Forest - Atmosphere Interaction at Howland Forest

The overall goal of the proposed work is to understand the various (and interacting) impacts of a changing climate on carbon cycling at the Howland AmeriFlux site, representative of an important component of the North American boreal forest. Our focus is on quantitatively partitioning respiration into aboveground and belowground processes and into autotrophic and heterotrophic processes to better constrain carbon cycle models. Whole-ecosystem flux measurements generally do a poor job of separating photosynthetic uptake from respiration and cannot constrain (or assign) respiration to the different sources within an ecosystem. This partitioning is difficult, but we will take advantage of new promising technologies. Such partitioning of fluxes into individual processes can provide powerful multiple constraints to carbon cycle models because of the different pool sizes, locations, and time scales for which these processes are important. By participating in data-model comparison activities such as the North American Carbon Program (NACP) site-level syntheses, and by carrying out our own data-model fusion and uncertainty studies, we will insure that data and insights from this work directly contribute to advancing carbon cycle science.