EAR-PF: Millennial scale environmental changes in Pleistocene Florida can inform the causes and effects of trophic downgrading after megaherbivore extinction

安吉丽娜·佩罗蒂博士已被授予NSF博士后奖学金，在布朗大学和威斯康星州大学开展研究和教育计划。该项目旨在揭示气候，植被，火灾，草食动物，和人类之间的联系，在最后一次冰期和随后的冰川消退在杜兰湖，佛罗里达。通过地球化学、木炭和花粉分析，这项研究将把过去的植被变化与食草动物、气候和火灾的变化紧密联系起来，这对目前通过重新引入控制放牧和火灾制度来恢复生态系统生物多样性和功能的努力有直接影响。该项目在新的和变革性的学习经验和外联领域产生了多方面的广泛影响，包括为大学考古学课程开发教学模块，以及通过公共图书馆讲座和科学节与当地社区接触。末次冰期末猛犸象和乳齿象等大型食草动物的灭绝可能导致了一连串的生态系统影响。为了将过去的植被变化记录与巨型食草动物活动和灭绝联系起来，佩罗蒂将重新访问杜兰湖，这是一个经典的地点，在过去的6万年里，这里有着完善的植被和水文变化记录。新的生态代理，如粪便栖息的真菌孢子和粪便和温度生物标志物将使新的调查之间的联系气候变化，大型草食动物的动态和植被周转。本研究将1）评估和比较大型草食动物种群丰度的不同指标记录的信号（即真菌孢子和粪便生物标志物）; 2）建立佛罗里达的地球化学生物标志物温度记录，并提供最后一次冰消期佛罗里达变暖的第一个量化估计; 3）调查冰川和冰消期气候变化对佛罗里达大型草食动物群落的影响; 4）综合多个代理分析气候、大型食草动物栖息地、火灾和人类到达对植被的相互影响。该奖项反映了NSF的法定使命，并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，被认为值得支持。

Dr. Angelina Perrotti has been granted a NSF EAR Postdoctoral fellowship to carry out research and education plans at Brown University and the University of Wisconsin. This project seeks to reveal linkages among climate, vegetation, fire, herbivory, and humans during the last glacial period and subsequent deglaciation at Lake Tulane, Florida. Through geochemical, charcoal, and pollen analyses, this research will closely link past vegetation changes with changes in herbivory, climate, and fire, which has direct implications for current efforts to restore ecosystem biodiversity and function through reintroduction of controlled grazing and fire regimes. This project has multiple broader impacts in the areas of new and transformational learning experiences and outreach, including the development of teaching modules for university-level archaeology courses and engagement with local communities through public library lectures and science festivals. The extinction of megaherbivores such as mammoths and mastodons at the end of the last glacial period may have resulted in a cascade of ecosystem effects. To link past records of vegetation change with megaherbivore activity and extinction, Perrotti will revisit Lake Tulane, a classic site with a well-established record of vegetation and hydrological changes over the last 60,000 years. New ecological proxies, such as dung-inhabiting fungal spores and fecal and temperature biomarkers will enable new investigations of the linkages among climate change, megaherbivore dynamics, and vegetation turnover. This research will 1) Assess and compare the signals recorded by different indicators of megaherbivore population abundances (i.e. fungal spores and fecal biomarkers); 2) Establish a geochemical biomarker temperature record for Florida and provide the first quantified estimates of Florida warming during the last deglaciation; 3) Investigate the effects of glacial and deglacial climate variability on megaherbivore communities in Florida; 4) Integrate multiple proxies to analyze the interacting influences of climate, megaherbivore extinctions, fire, and human arrival on vegetation.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.