Recovery of big sagebrush communities after burning in south-western Montana

Prescribed burning of big sagebrush (Artemisia tridentata Nutt.) communitie s is conducted with the intention of increasing either the productivity of the understory plants or the big sagebrush. it was our objective to compare the recovery of big sagebrush communities from prescribed fire at as many sites as we could locate in south-western Montana with environmentally pair ed unburned portions. We located and sampled 13 sites that had been burned over a span of two to 32 growing seasons earlier. Big sagebrush canopy cove r, density, and production of winter forage were significantly greater (P l ess than or equal to 0.05) in the unburned portions in 34 of 38 comparisons . Canopy coverage of Idaho fescue (Festuca idahoensis Elmer), the dominant herbaceous species, was greater in the burned portion at only one site whil e it was less (P less than or equal to 0.05) at four sites. Total perennial grass canopy coverage was not different (P less than or equal to 0.05) bet ween treatments over the 13 sites. Managers considering prescribed burning of big sagebrush communities should be aware that herbaceous plant response s may be minimal while shrub values will likely be lost for many years. The loss of the dominant shrubs in any ecosystem will affect many other organi sms and severely impact species that have an obligate habit with the shrubs . (C) 2001 Academic Press.