Reconstructing Past Climates of the Amazon Basin from the Isotopic Analysis of Tropical Trees

从热带树木的同位素分析重建亚马逊河流域过去的气候

• 批准号: 0602329
• 负责人: Paul Baker
• 金额: $ 28万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0602329&HistoricalAwards=false
• 关键词: Reconstructing; Past; Climates; Amazon; Basin

The primary goal of this research is to reconstruct Amazon climate, primarily precipitation at annual resolution, for the past few centuries by constructing tree-ring width chronologies and analyzing the carbon and oxygen isotopic composition of cellulose from tropical trees that are known to produce annual rings. The research will be conducted, primarily, in the Amazon Basin and includes a Peruvian Andes altitudinal transect, Peruvian lowlands site, and two Brazilian lowlands sites.Previous research has shown that tree-ring width indices and oxygen isotope ratios are correlative with precipitation and that carbon isotopic ratios are related to water-use efficiency and precipitation. Further calibration of the isotopic and ring-width proxies, however, is needed. Likewise the ring-width chronology will be tested at each site by analyzing Carbon-14 in tree cellulose and comparing these values with the known Southern hemisphere atmospheric Carbon-14 signal. Broad goals of the research include a better understanding of climate variability from the geochemical examination of tropical tree rings, support of a post-doctoral scholar, and close international collaboration with colleagues in South America.

这项研究的主要目标是通过构建树木年轮宽度年表和分析已知产生年轮的热带树木纤维素的碳氧同位素组成，重建过去几个世纪的亚马逊气候，主要是年分辨率的降水。研究将主要在亚马逊盆地进行，包括秘鲁安第斯山脉的一个垂直样带、秘鲁低地地点和两个巴西低地地点。已有研究表明，树木年轮宽度指数和氧同位素比值与降水相关，碳同位素比值与水分利用效率和降水相关。然而，需要进一步校准同位素和环宽代用物。同样，通过分析树木纤维素中的碳-14，并将这些值与已知的南半球大气碳-14信号进行比较，将在每个地点测试环宽年表。这项研究的广泛目标包括通过对热带树木年轮的地球化学检查更好地了解气候变化，支持一名博士后学者，以及与南美洲同事密切的国际合作。