Scholarlink

<p>Solar radiation (SR) and vapor pressure deficit (VPD) serve as critical determinants in vegetation energy-water interactions. Although the impacts of SR and VPD on ecosystem photosynthesis have been widely studied, their relative effects remain insufficiently understood, which affects the evaluation of global ecosystem productivity drivers. In this study, based on eddy covariance observations at 82 globally distributed sites, we decoupled the correlation between SR and VPD by sorting and binning hourly SR and VPD data. Then we quantified how decoupled SR and VPD affected ecosystem light utilization efficiency (eLUE). We found that more sites (54 out of 82 sites) experienced reduced eLUE from high SR than from high VPD over the study periods and the eLUE sensitivity to SR (or VPD) decreases with VPD (or SR) percentile. Further, the impacts of SR and VPD on eLUE are tightly linked with the site aridity. While SR dominates VPD in controlling eLUE at wetter sites, their relative influence converges with increasing aridity, and VPD even may become the stronger driver in drier sites. This pattern is further supported by its close association with stomatal behavior. Our results shed light on the relative effects of SR and VPD on vegetation productivity and provide critical insights into the energy-water interactions under current and future climate conditions.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Disentangling the relative effects of solar radiation and vapor pressure deficit on ecosystem photosynthetic efficiency based on global eddy-covariance observations

  • 期刊论文

  • 发表日期：

    2025年9月2日

查看全文
  • Lijiang Fu,
  • Jinglu Tan,
  • Vladimir Lysenko,
  • Ya Guo

摘要

Solar radiation (SR) and vapor pressure deficit (VPD) serve as critical determinants in vegetation energy-water interactions. Although the impacts of SR and VPD on ecosystem photosynthesis have been widely studied, their relative effects remain insufficiently understood, which affects the evaluation of global ecosystem productivity drivers. In this study, based on eddy covariance observations at 82 globally distributed sites, we decoupled the correlation between SR and VPD by sorting and binning hourly SR and VPD data. Then we quantified how decoupled SR and VPD affected ecosystem light utilization efficiency (eLUE). We found that more sites (54 out of 82 sites) experienced reduced eLUE from high SR than from high VPD over the study periods and the eLUE sensitivity to SR (or VPD) decreases with VPD (or SR) percentile. Further, the impacts of SR and VPD on eLUE are tightly linked with the site aridity. While SR dominates VPD in controlling eLUE at wetter sites, their relative influence converges with increasing aridity, and VPD even may become the stronger driver in drier sites. This pattern is further supported by its close association with stomatal behavior. Our results shed light on the relative effects of SR and VPD on vegetation productivity and provide critical insights into the energy-water interactions under current and future climate conditions.