Forest Investment Account (FIA) - Forest Science Program
FIA Project F090112

    Preliminary assessments of climate change impacts on the carbon balance of BCís forest ecosystems
Project lead: Spittlehouse, David (Ministry of Forests and Range)
Contributing Authors: Metsaranta, Juha M.; Dymond, Caren C.; Kurz, Werner A.; Spittlehouse, David L.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Canadaís forests play an important role in the global carbon cycle. Under the United Nations Framework Convention on Climate Change, Canada is required to report changes in forest carbon stocks and non-CO2 greenhouse gas emissions resulting from forest management and land-use change that has occurred since 1990. Climate change could alter the future productivity of Canadian forests and subject them to a more severe disturbance regime, including more frequent wind damage, greater drought stress, and more frequent and severe fire and insect disturbances. As a result, detailed assessments of the future carbon balance of Canadaís forests are required. Forecast increases in productivity may not be sufficient to counter the impacts of the forecast increases in the frequency and severity of disturbances (Kurz et al. 2007)

The Canadian Forest Service Carbon Accounting Team and the BC MoFR have cooperated over the past six years on determining the carbon balance of forests in BC using the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3 - Kurz et al. 1992, Kurz & Apps 1999, Kull et al. 2006). CBM-CFS3 simulates the dynamics of above-ground and below-ground forest biomass and dead organic matter. Disturbances due to harvesting, fire, and insects, as well as tree growth, death and decomposition are explicit components of the CBM-CFS3.

Climate change will impact the net ecosystem carbon balance by interacting with three groups of processes: (1) growth and mortality rates, (2) dead organic matter decomposition rates, and (3) disturbance regimes. Each of these three processes can either increase or decrease the rate of forest carbon uptake and release. We propose to evaluate methods for enabling CBM-CFS3 to incorporate the influence of climate change on these processes. We will do this using a combination of literature review, expert opinion, and an analysis that compares periodic stand level growth from permanent sample plots, annual growth obtained from tree-ring data, and regional climate data. This work will provide the basis for a preliminary assessment of the potential effects of climate change on the carbon balance of BCís forests over the next 50 years. The uncertainty in the climate response functions, future management actions, and projections of the future climate does not justify extending the projections further into the future. The sensitivity of the model to the assumptions underlying the climate response functions will also be evaluated.

Vulnerability studies of BCís forest and range resources are also required to inform model projections of the future forest carbon balance. For example, species suitability for an area under climate change will change and how and when management might respond is unknown. As a result, a full assessment of climate change impacts on the carbon balance cannot be completed in one year. This project will provide the framework for future analyses that also take into account future harvest rates, planting strategies, and other disturbances that will be defined over the next decade by other studies.

Kull, S.J., W.A. Kurz, G.J. Rampley, G.E. Banfield, R.K. Schivatcheva, and M.J. Apps. 2006. Operational-Scale Carbon Budget model of the Canadian Forest Sector (CBM-CFS3) Version 1.0: Userís Guide. Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta.
Kurz, W.A. and M.J. Apps. 1999. A 70-year retrospective analysis of carbon fluxes in the Canadian forest sector. Ecol. Appls. 9:526-547.
Kurz, W., Stinson, G. and Rampley, G. 2007 Could increased boreal forest ecosystem productivity offset carbon losses from increased disturbances? Phil. Trans. R. Soc. B 363. (doi:10.1098/rstb.2007.2198).


Annual report (0.1Mb)
Poster (1.4Mb)

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Updated August 16, 2010 

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