Increased burned area in the Pantanal over the past two decades

Wildfires are behaving differently now compared to other time in history in relation to frequency, intensity and affected ecosystems. In Brazil, unprecedented fires are being experienced in the last decade. Thus, to prevent and minimize similar disasters, we must better understand the natural and human drivers of such extreme events. The Brazilian Pantanal is the largest contiguous wetland in the world and a complex environmental system. In 2020, Pantanal experienced catastrophic wildfires due to the synergy between climate, inadequate fire management strategies and weak environmental regulations. In this study, we analyzed recent patterns and changes in fire behavior across the Pantanal based on land use and cover (LULC) classes. The inter-annual variability of the fire and land cover changes between 2000 and 2021 was assessed using BA from MCD64A1 V.6 product and LULC data from Landsat satellite. Our work reveals that fires in the Pantanal over the last two decades tended to occur more frequently in grassland than in others land cover types, but the 2020 fires have preferentially burned forest regions. Large fire patches are more frequent in forest and grasslands; in contrast, croplands exhibit small patches. The results highlight that a broad scale analysis does not reflect distinct localized patterns, thus stratified and refined studies are required. Our work contributes as a first step to disentangling the role of anthropogenic-related drivers, namely LULC changes, in shaping the fire regime in the Pantanal biome. This is crucial not only to predict future fire activity but also to guide appropriated fire management in the region.

与历史上的其他时期相比，野火在发生频率、强度和受影响的生态系统方面表现不同。在巴西，过去十年经历了前所未有的火灾。因此，为了预防和尽量减少类似灾难，我们必须更好地了解此类极端事件的自然和人为驱动因素。巴西的潘塔纳尔湿地是世界上最大的连片湿地，也是一个复杂的环境系统。2020年，由于气候、不当的火灾管理策略和薄弱的环境法规之间的协同作用，潘塔纳尔湿地经历了灾难性的野火。在这项研究中，我们根据土地利用和覆盖（LULC）类别分析了潘塔纳尔湿地火灾行为的近期模式和变化。利用MCD64A1 V.6产品的燃烧面积（BA）和来自陆地卫星的LULC数据，评估了2000年至2021年期间火灾和土地覆盖变化的年际变异性。我们的研究表明，过去二十年潘塔纳尔湿地的火灾在草原上发生的频率比在其他土地覆盖类型上更高，但2020年的火灾优先烧毁了森林地区。大面积的火斑在森林和草原中更为常见；相比之下，农田呈现出小面积的火斑。结果强调，大规模分析不能反映明显的局部模式，因此需要进行分层和细化的研究。我们的工作作为解开与人为相关的驱动因素（即LULC变化）在塑造潘塔纳尔生物群落火灾状况中作用的第一步具有贡献。这不仅对于预测未来的火灾活动至关重要，而且对于指导该地区适当的火灾管理也至关重要。