Modeling carbon sequestration and timber production in a regional case study

Abstract

Forests make up large ecosystems and by the uptake of carbon dioxide can play an important role in mitigating the greenhouse effect. In this study, mitigation of carbon emissions through carbon uptake and storage in forest biomass and the use of forest biofuel for fossil fuel substitution were considered. The analysis was performed for a 3.2 million hectare region in northern Sweden. The objective was to maximize net present value for harvested timber, biofuel production and carbon sequestration. A carbon price for build-up of carbon storage and for emissions from harvested forest products was introduced to achieve an economic value for carbon sequestration. Forest development was simulated using an optimizing stand-level planning model, and the solution for the whole region was found using linear programming. A range of carbon prices was used to study the effect on harvest levels and carbon sequestration. At a zero carbon price, the mean annual harvest level was 5.4 million m 3 , the mean annual carbon sequestration in forest biomass was 1.48 million tonnes and the mean annual replacement of carbon from fossil fuel with forest biofuel was 61 000 tonnes. Increasing the carbon price led to decreasing harvest levels of timber and decreasing harvest levels of forest biofuel. Also, thinning activities decreased more than clear-cut activities when the carbon prices increased. The level of carbon sequestration was governed by the harvest level and the site productivity. This led to varying results for different parts of the region.

Forest carbon management and carbon trading: A review of Canadian forest options for climate change mitigation

“…In this example, crediting C in forests but not in wood products would seem to promote reduced harvest to store more C in forests at the expense of creating wood products. This point was demonstrated by Backéus et al (2006), who projected that an increased price for C would decrease harvest levels. Both Backéus et al (2006) and Colombo et al (2007) assumed current forest management and climate would prevail over the next century, while it appears inevitable that timber production and forest C will be effected by climate change over this period.…”

“…Management for timber and C credits, when C prices are high, may lead to decreased timber harvesting (Backéus et al 2006). When managing a forest for timber is less profitable than managing the same forest for conservation, "carbon investors will readily give away the potential financial returns from the timber investment to get low-price carbon credits" (Binkley et al 2002).…”

“…There is also a carbon-price link between using forests for C storage and forest fuel products (Backéus et al 2006). The expansion of the biofuels industry, including fuels from wood stocks, is anticipated to have substantial impacts on global C storage (Negra et al 2008).…”

“…Backéus et al (2006) showed that in Sweden, optimizing the net present value of forest operations discouraged harvest of forests for biofuel at higher C prices. They concluded that the greatest financial benefit came if C was left in the forest rather than by harvesting trees, collecting harvest residues, or thinning to obtain biomass for energy generation in place of oil.…”

“…They concluded that the greatest financial benefit came if C was left in the forest rather than by harvesting trees, collecting harvest residues, or thinning to obtain biomass for energy generation in place of oil. However, the conclusions made by Backéus et al (2006) are highly dependent on assumptions concerning decomposition rates, risk of natural disturbance, forest longevity, growth rates if not disturbed, and the type of fossil fuel being replaced. Thus, it is not necessarily straightforward to extrapolate these results from Sweden to Canada, or from one part of Canada to another.…”