Quantifying responses to abrupt climate change in the Andes, South America: Empirical data and model synergies

在南美洲，80%以上的人口饮用水和农业依赖山区供水。这种水排放的主要来源储存在山脉冰川中，众所周知，由于气候变化，冰川正在以前所未有的速度消退。一旦非洲乞力马扎罗山顶端的冰川融化，世界上所有的热带冰川都将位于安第斯山脉(Kaser，1999)，主要在玻利维亚或秘鲁，这一事实突显了这个问题的严重性。因此，山地冰川是干旱、季节性旱地环境中的重要水源，但也是目前和未来气候变化的一个非常敏感的指标。这些冰川反过来又滋养着高地的安第斯湖泊和沼泽，使它们成为气候变化及其相关环境变化(包括土地利用)的非常敏感的储存库。因此，秘鲁安第斯山脉的安第斯湖泊和沼泽为探索气候变化的历史及其对环境的影响提供了机会，并为未来的情景提供了重要的古类比。安第斯山脉的一些考古、古气候和古环境研究已经强调了过去的气候波动与重大的文化扩张和崩溃之间的可能联系，以及经济和社会政治结构的相关变化，主要是在过去2000年里。然而，这种关系仍然不清楚，在这些数据在未来的情景中有用之前，需要进行更高的空间和时间分辨率研究，特别是在有关水资源供应和管理的问题上。因此，高地安第斯山脉环境是测试各种气候和环境指标的敏感性以及人类对气候变化反应的性质和时机的理想自然实验室。此外，高地安第斯山脉系统1000年来一直是人类社会的重要农业基础，S说，这使得它们对未来的粮食安全和对可持续农业用地的需求至关重要。目的：该项目旨在将同位素和古生态数据与定量模型相结合，以确定前哥伦布时代气候和环境变化对秘鲁安第斯山脉土地利用和人类占领的影响。在过去15年中，获得经验气候和环境重建数据的技术越来越多。我们现在能够收集时间综合的材料(湖心、泥炭、沼泽和洞穴沉积)，这些材料可以准确地测年，并包含一系列环境和气候标记和指纹。然而，到目前为止，这些代理在很大程度上是单独进行调查的，或者偶尔作为组件的组合进行调查。这项奖学金申请将汇集有机地球化学(脂肪、粪便和胆汁生物标记物)、古生态学(来自动物的非花粉孢子形态)、无机地球化学(重稳定同位素和轻稳定同位素)以及来自高地安第斯湖和沼泽系统的古代DNA的数据，以探索人类职业与农业之间的联系，以应对过去的气候变化。将在秘鲁的高地湖泊(奇隆和乌鲁班巴山谷)取两个新的岩心，分析上面的多代理信号，并将其添加到美国国家海洋和大气局古气候数据库(https://www.ncdc.noaa.gov/).)现有岩心材料的单一记录中这些环境和气候标志将与最新的气候模型结合使用，以提供有关关键气候和环境指标的预测。然后，将使用基于地理预测的模型(在ArcGIS ModelBuilder中构建)将所有数据组合在一起，以产生环境和气候敏感性的时间切片地理输出，这将有助于应对未来的气候变化。

In South America, more than 80% of the population is reliant on water supplies from mountainous areas for drinking water and agriculture. The main source of this water discharge is stored in mountain glaciers, which are known to be retreating at an unprecedented rate due to climate change. The severity of this problem is highlighted by the fact that once the glacier at the top of Mt Kilimanjaro in Africa has melted, all of the world's tropical glaciers will be located in the Andes (Kaser, 1999), mainly in Bolivia or Peru. Thus, mountain glaciers are important water sources in the dry, seasonal upland environments, but are also a very sensitive measure of present day and future climate change. These glaciers in turn feed upland Andean lakes and mires making them very sensitive repositories of climate change, and associated changes in the environment, including land-use. .Therefore, Andean lakes and mires in the Peruvian Andes provide an opportunity to explore the history of climate change and its impact on the environment, and to provide an important palaeo-analogue for future scenarios. A number of archaeological, palaeoclimatic and palaeoenvironmental studies in the Andes have already highlighted the possible connection between past climate fluctuations, and significant cultural expansion and collapse, and associated changes in economic and socio-political structures, mainly over the last 2000 years. However, the relationship remains unclear, and there is a need for much higher spatial and temporal resolution studies before these data are useful in future scenarios, especially with respect to issue surrounding water availability and management. Highland Andean environments are thus the ideal natural laboratory to test the sensitivity of various climate and environmental proxies, and the nature and timing of human responses to climate change. In addition, the upland Andean systems have been an important agricultural base for human communities for 1000's of years making them particularly important for the future where food security and demand for viable agricultural land are key.Aim: This project aims to integrate isotope and palaeoecological data with quantitative modelling to determine the impact of pre-Columbian climate and environmental change on land use and human occupation for the Peruvian Andes. In the last 15 years techniques for obtaining empirical climate and environmental reconstruction data has become increasingly available. We are now in a position to be able to collect time-integrated materials (lake cores, peat, mire and cave deposits) that can be dated accurately, and contain a range of environmental and climatic markers and fingerprints. However, until now these proxies have largely been investigated in isolation or occasionally as a combination of components. This studentship application will bring together data from organic geochemistry (lipid, faecal and bile biomarkers), palaeoecology (non-pollen palynomorphs from animals), inorganic geochemistry (heavy and light stable isotopes) and ancient DNA from upland Andean lake and mire systems to explore the connections between human occupation and agriculture in response to past climate changes. Two new sites will be cored in upland lakes from Peru (Chillón and Urubamba Valleys) and analysed for multi-proxy signals above and added to singular records from existing core material available on the NOAA palaeoclimate database (https://www.ncdc.noaa.gov/). These environmental and climatic markers will be used in conjunction with the latest climate models to offer predictions regarding key climate and environment indicators. A predictive geographical-based model (built in ArcGIS ModelBuilder) will then be used to combine all the data together to produce time-sliced geographical outputs of environmental and climate sensitivity which will be useful for coping with future climate change.