Results were aggregated and summarized for 8 geographic units which included the three national parks (Glacier, Kootenay, Yoho) individually, all provincial parks and protected areas combined together selleck into one category (‘ProtArea’), as well as four Reference areas (Glacier_Ref, Kootenay_Ref, Yoho_Ref, and ProtArea_Ref). The Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) was used to estimate the C stocks and changes during the period 1970–2008 in annual time steps. CBM-CFS3 is a forest C dynamics model that operates at scales from individual stands to nations (Kurz et al., 2009). The model uses empirical yield functions to describe stand-level forest growth rates. It converts estimates of volume per hectare
into aboveground biomass components using a library of stand-level volume to biomass conversion equations (Boudewyn et al., 2007). Below-ground biomass in fine and coarse
roots is estimated from stand-level equations for softwood and hardwood species (Li et al., 2003). The model simulates dynamics of dead organic selleck kinase inhibitor matter and soil C in 11 pools, including standing dead trees, coarse woody debris, fine woody debris, litter and humified organic matter in the forest floor and mineral soil (Kurz et al., 2009). Here in this paper, we refer to all these dead organic matter and soil C pools collectively as DOM. The CBM-CFS3 accounts for continuous processes (growth, decomposition) that occur in all forest stands in all years, and disturbances that occur in some stands in some years. Disturbances represented in the model include
Methocarbamol fires, insects, and human activities such as clearcut, partial cut and salvage harvesting (Kurz et al., 2009). Disturbances affect the distribution and quantity of C in all pools and can transfer C to the atmosphere (e.g. in the case of fire) and to the forest product sector (e.g. in the case of harvesting). Disturbances can also affect stand age, and the post-disturbance yield trajectory. Following international reporting conventions, here we assumed that all C contained in wood harvested and removed from the forest is subject to instantaneous oxidation and release to the atmosphere. While it is understood that harvested wood products in use and in landfills store C for many years to decades (Apps et al., 1999 and Skog, 2008), tracking the processing steps and fate of C harvested from our study areas is beyond the scope of this study. Woody biomass, slash, and roots left on site after harvesting (or other disturbances) will decompose and the release of CO2 to the atmosphere in the years after the disturbance events is represented in the model. The CBM-CFS3 is used widely in Canada and internationally and numerous papers describe its application at various spatial scales and for various scientific questions. Recent national-scale applications in Canada are described in Stinson et al. (2011), and Metsaranta et al. (2010) and regional-scale applications in BC include Trofymow et al.