Graphs a and b describe how changes in autotrophic respiration (Ra) and gross primary production (GPP) contribute to age-related decline in forest net primary production (NPP). For additional information, see Barnes et al. (1998) and Ryan et al. (2004) for (a) and Ryan, Binkley, and Fownes (1997) and Gower, McMurtrie, and Murty (1996) for (b).
Credit or Source: Office of Biological and Environmental Research of the U.S. Department of Energy Office of Science. science.energy.gov/ber/
U.S. DOE. 2008. Carbon Cycling and Biosequestration: Report from the March 2008 Workshop, DOE/SC-108, U.S. Department of Energy Office of Science. (p. 72) (website)