More Science on Salvaging Timber

From a new study published in Frontiers in Forests and Global Change — online and free. A complete life-cycle analysis would account for harvests in the effects area as well as in areas where normal harvests change as more (or less) is harvested in the disturbed forest. Markets matter. If landowners in one area harvest more than their average annual volumes, landowners in other areas might harvest less: the overall demand for timber hasn’t been changed.

Forest Carbon Resilience of Eastern Spruce Budworm (Choristoneura fumiferana) Salvage Harvesting in the Northeastern United States


The next major eastern spruce budworm (Choristoneura fumiferana) outbreak is likely to begin impacting the forests of the northeastern US over the next few years. More than 4.7 million ha of forest and 94.8 million Mg of carbon in spruce (Picea spp.) and balsam fir (Abies balsamea) are at risk. Vegetation shifts in at-risk forest stands are likely to occur as a direct result of mortality caused by spruce budworm and through post-outbreak salvage harvest operations designed to minimize economic impact. Management interventions have short-term and long-term consequences for the terrestrial carbon budget and have significant implications for the role of the region’s forests as a natural climate solution. We used regional forest inventory data and 40 years growth and harvest simulations from the USDA Forest Service Forest Vegetation Simulator to quantify a range of forest carbon outcomes for alternative silvicultural interventions in the northeastern US. We performed a life cycle assessment of harvested wood products, including bioenergy, to evaluate the full greenhouse gas (GHG) emissions consequences of salvage and business as usual silvicultural scenarios across a range of stand risk profiles in the presence and absence of spruce budworm attack. Salvaging dead trees in the most at-risk stands tends to produce net emissions of carbon dioxide for at least 10 years compared to a baseline where dead trees are left standing. In most scenarios, GHG emissions reached parity with the baseline by year 20. Changes in forest carbon stocks were the biggest driver of net emission differences between salvage and no salvage scenarios. A benchmark scenario without timber harvesting or the occurrence of a spruce budworm outbreak had the greatest net carbon sequestration profile after 40 years compared to all other scenarios. Salvaging trees killed by a severe and widespread insect infestation has potential negative short-term implications for GHG emissions, but long-term resilience of these climate benefits is possible in the absence of future outbreaks or subsequent harvest activities. The results provide guidance on silvicultural interventions to minimize the impact of spruce budworm on forest carbon.

Discussion excerpt:

We found that forest management actions such as salvage harvesting designed to mitigate pest impacts over time can have positive impacts on overall C balances by reducing the risk of catastrophic loss in susceptible stands and landscapes and by shifting C from at-risk or dying trees to wood used as building materials or displacing fossil-fuel intensive energy sources. However, this C resilience comes at a short-term cost to the atmosphere that can last up to 20 years. Therefore, the resilience is dependent upon the recovery of the forest C stocks in the absence of subsequent natural or anthropogenic disturbances. If forest management interventions or large-scale mortality interrupt the growth response of the post salvage forest, then there is likely to be a longer period of time required to reach parity with the baseline scenarios.



4 thoughts on “More Science on Salvaging Timber”

  1. At the joint risk of seeming like an armchair social scientist and/or an old person (isn’t budworm where I came in?) Is there a Northeast equivalent of BBER at U of Montana?

    Northeastern forests are incredibly diverse (Maine, Delaware, Pennsylvania, New York) and mostly owned by NIPF’s- not sure there is mill capacity for a major salvage operation should budworm mortality occur. Which might argue for some kind of portable sawmilling capacity that could move around when there is a pest outbreak. Kind of like magpies on elk carcasses, flock and fly away to the next one.

    • “Is there a Northeast equivalent of BBER at U of Montana?”

      Yes, I believe it’s called the Chamber of Commerce.

      If you do a search on “Bureau of Business and Economic Research” you will see that they are scattered throughout the country. A quick search found one in West Virginia and Minnesota. I’d think there are more.

  2. The phrase “flattening the curve” hadn’t come into fashion yet when we talked about this before, but I recall that the greatest carbon risk is in the short-term (20-30 years). If so (and correct me if I’m wrong), this research would then suggest that we should not be doing salvage logging during that period because it produces a short-term carbon increase. (A quick look didn’t find our earlier discussion of this.)


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