Collaborative Research: Assessing climate-biosphere linkages using Late Holocene records of climate variability and vegetation dynamics from the Brazilian Amazon and Savanna

合作研究：利用巴西亚马逊和稀树草原的全新世晚期气候变化和植被动态记录评估气候与生物圈的联系

• 批准号: 1912100
• 负责人: Daniel Breecker
• 金额: $ 18.01万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1912100&HistoricalAwards=false
• 关键词: Collaborative; Research; Assessing; climate; biosphere; Collaborative; Research; Assessing; climate; biosphere

This collaborative project aims to investigate the role of changes in the South American Summer Monsoon (SASM) intensity on forest-savanna biome shifts that occurred during the Late Holocene. Development of paleoclimate records from in and near the core of the monsoon region enables an assessment of the strength of the paleo-monsoon signal across the region.The researchers look to generate independent, yet co-located, records of past climate (speleothems) and vegetation (soil profiles) dynamics from the Brazilian Amazon and Cerrado (savanna), for which existing records are absent. Paleoclimate and ecological interpretations will be validated using cave monitoring and proxy system modeling.The researchers intend to evaluate the following questions: i) Do speleothem delta 18-Oxygen values reflect variations in SASM intensity, ii) Do variations in SASM intensity drive corresponding variation in local moisture conditions, iii) What was the nature and driver of Late Holocene variability in SASM intensity and local moisture conditions, and iv) how sensitive were biomes in vegetative transition zones to variability in SASM intensity and local moisture conditions. The project involves the monitoring of modern cave environments to evaluate speleothem delta 18-Oxygen values as a proxy of SASM intensity and speleothem trace element concentrations and Strontium isotope compositions as a proxy of local moisture conditions. The research will extend existing speleothem delta 18-Oxygen records of the last millennium from the Amazon and Cerrado further back in time and develop corresponding records of speleothem trace element and 87- Strontium /86-Strontium and soil organic matter delta 13-Carbon to assess the co-variability between regional monsoon intensity, local moisture conditions, and biome shifts.The project helps promote greater understanding of the SASM and strong collaboration with Brazilian scientists. The SASM is the most important source of rainfall to the region with great socio-economic and environmental relevance, including defining current ecosystem distribution and stability, hydroelectric production, and agriculture.

该协作项目旨在调查南美夏季季风（SASM）强度变化对全新世纪晚期发生的森林 - 萨瓦纳生物群落转变的作用。 从季风区域内外开发古气候记录的开发，可以评估整个地区的古季风信号的强度。研究人员希望产生与巴西亚马逊和塞拉多（Caverado）的独立，但共同置于过去气候（Speleothems）和植被（Speleothems）的记录（Speleothems）和植被（土壤概况）的动态，这些记录是现有记录的，这些记录是现有记录的，这些记录是不考虑的。 Paleoclimate and ecological interpretations will be validated using cave monitoring and proxy system modeling.The researchers intend to evaluate the following questions: i) Do speleothem delta 18-Oxygen values reflect variations in SASM intensity, ii) Do variations in SASM intensity drive corresponding variation in local moisture conditions, iii) What was the nature and driver of Late Holocene variability in SASM intensity and local moisture conditions, and iv) how敏感的是营养过渡区中的生物群落，可对过程强度和局部水分条件的变异性。该项目涉及对现代洞穴环境的监测，以评估Speleothem Delta 18-氧值，作为萨尔斯强度和Speleothem痕量元素浓度的代表，以及畸形同位素组成的代理，作为局部水分条件的代理。 这项研究将扩大来自亚马逊和塞拉多的上一个千年的现有Speleothem Delta 18-Oxygen记录，并在时间上更及时地延伸，并制定Speleothem Trace Element的相应记录，以及87-延伸 /86-斜角 /86层和土壤有机物三角洲13-碳，以更大的良好状态和局部湿度的潮流，并促进潮湿，并促进尼斯州潮湿，并促进潮湿，并促进SSO湿度，并促进SSO湿度，并促进SSO湿度，并促进SSO潮气，并促进SSO湿度，并促进SSO潮流，并促进SSO潮流，并促进SSO潮流，并促进SSO潮流，并促进SSO潮流的合作。巴西科学家。 SASM是该地区最重要的降雨来源，具有很大的社会经济和环境相关性，包括定义当前的生态系统分布和稳定性，水力发电生产和农业。