Development of the Relaxed Eddy Accumulation Technique and Stable Isotope Analysis for Studies of Ecosystem CO2 Exchange - A One Year Scoping Proposal

蒙森9814507 将进行研究，以开发一种捕捉森林树冠上方气流的新技术。气流将被捕获，这样我们就可以准确地分析二氧化碳分子中碳和氧的稳定同位素。不同同位素的相对分数将使我们能够分离和研究森林生态系统中土壤呼吸和光合作用的大小。反过来，这些研究将使我们能够确定有多少来自大气的二氧化碳正在森林中积累（即，光合作用减去呼吸作用），以及未来气候变化是否会通过刺激呼吸作用而不是光合作用来影响这种积累。在本提案中，PI将仅测试和开发该技术。这笔资金将用于支持田纳西州西部橡树山核桃林一年中不同时间的三项活动。未来的努力将旨在将该技术应用于不同类型的生态系统。有了这项技术，PI将能够更好地评估森林在全球碳平衡中的作用。

Monson 9814507 Studies will be conducted to develop a new technique for capturing air drafts above a forest canopy. The air drafts will be captured in such a way that we can accurately analyze the stable isotopes of carbon and oxygen in carbon dioxide molecules. The relative fractions of the different isotopes will allow us to separate and study the magnitude of soil respiration and photosynthesis within the forest ecosystem. These studies, in turn, will allow us to determine how much carbon dioxide from the atmosphere is being accumulated in the forest (i.e., the photosynthesis minus respiration), and whether future changes in climate will affect this accumulation by stimulating respiration more than photosynthesis. In this proposal, the PIs will only test and develop the technique. The funds will be used to support three campaigns at different times of the year in an oak-hickory forest in western Tennessee. Future efforts will be aimed at applying the technique to different types of ecosystems. With this technique, the PIs will be able to better assess the role of forests in the global carbon balance.