THE EFFECTS OF BURNING ON FESTUCA-HALLII IN THE PARKLANDS OF CENTRAL ALBERTA

The response of Festuca hallii (Vassey) Piper to time of burning was e xamined on the Festuca-Stipa grasslands of the Aspen Parklands at the University of Alberta Ranch located 150 km southeast of Edmonton, Albe rta. Two defoliation treatments (burning and mowing) were examined on five dates in 1978 (8 April, 27 April, 1 June, 31 July, and 18 October ), corresponding to different phenological stages of F. hallii. Burnin g and mowing reduced the standing crop of F. hallii produced in the fi rst growing season after treatment, but tiller densities increased. De foliation in early spring (8 April) had little effect on the standing crop; apparently the increase in tiller density compensated for the re duction in tiller length. Inflorescence density also increased followi ng burning or mowing from 8 April to 1 June. Soil temperature (3 cm de ep) on previously burned or mown sites was greater than on the control the year after treatment. Festuca hallii tolerates single burns at an y time of the year, but early spring fires have the greatest benefits by increased tillering and standing crop.