Doctoral Dissertation Improvement Award: Aridification and Environmental Change

博士论文改进奖：干旱化与环境变化

• 批准号: 1838393
• 负责人: Douglas Kennett
• 金额: $ 3.17万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1838393&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Improvement; Award; Aridification

The intrinsic and economic values of biodiversity make species extinction a significant societal concern. To conserve the existing variety of species, it is important to understand past and present drivers of biodiversity loss. Archaeology and paleoecology provide relevant, long term perspectives on interactions among humans, other organisms, and climate that contribute to extinctions. This project will answer several longstanding questions regarding how a drying climate and the early colonization of Madagascar by humans and associated introduced species may have contributed to past extinctions of large animals on the island. For example, to what extent did humans hunt the now extinct animals? Did introduced animals compete with now-extinct natives, and were introduced animals drought-tolerant relative to natives? Recognizing feedbacks among sources of regional change is a challenge, but this case study of datasets from Madagascar is broadly applicable to the study of past interactions among organisms in the face of aridification. Given the relevance of this research to present environmental concerns and the ongoing development of drought-related policy in arid southwest Madagascar, community and local government outreach is a project priority. This interdisciplinary work involves students and faculty at Malagasy universities, and the students trained through the field component of this research will gain skills applicable to data gathering and natural resource management.This research investigates some of the many ways in which the arrival of humans and introduced species in a novel environment may have contributed to past and ongoing biodiversity loss. The field component of this project focuses on the coast of southwest Madagascar. This region is ideal for studies of environmental changes associated with human activity, because humans and human-introduced animals (e.g. goats, pigs, cattle, dogs, cats, and rats) arrived on the island several thousand years ago, and the bones of extinct endemic animals (e.g. pygmy hippos, giant tortoises, elephant birds, and giant lemurs) are abundant along this coastline. Survey and excavation of a series of coastal ponds with traces of past human presence serve to recover the material record of past human activity and biodiversity loss. Radiocarbon dating of bone recovered from fieldwork and museum collections provides the chronological control that is necessary to infer past interactions among humans, other organisms, and environmental change. A series of chemical analyses of radiocarbon-dated bone protein is used to trace aspects of organisms' diets and environments through time. These analyses, coupled with a separately-funded effort to reconstruct the past climate of the region through the chemical analysis of ancient lake sediments, make it possible to examine potential synergies between past human activity and the changing climate that may have driven past extinctions on the island.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.

生物多样性的内在价值和经济价值使物种灭绝成为重要的社会问题。为了保护现有的物种多样性，了解过去和现在生物多样性丧失的驱动因素非常重要。考古学和古生态学为人类、其他生物和气候之间导致灭绝的相互作用提供了相关的长期视角。该项目将回答几个长期存在的问题，即干燥的气候以及人类和相关引进物种对马达加斯加的早期殖民可能如何导致了岛上大型动物的灭绝。例如，人类对现已灭绝的动物的捕猎程度如何？引入的动物是否会与现已灭绝的本地动物竞争，并且引入的动物相对于本地动物是否耐旱？认识区域变化来源之间的反馈是一项挑战，但马达加斯加数据集的案例研究广泛适用于研究干旱时期生物体之间过去的相互作用。鉴于这项研究与当前环境问题的相关性以及马达加斯加干旱西南部干旱相关政策的持续制定，社区和地方政府的外展活动是项目的优先事项。这项跨学科工作涉及马达加斯加大学的学生和教师，通过这项研究的实地培训的学生将获得适用于数据收集和自然资源管理的技能。这项研究调查了人类到来的多种方式中的一些，并介绍了新环境中的物种可能导致过去和现在的生物多样性丧失。该项目的现场部分重点关注马达加斯加西南部海岸。该地区非常适合研究与人类活动相关的环境变化，因为人类和人类引入的动物（例如山羊、猪、牛、狗、猫和老鼠）在几千年前抵达该岛，并且已经灭绝的骨头沿着海岸线，特有动物（例如侏儒河马、巨型陆龟、象鸟和巨型狐猴）非常丰富。对一系列带有过去人类存在痕迹的沿海池塘进行调查和挖掘，有助于恢复过去人类活动和生物多样性丧失的物质记录。对从田野工作和博物馆藏品中回收的骨骼进行放射性碳测年，提供了推断人类、其他生物和环境变化之间过去相互作用所必需的时间控制。对放射性碳测年骨蛋白进行一系列化学分析，用于追踪生物体饮食和环境随时间变化的各个方面。这些分析，再加上单独资助的一项工作，通过对古代湖泊沉积物的化学分析来重建该地区过去的气候，使得研究过去的人类活动与可能导致过去灭绝的气候变化之间的潜在协同作用成为可能。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。