Collaborative Research: The Ecological Context of Complex Society Emergence

古气候研究试图了解环境变化对人类社会的作用。考古遗迹为人类与环境的互动提供了其他来源所不能提供的长期视角。该项目将通过重建导致秘鲁南部一个山谷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对未来气候变化的影响、人类影响和社会对这种变化的反应进行建模。这项研究始于2012年在秘鲁南部钦查山谷的一处泛滥平原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，研究人员在一处2300年前的考古遗址附近的一块农田中挖掘时，发现了大约7000-1500年前的中期全新世期间距离海洋5公里处潮湿和沼泽条件的证据。这是相当出人意料的，因为考古学家和古气候专家曾假设该地区在人类占领之前就是开阔的沙漠。之前的科学共识是，大约3000年前，人们使用从流经山谷的根深蒂固的河流中抽取的运河灌溉了沙漠。其他工作发现了类似的水文(淹水)土壤模式，以及使用人工排水渠的证据。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年前郁郁葱葱的景观的证据，其中包括香茅、莎草和灯心草等植物。该项目的系统科学研究将证实、修改或否定古湿地的假说。该项目吸收了来自两所美国大学的学生，他们将与秘鲁的学生合作，从而增加跨境培训，并为未来的合作奠定基础。这些早期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。太平洋沙漠分水岭从智利延伸到加利福尼亚州，是当今人口非常密集的家园，为数千年来的人类提供了有利的生存地点。这些地区也是世界上最肥沃的农田之一。充分了解他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。为了正确了解植被、水、灌溉、地质和人类住区的错综复杂的历史，该项目将从秘鲁沿海整个钦查山谷具有代表性的狭长地带获取数据。将精心重建植被、地质和地貌历史。项目参与者将测量数千年来的地下水水位。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关联将揭示文化适应和环境变化之间的关系。被掩埋的考古遗址和运河将用探地雷达探测。在项目结束时，该项目将提供对太平洋一个关键分水岭流域人类环境历史的非常详细的了解。该奖项反映了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。

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.