Long-term effects of burning Festuca and Stipa-Agropyron grasslands

Abstract

The effects of early spring burning on current year standing crop, litter, and total standing crop (current year standing crop plus litter) were examined in Festuca- and Stipa-Agropyron-dominated communities in central Saskatchewan over an 11-year period in a paired design with burned sites compared to adjacent control sites that were not burned. In Festuca communities current year standing crop was reduced in the first and third years (P = 0.010) after burning. Burning Stipa-Agropyron-communities tended to reduce current year standing crop, but the differences were not significant (P 0.050) compared to control. Increasing precipitation stimulated current year standing crop after burning Festuca (P < 0.001, r2 = 0.33) and Stipa-Agropyron (P < 0.001, r2 = 0.55) communities. Litter and current year standing crop were correlated (R2 = 0.24, P = 0.002) for Festuca indicating beneficial and detrimental effects of litter on production at low and high amounts, respectively. Litter and current year standing crop were not correlated (P = 0.964) for Stipa-Agropyron. In both communities total standing crop increased until about the eighth year after burning while the mass of litter appeared to reach a plateau around 11 years.