Understanding the coupled response of vegetation and fire to climatic variation since the Last Glacial Maximum

詹妮弗·马龙博士被授予NSF地球科学博士后奖学金，在威斯康星州-麦迪逊大学开展研究和教育计划。马龙博士将使用古环境数据和动态全球植被火灾模型来研究过去气候变化对火灾植被相互作用的影响。她将首先对湖泊沉积物中的木炭和花粉数据进行荟萃分析，以重建百年至千年尺度的区域至大陆尺度的火灾和植被变化模式。然后，将使用一个尖端的、支持火的动态全球植被模型来模拟在与今天非常不同的气候条件下的古火活动（即，距今6000年至21,000年）。 木炭和花粉分析的结果将用于通过数据-模型比较评估模型性能。 最后，从合成和数据模型比较的结果将被用来设计和实施耦合植被火灾模型的敏感性实验。 这些实验的目的是增进我们对气候和植被如何控制火灾状况的理解，以及植被和火灾对未来潜在气候变化的反应范围。全球变暖对植被和野火在广阔空间尺度上的可能影响在很大程度上是未知的。 然而，我们知道，预计的气候变化将对生态系统动态产生重大影响，包括干扰机制，特别是火灾机制变化的反馈将影响全球生物地球化学循环以及大气化学和物理学。 这些后果反过来又威胁到生态系统服务，如提供清洁的空气和水，从而威胁到人类健康和生计。 古火记录表明，火况对气候变化高度敏感，特别是当变化突然且无论变化方向如何时。这项研究将提高我们对火灾状况自然变化的理解，从而提高我们模拟未来火灾变化的能力。研究结果还将为生态学家和自然资源管理人员提供北美当前火灾状况变化的关键背景。与这项研究有关的外联和教育活动包括开发过去火灾和植被变化的标准化和综合数据集，这些数据集将在一个公共网站上提供给更广泛的社区。马龙博士还将为主办机构的本科生和研究生开发有关火灾、古生态学和古气候学的课程材料。

Dr. Jennifer Marlon is awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the University of Wisconsin - Madison. Dr. Marlon will use paleoenvironmental data and a dynamic global vegetation-fire model to study past climate change impacts on fire-vegetation interactions. She will first conduct meta-analyses of charcoal and pollen data from lake sediments to reconstruct centennial- to millennial-scale patterns of fire and vegetation change at regional to continental scales. A cutting-edge, fire-enabled dynamic global vegetation model will then be used to simulate paleofire activity under climate conditions very different from today (i.e., 6000 and 21,000 years ago). Results from the charcoal and pollen analyses will be used to assess model performance through data-model comparisons. Finally, results from the synthesis and data-model comparison will be used to design and implement sensitivity experiments with the coupled vegetation-fire model. The aim of the experiments will be to advance our understanding of how climate and vegetation control fire regimes, and of the range of responses in vegetation and fire to potential future climate changes.The likely impacts of global warming on vegetation and wildfires at broad spatial scales are largely unknown. Yet, we know that projected climate changes will have major consequences for ecosystem dynamics, including disturbance regimes, and that feedbacks from changing fire regimes in particular will affect global biogeochemical cycles, as well as atmospheric chemistry and physics. Such consequences, in turn, threaten ecosystem services, such as the provisioning of clean air and water, and thus human health and livelihoods. Paleofire records indicate that fire regimes are highly sensitive to climate changes, particularly when the changes are abrupt, and regardless of the direction of change. This research will improve our understanding of natural variability in fire regimes and thus improve our ability to model future changes in fire. Results will also provide ecologists and natural resource managers with critical context for current fire-regime changes in North America. Outreach and education activities associated with this research include the development of standardized and integrated datasets of past fire and vegetation changes that will be made available to the broader community on a public website. Dr. Marlon will also develop course material on fire, paleoecology and paleoclimatology for undergraduates and graduates at the host institution.