Terrestrial C sequestration at elevated CO2 and temperature: the role of dissolved organic N loss

We used a simple model of carbon–nitrogen (C–N) interactions in terrestrial ecosystems to examine the responses to elevated CO₂ and to elevated CO₂ plus warming in ecosystems that had the same total nitrogen loss but that differed in the ratio of dissolved organic nitrogen (DON) to dissolved inorganic nitrogen (DIN) loss. We postulate that DIN losses can be curtailed by higher N demand in response to elevated CO₂, but that DON losses cannot. We also examined simulations in which DON losses were held constant, were proportional to the amount of soil organic matter, were proportional to the soil C:N ratio, or were proportional to the rate of decomposition. We found that the mode of N loss made little difference to the short‐term (