MONDAY, November 29, 2004
3:00 - 4:00 p.m.
CAB 657


Mr. Piotr Weclaw

Department of Renewable Resources
University of Alberta



*Practical application of a computer simulation model in ecological conservation

The decline in woodland caribou (Rangifer tarandus caribou) populations in Alberta lead to classification as a threatened species in 1987. Rapid industrial development continues to affect caribou habitat. Natural and anthropogenic factors, which affect population dynamics, act cumulatively. Using STELLA Research modelling software we developed an interactive cumulative effects model, which could be used to assess both natural and anthropogenic factors influencing dynamics of caribou populations. Our model is based on functional and numerical responses of carnivores (wolves (Canis lupus)), herbivores (caribou and moose (Alces alces)) and resources (lichen and vascular plants). It includes stochasticity and is aspatial (but divides habitat into categories depending on habitat type and age). Based on simulation experiments, we suggest that the most detrimental factor on caribou population dynamics is the functional loss of habitat due to avoidance of good quality habitat in proximity of industrial infrastructures. We argue that in the natural boreal ecosystem, habitat was not limiting caribou in northern Alberta, and caribou could coexist with an uncontrolled wolf population. Our simulation experiments explain why wolf control is not a practical solution in caribou conservation and, based on our findings, we propose different alternatives. We also suggest potential thresholds for industrial development for specific interactions of different predation pressures and habitat carrying capacity.

Our model was originally published in Ecological Modelling (Weclaw, P., R.J. Hudson. 2004. Simulation of conservation and management of woodland caribou. Ecological Modelling 177(1-2): 75-94).

More details available at:

(With Dr. Robert J. Hudson, Renewable Resources)