Carbon sinks within a forest
TO ESTIMATE THE AMOUNT OF CARBON DIOXIDE EQUIVALENT emissions released by logging, this project is using the breakdown of carbon sinks in a forest as outlined in the BC-based study on the impact of harvest intensity on forest carbon stocks (2020) by Suzanne Simard et al. That study provided the relative fraction of carbon from several different, but interconnected, sinks in a forest that are disturbed by logging and result in the eventual premature release of carbon to the atmosphere (compared with leaving the forest undisturbed).
We reconstruct the live biomass that was killed in an area by working backwards from the volume of wood recorded by the ministry of forests' Harvest Billing System to find the total volume harvested from that area.
This HBS volume represents only a fraction of the total biomass killed by logging. Specifically, the volume recorded by the ministry is only a part of the "Live trees" (aboveground) category in Simard et al's breakdown.
To recontruct the forest, we use the ministry's volume for the merchantable portion of stems and then add the volume of branches, foliage, discarded tops, breakage, rejects and non-merchantable trees. The sum of these categories of live trees equals the "Live trees (aboveground)" in Simard's analysis. The table below shows our current best estimates for each of these categories.