WHAT THE EVIDENCE SAYS
Researchers compared repeat burning at 5-, 10- and 20-year intervals with unburned controls. Five-year fires most consistently reduced litter and bitterbrush cover, but removing that shrub can also reduce forage and cover for wildlife. Longer intervals protected more bitterbrush in some periods yet sometimes favored snowbrush or brackenfern after overstory loss; species richness did not rise simply with repeated burning.
WHY IT MATTERS / OUR READ
Choose fire-return schedules from an explicit map of desired fuel, wildlife-forage and understory states rather than treating frequent burning as one universal prescription. A spatial mosaic of untreated patches and differently burned units may preserve habitat diversity while meeting fuels objectives.
CAVEATS / UNCERTAINTY
Results come from a particular long-term dry-forest experiment; fire severity, past stand structure, missed treatments and species composition matter. No fixed 5-, 10- or 20-year schedule is a site-independent recommendation.
SOURCE
Fire Ecology / USDA Forest Service — primary long-term experimental study
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