Doctoral Dissertation Research: Global Fire Since the Last Glacial Maximum

近年来，世界许多地区的野火活动异常极端。 这些大范围的火灾状况变化对人类健康、生态系统和全球气候系统构成了重大威胁。 如果没有长期的全球火灾历史数据，就很难理解这些变化是如何以及为什么发生的。 卫星图像，历史记录和树木年代学数据已被用来创建长达100年的短历史，但没有空间明确的合成存在更长的时间段。 本博士论文研究项目将汇编和综合已发表的木炭数据，以重建自末次盛冰期以来的全球火灾活动。 博士生将研究在逐渐和突然的气候变化期间生物质燃烧的变化，并比较古火和花粉数据，以研究长期火灾，植被和气候动态。 更具体地说，她将创建一个跨越过去21,000年的基于木炭的古火记录的全球数据库;对最高分辨率的古火记录进行荟萃分析，这些记录集中在北美;整合来自北美的木炭和花粉数据，以研究在不断变化的气候条件下火和燃料的关系;并利用观测和模拟的古火数据，对末次冰期最大期和中期的火活动进行全球数据模型比较，这项研究的结果将加强对火灾活动的空间和时间模式的基本理解，以及对自2000年以来发生的火灾状况重大变化背后的机制的基本理解。末次盛冰期 对高分辨率木炭数据和花粉数据的详细分析将为火灾状况变化的具体方面提供新的见解，例如火灾频率与火灾严重程度如何在气候和植被梯度上变化。 数据-模型比较将验证植被-火灾耦合模型，并为检验关于火灾、气候、植被和人类活动之间相互作用的假设提供新的工具。 数据将与NOAA古气候学世界数据中心赞助的国际多代理古火数据库共享。 作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。

Wildfire activity has been unusually extreme in many parts of the world in recent years. These broadscale changes in fire regimes pose a significant threat to human health, ecosystems, and the global climate system. It is difficult to understand how and why these changes are occurring without long-term, global fire-history data. Satellite images, historical records, and dendrochronological data have been used to create short histories of up to 100 years in duration, but no spatially explicit syntheses exist for longer time periods. This doctoral dissertation research project will compile and synthesize published charcoal data to reconstruct global fire activity since the last glacial maximum. The doctoral candidate will examine changes in biomass burning during periods of both gradual and abrupt climate change and compare paleofire and pollen data to investigate long-term fire, vegetation, and climate dynamics. More specifically, she will create a global database of charcoal-based paleofire records that spans the last 21,000 years; perform a meta-analysis of the highest-resolution paleofire records, which are concentrated in North America; integrate charcoal and pollen data from North America to examine fire and fuel relationships under changing climate conditions; and use observed and simulated paleofire data to make a global data-model comparison of fire activity at the time of the last glacial maximum and during the mid-Holocene.Results from this study will enhance basic understanding of the spatial and temporal patterns of fire activity and of the mechanisms behind major shifts in fire regimes that have occurred since the last glacial maximum. The detailed analysis of high-resolution charcoal data and pollen data will provide new insights into specific dimensions of fire-regime changes, such as how fire frequency versus fire severity have varied across climate and vegetation gradients. The data-model comparisons will validate a coupled vegetation-fire model and provide a new tool for testing hypotheses about interactions between fire, climate, vegetation and human activities. Data will be shared with the International Multiproxy Paleofire Database sponsored by the World Data Center for Paleoclimatology at NOAA. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.