What controls the isotopic signature of terrestrial organic carbon? A biomarker study of the Paleocene and Eocene section in the Bighorn Basin (WY, USA)

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。近年来，地球气候正在以前所未有的速度和幅度变暖，对陆地生态和水文产生了深远的（但不容易预测的）后果。碳同位素特征是地质学家研究长时间尺度陆地环境变化的重要工具。然而，碳同位素特征可能变化很大，对现代植物的研究表明，环境和群落组成都可能受到同样重要的影响。虽然大气二氧化碳的长期碳同位素变化肯定会转化为古植物碳，进而转化为土壤碳，但调节植物生物量与二氧化碳之间碳同位素分馏以及其他输入（如微生物或风化碳）的生态生理差异（如系统发育、叶片习性、水分利用）也会转化为土壤碳。该基金支持的工作将评估环境与群落组成的相对重要性，作为控制比格霍恩盆地（WY，美国）古新世和始新世古土壤和陆地沉积物中陆地植物输入的碳同位素值和分子特征的主要机制，在短期（PETM）和更长期（始新世）全球变暖期间。

This award is funded under the American Recovery and Reinvestment Actof 2009 (Public Law 111-5). Earth's climate is warming at a pace and magnitude unprecedented in recent times, with profound (but not easilypredicted) consequences for terrestrial ecology and hydrology. Carbonisotopic signatures are an important tool for geologists studyingterrestrial environmental change on long time scales. However, carbonisotopic signatures can vary widely and work on modern plants reveals both environment and community composition can be equally significantinfluences. Although secular carbon isotope variations of atmospheric carbon dioxide are certainly transferred into ancient plant carbon, and thus soil carbon, so also are ecophysiological differences (e.g.,phylogeny, leaf habit, water use)that modulate carbon isotope fractionation between plant biomass and carbon dioxide and as well as carbon from other inputs such as microbes or weathered carbon. Worksupported by this grant will evaluate the relative importance of environment versus community composition as major mechanisms controlling carbon isotope values and molecular signatures of terrestrial plant inputs in the ancient soils and terrestrial sediments in the Paleoceneand Eocene of the Bighorn Basin (WY, USA) across both short term (PETM) and more protracted (Eocene) global warming.