Conserving woodland caribou habitat while maintaining timber yield: a graph theory approach

• Published in: Canadian Journal of Forest Research
• Main Authors: Ruppert, Jonathan L.W., Fortin, Marie-Josée, Gunn, Eldon A., Martell, David L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2016
• Subjects: Ecology; Forestry; Global and Planetary Change; Canada; Rangifer tarandus
• Online Access: http://dx.doi.org/10.1139/cjfr-2015-0431; http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjfr-2015-0431; http://www.nrcresearchpress.com/doi/pdf/10.1139/cjfr-2015-0431

The fragmentation and loss of old-growth forest has led to the decline of many forest-dwelling species that depend on old-growth forest as habitat. Emblematic of this issue in many areas of the managed boreal forest in Canada is the threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). We develop a methodology to help determine when and how timber can be harvested to best satisfy both industrial timber supply and woodland caribou habitat requirements. To start, we use least-cost paths based on graph theory to determine the configuration of woodland caribou preferred habitat patches. We then developed a heuristic procedure to schedule timber harvesting based on a trade-off between merchantable wood volume and the remaining amount of habitat and its connectivity during a planning cycle. Our heuristic can attain 84% of the potential woodland caribou habitat that would be available in the absence of harvesting at the end of a 100 year planning horizon. Interestingly, this is more than that which is attained by the current plan (50%) and a harvesting plan that targets high volume stands (32%). Our results indicate that our heuristic procedure (i.e., an ecologically tuned optimization approach) may better direct industrial activities to improve old-growth habitat while maintaining specified timber production levels.