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After a devastating wildfire season in the Pacific Northwest, the U.S. Forest Service proposed a plan to remove existing restrictions on cutting down large trees on public lands east of the Cascades in Oregon and Washington. However, recently published research suggests that cutting down these big trees will greatly decrease the amount of carbon stored in PNW forests.

Why This Matters: Carbon sinks (or sources that help sequester carbon dioxide from our atmosphere) are crucial because there’s more carbon in our atmosphere than at any time in human history.  In fact, it might be the highest atmospheric carbon levels in three million years. 

Trees are an integral component of storing carbon and fighting the effects of climate change–they’re one of our most effective tools. This is also why any plans to thin forests must be undertaken thoughtfully and not hastily. We also know that big, mature trees play an especially important part in fighting climate change through their unique carbon-storing potential. Any plans to clear these trees must proceed with the utmost diligence.

Finding a Compromise: As the East Oregonian explained, the U.S. Forest Service has had a long-standing provision that prevents the harvest of trees greater than 21 inches in diameter on six national forests in eastern Oregon and Washington.

The limitation on harvesting trees of that size was put in place 25 years ago under a land-management plan amendment known as the Eastside Screens. 

But in the wake of record wildfires in the Pacific Northwest, forest managers are asking for a reconsideration of this rule. NOAA’s recent environmental assessment suggests that cutting down large trees would “better protect old trees and better provide for resilience of forest stands to future climate and disturbance stressors” like drought, wildfire and destructive insects.

However, this new study suggests that cutting down old-growth trees would be detrimental to Oregon’s carbon storage. While only 3% of Oregon’s trees are considered large (21 inches or larger), these trees contain 42% of the above-ground carbon stored in these forests. Because climate change contributes to the wildfires and droughts that the U.S. Forest Service is trying to prevent, some researchers think that the trees should be spared.

The U.S. Forest Service is currently reviewing comments on the draft of their plan to try to accommodate concerns about carbon storage. The service is considering felling smaller trees and only cutting down large trees in extreme scenarios.