Collaborative Research: Megaherbivore and climatic controls on fire and vegetation dynamics during the last deglaciation

合作研究：末次冰消期期间大型食草动物和气候对火灾和植被动态的控制

• 批准号: 1353896
• 负责人: John Williams
• 金额: $ 71.8万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1353896&HistoricalAwards=false
• 关键词: Collaborative; Research; Megaherbivore; climatic; controls

Ecologists have long sought to understand how species reshuffle into novel ecological communities during periods of major environmental change, and the consequences of this reshuffling for the services that those ecological communities provide for human society. This project capitalizes on a major historical event - massive changes in plant communities roughly 17,000 years ago - to determine the relative roles that climate change, species interactions, and fire played in the creation of novel communities. Results from this research will inform contemporary debates about the potential for climate change to create 'no analog' communities that differ fundamentally in their structure, function, and the services they provide to society. They will also guide management practices intended to restore communities to prior states and improve our understanding of the consequences of widespread extinctions.This project builds on prior evidence that plant communities changed dramatically during the last deglaciation because the extinction of large grazers released plants from herbivore suppression. New research will test the novel Megafaunal Release Hypothesis by assessing the relative importance of climate and species interactions on vegetation and fire dynamics. The investigators will collect and analyze a series of lake-sediment cores in the eastern US, and quantify relationships among independent climatic and ecological proxies within and across sites in order to test the Megafaunal Release Hypothesis. Eight new lake sites will be analyzed for indicators of past vegetation composition (fossil pollen), fire regime (sedimentary charcoal), megafaunal abundance (spores from fungi found in dung), and temperature (organic geochemistry). Broader impacts include the mentoring and training of a postdoctoral research scientist, a graduate student, and several undergraduates, and the expansion of collaborations among paleontologists, geographers, and ecologists to understand future environmental change. All data will be made publicly available through standard community data repositories.

生态学家长期以来一直试图了解在重大环境变化期间物种如何重新洗牌成新的生态群落，以及这种重新洗牌对这些生态群落为人类社会提供的服务的影响。该项目利用重大历史事件——大约 17,000 年前植物群落的巨大变化——来确定气候变化、物种相互作用和火灾在新群落创建中所发挥的相对作用。这项研究的结果将为当代有关气候变化是否有可能创建“非类似”社区的争论提供信息，这些社区在结构、功能和向社会提供的服务方面存在根本差异。 它们还将指导旨在将群落恢复到先前状态的管理实践，并提高我们对大范围灭绝后果的理解。该项目建立在先前的证据之上，即植物群落在上次冰消期间发生了巨大变化，因为大型食草动物的灭绝使植物免受草食动物的抑制。新的研究将通过评估气候和物种相互作用对植被和火灾动态的相对重要性来测试新的巨型动物释放假说。研究人员将收集和分析美国东部的一系列湖泊沉积物核心，并量化地点内和地点之间的独立气候和生态指标之间的关系，以测试巨型动物释放假说。将分析八个新湖点的过去植被组成（化石花粉）、火灾状况（沉积木炭）、巨型动物丰度（粪便中真菌孢子）和温度（有机地球化学）等指标。更广泛的影响包括对一名博士后研究科学家、一名研究生和几名本科生的指导和培训，以及扩大古生物学家、地理学家和生态学家之间的合作，以了解未来的环境变化。 所有数据将通过标准社区数据存储库公开提供。