DOI: 10.1111/gcb.14139
Scopus记录号: 2-s2.0-85045377399
论文题名: Elevated CO2 did not affect the hydrological balance of a mature native Eucalyptus woodland
作者: Gimeno T.E. ; McVicar T.R. ; O'Grady A.P. ; Tissue D.T. ; Ellsworth D.S.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2018
卷: 24, 期: 7 起始页码: 3010
结束页码: 3024
语种: 英语
英文关键词: climate change
; Eucalyptus tereticornis
; free-air CO2 enrichment
; interception
; stomatal conductance
; tree water
; water-use efficiency
Scopus关键词: carbon dioxide
; climate change
; interception
; soil water
; stomatal conductance
; tree
; water budget
; water content
; water use efficiency
; woodland
; Eucalyptus
; Eucalyptus tereticornis
英文摘要: Elevated atmospheric CO2 concentration (eCa) might reduce forest water-use, due to decreased transpiration, following partial stomatal closure, thus enhancing water-use efficiency and productivity at low water availability. If evapotranspiration (Et) is reduced, it may subsequently increase soil water storage (ΔS) or surface runoff (R) and drainage (Dg), although these could be offset or even reversed by changes in vegetation structure, mainly increased leaf area index (L). To understand the effect of eCa in a water-limited ecosystem, we tested whether 2 years of eCa (~40% increase) affected the hydrological partitioning in a mature water-limited Eucalyptus woodland exposed to Free-Air CO2 Enrichment (FACE). This timeframe allowed us to evaluate whether physiological effects of eCa reduced stand water-use irrespective of L, which was unaffected by eCa in this timeframe. We hypothesized that eCa would reduce tree-canopy transpiration (Etree), but excess water from reduced Etree would be lost via increased soil evaporation and understory transpiration (Efloor) with no increase in ΔS, R or Dg. We computed Et, ΔS, R and Dg from measurements of sapflow velocity, L, soil water content (θ), understory micrometeorology, throughfall and stemflow. We found that eCa did not affect Etree, Efloor, ΔS or θ at any depth (to 4.5 m) over the experimental period. We closed the water balance for dry seasons with no differences in the partitioning to R and Dg between Ca levels. Soil temperature and θ were the main drivers of Efloor while vapour pressure deficit-controlled Etree, though eCa did not significantly affect any of these relationships. Our results suggest that in the short-term, eCa does not significantly affect ecosystem water-use at this site. We conclude that water-savings under eCa mediated by either direct effects on plant transpiration or by indirect effects via changes in L or soil moisture availability are unlikely in water-limited mature eucalypt woodlands. © 2018 John Wiley & Sons Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110342
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: INRA, UMR ISPA, Villenave d'Ornon, France; Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia; CSIRO Land and Water, Canberra, ACT, Australia; Australian Research Council Centre of Excellence for Climate System Science, Sydney, NSW, Australia; CSIRO Land and Water, Hobart, TAS, Australia; Basque Centre for Climate Change (BC3), Leioa, Spain
Recommended Citation:
Gimeno T.E.,McVicar T.R.,O'Grady A.P.,et al. Elevated CO2 did not affect the hydrological balance of a mature native Eucalyptus woodland[J]. Global Change Biology,2018-01-01,24(7)