期刊
AGRICULTURAL AND FOREST METEOROLOGY
卷 326, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.agrformet.2022.109158
关键词
Water -use efficiency; Carbon cycle; FLUXNET
资金
- Global Modeling Analysis (RGMA) program in the Climate and Environmental Sciences Division (CESD) of the Biological and Envi- ronmental Research (BER) Program in the U.S. Department of Energy Office of Science [DE-AC02-05CH11231]
- NASA Terrestrial Ecology Program IDS Award [80NSSC21K1705]
- European Union H2020 projects
- U.S. Department of Energy Office of Science
Plant stomatal conductance regulates photosynthesis and transpiration, affecting ecosystem responses to microclimate. Ecosystem-scale water use efficiency (WUE) trends are more sensitive to hourly weather conditions than longer-term changes in atmospheric factors. Earth System Models have not fully captured the observed WUE sensitivity to microclimatic conditions.
Plant stomatal conductance regulates photosynthesis and transpiration. This physiological link affects ecosystem responses to microclimate and harmonizes carbon, energy, and water exchanges between the biosphere and atmosphere. The relationship between water losses via transpiration and carbon gains via photosynthesis can be quantified by plant water-use efficiency (WUE). While leaf-and ecosystem-scale observations both suggest rising WUE in recent decades, WUE trends inferred from the ecosystem scale are much larger than those inferred from the leaf scale or implied by theory. The unexpectedly large ecosystem-scale WUE trends complicate interpre-tation of ecophysiological responses to changing environmental conditions. Here, we analyze ecosystem-scale WUE inferred from 40 FLUXNET sites, each with at least 10 years of measurements. Our results demonstrate that observed ecosystem-scale WUE trends are more sensitive to hourly weather conditions than longer-term changes in atmospheric carbon dioxide or vapor pressure deficit. Our analysis shows that Earth System Models participating in CMIP6 did not capture the observed WUE sensitivity to inter-site variability and microclimatic conditions. Collectively, our findings suggest that ecosystem-scale WUE trends reflect water -carbon interactions across multiple temporal scales, and disentangling factors contributing to emergent ecosystem responses is needed to infer ecophysiological relationships and model structures from observations.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据