Fire Techniques

The fire-oak hypothesis asserts that the current lack of fire is a reason behind the widespread oak (Quercus spp.) regeneration difficulties of eastern North America, and use of prescribed burning can help solve this problem. We performed a meta-analysis on the data from 32 prescribed fire studies conducted in mixed-oak forests to test whether they supported the latter assertion. Overall, the results suggested that prescribed fire can contribute to sustaining oak forests in some situations, and we identified several factors key to its successful use. Prescribed fire reduced midstory stem density, although this reduction was concentrated in the smaller diameter stems. Prescribed fire preferentially selected for oak reproduction and against mesophytic hardwood reproduction, but this difference did not translate to an increase in the relative abundance of oak in the advance regeneration pool.

Prescribed burning is a common management tool for upland hardwood forests, with wildlife habitat improvement an often cited goal. Fire management for wildlife conservation requires understanding how species respond to burning at different frequencies, severities, and over time. In an earlier study, we experimentally assessed how breeding bird communities and species responded to fuel reduction treatments by mechanical understory reduction, low-severity prescribed fires, or mechanical understory reduction followed a year later by high-severity prescribed fires in upland hardwood forest. Here, we assess longer-term response to the initial mechanical treatment (M), and a second low-intensity burn in twice burned (B2) and mechanical + twice burned (MB2) treatments and controls (C). ...

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The objectives of this thesis were to determine eastern red bat (L. borealis) and eastern pipistrelle (P. subflavus) maternal roost use and selection at the tree, microhabitat, and macrohabitat scales. The study was conducted on and around the Clemson Experimental Forest, located in the upper piedmont of South Carolina. During the summers of 2002 and 2003, reproductive female red bats (n=11) and pipistrelles (n=4) were radiotracked to 32 and 7 roost trees, respectively. Red bats roosted within live foliage of a diversity of overstory hardwood tree species, however they roosted in hickories (Carya spp.), yellow-popar (L. tulipfera), and oaks (Quercus spp.) most often. ...

Prescribed burning has become more common for the management of eastern forests in North America, so understanding if and how foraging bats respond to structural changes generated by fire is of increasing importance. Our objective was to investigate the effects of post-fire landscape conditions on the occurrence of foraging bats in mixed forests of the Cumberland Plateau physiographic region. We deployed Anabat II bat detectors in 164 paired burned and unburned forest sites for ≥2 nights from mid-May through August 2014 and 2015 to monitor bat foraging and commuting habitat use. We conducted vegetation surveys to quantify site specific structural characteristics, which indicated that measures of structure were significantly lower in burned sites than unburned sites...

Fire is being prescribed and used increasingly to promote ecosystem restoration (e.g., oak woodlands and savannas) and to manage wildlife habitat in the Central Hardwoods and Appalachian regions, USA. However, questions persist as to how fire affects hardwood forest communities and associated wildlife, and how fire should be used to achieve management goals. We provide an up-to-date review of fire effects on various wildlife species and their habitat in the Central Hardwoods and Appalachians. Documented direct effects (i.e., mortality) on wildlife are rare. Indirect effects (i.e., changes in habitat quality) are influenced greatly by light availability, fire frequency, and fire intensity. ...

Before treatments, woody plants and leaf-litter-dominated groundcover and herbaceous plants were rare (<6% groundcover, 118 species). By 2016, herbaceous groundcover averaged 59% after heavy thinning and three biennial burns, and 359 herbaceous species were documented. Only 6% (23) of these species appeared negatively affected by applied disturbances. Across sites, thin-and-burn treatments increased graminoid groundcover 14-fold, forb groundcover 50-fold, herbaceous richness 9-fold, and herbaceous diversity 10-fold, relative to unmanaged stands. ...

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We investigated how variation in fire severity (control or no fire; low, medium, and high severity fires) and interval (1–2 years vs. 3–6 years after fires) affected habitat and avian abundance, species diversity, richness, and evenness in the southern Appalachian Mountains. Fire severity and interval had significant implications for both habitat and avian communities. Species richness within 2 years of fires was on average 26% higher in areas receiving medium and high severity treatments than in unburned control units. Species diversity and species richness were markedly greater 3–6 years after fires within high severity treatments (12 and 44%, respectively), compared to unburned controls. ...

Some bat species, including eastern red bats (Lasiurus borealis), roost for short periods beneath leaf litter on the forest floor during winter in the south-eastern USA, a region subjected to frequent fire. The variability in fuel consumption, the heterogeneous nature of burns, and the effects of litter and duff moisture on forest-floor temperatures during winter burning could influence potential survival for bats beneath the leaf litter if they are unable to escape on-coming flames. We measured temperatures below leaf litter in 64 south-slope plots during nine controlled burns in the Ouachita Mountains of Arkansas to determine the probability of survival. Maximum temperature recorded under leaf litter at each plot averaged 2928C (
20 s.e.) and ranged from 10 to 7178C. ...

Guidelines for using prescribed fire to regenerate and restore upland oak forests, woodlands, and savannas in eastern North America were developed by synthesizing the results of more than 100 scientific publications. The first four chapters provide background information on the values of oak ecosystems, eastern fire history, oak’s adaptations to fire, and the findings of fire-oak research conducted over the past 50 years...

The use of a fuels photo series to characterize potential combustibles and adequately anticipate and predict potential wildfire and prescribed fire behavior and effects in a given area is a practice that began nearly 50 years ago. These photo series are regional in nature and have tended to characterize the variability in Western United States fuel complexes in finer detail than Eastern United States fuel complexes. Managers and practitioners have long expressed great interest in a more site-specific, Southern Appalachian Mountain fuels photo series. In this article, we present the developmental framework for a new Southern Appalachian Mountain fuels photo series that was created in 2019 (Coates and others 2019).

Following basal area reductions ranging from 30 to 60% and three prescribed fires across three sites, mean oak seedling densities rose from 10 200 ha−1 to 17 900 ha−1. Post-treatment oak seedling densities were related to pretreatment densities (R2 = 0.55, P < 0.0001) and the number of oak trees >20 cm diameter within 10 m of plot center (R2 = 0.15, P = 0.01). Three years after the last prescribed fire, bat activity (mean passes per night) was significantly higher in the treated stands compared to adjacent undisturbed forest. We did not detect any significant differences in rodent activity between our treated stands and forest controls for two of the three years studied.

Forest management practices that mimic natural canopy disturbances, including prescribed fire and timber harvests, may reduce competition and facilitate establishment of favorable vegetative species within various ecosystems. Fire suppression in the central Appalachian region for almost a century has contributed to a transition from oak-dominated to more mesophytic, fire-intolerant forest communities. Prescribed fire coupled with timber removal is currently implemented to aid in oak regeneration and establishment but responses of woodland salamanders to this complex silvicultural system is poorly documented. ...