Soil moisture dominates the severe decline in gross primary productivity during a 2023–2024 compound heatwave-drought event over the Amazon

作者：Te Yang, Bin Chen, Xiaobo Wang, Xiyan Xu, Paulo Artaxo, Tingyu Li, Huiying Peng, Yu Xin · 发表于：Environmental Research Letters · 年份：2025 · DOI：10.1088/1748-9326/adb0e1 · 被引用次数：13 · 研究领域：Plant Water Relations and Carbon Dynamics、Climate variability and models、Solar Radiation and Photovoltaics

Abstract The Amazon, the world’s largest tropical forest, plays a critical role in the global carbon cycle. It has a large carbon pool and acts as a major carbon sink. However, in 2023–2024, a compound heatwave-drought (CHWD) event (HD2023) hit the Amazon region, resulting in extreme temperatures and soil moisture deficits, threatening the region’s carbon sink capacity. Using advanced multisource satellite data and meteorological reanalysis, we quantified the impact of various climatic factors on vegetation productivity during HD2023 and analyzed its progression. Our findings showed that HD2023 led to a 530 Tg C decline in gross primary productivity (GPP) and 0.003 reduction in near-infrared reflectance of vegetation. The strongest phase of the event spanned 5 months, causing persistently high temperatures and reduced precipitation, leading to a continuous decline in soil moisture and marked reduction in GPP. The most severe decrease in GPP occurred in January 2024. The event originated in the northwest and gradually spread to the southeast. Soil moisture was the dominant factor in the decline of photosynthesis across vegetation types, whereas high solar radiation mitigated the impact of drought in evergreen broad forests and savannas. Moreover, the sensitivity of GPP to CHWD varied across vegetation types, ranking as grassland > savanna > evergreen broad forest. This study assessed the impact of HD2023 on regional carbon flux in the Amazon. As climate projections indic...