Fire plays a critical role in shaping the Amazon’s ecosystem and carbon dynamics, yet the relative contributions of climatic and land-use drivers remain debated. Here, we used 0.5° by 0.5° aggregated satellite-based active fire (AF) data (2002–2020) combined with land-cover change and climate reanalysis datasets to (1) quantify spatiotemporal change of fire patterns, (2) evaluate the interrelationships between drought, deforestation, and fires while comparing the relative contributions of climatic and land-use drivers, and (3) assess the impact of policy interventions on fire incidence. Our findings reveal that, despite a declining trend in overall fire detections, fire activity has shifted from regional concentration to broader dispersion, advancing deeper into the forest interior. While drought anomalies account for approximately 30 % of fire variability, spatial regression analysis highlights the dominant role of deforestation (coefficient=0.67) and farmland expansion (coefficient=0.20), compared to drought (coefficient=0.05). Notably, deforestation’s contribution to positive fire anomalies declined from ∼ 69 % (Phase I: 2004–2008) to ∼ 41 % (Phase IV: 2016–2020) of the Action Plan for the Prevention and Control of Deforestation in the Legal Amazon (PPCDAm), reflecting the partial effectiveness of conservation policies in mitigating fire risk. Nevertheless, the persistent interaction among fires, deforestation, and farmland expansion underscores the critical role of human activities in creating ignition-prone landscapes and stimulating fire occurrences. This study demonstrates the compounding effects of climate and land-use changes on Amazonian fire dynamics, and emphasizes the urgent need for integrated land use policies and climate adaptation strategies to address the enduring fire pressures and safeguard the Amazon’s carbon stocks and biodiversity.

中文翻译：

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21 世纪初亚马逊火灾活动的土地利用和气候驱动因素

火灾在塑造亚马逊生态系统和碳动态方面发挥着关键作用，但气候和土地利用驱动因素的相对贡献仍然存在争议。在这里，我们使用 0.5° x 0.5° 聚合的基于卫星的主动火灾 （AF） 数据（2002-2020 年）结合土地覆盖变化和气候再分析数据集来 （1） 量化火灾模式的时空变化，（2） 评估干旱、森林砍伐和火灾之间的相互关系，同时比较气候和土地利用驱动因素的相对贡献，以及 （3） 评估政策干预对火灾发生率的影响。我们的研究结果表明，尽管整体火灾探测呈下降趋势，但火灾活动已从区域集中转变为更广泛的分散，并深入到森林内部。虽然干旱异常约占火灾变异性的 30%，但空间回归分析突出了与干旱（系数=0.05）相比，森林砍伐（系数=0.67）和农田扩张（系数=0.20）的主导作用。值得注意的是，森林砍伐对积极火灾异常的贡献从预防和控制合法亚马逊森林砍伐行动计划 （PPCDAm） 的约 69%（第一阶段：2004-2008 年）下降到约 41%（第四阶段：2016-2020 年），反映了保护政策在减轻火灾风险方面的部分效果。然而，火灾、森林砍伐和农田扩张之间的持续相互作用凸显了人类活动在创造易着火景观和刺激火灾发生方面的关键作用。 本研究展示了气候和土地利用变化对亚马逊火灾动态的复合影响，并强调了迫切需要综合的土地利用政策和气候适应战略，以应对持久的火灾压力并保护亚马逊的碳储存和生物多样性。