Native and exotic plant species respond differently to wildfire and prescribed fire as revealed by meta-analysis
Abstract
Wildfire is a natural disturbance that shapes vegetation characteristics worldwide, while prescribed fire is increasingly used to modify vegetation composition and structure. Due to invasion of many ecosystems by exotic species, a concern of land managers is whether wildfire and prescribed fire alter plant communities in favor of exotics.
We assessed the global literature describing community-level responses of native and exotic species groups to wildfire and prescribed fire and characterized the geographic and temporal scope of the data to inform research needs. We then used meta-analysis to (1) test whether native and exotic species composition (richness or diversity) and performance (cover, density, and biomass) differ in response to wildfire and prescribed fire and (2) assess how the composition and performance of these species groups vary with time elapsed since fire and habitat types.
The meta-analysis revealed strong evidence for a positive response of exotics to wildfire coupled with a striking near-absence of negative responses. The assessment additionally suggests that while prescribed fire does benefit native composition, on average it does not appear to greatly facilitate native performance; however site-specific variation in how communities responded to fire was pronounced.