DOI: 10.1111/gcb.13151
论文题名: Canopy leaf area of a mature evergreen Eucalyptus woodland does not respond to elevated atmospheric [CO2] but tracks water availability
作者: Duursma R.A. ; Gimeno T.E. ; Boer M.M. ; Crous K.Y. ; Tjoelker M.G. ; Ellsworth D.S.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2016
卷: 22, 期: 4 起始页码: 1666
结束页码: 1676
语种: 英语
英文关键词: Drought
; Free-air CO2 enrichment
; Leaf area index
; Litter production
; Phenology
Scopus关键词: canopy
; carbon dioxide enrichment
; drought
; evergreen tree
; leaf area index
; litter
; phenology
; woodland
; Eucalyptus
; carbon dioxide
; water
; atmosphere
; Eucalyptus
; forest
; growth, development and aging
; New South Wales
; plant leaf
; Atmosphere
; Carbon Dioxide
; Eucalyptus
; Forests
; New South Wales
; Plant Leaves
; Water
英文摘要: Canopy leaf area, quantified by the leaf area index (L), is a crucial driver of forest productivity, water use and energy balance. Because L responds to environmental drivers, it can represent an important feedback to climate change, but its responses to rising atmospheric [CO2] and water availability of forests have been poorly quantified. We studied canopy leaf area dynamics for 28 months in a native evergreen Eucalyptus woodland exposed to free-air CO2 enrichment (the EucFACE experiment), in a subtropical climate where water limitation is common. We hypothesized that, because of expected stimulation of productivity and water-use efficiency, L should increase with elevated [CO2]. We estimated L from diffuse canopy transmittance, and measured monthly leaf litter production. Contrary to expectation, L did not respond to elevated [CO2]. We found that L varied between 1.10 and 2.20 across the study period. The dynamics of L showed a quick increase after heavy rainfall and a steady decrease during periods of low rainfall. Leaf litter production was correlated to changes in L, both during periods of decreasing L (when no leaf growth occurred) and during periods of increasing L (active shedding of old foliage when new leaf growth occurred). Leaf lifespan, estimated from mean L and total annual litter production, was up to 2 months longer under elevated [CO2] (1.18 vs. 1.01 years; P = 0.05). Our main finding that L was not responsive to elevated CO2 is consistent with other forest FACE studies, but contrasts with the positive response of L commonly predicted by many ecosystem models. © 2016 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61441
Appears in Collections: 影响、适应和脆弱性
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作者单位: Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia; UMR 1391 ISPA, INRA, Villenave d'Ornon, France
Recommended Citation:
Duursma R.A.,Gimeno T.E.,Boer M.M.,et al. Canopy leaf area of a mature evergreen Eucalyptus woodland does not respond to elevated atmospheric [CO2] but tracks water availability[J]. Global Change Biology,2016-01-01,22(4)