Effects of Disturbance and Landscape Position on Vegetation Structure and Productivity in Ontario Boreal Forests: Implications for Woodland Caribou (Rangifer tarandus caribou) Forage
Hypotheses explaining recent declines in the abundance of woodland caribou in boreal Ontario include increased disturbances and predation. Caribou may select peatlands to avoid predation. Peatlands are regarded as low productivity, nutrient-limited systems, caribou may face a trade-off between predation risk and nutrient intake through foraging. I quantified differences in plant community and plant foliar quality in boreal stands across drainage class, disturbance type and time-following-disturbance. I found that understory productivity was influenced more by drainage and time-following-disturbance than by disturbance type. I also quantified variation among stand characteristics and plant functional types using measures of plant foliar quality. Foliar quality varied mostly by plant functional type. Overall, this thesis does not support the hypothesis that caribou face a trade-off between forage quality and predation risk by selecting peatlands, as peatlands had greater levels of understory productivity and foliar quality relative to uplands.