Departamento de Meteorologia, Instituto de Geociências, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-916, Brazil.
Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017, Lisboa, Portugal.
Sci Rep. 2021 Feb 23;11(1):4400. doi: 10.1038/s41598-021-82158-8.
Biomass burning in the Brazilian Amazon is modulated by climate factors, such as droughts, and by human factors, such as deforestation, and land management activities. The increase in forest fires during drought years has led to the hypothesis that fire activity decoupled from deforestation during the twenty-first century. However, assessment of the hypothesis relied on an incorrect active fire dataset, which led to an underestimation of the decreasing trend in fire activity and to an inflated rank for year 2015 in terms of active fire counts. The recent correction of that database warrants a reassessment of the relationships between deforestation and fire. Contrasting with earlier findings, we show that the exacerbating effect of drought on fire season severity did not increase from 2003 to 2015 and that the record-breaking dry conditions of 2015 had the least impact on fire season of all twenty-first century severe droughts. Overall, our results for the same period used in the study that originated the fire-deforestation decoupling hypothesis (2003-2015) show that decoupling was clearly weaker than initially proposed. Extension of the study period up to 2019, and novel analysis of trends in fire types and fire intensity strengthened this conclusion. Therefore, the role of deforestation as a driver of fire activity in the region should not be underestimated and must be taken into account when implementing measures to protect the Amazon forest.
生物质燃烧在巴西亚马逊地区受到气候因素(如干旱)和人为因素(如森林砍伐和土地管理活动)的调节。在干旱年份森林火灾的增加导致了这样一种假设,即在 21 世纪,火灾活动与森林砍伐脱钩。然而,对这一假设的评估依赖于一个不正确的活跃火灾数据集,这导致了火灾活动下降趋势的低估,并导致 2015 年在活跃火灾数量方面的排名虚高。最近对该数据库的修正需要重新评估森林砍伐与火灾之间的关系。与早期的研究结果相反,我们发现,干旱对火灾季节严重程度的加剧影响并没有从 2003 年到 2015 年增加,而且 2015 年破纪录的干旱条件对所有 21 世纪严重干旱的火灾季节的影响最小。总的来说,我们对最初提出火灾-森林砍伐脱钩假设的研究期间(2003-2015 年)进行了相同的分析,结果表明脱钩现象明显比最初提出的要弱。将研究期延长至 2019 年,并对火灾类型和火灾强度的趋势进行新的分析,强化了这一结论。因此,森林砍伐作为该地区火灾活动的驱动因素的作用不应被低估,在实施保护亚马逊森林的措施时必须加以考虑。