Collaborative Research: The Ecological Context of Complex Society Emergence

古气候研究旨在了解环境变化对人类社会的作用。考古遗迹提供了从其他来源无法获得的人类与环境相互作用的长期视角。该项目将通过重建秘鲁南部山谷9000年植被历史的文化和环境因素，为这一跨学科科学领域做出贡献。这些信息将使科学家能够模拟未来气候变化的影响、人类的影响以及对这种变化的社会反应。这项研究始于2012年在秘鲁南部钦查河谷洪泛区进行考古发掘时的一次偶然发现。为了更好地评估史前农业实践，研究人员在一个2300年历史的考古遗址附近的一个农场进行挖掘时，发现了大约7000 -1500年前全新世中期距离海洋5公里处潮湿和沼泽环境的证据。这是相当出乎意料的，因为考古学家和古气候专家一直认为，在人类占领之前，该地区是一片开阔的沙漠。此前的科学共识是，大约3000年前，人们利用从山谷中根深蒂固的河流中抽出的运河灌溉沙漠。进一步的研究发现了类似的水态（浸水）土壤模式和人工排水渠使用的证据。对古代种子、花粉、植物微化石和硅藻（藻类化石）的分析证实了9000年前繁茂景观的证据，其中包括香蒲、莎草和灯心草等植物。本项目系统的科学研究将证实、修改或否定古湿地假说。该项目包括来自两所美国大学的学生，他们将与秘鲁的学生一起工作，从而增加跨境培训并播种未来的合作。这些早期的职业研究人员将学习先进的实验室技术来重建过去的环境，包括最先进的探地雷达技术和考古方法。从智利延伸到加利福尼亚，太平洋沙漠流域是今天人口非常密集的家园，并为数千年来的生活提供了有利的场所。这些地区也是世界上最富饶的农业用地之一。充分了解它们的环境和文化历史是至关重要的，尤其是因为淡水是人口增长和农业生产力的限制因素。为了正确地了解植被、水、灌溉、地质和人类住区的复杂历史，该项目将从秘鲁沿海整个钦查山谷的代表性土地上获取数据。植被、地质和地貌历史将被精心重建。项目参与者将测量数千年来的地下水位。文化和环境记录与厄尔尼诺事件、海啸、构造事件和其他自然过程的相关性将揭示文化适应与环境变化之间的关系。将利用探地雷达探测埋藏的考古遗址和运河。最后，该项目将提供一个非常详细的了解一个关键的太平洋流域排水的人类环境历史。该奖项反映了美国国家科学基金会的法定使命，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。

Paleoclimate research seeks to understand the role of environmental change on human society. Archaeological remains provide a long-term perspective on human-environment interaction not available from other sources. This project will contribute to this interdisciplinary field of science by reconstructing the cultural and environmental factors responsible for a 9000-year vegetation history of a valley in southern Peru. This information will allow scientists to model the effects of future climate change, human impact, and social responses to that change. This research began with a chance finding in 2012 during archaeological excavations in a floodplain in the Chincha valley of southern Peru. While excavating in a farm field near a 2300-year-old archaeological site to better assess prehistoric agricultural practices, researchers found evidence of wet and marshy conditions five kilometers from the ocean during the middle Holocene circa 7000 -1500 years ago. This was quite unexpected because archaeologists and paleo-climate specialists had assumed the area to have been open desert prior to human occupation. Previous scientific consensus was that the desert was irrigated around 3000 years ago by people using canals drawn from the deeply entrenched rivers that course through the valley. Additional work found similar patterns of hydromorphic (waterlogged) soils and evidence of the use of artificial drainage canals. Analyses of ancient seeds, pollen, plant microfossils, and diatoms (fossil algae) confirmed evidence of a lush landscape back to 9000 years ago that included plants such as cattails, sedges, and rushes. This project's systematic scientific research will confirm, modify, or reject the hypothesis of a paleo-wetland. The project incorporates students from two US universities who will work with students in Peru, thereby increasing cross-border training and seeding future collaboration. These early career researchers will learn advanced laboratory techniques to reconstruct past environments, including state-of -the- art techniques in ground-penetrating radar and archaeological methods. Stretching from Chile to California, the Pacific desert watershed is home to very dense human populations today and has provided favored locations to live for millennia. These areas are also some of the richest agricultural lands in the world. A full appreciation of their environmental and cultural histories is vital, not least because fresh water is the limiting factor in population growth and agricultural productivity. To properly understand the intricate history of vegetation, water, irrigation, geology, and human settlement, this project will obtain data from a representative swath of land in the entire Chincha Valley of coastal Peru. The vegetation, geological, and geomorphological history will be meticulously reconstructed. Project participants will measure the ground water levels over millennia. Correlations of cultural and environmental records with El Nino events, tsunamis, tectonic events, and other natural processes will shed light on the relationship between cultural adaptations and environmental change. Buried archeological sites and canals will be detected with ground-penetrating radar. At its conclusion, the project will provide a highly detailed understanding of the human-environment history of a key Pacific watershed drainage.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.