EAR PF: Examining paleoclimatic influences underlying Pleistocene-Holocene mammalian dietary ecology and trophic positioning in mainland Southeast Asia

Aliya Akhtar博士被授予NSF EAR博士后奖学金，在普林斯顿大学和威廉·帕特森大学开展研究和教育计划。随着全球气候、水文和人类土地利用的不断变化，对生物多样性和生态系统的全面影响是一个令人非常感兴趣的话题。今天，东南亚大陆是世界上最容易受到气候变化影响的地区之一。例如，即使季风降雨的强度和时间稍有变化，也会对生活在该地区的数十亿人产生重大影响，因为这会影响人类用水、农业和动物群落的供水。这项研究旨在通过观察地质记录，更好地了解这些方面在当今的相互作用，以及对未来生态系统可能产生的影响。东南亚大陆更新世末期(距今11700年)至全新世中期(距今5000年)是气候、自然生态系统和人类社会共同演化的关键时期。这一时期包括10,000年前最后一个大冰河时代∼的结束和一个充满活力和多变的亚洲季风。随之而来的气温和降水增加可能会影响到该地区的生物资源。此外，目前人类土地使用的变化可能导致新的农业和以生存为基础的做法(包括森林砍伐)造成的景观变化，这可能会进一步影响动物群落并影响区域气候和水文。综合、多指标记录的发展将有助于理解古环境对动物群食物网动态和人类行为进化的作用。阿赫塔尔博士还将通过暑期研究经验和高级论文和顶尖项目的指导，让来自历史上代表性较低的少数族裔的学生(特别是指定的西语裔服务机构威廉·帕特森大学的本科生)参与研究项目的各个方面。阿赫塔尔博士的研究议程将遵循三个主题。首先，探索新的地球化学替代物(包括钙、镁和锌的稳定同位素)在具有已知觅食行为的现代哺乳动物类群中的营养水平动态的应用。第二，利用这一多代理调查的结果，帮助指导对各种陆地动物群材料进行的类似研究的解释，包括来自东南亚的晚更新世和全新世化石牙齿组合。第三，进行痕量元素吸收实验，研究铀(U)和其他稀土元素(REE)的结合，希望完善扩散铀结合模式和U系列测年协议，以准确和精确地确定年龄。这三个节点共同构成了一个重要的基础，用于测试从晚更新世到全新世中期，区域和局部水气候变化对东南亚大型动物营养水平和食物网动态的影响，并对预测未来的生态系统行为具有深远的影响。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Dr. Alliya Akhtar has been awarded an NSF EAR Postdoctoral Fellowship to carry out research and education plans at Princeton University and William Paterson University. As global climate, hydrology and human land uses continue to change, the full extent of the impact on biodiversity and ecosystems is a topic of great interest. Today, mainland southeast Asia is one of the world’s most vulnerable regions to climate change. For example, even slight changes in the intensity and timing of the monsoon rainfall can significantly impact the billions of people who live in this region, by affecting water supplies for human use, agriculture, and faunal assemblages. This research aims to better understand the interplay between these aspects in the present day, and the possible impact on future ecosystems, by looking at the geological record. The end-Pleistocene (11,700 years ago) to mid-Holocene (5,000 years ago) period of mainland Southeast Asia represents a critical interval in the co-evolution of climate, natural ecosystems, and human societies. This period includes the termination of the last great ice age ∼ 10,000 years ago and a dynamic and variable Asian monsoon. Associated increases in temperature and precipitation likely influenced the biotic resources of the region. In addition, changes in land use by human populations at this time likely resulted in landscape changes from new agrarian and subsistence-based practices (including forest clearance) that could have further impacted faunal assemblages and affected regional climate and hydrology. The development of a comprehensive, multi-proxy record will aid in understanding the role of paleoenvironment on faunal food-web dynamics and evolution of human behavior. Dr. Akhtar will also involve students from historically underrepresented minority affiliations (especially undergraduates from William Paterson University, a designated Hispanic-serving institution) in every aspect of the research project through summer research experiences and mentorship through senior thesis and capstone projects. Dr. Akhtar’s research agenda will follow three themes. First, exploring the utility of novel geochemical proxies (including stable isotopes of calcium, magnesium and zinc) for trophic level dynamics in modern mammalian taxa with known foraging behaviors. Second, leveraging the results of this multi-proxy survey to help to guide the interpretation of similar studies conducted across a variety of terrestrial faunal materials, including late-Pleistocene and Holocene aged fossil tooth assemblages from southeast Asia. Third, conducting trace-element uptake experiments to study the incorporation of uranium (U) and other rare earth elements (REEs) in hopes to refine models of diffusive uranium incorporation and U-series dating protocols for accurate and precise age determination. Together, these three nodes constitute an important foundation for testing the impact of changing regional and local hydroclimate on megafaunal trophic level and food web dynamics in southeast Asian from the Late Pleistocene to mid-Holocene, and have profound implications for projecting ecosystem behavior in the future.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.