Modeling the Impacts of Disturbances on Carbon Dynamics Over Large Regions
The carbon balance of forest ecosystems is fundamentally linked to patterns of disturbance and recovery. Major disturbances entail either a rapid release of biomass carbon to the atmosphere (e.g. combustion), or a large transfer of biomass from live vegetation to dead material that either decomposes over a period of years (e.g. woody debris), or removed from the forest (e.g. wood products). Abrupt forest disturbances (e.g. fire, windstorms, land use) that generate gaps >0.001 km2 have been shown to impact roughly 0.4-0.7 million km2 y-1 globally. At the same time, due to the relatively slow timescale of recovery, much of the landscape is in some stage of recovery from prior disturbances, gaining carbon. The impact of stochastic disturbances on forest ecosystems, integrated over large areas and relatively long times scales (decades), is generally thought to be small, based on the equilibrium land-atmosphere carbon balance. However, forest disturbance rates may not be stationary, i.e., may not fluctuate within a constant range of variability, due to climate change, population growth and changing land-use and resource demands, and this has consequences for forest and atmospheric carbon balance, climate feedbacks, and policies aiming to achieve particular atmospheric CO2 concentration targets. Here we briefly review progress and challenges for incorporating disturbances in models, present findings from large-scale simulations of forest disturbance from hurricanes and fires, and identify emerging strategies and data needs for projecting the impacts of disturbances on carbon dynamics over large regions.
Fall Meeting, American Geophysical Union (AGU)
American Geophysical Union Publications
Hurtt, G. et al. (2011), Modeling the Impacts of Disturbances on Carbon Dynamics Over Large Regions, Abstract B21J-02 presented at 2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.