Wildfire

Prescribed fire is a common tool used to conserve and manage the integrity of forest ecosystems. We investigated short-term juvenile amphibian capture and body condition changes subsequent to fire (i.e., one prescribed burn and two wildfires) in a southern United States pine forest. We surveyed amphibians and predatory invertebrates before and after fires occurring during summer 2010. We tested for treatment (i.e., control, wildfire, or prescribed burn) and status (i.e., preburn or postburn) differences in 1) genus-level captures, 2) amphibian health (inferred through a body...

Old-growth forests provide unique insight into historical compositions of forests in the eastern United States. Plots established within a mixed forest community within Marshall Forest in Rome, Georgia, in 1960 (and remeasured in 1989) were reassessed to determine changes in forest composition. The community has experienced approximately 10% increase in basal area since the previous measurement period. However, changes in species importance have occurred. Chestnut oak (Quercus montana), mockernut hickory (Carya tomentosa), white oak (Quercus alba), and flowering dogwood (Cornus florida) have all decreased in importance, while pignut hickory (Carya glabra), winged elm (Ulmus alata), yellow poplar (Liriodendron tulipifera), and red maple (Acer rubrum) have all increased in importance. ...

Soil water repellency induced by wildfires can alter hydraulic properties and hydrologic processes; however, the persistence and vertical position (i.e., depth) of water repellent layers can vary between systems and fires, with limited understanding of how those variations affect infiltration processes. This study occurred in two forested locations in the south-central Appalachian Mountains that experienced wildfires in late 2016: Mount Pleasant Wildfire Refuge, Virginia, and Chimney Rock State Park, North Carolina. In each location, sites were selected to represent unburned conditions and low to moderate burn intensities.

Contains 14 full-length papers and 40 abstracts of posters that were presented at the 4th Fire in Eastern Oak Forests conference, held in Springfield, MO, May 17-19, 2011. The conference was attended by over 250 people from 65 different organizations and entities, representing 22 states and 1 Canadian province.

We compared the effects of three fuel reduction techniques and a control on the relative abundance and richness of reptiles and amphibians using drift fence arrays with pitfall and funnel traps. Three replicate blocks were established at the Green River Game Land, Polk County, North Carolina. Each replicate block contained four experimental units that were each approximately 14 ha in size. Treatments were prescribed burn (B); mechanical understory reduction (M); mechanical + burn (MB); and controls (C). Mechanical treatments were conducted in winter 2001–2002, and prescribed burns in March 2003. Hot fires in MB killed about 25% of the trees, increasing canopy openness relative to controls. ...

In 2016, mixed-severity wildfires in the southern Appalachians created a gradient of forest structures not typical following prescribed burns, providing a unique opportunity to study temporally dynamic conditions and breeding bird response. We measured forest structure and breeding bird communities across a fire-severity gradient in 3 burned and 3 unburned watersheds for 5 years (Y1-Y5). We categorized plots as unburned (NB), low- (L), moderate- (M), or high-severity (H) using a composite fire-severity index. Tree mortality increased with fire-severity category (FSC) and over time; by Y5, 7 % of trees in NB, 11 % in L, 38 % in M, and 71 % in H had died. Shrub recovery was...

From October to December of 2016, a confluence of human and environmental factors led to an outbreak of wildfires across the Southern Appalachian Mountains. This report examines the time trends of fire in the Southern Appalachian region, including mitigation activities and forecasting acres burned. The introduction (ch. 1) of this report describes the 2016 Southern Appalachian fires on public lands and provides a brief description of the methodology used to understand economic impacts of fire. Chapters 2 and 3 examine how prescribed fire is used in this region. The final chapter (ch. 4) describes how we can expect area burned by both human- and lightning-caused fires to change given increases in global temperatures, fuels, and wildland fire management.

During one of the warmest and driest droughts of the last century, the southern Appalachian Mountains experienced a regional outbreak of over a dozen large wildfires in late fall of 2016. We provide a synthesis of long-term forest changes leading up to the 2016 wildfires, examine the climatic setting and patterns of burn severity in relationship to topography, and discuss the ecological and management implications of these and future fires. During the pre- and post-European settlement periods, frequent low- and mixed-severity wildfires interacted with complex topographic gradients and maintained heterogenous landscapes dominated by several species of oak (Quercus spp.), pine (Pinus spp.), and the American chestnut (Castanea dentata). Land-use changes associated with European settlement, loss of the American chestnut, and 20th century fire exclusion resulted in large scale shifts towards mesic, fire-intolerant species (i.e. mesophication)...

Fire is a critical ecological process to the forests of the Southern Appalachians. Where fire was excluded from forest types that historically burned frequently, unanticipated changes can occur when fire is reintroduced. For example, the development of new fuel characteristics can change the patterns of fire mortality and associated ecological responses. To test the fire effects of delayed fire mortality (mortality initiated by fire that occurs subsequent to the fire year) in the Southern Appalachians, USA, we developed a fire-effects model using both field studies and remote sensing. We then simulated these effects at a landscape scale to estimate broader ecological effects...

The immediate effects of wildland fire on soil have been well documented. However, we know much less about the longer-term effects and their implications for plants. Post-fire soil temperature regimes, for example, have received relatively little research attention, despite potential effects on plant phenology and establishment. Using portable temperature datalogger units (iButtons), we conducted an experimental study to assess how fire severity (measured in terms of litter and duff consumption) influences biologically relevant temperature parameters such as diel minimums, maximums, means, and ranges. We also used these data to calculate cumulative soil growing degree days (GDDs). ...

Increasingly detailed records of long-term fire regime characteristics are needed to test ecological concepts and inform natural resource management and policymaking. We reconstructed and analyzed twelve 350+ yr-long fire scar records developed from 2612 tree-ring dated fire scars on 432 living and dead pine (Pinus pungens, Pinus rigida, Pinus resinosa, Pinus echinata) trees from across central Pennsylvania. We used multiple spatial and time series analysis methods to quantify fire regime characteristics (frequency, seasonality, percentages of trees scarred, extent) and fire–climate–human associations. Prior to the 20th century fire suppression, fire regimes at the majority of sites consisted of frequent, low-to-moderate severity, dormant season fires. ...

Wildfires can significantly impact air quality and human health. However, little is known about how different fuel bed components contribute to these impacts. This study investigates the air quality impacts of duff and peat consumption during wildfires in the southeastern United States, with a focus on the differing contributions of fine particulate matter less than 2.5 µm in size (PM2.5) and ozone (O3) to air quality episodes associated with the four largest wildfire events in the region during this century. The emissions of duff burning were estimated based on a field measurement of a 2016 southern Appalachian fire...

It is typically difficult to burn duff because of high fuel moisture; however, under persistent drought conditions, duff will burn readily. This study investigates the burning of a deep duff layer by the 2016 Rough Ridge Fire, in the southern United States, under drought conditions and evaluates the contribution of duff consumption to fire emissions and air pollution. Fuel...