On “Estimating carbon budgets for U.S. ecosystems”

Abstract

In a recent Eos article, Potter et al. [2006] describe an approach to developing terrestrial biogenic carbon budgets at regional to continental scales. Their primary scaling tool is the Carnegie‐Ames‐Stanford (CASA) model, and spatially explicit inputs include climate as well as vegetation type and vegetation greenness (from satellite imagery). Net primary production (NPP) is simulated with a light use efficiency approach, and heterotrophic respiration (Rh) is based on turnover rates of several litter and soil carbon pools. This approach is well‐suited to characterizing the response of net ecosystem production (NEPNPP‐Rh, as in the work by Lovett et al. [2006]) to interannual variation in climate, but it is worth pointing out that it largely misses the effects of forest management on NEE These management effects have a significant influence on the absolute carbon exchange with the atmosphere, and on the kind of carbon accounting needed for carbon dioxide emissions inventories.