干旱区生态环境知识资源中心(Arid): Shrubs proliferated within a six-year exclosure in a temperate grassland--Spatiotemporal relationships between vegetation and soil variables

Arid

	Shrubs proliferated within a six-year exclosure in a temperate grassland--Spatiotemporal relationships between vegetation and soil variables
	Zhang Yong; Gao Qiong; Xu Li; Yu Mei; Tian Yuqiang
来源期刊	Sciences in Cold and Arid Regions
ISSN	1674-3822
出版年	2014
卷号	6 期号:2 页码:139-149
英文摘要	Overgrazing has been considered one of the major causes that trigger shrub encroachment of grassland. Proliferation of shrubs in grassland is recognized as an important indicator of grassland degradation and desertification. In China, various conservation measures, including enclosures to reduce livestock grazing, have been taken to reverse the trend of grassland desertification, yet shrubs have been reported to increase in the grasslands over the past decades. In late 2007, we set up a 400-m-by-50-m exclosure in a long-term overgrazed temperate grassland in Inner Mongolia, with the objective to quantify the spatiotemporal relationship between vegetation dynamics, soil variables, and grazing exclusion. Soil moisture was continuously monitored within the exclosure, and cover and aboveground biomass of the shrubs were measured inside the exclosure in 2007, 2009, 2010, 2012, and 2013, and outside the exclosure in 2012 and 2013. We found the average shrub cover and biomass significantly increased in the six years by 103%and 120%, respectively. The result supported the hypothesis that releasing grazing pressure following long-term overgrazing tends to trigger shrub invasion into grassland. Our results, limited to a single gradient, suggest that any conservation measures with quick release of overgrazing pressure by enclosure or other similar means might do just the opposite to accelerate shrub encroachment in grassland. The changes in vegetation cover and biomass were regressed on the temporal average of the soil moisture content by means of the generalized least square technique to quantify the effect of the spatial autocor-relation. The result indicates that the grass cover and biomass significantly increased with the top, but decreased with the bottom layer soil moisture. The shrub cover and biomass, on the other hand, decreased with the top, but increased with bottom soil moisture, although the regression coefficients for the shrubs were not statistically significant. Hence this study supports the two-layered soil model which assumes grasses and shrubs use belowground resources in different depths.
英文关键词	shrubs encroachment in grassland two-layered soil model grassland conservation spatial autocorrelation northern China
类型	Article
语种	英语
收录类别	CSCD
WOS研究方向	Science & Technology - Other Topics
CSCD记录号	CSCD:5135554
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/335354
作者单位	Zhang Yong, College of Natural Resources and Technology, Beijing Normal University, State Key Laboratory of Earth Surface Processes and Resources Ecology, Beijing 100875, China.; Gao Qiong, College of Natural Resources and Technology, Beijing Normal University, State Key Laboratory of Earth Surface Processes and Resources Ecology, Beijing 100875, China.; Xu Li, College of Natural Resources and Technology, Beijing Normal University, State Key Laboratory of Earth Surface Processes and Resources Ecology, Beijing 100875, China.; Tian Yuqiang, College of Natural Resources and Technology, Beijing Normal University, State Key Laboratory of Earth Surface Processes and Resources Ecology, Beijing 100875, China.; Yu Mei, Department of Environmental Science, University of Puerto Rico-Rio Piedras, San Juan 00931, USA.
推荐引用方式 GB/T 7714	Zhang Yong,Gao Qiong,Xu Li,et al. Shrubs proliferated within a six-year exclosure in a temperate grassland--Spatiotemporal relationships between vegetation and soil variables[J],2014,6(2):139-149.
APA	Zhang Yong,Gao Qiong,Xu Li,Yu Mei,&Tian Yuqiang.(2014).Shrubs proliferated within a six-year exclosure in a temperate grassland--Spatiotemporal relationships between vegetation and soil variables.Sciences in Cold and Arid Regions,6(2),139-149.
MLA	Zhang Yong,et al."Shrubs proliferated within a six-year exclosure in a temperate grassland--Spatiotemporal relationships between vegetation and soil variables".Sciences in Cold and Arid Regions 6.2(2014):139-149.