Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1111/gcb.13893 |
Towards physiologically meaningful water-use efficiency estimates from eddy covariance data | |
Knauer, Juergen1,2,3; Zaehle, Soenke1,4; Medlyn, Belinda E.3; Reichstein, Markus1,4; Williams, Christopher A.5; Migliavacca, Mirco1; De Kauwe, Martin G.6,7; Werner, Christiane8; Keitel, Claudia9; Kolari, Pasi10; Limousin, Jean-Marc11; Linderson, Maj-Lena12 | |
2018-02-01 | |
发表期刊 | GLOBAL CHANGE BIOLOGY |
ISSN | 1354-1013 |
EISSN | 1365-2486 |
出版年 | 2018 |
卷号 | 24期号:2页码:694-710 |
文章类型 | Article |
语种 | 英语 |
国家 | Germany; Australia; USA; Finland; France; Sweden |
英文摘要 | Intrinsic water-use efficiency (iWUE) characterizes the physiological control on the simultaneous exchange of water and carbon dioxide in terrestrial ecosystems. Knowledge of iWUE is commonly gained from leaf-level gas exchange measurements, which are inevitably restricted in their spatial and temporal coverage. Flux measurements based on the eddy covariance (EC) technique can overcome these limitations, as they provide continuous and long-term records of carbon and water fluxes at the ecosystem scale. However, vegetation gas exchange parameters derived from EC data are subject to scale-dependent and method-specific uncertainties that compromise their ecophysiological interpretation as well as their comparability among ecosystems and across spatial scales. Here, we use estimates of canopy conductance and gross primary productivity (GPP) derived from EC data to calculate a measure of iWUE (G(1), "stomatal slope") at the ecosystem level at six sites comprising tropical, Mediterranean, temperate, and boreal forests. We assess the following six mechanisms potentially causing discrepancies between leaf and ecosystem-level estimates of G(1): (i) non-transpirational water fluxes; (ii) aerodynamic conductance; (iii) meteorological deviations between measurement height and canopy surface; (iv) energy balance non-closure; (v) uncertainties in net ecosystem exchange partitioning; and (vi) physiological within-canopy gradients. Our results demonstrate that an unclosed energy balance caused the largest uncertainties, in particular if it was associated with erroneous latent heat flux estimates. The effect of aerodynamic conductance on G(1) was sufficiently captured with a simple representation. G(1) was found to be less sensitive to meteorological deviations between canopy surface and measurement height and, given that data are appropriately filtered, to non-transpirational water fluxes. Uncertainties in the derived GPP and physiological within-canopy gradients and their implications for parameter estimates at leaf and ecosystem level are discussed. Our results highlight the importance of adequately considering the sources of uncertainty outlined here when EC-derived water-use efficiency is interpreted in an ecophysiological context. |
英文关键词 | aerodynamic conductance canopy gradients eddy covariance energy imbalance intrinsic water-use efficiency Penman-Monteith equation slope parameter surface conductance |
领域 | 气候变化 ; 资源环境 |
收录类别 | SCI-E |
WOS记录号 | WOS:000423994700041 |
WOS关键词 | ENERGY-BALANCE CLOSURE ; NET ECOSYSTEM EXCHANGE ; BOREAL ASPEN FOREST ; CANOPY PHOTOSYNTHESIS ; SURFACE CONDUCTANCE ; HEAT-STORAGE ; CARBON ; RESPIRATION ; LEAF ; MODEL |
WOS类目 | Biodiversity Conservation ; Ecology ; Environmental Sciences |
WOS研究方向 | Biodiversity & Conservation ; Environmental Sciences & Ecology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/17051 |
专题 | 气候变化 资源环境科学 |
作者单位 | 1.Max Planck Inst Biogeochem, Dept Biogeochem Integrat, Jena, Germany; 2.Int Max Planck Res Sch Global Biogeochem Cycles I, Jena, Germany; 3.Western Sydney Univ, Hawkesbury Inst Environm, Richmond, NSW, Australia; 4.Michael Stifel Ctr Jena Data Driven & Simulat Sci, Jena, Germany; 5.Clark Univ, Grad Sch Geog, Worcester, MA 01610 USA; 6.Macquarie Univ, Dept Biol Sci, N Ryde, NSW, Australia; 7.Univ New South Wales, ARC Ctr Excellence Climate Extremes, Sydney, NSW, Australia; 8.Univ Freiberg, Dept Ecosyst Physiol, Freiburg, Germany; 9.Univ Sydney, Sch Life & Environm Sci, Brownlow Hill, NSW, Australia; 10.Univ Helsinki, Dept Phys, Helsinki, Finland; 11.Univ Montpellier, Ctr Ecol Fonct & Evolut, Montpellier, France; 12.Lund Univ, Dept Phys Geog & Ecosyst Sci, Lund, Sweden |
推荐引用方式 GB/T 7714 | Knauer, Juergen,Zaehle, Soenke,Medlyn, Belinda E.,et al. Towards physiologically meaningful water-use efficiency estimates from eddy covariance data[J]. GLOBAL CHANGE BIOLOGY,2018,24(2):694-710. |
APA | Knauer, Juergen.,Zaehle, Soenke.,Medlyn, Belinda E..,Reichstein, Markus.,Williams, Christopher A..,...&Linderson, Maj-Lena.(2018).Towards physiologically meaningful water-use efficiency estimates from eddy covariance data.GLOBAL CHANGE BIOLOGY,24(2),694-710. |
MLA | Knauer, Juergen,et al."Towards physiologically meaningful water-use efficiency estimates from eddy covariance data".GLOBAL CHANGE BIOLOGY 24.2(2018):694-710. |
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