The national Fire and Fire Surrogate study: Effects of fuel treatments in the western and eastern US after 20 years

The national Fire and Fire Surrogate (FFS) study was initiated more than
two decades ago with the goal of evaluating the ecological impacts of
mechanical treatments and prescribed fire in different ecosystems across
the United States. Since then, 4 of the original 12 sites remain active in
managing and monitoring the original FFS study which provides a unique
opportunity to look at the long-term effects of these treatments in
different regions. These sites include California (Blodgett Forest
Research Station), Montana (Lubrecht Experimental Forest), North Carolina
(Green River Game Land) and Ohio (Ohio Hills). Although regions differed
in ecosystem type (e.g., conifer- vs. hardwood-dominated), the overall
goals of the FFS study were to promote desirable, fire-adapted species,
reduce fire hazard, and improve understory diversity. Our study uses
multivariate techniques to compare how these desired outcomes were
maintained over the last 20 years and discusses whether we would modify
the original treatments given what we know now. Our findings indicate that
mechanical treatments and prescribed fire can promote desired tree
species, mitigate potential fire behavior by reducing fuels and retaining
larger-sized trees, decrease tree mortality, and stimulate regeneration –
effects that are still apparent even after 20 years. However, we also
found that maintaining desired outcomes was regionally specific with
western sites (California and Montana) showing more desirable
characteristics under mechanical treatments, while the eastern sites
(North Carolina and Ohio) showed more desirable characteristics after
prescribed burning. The beneficial effects of treatment were also more
apparent in the long term when sites followed up with repeated treatments,
which can be adapted to meet new objectives and conditions. These findings
highlight the FFS study as an invaluable resource for research and provide
evidence for meeting long-term restoration goals if treatments can be
adapted to ecosystem type, be maintained by repeated treatments, and can
accommodate new goals by adapting treatments to changing conditions.