MSB-ECA: Tropical biomes: how agriculture intensification and climate may alter fire regimes

森林和热带稀树草原是最大和多样化的生态系统。它们是一些最大的农业前沿地区。这些地区农业的迅速扩张是农业商品生产和出口的原因，也是向地球大气层释放大量碳的原因。这些农业成就中有许多是以高昂的环境代价取得的：森林砍伐和植被退化。在今后几十年里，农业道路将决定森林和热带稀树草原的分布，以及它们是否保持维持关键的全球生态系统服务的能力，或进入螺旋式下降，加速干扰，严重退化当地生态系统，造成全球后果。这项研究将量化如何干扰制度可能会随着农业的加剧和环境的变化而变化。这些假设是：（1）与持续农业集约化相关的灭火将改变灾难性野火的可能性，（2）预计气候变化可能导致更频繁，高强度的火灾。项目成果可以为区域土地和火灾管理提供信息，特别是制定新战略，以避免可能破坏基础设施、对人类健康和福祉产生负面影响的灾难性野火;并向大气中释放大量的碳。该提案将应用遥感图像，统计分析和数值模拟，以更清楚地了解气候，土地利用和森林及热带稀树草原的火灾状况。它将评估燃烧面积和火灾频率如何随着环境变化和农业集约化而变化，以及灭火和未来环境变化如何改变大范围野火的可能性。通过遥感分析，该项目将增进对全世界森林和热带稀树草原火灾扰动机制的了解，为在未来气候和土地使用变化情况下可能导致大规模生态系统变化的未量化阈值提供新的见解。为此，本研究侧重于四个关键组成部分。第一，利用标准遥感产品（如大地卫星、中分辨率成像分光仪）重建森林和稀树草原的火灾历史。第二，量化现有农业前沿土地利用转型地图固有的不确定性。第三，建立一个统计模型的变化，火灾制度的指标作为一个功能的土地利用变化，农业集约化，和极端气候。第四，改进空间显式火灾模型（FISC），该模型将用于模拟火灾状态的潜在轨迹，并将在土地使用和环境变化的情况下适用于地球仪其他地区的森林稀树草原地区。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Forests and savannas are largest and diverse ecosystems. They house some of the largest agricultural frontiers. The rapid expansion of agriculture in such regions is responsible for the production and export of agricultural commodities as well as releasing enormous amounts of carbon to Earth's atmosphere. Many of these agricultural achievements have come at a high environmental cost: deforestation and vegetation degradation. Over the next few decades, agricultural pathways will determine the distribution of forests and savannas and whether they retain the capacity to sustain key global ecosystem services or enter a downward spiral with accelerating disturbances that severely degrade native ecosystems, with global consequences. This study will quantify how disturbance regimes may shift as agriculture intensifies and the environment changes. The hypotheses are that (1) fire suppression associated with ongoing agricultural intensification will change the likelihood of catastrophic wildfires, and (2) projected changes in climate may results in more frequent, high-intensity fires. The project outcomes could inform regional land and fire management, particularly the development of new strategies to avoid catastrophic wildfires that can damage infrastructure; negatively impact human health and well-being; and release large amounts of carbon to the atmosphere.This proposal will apply remote sensing imagery, statistical analyses, and numerical modeling to build a clearer understanding of the spatially varying synergies between climate, land use, and fire regimes in forests and savannas at a global scale. It will evaluate how burned area and fire frequency change as a function of environmental change and agricultural intensification, as well as how fire suppression and future environmental changes may alter the probability of widespread wildfires. Through remote sensing analyses, this project will advance understanding of fire disturbance regimes in forests and savannas worldwide, providing new insights into the unquantified thresholds that may lead to large-scale ecosystem change under future climate and land-use changes. To do so, the study focuses on four key components. First, reconstructing fire histories in forests and savannas using standard remote sensing products (e.g. Landsat, MODIS). Second, quantifying uncertainties inherent to the existing maps of land-use transitions in the agricultural frontier. Third, building a statistical model of changes in fire regime metrics as a function of land-use change, agriculture intensification, and climatic extremes. Fourth, improving the spatially explicit fire model (FISC) that will be used to simulate potential trajectories of fire regimes, and will also be applicable to forest-savanna areas in the rest of the globe, under scenarios of land-use and environmental change.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.