势。结果表明：样地群落物种数表现为轻牧>中牧>重牧，而小尺度样方内物种数与物种多样性均呈现中牧>轻牧>重牧趋势；在轻牧条件下，整体来看，小样方内物种数目的分布围绕平均值具有较小波动；在重度放牧区，不存在维持多个物种数的样方；而在中度放牧区，物种数的空间分布呈现凹型格局，相比于轻牧、重牧阶段，物种数在样方中的平均分布程度降低，即物种数目很多或很少的样方大量存在。从物种结构的空间异质性来看，轻牧区样方之间种类组成的相似性不明显，群落物种形成均匀分布；中度和重度放牧区，具有随机分布的群落物种结构。牧压影响小尺度区间面积上的物种数、种类构成及其空间异质性，物种数目的频度分布及种类成分相似性的蒙特卡罗模似统计运算，能够较好地拟合不同放牧梯度上物种分布的空间格局，反映群落演替动态。
英文摘要	Spatial heterogeneity is a very important structural property in ecosystem and is closely associated with many ecological phenomena. Heterogeneity is defined as "the complexity and/or variability of a system property in space and/or time" - could be an important component controlling plant community structure and composition. The spatial distribution of biological and abiotic factors in ecosystem has the features of spatial heterogeneity. Although the effects of grazing on the vegetation patches in arid and semiarid ecosystems have been extensively described, knowledge of these ecological processes in China is rather poor, particularly in Inner Mongolian, northern China. In this paper, the spatial heterogeneity of vegetation under different grazing intensities was examined using geostatis- tical methods. The effect of grazing disturbance on plant functional group and community structure of grass community is an important component of community ecology. In the present study, we arranged 100 quadrats of 50 cm * 50 cm in three grassland sites with different grazing intensities (light, medium, and heavy) in the northeast Inner Mongolian steppe. There are 4 cells of 25 cm * 25 cm in each quadrats. Through investigation of grass species, the spatial heterogeneities of small-scale species richness and small-scale species compositions were compared and studied. The Bray-Curtis was used to express the spatial heterogeneity of species composition with different grazing intensities. Results show that: The order of species richness for the entire area was light grazing > moderate grazing > heavy grazing. However, the order of species richness for small quadrat was medium grazing > light grazing > heavy grazing. Over all, the number of species occurring in each quadrat did not deviate substantially from the mean; in the heavily grazed site, quadrats with numerous species did not exist; in the medium grazing site, the distribution of spatial richness showed the "concave" pattern and the average distribution of species richness reduced (i.e. quadrats with numerous species existed). Over all, understanding the spatial heterogeneity in community structure the lightly grazed quadrats showed lower similarity. In the remaining two sites, the species composition was random distribution among quadrats. The grazing pressure could affect the small-scale species richness, species composition and the spatial heterogeneities of them. The Monte Carlo method modal of distribution frequency and the simulation of species composition could represent the spatial structure of species distribution and the dynamics of community succession. The purpose of this study is to examine the effect of grazing on spatial heterogeneity of soil organic matter and plant populations in Hulunbeir grassland using geostatistical methods. Moreover, we want to know the effect of grazing on the spatial heterogeneity of soil and the vegetation patches. This study would provide a scientific basis for the prediction and management of the grazing on grassland ecosystem in arid and semiarid grassland areas.
中文关键词	物种数目 ; 物种结构 ; 空间异质性 ; 草原群落 ; 放牧梯度
英文关键词	species number species composition spatial heterogeneity grassland communities grazing gradient
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PLANT SCIENCES
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:4395447
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/226489
作者单位	1.大连民族学院环境与资源学院, 大连, 辽宁 116600, 中国; 2.日本茨城大学, 茨城水户, 310-8512
推荐引用方式 GB/T 7714	乌云娜,张凤杰,盐见正卫. 放牧梯度上群落物种数与物种组成结构异质性的数量分析[J],2011,34(6):904-911.
APA	乌云娜,张凤杰,&盐见正卫.(2011).放牧梯度上群落物种数与物种组成结构异质性的数量分析.干旱区地理,34(6),904-911.
MLA	乌云娜,et al."放牧梯度上群落物种数与物种组成结构异质性的数量分析".干旱区地理 34.6(2011):904-911.