A brown-world cascade in the dung decomposer food web of an alpine meadow: effects of predator interactions and warming

	A brown-world cascade in the dung decomposer food web of an alpine meadow: effects of predator interactions and warming
	Wu, Xinwei ; Duffy, J. Emmett ; Reich, Peter B. ; Sun, Shucun
刊名	ECOLOGICAL MONOGRAPHS
	2011
卷号	81 期号:2 页码:313-328
关键词	alpine meadow artificial warming beetles biodiversity and ecosystem function Qinghai-Tibetan Plateau China coprophagy dung decomposers food webs nutrient cycling predator top-down control trophic cascade
ISSN号	0012-9615
通讯作者	Sun, SC (reprint author), Nanjing Univ, Sch Life Sci, Dept Biol, 22 Hankou Rd, Nanjing 210093, Peoples R China.
产权排序	1
英文摘要	Top-down control has been extensively documented in food webs based on living plants, where predator limitation of herbivores can cascade to facilitate plant growth (the green-world hypothesis), particularly in grasslands and aquatic systems. Yet the ecosystem role of predators in detrital food webs is less explored, as is the potential effect of climate warming on detritus-based communities. We here show that predators have a "brown-world" role in decomposer communities via a cascading top-down control on plant growth, based on the results of an experiment that factorially manipulated presence and size of two predator species as well as temperature (warmed vs. unwarmed). The inclusion of predatory beetles significantly decreased abundance of coprophagous beetles and thus the rate of dung decomposition and productivity of plants growing surrounding the dung. Moreover, the magnitude of these decreases differed between predator species and, for dung loss, was temperature dependent. At ambient temperature, the larger predators tended to more strongly influence the dung loss rate than did the smaller predators; when both predators were present, the dung loss rate was higher relative to the treatments with the smaller predators but comparable to those with the larger ones, suggesting an antagonistic effect of predator interaction. However, warming substantially reduced dung decomposition rates and eliminated the effects of predation on dung decomposition. Although warming substantially decreased dung loss rates, warming only modestly reduced primary productivity. Consistent with these results, a second experiment exploring the influence of the two predator species and warming on dung loss over time revealed that predatory beetles significantly decreased the abundance of coprophagous beetles, which was positively correlated with dung loss rates. Moreover, experimental warming decreased the water content of dung and hence the survival of coprophagous beetles. These results confirm that the "brown-world" effect of predator beetles was due to cascading top-down control through coprophagous beetles to nutrient cycling and primary productivity. Our results also highlight potentially counterintuitive effects of climate warming. For example, global warming might significantly decrease animal-mediated decomposition of organic matter and recycling of nutrients in a future warmed world.
学科主题	Environmental Sciences & Ecology
收录类别	SCI
资助信息	Action-plan for West Development[KZCX2-XB2-02]; Chinese Academy of Sciences
语种	英语
WOS记录号	WOS:000290707600008
公开日期	2012-11-09
内容类型	期刊论文
源URL	[http://210.75.237.14/handle/351003/23449]
专题	成都生物研究所_生态研究
推荐引用方式 GB/T 7714	Wu, Xinwei,Duffy, J. Emmett,Reich, Peter B.,et al. A brown-world cascade in the dung decomposer food web of an alpine meadow: effects of predator interactions and warming[J]. ECOLOGICAL MONOGRAPHS,2011,81(2):313-328.
APA	Wu, Xinwei,Duffy, J. Emmett,Reich, Peter B.,&Sun, Shucun.(2011).A brown-world cascade in the dung decomposer food web of an alpine meadow: effects of predator interactions and warming.ECOLOGICAL MONOGRAPHS,81(2),313-328.
MLA	Wu, Xinwei,et al."A brown-world cascade in the dung decomposer food web of an alpine meadow: effects of predator interactions and warming".ECOLOGICAL MONOGRAPHS 81.2(2011):313-328.