COLLABORATIVE RESEARCH: HOW DID THE GRASSLAND BIOME EVOLVE IN SOUTH AMERICA?: INTEGRATING CENOZOIC CLIMATE, FLORAL AND FAUNAL RECORDS FROM PATAGONIA, ARGENTINA

合作研究：南美洲的草原生物群落是如何演变的？：整合阿根廷巴塔哥尼亚的新生代气候、花卉和动物记录

• 批准号: 0819910
• 负责人: Caroline Stromberg
• 金额: $ 14.96万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0819910&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; HOW; DID; GRASSLAND

COLLABORATIVE RESEARCH: HOW DID THE GRASSLAND BIOME EVOLVE IN SOUTH AMERICA?: INTEGRATING CENOZOIC CLIMATE, FLORAL AND FAUNAL RECORDS FROM PATAGONIA, ARGENTINASTROMBERG, KOHN AND MADDEN PISGrasslands, which today form ~1/4 of Earth?s vegetative cover, are thought to have developed earlier in South America than on other continents, based on floral, faunal, and sedimentological evidence at Gran Barranca, Argentina, and nearby. However, the timing and rate of change remain unclear, as well as causal mechanisms. We will determine the timing and nature of climatic, vegetational, and faunal events related to the evolution of Earth?s earliest grassland ecosystems in southern Argentina by integrating floral, stable isotopic, and faunal data through the long, well-dated, and nearly continuous sedimentological record at Gran Barranca (~42.0 to ~18.5 Ma). We will focus on evaluating whether: (1) The rise to dominance of open-habitat grasses in South America occurred in parallel with their appearance, (2) An increase in openness of habitats occurred in parallel with the rise to ecological dominance of open-habitat grasses, (3) Changes in vegetation were correlated with climate change, and (4) Hypsodonty in South American mammalian herbivores responded rapidly to the spread of open, grass-dominated habitats. Fossil phytoliths (plant silica) will be analyzed to provide detailed, continuous floral records of grasses as well as other climate- or ecology-sensitive plant groups (e.g., palms, sedges). Fossil teeth will be analyzed for stable isotope compositions, focusing on bulk d13C values and isotopic zoning of d13C and 18O values. Together with phytolith assemblage data and sedimentology, this isotopic information will be used to infer changes in habitat openness, aridity, and seasonality in terms of temperature and precipitation. Comparison with records of faunal community composition and functional morphology will elucidate the patterns of grassland expansion and faunal responses. Our data will additionally help answer the following two questions: (1) How does the timing and rate of climate change in Argentina compare with the marine record? (2) How do patterns of fauna-flora-climate evolution in South America compare with putatively similar changes that occurred later, e.g., in central North America? The proposed project incorporates several avenues for disseminating the research to the public through the Burke Museum, including an in-museum exhibit, materials for traveling study kits on the evolution of grasslands, and development of a phytolith database with images accessible on-line through the Museum's website.

合作研究：南美草原生物群落如何发展？阿根廷和附近。 但是，变化的时机和变化率尚不清楚，以及因果机制。我们将通过整合长期，良好的日期和几乎连续的Satimenticological Record在Gran Barranca（〜42.0至〜18.5 Ma）中整合花卉，稳定的同位素和动物学数据，从而确定与地球最早的草地生态系统发展有关的气候，植被和动物事件的时机和性质。我们将专注于评估：（1）南美开放式草的占主导地位是否与它们的外观同行发生，（2）栖息地的开放性增加与开放式草的生态占主导地位并行，（3）植被的变化与气候变化相关，并与气候变化相关，以及（4）与南美乳房相关的，（4）与南美乳房相关联，（4）与南美乳房的相关性，（4）与南美的乳房相关。草为主的栖息地。将分析化石植物石（植物二氧化硅），以提供详细的，连续的草记录以及其他对气候或生态敏感的植物群（例如，Palms，Sedgus）。化石牙齿将分析稳定的同位素组成，重点是散装D13C值和D13C和18O值的同位素分区。连同植物岩的组合数据和沉积学一起，该同位素信息将用于在温度和降水方面推断栖息地开放，干旱和季节性的变化。与动物群落组成和功能形态的记录进行比较将阐明草原扩张和动物反应的模式。我们的数据还将帮助回答以下两个问题：（1）阿根廷气候变化的时间和气候变化与海洋记录相比如何？ （2）南美的动物群气候进化的模式与以后发生的预定的变化相比，例如在北美中部？拟议的项目结合了通过伯克博物馆（Burke Museum）向公众传播研究的几种途径，包括一场杂乱无章的展览，用于草原演化的旅行学习套件的材料以及开发植物数据库，并通过博物馆网站上的网络上访问图像。