The effects of thinning and burning on understory vegetation in North America: a meta-analysis

This meta-analysis was conducted to determine if there were consistent responses of understory vegetation to fire and thinning treatments in North American forests that historically experienced frequent surface fire regimes (<20 years fire return interval, FRI). The most consistent effect of the treatments was the increase in non-native species following mechanical thinning and reduction in shrub cover following a burn. These differences suggest the two treatments may not be surrogates in the short-term (less than 5 years). Prescribed fire and thinning treatments can be used successfully to restore understory species richness and cover, but they can create different conditions and these potentially different outcomes need to be considered in the planning of a fuels reduction treatment.