Darkwoods Project: Calculation of Carbon Stored in Standing Timber
DRAFT FOR DISCUSSION PURPOSES ONLY
Assumptions:
 Darkwoods property has a standing volume of 5,630,004 cubic metres
 Volume data refers to fresh merchantable stemwood
 Timber is mostly coniferous trees
 Conversion factor for conifer volume to dry weight of that volume is 0.37 t dw/m3
 Merchantable stemwood comprises 61% of the above-ground biomass, so the conversion factor to
estimate whole-tree (or above-ground) biomass from merchantable dry weight (dw) is 1.64 (i.e.,
1/0.61)
 To estimate total-tree (a-g + b-g) biomass from whole-tree (a-g only), multiply times 1.35
 To convert dry tree biomass to carbon, multiply times 0.5
In 2007, there is 5.630 x 106 m3 of timber:
 dry biomass: 5.630 x 106 m3 x 0.37 t dw/m3 = 2.083 x 106 t dw
 whole-tree biomass: 2.083 x 106 t x 1.64 = 3.416 x 106 t
 total-tree biomass: 3.416 x 106 t x 1.35 = 4.612 x 106 t
 carbon in total-tree biomass: 4.612 x 106 t x 0.5 = 2.306 x 106 t C
In 2024, assuming no catastrophic loss of tree biomass, there will be 7.003 x 106 m3 of timber:
 dry biomass: 7.003 x 106 m3 x 0.37 t dw/m3 = 2.591 x 106 t dw
 whole-tree biomass: 2.591 x 106 t x 1.64 = 4.249 x 106 t
 total-tree biomass: 4.249 x 106 t x 1.35 = 5.737 x 106 t
 carbon in total-tree biomass: 5.737 x 106 t x 0.5 = 2.868 x 106 t C
The difference in carbon storage between the 2007 and 2024 is:
 0.562 x 106 t C over 18 years
 or 31.2 x 103 t C/year
One tonne of carbon (t C) in forest biomass is equivalent to 3.67 tonnes of atmospheric carbon dioxide or
1 t C = 3.67 volume tonnes of CO2 (tCO2eq) sequestered. Therefore 31,200 tonnes of carbon increase
per year x 3.67 = 114,504 volume tonnes of CO2 equivalent sequestered annually.
Also note that:
 There would likely be successional increases in organic carbon stored in the forest floor, soil, and
large-woody debris. However, these increases cannot be determined without additional information.
 If the forest were to suffer a catastrophic loss of tree biomass because of a wildfire, windstorm, or
insect epidemic, then there would be a loss of tree-carbon.
References:
Freedman, B., F. Meth, and C. Hickman. 1992. Temperate forest as a carbon-storage reservoir for
carbon dioxide emitted from coal-fired generating stations. A case study for New Brunswick.
Forest Ecology and Management, 55: 15-29.
Freedman, B. and Keith, T. 1996. Planting trees for carbon credits. A discussion of context, issues,
feasibility, and environmental benefits, with particular attention to Canada. Environmental
Reviews, 4: 100-111.
Fleming, T.L. and B. Freedman. 1998. Conversion of natural, mixed-species forests to conifer
plantations: Implications for dead organic matter and carbon storage. Ecoscience, 5: 213-221.
Stinson, G. and B. Freedman. 2001. Potential for carbon sequestration in Canadian forests and
agroecosystems. Mitigation and Adaptation Strategies for Global Change (6): 1-23.
Dr. B. Freedman, on behalf of the Nature Conservancy of Canada
March 2, 2007