Soil CO2 flux in response to elevated atmospheric CO2 and nitrogen fertilization: patterns and methods
The evolution of carbon dioxide (CO2) from soils is due to the metabolic activity of roots, mycorrhizae, and soil micro- and macro-organisms. Although precise estimates of carbon (C) recycled to the atmosphere from belowground sources are unavailable, Musselman and Fox (1991) propose that the belowground contribution exceeds 100 Pg y-1 globally. This represents a major component of C flux in the global C cycle. Belowground C cycling processes and subsequent soil CO2 fluxes are equally important at ecosystem scales; however, we have limited knowledge of the magnitude of fluxes within and across ecosystems. Increased knowledge of the magnitude of C fluxes, as well as the factors which regulated these fluxes is critical for understanding ecosystem C cycling and potential responses to factors such as climatic change. In this study, we quantified soil CO2 flux from soils growing ponderosa pine (Pinus ponderosa L.) Under conditions of elevated atmospheric CO2 and soil nitrogen (N).