Gross primary productivity is more sensitive to droughts than to heatwaves in China

期刊论文
发表日期：

2025年9月27日

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Weijiao Wang,
Hongquan Song,
Haoming Xia,
Dong Wang,
Qianfeng Wang

摘要

The increasing frequency of droughts and heatwaves poses a significant threat to terrestrial ecosystems and has the potential to alter the carbon cycle by influencing gross primary production (GPP) under global warming. However, how droughts and heatwaves affect GPP across different climate zones and vegetation types remain unclear. Here, we employed the Spatially Explicit Individual-based Dynamic Global Vegetation Model to investigate how GPP responds to droughts and heatwaves across different vegetation types and precipitation gradients in China from 1950 to 2020. Overall, GPP in China exhibits greater sensitivity to droughts than to heatwaves, and it also shows notable spatial variations across different vegetation types and precipitation gradients. Results showed that subtropical broadleaf forests and shrublands along the southeast China were greatly affected by precipitation, and the 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) was the highest. GPP had 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) in southeastern Qinghai-Tibet Plateau, where alpine meadow was the dominant vegetation type. The sensitivity of GPP to droughts and heatwaves showed significant spatial variations with changes in precipitation gradients. In areas where the precipitation gradient is less than and greater than 800 mm, GPP exhibited positive sensitivity and negative sensitivity to droughts and heatwaves, respectively. These results revealed that different vegetation types respond differently to droughts and heatwaves. Above the 800 mm isohyet, characterized by low elevation and primarily covered by broadleaf forests, was identified as China’s most susceptible ecosystem to the adverse impacts of severe droughts and heatwaves. These findings emphasize the need to consider vegetation types affected by precipitation when examining the effects of droughts and heatwaves on GPP and highlights the importance of understanding ecosystem responses to climate extremes.