Natural Revegetation of Winter Roads on Peatlands in the Hudson Bay Lowland, Canada

Abstract

Winter roads across subarctic peatlands are increasingly being used to access remote communities and resource development camps, yet relatively little is known on their ability to recover after abandonment. We evaluated the natural recovery of winter roads abandoned within 7 years on peatlands in the Hudson Bay Lowland, Canada. We sampled 5 winter roads of increasing age of abandonment and compared surface elevation, microtopography, active layer thickness, species cover, diversity, and composition between winter road clearances and adjacent undisturbed peatland. No differences in surface elevation and hummock-hollow microtopography were detected between road clearances and adjacent peatlands, but clearances had significantly thinner active layer, which persisted at least 7 years after abandonment. The cover of lichens, bryophytes, and vascular plants returned within 5 years to similar levels as in undisturbed peatlands, although species richness per quadrat remained lower and species composition differed. The limited recovery of black spruce on these peatlands and their slow growth indicates that the full recovery of vegetation structure on these road clearances will take decades. Future research should focus on the restoration of a Sphagnum carpet and on the interactions between a shallower active layer and the revegetation of abandoned winter roads.

Acknowledgments

We would like to thank Angie Corson and Kristina Skeries for their assistance during field work. We gratefully acknowledge the support from the De Beers Canada Victor Mine, especially Ruben Wallin, Brian Steinback, Rod Blake, Terry Ternes, Charles Hookimaw, Andrew Sutherland, David Iserhoff, Victor Wesley, Andrea Labelle, Anne Boucher, Aline de Chevigny, Marnie Couture, and Laurie LaFleche. The research was made possible from financial support from a Collaborative Research and Development grant between De Beers Canada, the Centre of Excellence in Mining Innovation and the Natural Science and Engineering Research Council of Canada (NSERC), and from an NSERC Undergraduate Student Research Award to Jaimée Bergeron. We thank two anonymous reviewers for their constructive suggestions on an earlier version of this manuscript.