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

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热带树木纤维素的碳和氧同位素组成来重建过去几个世纪的亚马逊气候，主要是年分辨率的降雨量。这项研究将主要在亚马逊盆地进行，包括秘鲁安第斯山脉垂直样带、秘鲁低地站点和两个巴西低地站点。先前的研究表明，树木年轮宽度指数和氧同位素比率与降水量相关，碳同位素比率与水分利用效率和降水量有关。然而，还需要进一步校准同位素和环宽度的替代物。同样，将在每个地点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信号进行比较来测试年轮宽度。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，以及与南美洲的同事进行密切的国际合作。

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.