Wang et al. (2025) Gross primary productivity is more sensitive to droughts than to heatwaves in China

Identification

• Journal: Climate Dynamics
• Year: 2025
• Date: 2025-09-27
• Authors: Weijiao Wang, Hongquan Song, Haoming Xia, Dong Wang, Qianfeng Wang
• DOI: 10.1007/s00382-025-07877-4

Research Groups

• State Key Laboratory of Spatial Datum, Henan Key Laboratory of Air Pollution Control and Ecological Security, Faculty of Geographical Science and Engineering, Henan University, Zhengzhou, China
• School of Life Sciences, Henan University, Kaifeng, China
• College of Environmental and Safety Engineering, The Academy of Digital China (Fujian), Fuzhou University, Fuzhou, China

Short Summary

This study investigated the response of Gross Primary Productivity (GPP) to droughts and heatwaves across different climate zones and vegetation types in China from 1950 to 2020 using the SEIB-DGVM model, revealing that GPP is generally more sensitive to droughts than to heatwaves, with significant spatial variations influenced by precipitation gradients.

Objective

• To simulate the differential impacts of droughts and heatwaves on GPP under control, drought-free, and heatwave-free scenarios.
• To quantify the varied impacts of droughts and heatwaves on GPP across eight major vegetation regions in China.
• To assess the sensitivity of GPP to droughts and heatwaves across multiple ecosystems, plant functional types, and precipitation gradients.

Study Configuration

• Spatial Scale: China, classified into eight vegetation regions, with simulations at 0.5° spatial resolution and a plant functional type (PFT) map at 1 km resolution.
• Temporal Scale: 1950 to 2020 (71 years) for transient simulation, preceded by a 2000-year spin-up simulation.

Methodology and Data

• Models used: Spatially Explicit Individual-based Dynamic Global Vegetation Model (SEIB-DGVM). Droughts were identified using the Standardized Precipitation Evapotranspiration Index (SPEI) at a 1-month timescale.
• Data sources:
  • Daily climate data (surface air temperature, daily diurnal temperature range, precipitation, total cloudiness, wind velocity, specific humidity, soil temperature): European Center for Medium-Term Weather Forecast (ECMWF) Reanalysis v5 (ERA5) at 0.5° spatial resolution (1950-2020).
  • Atmospheric CO2 concentration data: National Centers for Environmental Prediction/National Center and Atmospheric Research (NCEP/NCAR) reanalysis (1950-2020).
  • Plant functional types (PFTs) map: National Tibetan Plateau / Third Pole Environment Data Center (1 km resolution).
  • GPP evaluation data: Terra Moderate Resolution Imaging Spectroradiometer (MODIS) GPP product (MOD17A3, 8-day cumulative, 500 m resolution) and ChinaFLUX GPP dataset (annual, 30 arcseconds resolution) for 2000, 2005, 2010, 2015, and 2020.

Main Results

• Gross Primary Productivity (GPP) in China generally exhibits greater sensitivity to droughts than to heatwaves.
• GPP showed a pronounced southeast to northwest declining gradient, with the highest GPP (> 800 gC m⁻² yr⁻¹) in subtropical evergreen broadleaf forests and tropical monsoon forests in southeast China, and the lowest (< 200 gC m⁻² yr⁻¹) in northwest desert areas.
• Subtropical broadleaf forests and shrublands in southeast China were most negatively affected by precipitation, showing the highest negative sensitivity of GPP to droughts (182.2 gC m⁻² yr⁻¹ freq⁻¹) and heatwaves (104.4 gC m⁻² yr⁻¹ freq⁻¹).
• Alpine meadows in the southeastern Qinghai-Tibet Plateau exhibited the highest positive sensitivity to droughts (156.1 gC m⁻² yr⁻¹ freq⁻¹) and heatwaves (138.6 gC m⁻² yr⁻¹ freq⁻¹).
• The 800 mm annual precipitation isohyet broadly delineates contrasting GPP sensitivities: regions with precipitation less than 800 mm generally showed positive GPP sensitivity to droughts and heatwaves, while regions with precipitation greater than 800 mm exhibited negative sensitivity.
• Ecosystems above the 800 mm isohyet, characterized by low elevation and broadleaf forests, were identified as China's most susceptible to the adverse impacts of severe droughts and heatwaves.

Contributions

• This is the first study to investigate the response of GPP to climate extremes over a multi-decadal timescale (1950-2020) using the SEIB-DGVM.
• It integrates both precipitation-based and vegetation-based zoning to explore vegetation adaptive characteristics under climate extremes.
• The study quantitatively assesses the differential impacts and sensitivities of GPP to droughts and heatwaves across diverse ecosystems and precipitation gradients in China.
• It highlights the critical importance of considering vegetation types affected by precipitation when analyzing the effects of droughts and heatwaves on GPP.

Funding

• Natural Science Foundation of Henan Province (242300421143, 252300420830)
• Science and Technology Innovation Talents in Universities of Henan Province (24HASTIT016)
• National Natural Science Foundation of China (32130066)
• Outstanding Talent Program for Postgraduate Students of Henan University (SYLYC2022016)

Citation

@article{Wang2025Gross,
  author = {Wang, Weijiao and Song, Hongquan and Xia, Haoming and Wang, Dong and Wang, Qianfeng},
  title = {Gross primary productivity is more sensitive to droughts than to heatwaves in China},
  journal = {Climate Dynamics},
  year = {2025},
  doi = {10.1007/s00382-025-07877-4},
  url = {https://doi.org/10.1007/s00382-025-07877-4}
}