Experimental designs for studying small-mammal responses to fire in North American conifer forests

Abstract

Climate change is altering fire regimes. As fire regimes change, it is important to understand how mammals respond to these altered post-fire landscapes. Because fires vary in size, severity and landscape context, it is important to know the experimental designs and response variables used to address post-fire responses of mammals. We analysed 48 papers published from 1988 to 2015 that examined responses of small mammals to natural or prescribed fire in North American conifer forests. These papers used different experimental contrasts (e.g. burned vs unburned sites, time series, within-fire heterogeneity). Most studies (89.6%) presented species richness or index-derived abundances of common species as their response variable(s). Many studies did not fully describe the fires being examined; these omissions make it more difficult to interpret and compare results among studies. The limited scope of inference presented by the papers in this review leads us to recommend a minimal set of information that should be presented about each fire studied. We conclude by outlining how different experimental designs and response variables can be used for effective inference. We highlight major pathways forward for examining responses of small forest mammals to the important changes in fire regime that are occurring.

Post-fire movements of Pacific marten (Martes caurina) depend on the severity of landscape change

“…In addition to habitat losses from fire, further fragmentation via post-fire salvage logging threatens biodiversity in burned forests [ 31 – 33 ]. In the face of such rapid landscape change, it is critical to understand how wildlife use burned landscapes [ 53 , 124 ] and rethink forest management with fire in mind [ 125 – 127 ].…”

“…Although some forest wildlife is well-studied post-fire, important knowledge gaps remain for many species [ 53 , 124 , 128 ]. For marten, we recommend further work to understand the impacts of burn severity and salvage logging on landscape connectivity [ 129 , 130 ] and population change [ 114 ].…”

Impact of wildfire size on snowshoe hare relative abundance in southern British Columbia, Canada

“…Future research into other prey species in response to fire size would be insightful, especially in the context of trying to manage mesopredators or raptors that prey on small mammals in these altered landscapes. Few studies have addressed the impact of fire size on wildlife responses (Hutchen et al 2017), but the results of this paper contribute to the growing body of literature suggesting that mammal responses to wildfire disturbances are spatially nuanced.…”

“…Previous work on how small mammals respond to post-fire landscapes have tended to focus on one or a few fires (Zwolak 2009;Griffiths and Brook 2014;Hutchen et al 2017). Very few studies of small-mammal response to fire have compared multiple fires in a single study (Hutchen et al 2017), and those that did tended to focus on multiple prescribed burns of the same size (Kennedy and Fontaine 2009;Fontaine and Kennedy 2012). We are not aware of studies that have examined how wildfire size affects post-fire population responses of wildlife.…”

“…In the context of large wildfires, there still remain large knowledge gaps as to how the high heterogeneity of post-fire vegetation affects the distribution of preferred snowshoe hare habitat. Previous work has not examined impacts of fire size on hares (Hutchen et al 2017).…”