Effects of a Fall Wildfire on Herbaceous Vegetation on Xeric Sites in the Selway-Bitterroot Wilderness, Idaho

Abstract

Trends in productivity and mineral content of herbaceous vegetation in Ponderosa pine and montane grassland over a 4-year period are reported. Dry matter production on burned areas was 1.4, 1.3, 2.2 and 1.6 times that on unburned sites in the four successive years following the fire. Annual forbs and annual grasses contributed 56% of total dry matter the first year following fire. Perennial forbs contributed 40, 75, 75, and 77% of dry matter on the burned sites in successive years following the fire, compared with 66% on the unburned site. Herbage mineral concentrations did not change appreciably following fire, although low values for nitrogen and potassium were apparent in the first year.