Effects of prescribed fire on habitat of beaver (Castor canadensis) in Elk Island National Park, Canada Glynnis A. Hood a,b, * , Suzanne E. Bayley a , Wes Olson b a Department of Biological Sciences, CW 405 Biological Sciences Centre, University of Alberta, Edmonton, Alberta T6G 2E9, Canada b Parks Canada, Elk Island National Park of Canada, Site 4, RR 1, Fort Saskatchewan, Alberta T8L 2N7, Canada Received 26 July 2006; received in revised form 6 November 2006; accepted 6 December 2006 Abstract Fire, flooding, herbivory, and the effects of climate are all topical issues for today’s land managers. Effective resource management requires a balance among these processes, which in turn, requires a better understanding of their interactions. Beaver (Castor canadensis) are strong colonizers and have been successfully reintroduced to much of their former range. Prescribed fire has also been introduced in many areas as a management tool to restore ecological function. Resource managers have often assumed fire would also benefit non-target species like beaver; however, its effect on beaver has not been well studied. In this study, part of a broader project in Elk Island National Park, Canada, we examine the effect of prescribed fire on beaver lodge occupancy in the context of high ungulate populations. Elk Island National Park has an active beaver population, high ungulate densities, and a well-established prescribed fire program. We examine whether frequency, size, and timing of burns influence beaver lodge occupancy and the establishment of new lodges. Since 1979, over 51% of the park (99.3 km 2 ) has been burned with prescribed fire. By comparing lodge occupancy over a period prior to and after a series of prescribed burns, we analyzed beaver occupancy rates pre- and post-burn. Our results show that repeated burning dramatically decreases beaver lodge occupancy, and that even after one burn the number of active colonies declines and does not recover to pre-fire populations. Especially when combined with drought and herbivory, prescribed fire does not improve beaver habitat. # 2006 Elsevier B.V. All rights reserved. Keywords: Beaver; Beaver habitat; Castor canadensis; Prescribed fire; Elk Island National Park; Fire management; Ungulates; Herbivory; Aspen Parkland; Boreal mixed-wood forest; Drought; Climate 1. Introduction Flooding by beaver (Castor canadensis) and the effects of fire are viewed as major natural landscape processes that drive vegetation dynamics and alter ecosystems at both local and regional scales (Naiman et al., 1988; Johnston and Naiman, 1990a; Ford et al., 1999; Bisson et al., 2003). So important is the beaver’s role in maintaining wetlands on the landscape that in many areas in North America beaver have been reintroduced to former ranges (Naiman et al., 1988; Wright et al., 2002). The beaver’s ability to impound large areas of water, alter vegetation communities, and change sediment loads and water chemistry is well documented (Naiman et al., 1986; Smith et al., 1991; Klotz, 1998). For separate management objectives, fire has also been reintroduced in many places where fire suppression, landscape fragmentation, and climate have altered historic fire regimes and vegetation communities (Bartos and Mueggler, 1979; White et al., 1998; Ford et al., 1999; Weir et al., 2000). The interaction between fire and beaver has been assumed to be beneficial to beaver (Kellyhouse, 1979; Naiman et al., 1988), although this assumption has rarely been tested. Prescribed fire, also referred to as ‘‘ecological burning’’ (Meers and Adams, 2003), is often used to restore grasslands (Bailey et al., 1990; Roques et al., 2001) and stimulate growth of woody plants (Bartos and Mueggler, 1979; Elliot et al., 1999; Hiers et al., 2003). Use of fire to manipulate vegetation communities can also benefit various wildlife species by improving forage quality (Vinton et al., 1993) and habitat structure (Mushinsky, 1985). A growing body of literature however, reveals that, in the context of other ecological disturbances such as high herbivory and climate (e.g., drought), use of prescribed fire does not always achieve expected www.elsevier.com/locate/foreco Forest Ecology and Management 239 (2007) 200–209 * Corresponding author at: Parks Canada, Elk Island National Park of Canada, 8336-76 Avenue, Edmonton, Alberta T6C 0J1, Canada. Tel.: +1 780 992 2967; fax: +1 780 992 2951. E-mail address: ghood@ualberta.ca (G.A. Hood). 0378-1127/$ – see front matter # 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.foreco.2006.12.005