Intended to serve as a guide for forest professionals, a report issued following the 2017 wildfires details the many changes resulting from the wildfires.
The document, titled Post-Natural Disturbance Forest Retention Guidance by authors Diane Nicholls Chief Forester, Dave Peterson and Tom Ethier, was released Jan. 19 to provide guidance for forest professionals who will plan and implement retention strategies in areas that have experienced extensive natural disturbances.
When planning retention during salvage logging the authors list six points that should be contemplated in order of priority. The first four relate to human safety and existing infrastructure, ecosystem values related to water quality and wildlife habitat, impacts on environmental and societal values and adaptation of forests to improve resilience to climate change.
The last two points concern shifting logging from un-damaged stands to damaged stands wherever possible and recovering value from the burnt timber before the wood quality deteriorates.
Using post fire satellite images, maps and reports as well as field checks, the authors show how the 2017 wildfires impacted the four Interior Timber Supply Areas (TSAs) of Quesnel, Williams Lake, 100 Mile and Kamloops. Table 2 shows that a total of 11.3 million cubic metres of timber was killed in the timber supply area of the Williams Lake TSA. It was estimated that the wildfires consumed a total of 8.15 million cubic metres of live timber and 3.2 million cubic metres of dead timber (previously killed by the mountain pine beetle). In order to see how the dead timber might impact the TSAs it is important to review the Allowable Annual Cut (AAC) determinations.
In his 2015 AAC determination for the Williams Lake TSA, Chief Forester Dave Peterson describes how his determination of three million cubic metres for a 10-year period is derived from a review of risk factors, current management practices and socio-economic objectives of the Crown. He then outlines the constraints associated with his determination.
The AAC includes a maximum of one and a half million cubic metres per year for live trees which also leaves half of the harvest for salvaging dead trees killed by the mountain pine beetle and other agents. He goes on to say that non-pine leading stands contribute a maximum of .88 million cubic metres and the remaining live component will come from the live volume of beetle-killed pine leading stands.
In order to meet priorities five and six above if industry could shift the majority of the three million AAC to the salvaged timber, the 11 million cubic metres of fire-killed timber could be harvested in a little over three years.
Since some facilities like the plywood plant can’t use burned logs and using some mill capacity for the ongoing harvesting of fir bark beetle timber and the potential harvest of urban wildland interfaces a more realistic salvage rate might be around two to two and a half million cubic metres per year.
This lower harvest rate would mean the salvage logging would be finished in about five years which turns out to be the optimistic shelf life of both burned logs and probably the unburned dead pine. The 2018 report has a more conservative shelf life of two to three years for the salvage wood.
With the uncertainty about how much salvage timber might not be available due to retention concerns described in priorities one to four above along with variable log shelf life and market uncertainties the chief forester will no doubt want to revisit the AAC assumptions in each TSA and make the necessary adjustments prior to end of the 10-year terms.
Jim Hilton is retired professional argologist and forester from the Cariboo Chilcotin.