Concerns about rising wildfire fuels may be overblown
Many fear that fire suppression efforts in the U.S. have made forests denser, increasing the risk of catastrophic wildfires. But a study in Forest Ecology and Management suggests that this assumption doesn’t hold true for all forests.
Fuel-reduction schemes, which aim to thin out forests by removing trees and conducting controlled burns, operate on the premise that forests are denser today than they used to be. Researchers analyzed aerial photographs of Colorado Front Range forests from 1938 and 1940 and compared them to images taken in 1999. They found that average tree cover increased by only 4 percent, with high-elevation conifer forests showing no significant change over six decades.
Density did go up substantially in historically open areas such as low-elevation ponderosa pine forests, the team notes, but these made up only 11 percent of the total region. They suggest that the results could help forest managers target areas that have changed the most. – Roberta Kwok
Source: Platt, R.V. and T. Schoennagel. 2009. An object-oriented approach to assessing changes in tree cover in the Colorado Front Range 1938-1999. Forest Ecology and Management DOI: 10.1016/j.foreco.2009.06.039
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