 Boise National Forest 's 2010 forest plan recognizes that fire and other disturbances play important roles in maintaining the character and function of ecosystems . However , previous management strategies ( as recently as the 1990 forest plan ) treated fire as an undesirable process , and the <unk> Act of 1897 explicitly stated that forests were to be protected from destruction by fire . In historic conditions fires naturally occurred on the landscape ; the suppression of fires allowed dead trees to accumulate in excess of historic levels and land cover types to change , such as a shift to higher shrub and tree densities . An estimated 14 percent of the land in Boise National Forest has been affected by fires since the early 1990s , and about 10 percent of the land capable of timber production was burned so severely that land cover shifted from forest to grass and <unk> ( as of 2010 ) . 
