| DOI: | 10.1111/gcb.14500
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| Scopus记录号: | 2-s2.0-85057087947
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| 论文题名: | Arctic browning: Impacts of extreme climatic events on heathland ecosystem CO 2 fluxes |
| 作者: | Treharne R.; Bjerke J.W.; Tømmervik H.; Stendardi L.; Phoenix G.K.
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| 刊名: | Global Change Biology
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| ISSN: | 13541013
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| 出版年: | 2019
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| 卷: | 25, 期:2 | | 起始页码: | 489
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| 结束页码: | 503
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| 语种: | 英语
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| 英文关键词: | arctic
; browning
; Calluna vulgaris
; climate change
; dwarf shrub
; extreme events
; snow cover
; stress
; winter
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| Scopus关键词: | angiosperm
; carbon dioxide
; carbon flux
; climate change
; extreme event
; heathland
; seasonal variation
; shrub
; snow cover
; Calluna vulgaris
|
| 英文摘要: | Extreme climatic events are among the drivers of recent declines in plant biomass and productivity observed across Arctic ecosystems, known as “Arctic browning.” These events can cause landscape-scale vegetation damage and so are likely to have major impacts on ecosystem CO 2 balance. However, there is little understanding of the impacts on CO 2 fluxes, especially across the growing season. Furthermore, while widespread shoot mortality is commonly observed with browning events, recent observations show that shoot stress responses are also common, and manifest as high levels of persistent anthocyanin pigmentation. Whether or how this response impacts ecosystem CO 2 fluxes is not known. To address these research needs, a growing season assessment of browning impacts following frost drought and extreme winter warming (both extreme climatic events) on the key ecosystem CO 2 fluxes Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP), ecosystem respiration (R eco ) and soil respiration (R soil ) was carried out in widespread sub-Arctic dwarf shrub heathland, incorporating both mortality and stress responses. Browning (mortality and stress responses combined) caused considerable site-level reductions in GPP and NEE (of up to 44%), with greatest impacts occurring at early and late season. Furthermore, impacts on CO 2 fluxes associated with stress often equalled or exceeded those resulting from vegetation mortality. This demonstrates that extreme events can have major impacts on ecosystem CO 2 balance, considerably reducing the carbon sink capacity of the ecosystem, even where vegetation is not killed. Structural Equation Modelling and additional measurements, including decomposition rates and leaf respiration, provided further insight into mechanisms underlying impacts of mortality and stress on CO 2 fluxes. The scale of reductions in ecosystem CO 2 uptake highlights the need for a process-based understanding of Arctic browning in order to predict how vegetation and CO 2 balance will respond to continuing climate change. © 2018 The Authors. Global Change Biology Published by John Wiley & Sons Ltd |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/117527
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| Appears in Collections: | 气候变化与战略
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| Recommended Citation: | |
Treharne R.,Bjerke J.W.,Tømmervik H.,et al. Arctic browning: Impacts of extreme climatic events on heathland ecosystem CO 2 fluxes[J]. Global Change Biology,2019-01-01,25(2)
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