Jack pine – lichen woodland on sandy soils in northern Saskatchewan and northeastern Alberta

Abstract

Open woodland forests dominated by Pinus banksiana occur on sandy soils in northeastern Alberta and northwestern Saskatchewan and are generally even-aged and uniform in height. Ordination techniques were used to divide the stands (n = 38) into the following communities: Pinus banksiana/Vaccinium myrtilloides seral community; Pinus banksiana/Cladina mitis, Pinus banksiana/Vaccinium myrtilloides/Cladina mitis in uplands; and Pinus banksiana–Picea mariana/Ledum groenlandicum/Cladina spp. in lowlands. Fires occur with a mean return interval of 38 years (range at six locations, 28–54 years). Pinus banksiana recolonizes rapidly after fire, and average thickness of lichen cover is reached in 45 years. This is a shorter time interval for recovery than is reported for the Northwest Territories. Stands that escape fire 90+ years become more open in upland sites, but in lowlands Picea mariana becomes codominant with associated shift in lichen species and an increase in bryophytes.