Forest residues (cull piles) burned each year in BC is equal to the burning of 20 million barrels of oil.
I estimated the barrels of oil from a forest residue estimate of 10 million oven dry tonnes per year from the February 2014 report by the Pacific Institute for Climate Change.
Based on some other sources that I have used to estimate the biomass in the logging cull piles I think this is a conservative estimate. For the purposes of this article it is a good place to start. My goal of this article and others to follow will be to encourage the government to phase out the burning of this material similar to the phasing out of the burning of mill residue in the old bee hive burners.
During my research on this topic I have heard a wide variety of views regarding the reasons that we continue to burn the cull piles. Some of the reasons include fire hazard reduction, tree planting concerns and because that is how we have always done it.
As is the case in many forest issues it will be necessary to look at the diversity of sites in order to look at options for reducing and eventually eliminating burning cull piles where ever possible.
In general we should leave the maximum amount of coarse woody debris after logging as long as we can still achieve a stocked stand through natural regeneration or planting. The addition of woody material is generally a positive thing especially on the drier pine sites in the Chilcotin.
The value of adding woody debris following logging is also beneficial on more productive sites that have experienced catastrophic fire damage.
Support for this approach is found in a 2012 paper by a local forester.
The author describes a small trial involving the redistribution of coarse woody debris using a grapple skidder when the skidding and processing operations occurred in close succession. The increased silviculture success and reduced debris handling costs resulted in an overall operational cost saving of $1.62 per cubic meter. A conclusion of the trial was that the overall ecological benefit and positive financial return were realized by the redistribution of coarse woody debris on blocks that have experienced catastrophic fire damage.
The paper also describes a number of additional improvements including the following:
• Improve artificial regeneration seedling survival by protecting seedlings from desiccation.
• Contributes to long-term forest productivity by improving soil-moisture retention.
• Adds a significant amount of organic matter to the soil.
• Provides habitat for decomposer organisms and nitrogen fixing bacteria.
• Habitat improvements include sites for nests, dens and burrows; energy source for complex food webs, hiding and protective cover for predators and prey, and travel corridors.
• Woody debris also increases slope stability, reduces erosion and surface runoff.
Even with all of these potential benefits it will be interesting to see how many hectares of these sites have seen the redistribution of coarse wood material. It seems old habits are hard to overcome. It is encouraging to see the initiative taken by some professional foresters and I would like to see more of this kind of research.
In closing, what is the impact of burning the equivalent of 20 million barrels of oil on the 4.6 million B.C. residents? For comparison first convert barrels to liters of fuel i.e. (45 times 4.5461 equals 4 billion litres).
In 2008 there were 2.7 million light vehicles in B.C. burning gas which travelled an average of 13 thousand kilometers per year. If we assume an average fuel consumption of 11.7 liters per 100 kilometres then the light vehicle fleet would consume 4 million liters of fuel each year. If we have done our calculations properly, the cull piles contribute 1000 times more carbon dioxide than our provinces light vehicle fleet. Any reductions on the burning of cull piles can have a major impact on our carbon foot print and in many cases contribute to job creation and improve forest productivity.
Jim Hilton is a professional agrologist and forester who has lived and worked in the Cariboo Chilcotin for the past 40 years. Now retired, Hilton still volunteers his skills with local community forests organizations.
