Trees and shrubs have proliferated in unmanaged forests in the eastern U.S. This growth, which marks a return of trees to the region after centuries of deforestation, is fueling a new surge in wildfires, a study finds.
Over the last four decades, the eastern U.S. has seen a marked uptick in tree cover, and in some places the number of large wildfires has grown tenfold. For a new analysis, researchers compared the growth of trees and shrubs with the spread of wildfires, finding that for every 1 percent increase in woody cover, the odds of a wildfire in the next year rose by 3.9 percent. The link between woody growth and wildfires was strongest in Texas and Appalachia.
The study, published in Geophysical Research Letters, shows how, as in the western U.S., the East is seeing more densely packed forests succumb to wildfires. Authors say that officials may need to thin forests to limit the risk of burning.
Curiously, the return of trees to the eastern U.S. has also kept local warming in check by supplying shade and moisture, a recent study found. Over the last century, the U.S. as a whole warmed by 1.2 degrees F, but across much of the East, temperatures actually dropped, by 0.5 degrees F.
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