DOI: 10.1111/gcb.12100
论文题名: Drought's legacy: Multiyear hydraulic deterioration underlies widespread aspen forest die-off and portends increased future risk
作者: Anderegg W.R.L. ; Plavcová L. ; Anderegg L.D.L. ; Hacke U.G. ; Berry J.A. ; Field C.B.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2013
卷: 19, 期: 4 起始页码: 1188
结束页码: 1196
语种: 英语
英文关键词: Biosphere-atmosphere interactions
; Climate change
; Ecosystem shift
; Forest mortality
; Vegetation model
; Xylem cavitation
Scopus关键词: annual variation
; atmosphere-biosphere interaction
; carbon balance
; carbon cycle
; climate change
; climate effect
; dieback
; drought
; ecosystem service
; feedback mechanism
; forest cover
; forest ecosystem
; global perspective
; mortality
; physiological response
; terrestrial ecosystem
; article
; climate change
; drought
; ecosystem
; risk
; tree
; Climate Change
; Droughts
; Ecosystem
; Risk
; Trees
; North America
; Populus
; Populus tremuloides
英文摘要: Forest mortality constitutes a major uncertainty in projections of climate impacts on terrestrial ecosystems and carbon-cycle feedbacks. Recent drought-induced, widespread forest die-offs highlight that climate change could accelerate forest mortality with its diverse and potentially severe consequences for the global carbon cycle, ecosystem services, and biodiversity. How trees die during drought over multiple years remains largely unknown and precludes mechanistic modeling and prediction of forest die-off with climate change. Here, we examine the physiological basis of a recent multiyear widespread die-off of trembling aspen (Populus tremuloides) across much of western North America. Using observations from both native trees while they are dying and a rainfall exclusion experiment on mature trees, we measure hydraulic performance over multiple seasons and years and assess pathways of accumulated hydraulic damage. We test whether accumulated hydraulic damage can predict the probability of tree survival over 2 years. We find that hydraulic damage persisted and increased in dying trees over multiple years and exhibited few signs of repair. This accumulated hydraulic deterioration is largely mediated by increased vulnerability to cavitation, a process known as cavitation fatigue. Furthermore, this hydraulic damage predicts the probability of interyear stem mortality. Contrary to the expectation that surviving trees have weathered severe drought, the hydraulic deterioration demonstrated here reveals that surviving regions of these forests are actually more vulnerable to future droughts due to accumulated xylem damage. As the most widespread tree species in North America, increasing vulnerability to drought in these forests has important ramifications for ecosystem stability, biodiversity, and ecosystem carbon balance. Our results provide a foundation for incorporating accumulated drought impacts into climate-vegetation models. Finally, our findings highlight the critical role of drought stress accumulation and repair of stress-induced damage for avoiding plant mortality, presenting a dynamic and contingent framework for drought impacts on forest ecosystems. © 2012 Blackwell Publishing Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62471
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Biology, Stanford University, Gilbert Building, 371 Serra Mall, Stanford, CA, 94305, United States; Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, United States; Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
Recommended Citation:
Anderegg W.R.L.,Plavcová L.,Anderegg L.D.L.,et al. Drought's legacy: Multiyear hydraulic deterioration underlies widespread aspen forest die-off and portends increased future risk[J]. Global Change Biology,2013-01-01,19(4)