The Impact of Late Quaternary Climate Change on Mammals Along an Elevational Gradient

晚第四纪气候变化对沿海拔梯度的哺乳动物的影响

• 批准号: 0344620
• 负责人: Felisa Smith
• 金额: $ 28.5万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0344620&HistoricalAwards=false
• 关键词: Impact; Late; Quaternary; Climate; Change

This study investigates the response of Neotoma (woodrats) to climatic change over the last 15,000 years along a severe elevational and environmental gradient. During the Pleistocene, lake Manly covered much of Death Valley; its abrupt draining in the mid-Holocene led to dramatic shifts in temperature and aridity. Today this area is the hottest and driest in the Western Hemisphere. By combining fieldwork, examination of museum specimens, and collection of paleofossils, this project will reconstruct the divergent evolutionary histories of animals from the Valley floor and along a nearby mountain gradient (-84 to 3400m). The investigators predict fundamental differences in the adaptive abilities of woodrat species related to elevation of the site and local microclimate. Predicted responses include: i) local extirpation when temperature thresholds are exceeded, ii) generation of novel adaptations, such as new life histories, and iii) morphological alterations, such as phenotypic changes in body size. The broader impacts of the work include the ability to characterize the relationship between the magnitude and rapidity of temperature shifts, the position in the geographic range, and the type of elucidated response. Such information about the responses of organisms to past climate change is invaluable for scientists studying anthropogenic warming. Moreover, the project will generate a high quality spatial and temporally resolved climate proxy that can be integrated with other paleodata. The characterization and interpretation of late Quaternary climates is a major research effort of governmental and geoscience agencies.

这项研究调查了Neotoma（林鼠）在过去15,000年沿着一个严重的海拔和环境梯度的气候变化的反应。在更新世，曼利湖覆盖了死亡谷的大部分地区;在全新世中期，它的突然排水导致了温度和干旱的急剧变化。今天，这个地区是西半球最热最干燥的地区。通过结合实地考察，博物馆标本的检查和古化石的收集，该项目将重建从谷底和沿着附近的山脉梯度（-84至3400米）的动物的不同进化历史。 研究人员预测，与海拔和当地小气候有关的林鼠物种的适应能力存在根本差异。预测响应包括：i）超过温度阈值时的局部根除，ii）新适应的产生，例如新的生活史，和iii）形态学改变，例如身体大小的表型变化。这项工作的更广泛的影响包括能够描述温度变化的幅度和速度之间的关系，在地理范围内的位置，以及阐明的反应类型。这些关于生物对过去气候变化的反应的信息对于研究人为变暖的科学家来说是非常宝贵的。此外，该项目将产生一个高质量的空间和时间分辨的气候代用品，可以与其他古数据相结合。晚第四纪气候的表征和解释是政府和地球科学机构的主要研究工作。