Meta‐analysis of avian and small‐mammal response to fire severity and fire surrogate treatments in U.S. fire‐prone forests

Abstract

Abstract. Management in fire-prone ecosystems relies widely upon application of prescribed fire and/or fire surrogate (e.g., forest thinning) treatments to maintain biodiversity and ecosystem function. Recently, published literature examining wildlife response to fire and fire management has increased rapidly. However, none of this literature has been synthesized quantitatively, precluding assessment of consistent patterns of wildlife response among treatment types. Using meta-analysis, we examined the scientific literature on vertebrate demographic responses to burn severity (low/moderate, high), fire surrogates (forest thinning), and fire and fire surrogate combined treatments in the most extensively studied fire-prone, forested biome (forests of the United States). Effect sizes (magnitude of response) and their 95% confidence limits (response consistency) were estimated for each species-by-treatment combination with two or more observations. We found 41 studies of 119 bird and 17 smallmammal species that examined short-term responses ( 4 years) to thinning, low/moderateand high-severity fire, and thinning plus prescribed fire; data on other taxa and at longer time scales were too sparse to permit quantitative assessment. At the stand scale (,50 ha), thinning and low/moderate-severity fire demonstrated similar response patterns in these forests. Combined thinning plus prescribed fire produced a higher percentage of positive responses. High-severity fire provoked stronger responses, with a majority of species possessing higher or lower effect sizes relative to fires of lower severity. In the short term and at fine spatial scales, fire surrogate forest-thinning treatments appear to effectively mimic low/moderate-severity fire, whereas low/moderate-severity fire is not a substitute for high-severity fire. The varied response of taxa to each of the four conditions considered makes it clear that the full range of fire-based disturbances (or their surrogates) is necessary to maintain a full complement of vertebrate species, including fire-sensitive taxa. This is especially true for high-severity fire, where positive responses from many avian taxa suggest that this disturbance (either as wildfire or prescribed fire) should be included in management plans where it is consistent with historic fire regimes and where maintenance of regional vertebrate biodiversity is a goal.

The importance of mammalian torpor for survival in a post-fire landscape

“…Prescribed fires to reduce fuel load are employed in many parts of the world to limit the frequency and severity of potential wildfires and may even promote biodiversity if a mosaic of habitats is created [13]. Nevertheless, the localized detrimental impact of hazard-reduction burns on plant and animal communities can still be substantial.…”

Effects of post-fire logging on California spotted owl occupancy

“…Spotted owls likely forage in complex early seral forests because abundant dead trees for perch sites are available for this sit-and-wait predator (Carey and Peeler 1995) and the small mammal prey base can increase in such habitat, particularly deer mice (Peromyscus maniculatus; Zwolak 2009, Fontaine and Kennedy 2012, Borchert et al 2014. Under this study design, all spotted owl sites were confirmed occupied prior to post-fire logging.…”

Short-term changes in summer and winter resident bird communities following a high severity wildfire in a southern USA mixed pine/hardwood forest

“…Previous research has shown that fire severity is a primary driver of fire influences on many ecosystem components (Knapp et al, 2009;Brown et al, 2014a), including influences on bird responses (Smucker et al, 2005;Fontaine and Kennedy, 2012;Lindenmayer et al, 2014). Thus, improving our understanding of community responses to high severity forest fires (i.e., wildfires that kill or top-kill the majority of live vegetation and consume the majority of dead organic matter) is currently of high interest to assist land managers with post-fire management decisions (Bisson et al, 2003;Beschta et al, 2004).…”

“…Given the vagility of birds, fire-induced changes in abundance and occupancy are likely driven by spatial responses to changes in habitat suitability (i.e., food resource and nesting site availability and structural habitat preferences; Hutto, 1995;Saab and Powell, 2005;Fontaine and Kennedy, 2012). At the extreme end, species such as Kirtland's warbler (Setophaga kirtlandii), red-cockaded woodpecker (Picoides borealis), and black-backed woodpecker (Picoides arcticus) are fire specialists, relying on wildfires to generate high suitability habitat under natural conditions (Probst, 1986;Saenz et al, 2001;Hutto et al, 2008).…”