Abstract
Drought stress, characterized by increased vapor pressure deficit (VPD) and soil water content (SWC) deficit, significantly impacts ecosystem productivity (GPP). Accurately assessing these factors in satellite remote sensing (RS) GPP products is crucial for understanding the large-scale ecological consequences of drought. However, the accuracy of RS GPP in capturing the effects of VPD and SWC deficit, compared to EC flux data, remains under-investigated. Here we evaluated 10 RS GPP products and their mean (RSmean) concerning VPD and SWC deficit across diverse ecosystems along a dryness gradient. Our results revealed that RSmean and individual products generally capture the GPP response direction (VPD: mainly negative, SWC deficit: mixed positive/negative) but consistently misestimate the absolute GPP changes. This discrepancy is ecosystem-specific and consistent across all RS products, underscoring the need to enhance RS products to better account for ecosystem-specific VPD effects and non-linear SWC deficit responses, thereby improving RS GPP accuracy under drought.
| Original language | English |
|---|---|
| Article number | e2024GL110785 |
| Journal | Geophysical Research Letters |
| Volume | 52 |
| Issue number | 8 |
| DOIs | |
| State | Published - Apr 28 2025 |
Funding
We thank the editor and two anonymous reviewers for their constructive comments to improve the rigor and clarity of our research. This work was supported by National Natural Science Foundation of China (31922090), Hong Kong RGC Collaborative Research Fund (C5062-21GF), the Hung Ying Physical Science Research Fund 2021–2022, HKU Faculty of Science RAE Improvement Fund 2023–2024, and the Innovation and Technology Fund (funding support to State Key Laboratory of Agrobiotechnology). DY was supported by the NGEE-Arctic project supported by the Office of Biological and Environmental Research in the US DOE Office of Science and the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US DOE. MD was supported by the Carbon Mitigation Initiative at Princeton University and NSF Grant 2017804. We also thank Prof. Youngryel Ryu for his valuable comments on our drafts and for producing the BESS GPP. We thank the editor and two anonymous reviewers for their constructive comments to improve the rigor and clarity of our research. This work was supported by National Natural Science Foundation of China (31922090), Hong Kong RGC Collaborative Research Fund (C5062‐21GF), the Hung Ying Physical Science Research Fund 2021–2022, HKU Faculty of Science RAE Improvement Fund 2023–2024, and the Innovation and Technology Fund (funding support to State Key Laboratory of Agrobiotechnology). DY was supported by the NGEE‐Arctic project supported by the Office of Biological and Environmental Research in the US DOE Office of Science and the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT‐Battelle, LLC, for the US DOE. MD was supported by the Carbon Mitigation Initiative at Princeton University and NSF Grant 2017804. We also thank Prof. Youngryel Ryu for his valuable comments on our drafts and for producing the BESS GPP.
Keywords
- atmospheric dryness
- drought stress
- eddy flux measurements
- gross primary productivity (GPP)
- satellite GPP products
- soil moisture deficit