Collaborative Research: Integrating modern and paleo perspectives to disentangle grazer and climate controls on fire activity

火是一个地球系统过程，同时具有植被和大气反馈。草原上的草火目前占全球燃烧面积的主导地位，但食草动物可能会吃足够的草来抑制景观尺度的火灾。这些过程如何影响全球地球化学循环还没有定量的了解。该项目将现代实验和观察与数千年时间尺度的古生态学观察相结合。该项目测试对火灾活动动态的预测，以应对气候和食草动物。总体假设是，食草动物控制火灾活动是实质性的，但取决于环境背景。耶鲁皮博迪自然历史博物馆和犹他州自然历史博物馆的展品正在开发中，以教授地球系统中的火。特别是，博物馆的参观者正在了解火在地球系统中的作用和动态。早期的职业科学家，如本科生，研究生和博士后助理正在通过这个项目得到指导，为STEM劳动力做出贡献。该项目使用非洲现今和古生态数据集的组合：（i）9个现代草食动物排除实验，（ii）空间广泛的现代遥感和地面监测相结合的观测记录，和（iii）东非的五个古生态档案，跨越过去20，000年。正在编纂查拉湖和坦噶尼喀湖的古生态记录。在肯尼亚卢肯亚山和维多利亚湖和图尔卡纳的现有记录正在加强与新的代理重建火灾历史和草食动物。这项提议的工作推进了我们对地球系统中被忽视的火驱动因素的理解，并产生了新的古记录，这些记录对考古学、古生物学、古生态学和古气候学等众多学科的研究人员都很有用。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智力价值和更广泛的影响审查标准进行评估来支持。

Fire is an Earth system process with both vegetation and atmospheric feedbacks. Grass-fueled fires in savannas currently dominate global burned area, but grazers potentially eat enough grass to suppress fires at the landscape scale. How these processes affect global biogeochemical cycles is not quantitatively understood. This project combines present-day experiments and observations with paleoecological observations on the timescale of thousands of years. The project tests predictions about the dynamics of fire activity in response to climate and herbivory. The overall hypothesis is that grazer controls on fire activity are substantial but depend on environmental context. Exhibits at the Yale Peabody Museum of Natural History and the Natural History Museum of Utah are being developed to teach about fire in the Earth system. Particularly, museumgoers are learning about the role and dynamics of fire in the Earth system through time. Early career scientists, such as undergraduate students, graduate students, and postdoctoral associates are being mentored through this project, contributing to the STEM workforce.The project uses a combination of present-day and paleoecological datasets across Africa: (i) nine present-day herbivore exclusion experiments, (ii) spatially extensive, present-day observational records from a combination of remote sensing and on-the-ground monitoring, and (iii) five paleoecological archives in eastern Africa, spanning the last 20,000 years. Paleoecological records are being compiled from Lakes Chala and Tanganyika. Existing records at Lukenya Hill, Kenya and Lakes Victoria and Turkana are being strengthened with new proxy reconstructions of fire history and herbivory. The proposed work advances our understanding of a neglected fire driver in the Earth system and generates new paleorecords that are useful to researchers from numerous disciplines, including archaeology, paleontology, paleoecology, and paleoclimatology.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.