Soil carbon and nitrogen interactions and biosphere-atmosphere exchange of nitrous oxide and methane

Abstract

Carbon (C) sequestration in terrestrial ecosystems and here specifically in soils is currently discussed as a potential strategy to contribute to reducing atmospheric carbon dioxide (CO2) concentrations. However, increases in soil C stocks may also have adverse effects on the exchange of greenhouse gases (GHGs) between terrestrial ecosystems and the atmosphere. In view of the unprecedented perturbation of the global nitrogen (N) cycle, increases in soil C stocks and the ongoing saturation of terrestrial ecosystems with reactive forms of N (Nr) may result in a stimulation of soil nitrous oxide (N2 O) emissions. These largely unexplored ecosystem C-N interactions and their importance for biosphere-atmosphere GHG exchange need to better understood to finally assess the climate benefits of C sequestration in soils.