Vegetative response to burning on Wyoming mountain-shrub big game ranges.

Abstract

Information on vegetative productivity and nutritive responses to burning in mesic, high elevation big sagebrush (Artemisia tridentata Nutt.) communities is limited. We investigated the effects of 2 wildfires and 3 prescribed fires on current year's production of herbs and selected shrubs for 3 years post-burn, and forage quality for 2 years post-burn in high elevation big sagebrush habitats in southcentral Wyoming. Production of perennial herbs on burned sites averaged twice that on controls, while production of annual herbs varied little 2-3 years post-burn. Burn-induced mortality of Saskatoon serviceberry (Amelanchier alnifolia (Nutt) Nutt. ex Roem.) was less than or equal to 15%, but a 6-fold increase in twig production more than compensated for plant losses. Mortality of true mountain mahogany (Cercocarpus montanus Raf.) and antelope bitterbrush (Purshia tridentata (Pursh) DC) averaged 25% and 55%, respectively, but these losses generally were compensated by increases in browse production. Crude protein content of herbs from late spring through early far was significantly higher on burns for 2 years post-burn. These results suggest well-managed prescribed burning programs have potential to improve May through September diets of large herbivores in southcentral Wyoming mountain-shrub communities.