Human Response To El Nino-Driven Environmental Change

气候的极端变化是全球关注的一个话题。犹他大学的杰克·布劳顿（Jack Broughton）和琼·科尔特雷恩（Joan Coltrain）将进行一项研究，研究墨西哥下加利福尼亚州北部在过去1.1万年中厄尔尼诺Niño事件的强度和频率变化是如何影响海洋和陆地鱼类、鸟类和哺乳动物的。他们的研究还将调查过去的人们如何应对不同动物资源可用性的变化。这项研究将提供新的数据集，据此预测在一系列预测的厄尔尼诺Niño-related变化情景下未来动物种群的变化，从而支持当前和未来东太平洋海洋和陆地动物的管理。该项目还将揭示人类如何应对过去的厄尔尼诺Niño事件，并深入了解未来的厄尔尼诺Niño事件对发展中国家沿海社会的影响。虽然古代厄尔尼诺Niño事件对过去人类社会和动物的影响已在个别个案中得到记录，但关于厄尔尼诺Niño变化对动物资源影响的连续、高分辨率、千年尺度的记录，以及由此导致的人类对北美景观利用的变化，尚未得到记录。在过去的11000年里，人类和猛禽（鹰、鹰、猫头鹰）占据了一个岩石避难所（Abrigo de los Escorpiones），距离墨西哥下加利福尼亚州北部太平洋海岸约100米，这个项目将从大量的动物骨骼和人工制品中产生这样的记录。目前存档的动物骨骼收集包括海洋和陆地物种，代表了北美太平洋沿岸动物种群基于气候变化的最大，分层良好，连续的记录之一。丰富的文物和特征记录（例如，火炉，海洋贝壳层）证明了人类大量但间歇性地使用避难所。该项目将确定人们是否在高厄尔尼诺Niño频率期间放弃了沿海地区。这种时期的特点是海面温度升高，破坏了海洋生态系统，降水增加，提高了内陆栖息地的生产力。这项研究将涉及：(1)从物种层面对动物骨骼进行鉴定；(2)对大量骨骼样本进行放射性碳定年，以建立沉积物的时间线和年代学；(3)通过人工制品计数和人类对动物骨骼造成损害的证据（如石器切割痕迹、燃烧），建立人类对该遗址的职业强度记录；(4)对骨骼和贝壳进行稳定同位素分析，以提供过去11000年来El Niño变化的信息。(5)统计分析，确定过去El Niño的变化与当地动物和人类种群的变化之间的相关性。

Extreme variation in climate is a topic of concern across the globe. Jack Broughton and Joan Coltrain, of the University of Utah, will undertake research to study how variation in the intensity and frequency of El Niño events in northern Baja California, Mexico over the past 11,000 years influenced marine and terrestrial fish, birds, and mammals. Their research will also investigate how past peoples responded to changes in the availability of different animal resources. This research will provide novel data sets from which to anticipate change in future animal populations under a range of forecasted El Niño-related variation scenarios and thus support current and future management of marine and terrestrial animals of the eastern Pacific. The project will also reveal how human populations responded to past El Niño and provide insight into the impact of future El Niño events on coastal societies in developing countries. Although the impacts of ancient El Niño events on past human societies and animals have been documented in specific isolated cases, continuous, high-resolution, millennial-scale records of the impact of El Niño variation on animal resources and the resulting changes in the human use of North American landscapes have yet to be documented. This project will generate just such a record from a massive collection of animal bones and artifacts that was deposited over the past 11,000 years by people and raptors (hawks, eagles, owls) that occupied a rock shelter site (Abrigo de los Escorpiones) located about 100 m from the Pacific coast of northern Baja California, Mexico. The currently archived animal bone collection includes both marine and terrestrial species and represents one of the largest, well-stratified, continuous, records of climate-based changes in animal populations on the Pacific coast of North America. A rich record of artifacts and features (e.g., fire hearths, marine shell layers) attest to a substantial but intermittent human use of the shelter. The project will determine whether people abandoned the coastal site during periods with high El Niño frequencies. Such times are characterized by both warm sea-surface temperatures that disrupt marine ecosystems and increased precipitation that enhances the productivity of inland habitats. The study will involve: (1) identification of the animal bones to the species level, (2) radiocarbon dating of a large sample of the bones to establish a time-line and chronology for the deposits, (3) establishing a record of human occupational intensity of the site through artifact counts and evidence of human-caused damage on animal bones (e.g., stone tool cut marks, burning), (4) stable isotope analysis of both bones and shells to provide information on El Niño variation over the past 11,000 years, and (5) statistical analysis to determine correlations between variation in past El Niño and change in local animal and human populations.