Details

Autor(en) / Beteiligte

• Xue, Baolin
• Wang, Guoqiang
• Xiao, Jingfeng
• Tan, Qian
• Shrestha, Sangam
• Sun, Wenchao
• Liu, Tingxi

Titel

Global evapotranspiration hiatus explained by vegetation structural and physiological controls

Ist Teil von

• Ecological engineering, 2020-12, Vol.158, p.106046, Article 106046

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2020

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• While evapotranspiration (ET) is an important component of the global water cycle, its temporal variations (ΔET) and underlying mechanisms are controversial. Based on the newest FLUXNET dataset and six ET products, we investigate ΔET for different ecosystem types during the recent two decades (1995–2014). We found an ET hiatus (decreasing in ET) at most sites (46 of 67) based on both in-situ observations and the ET products. The environmental drivers, surface conductance (Gs) and water use efficiency (WUE) are found to be responsible for ΔET. Changes in structural (by leaf area index, or LAI) and physiological (by Gs and WUE) variables contributed nearly equally to ΔET. Although Gs may impose a larger positive effect on ET than LAI, its effect may substantially offset the negative effect via WUE. Our study provides robust observational evidence that global ET stayed roughly unchanged in the past two decades. The results also highlight the importance of incorporating both vegetation structural and physiological effects in the projections of ΔET under a changing climate. •46 of 67 FLUXNET sites covering various ecosystems had no obvious temporal change in ET in the past 20 years.•Surface conductance (Gs) and water use efficiency (WUE) caused significant changes in ET for certain sites.•A structural equation model to show large contribution of structural and physiological variables to changes in ET.