Fires, warming cut forests' carbon storage

Pacific Northwest forests store more carbon than any other U.S. region but warming climate and resultant wildfires may undermine that potential, officials say. The U.S. Forest Service's Pacific Northwest Research Station and the Climate Impacts Group at the University of Washington say parts of Washington state could lose as much as a third of their carbon stores by 2040 as projected wildfires burn an increasing area of the state's forests. The study used statistical models and publicly available Forest Inventory and Analysis data to estimate the effects of a warming climate on carbon storage and fluxes on Washington's forests, a USDA release reported Monday. "When considering the use of forests to store carbon, it will be critical to consider the increasing risk of wildfire," research station biologist Crystal Raymond said. "Especially in the West, where climate-induced changes in fire are expected to be a key agent of change." Trees can remove and sequester carbon from the atmosphere in the form of carbon dioxide, acting as important stores or "sinks" of carbon that help offset its accumulation in the atmosphere that creates the "greenhouse" warming effect. When trees and other woody material in the forest burn, researchers said, they release carbon back to the atmosphere, mostly as carbon dioxide, where it may once again act as a greenhouse gas. "Forests on both the eastern and western slopes of the Cascade Range will lose carbon stored in live biomass because area burned across the state is expected to increase," Raymond said. "Even small increases in area burned can have large consequences for carbon stored in living and dead biomass."