Evaluating the role of organic N uptake in carbon dynamics of boreal terrestrial ecosystems

Organic nitrogen (N), especially small molecular amino acid like glycine, aspartate or even some complex form of protein, is an important nitrogen supply to plants in boreal N limited ecosystems. To date, most studies have been focusing on amino acid transformation between soils and plants at site levels. A quantitative understanding of how much organic N will be taken up and its effects carbon cycling is still lacking. Here we present a model to consider this N feedback to carbon dynamics in northern ecosystems. Site-level carbon flux data are used to verify the model. We further feed the surface carbon fluxes of boreal ecosystems simulated with the new version of Terrestrial Ecosystem Model (TEM) and original TEM into a 3-D Atmospheric Transport Model (GEOS-CHEM) to examine how the organic N uptake will affect the atmospheric CO2 concentration profiles by comparing the model outputs with observational data, such as GlobalView CO2 concentrations data.