VTechWorks staff will be away for the Thanksgiving holiday beginning at noon on Wednesday, November 27, through Friday, November 29. We will resume normal operations on Monday, December 2. Thank you for your patience.

Browsing by Author "Thomas-Van Gundy, Melissa A."

Now showing 1 - 4 of 4
  • Thumbnail Image
    Long-term impacts of silvicultural treatments on wildland fuels and modeled fire behavior in the Ridge and Valley Province, Virginia (USA)
    Hahn, George E.; Coates, T. Adam; Aust, W. Michael; Bolding, M. Chad; Thomas-Van Gundy, Melissa A. (Elsevier, 2021-09-15)
    Active forest management operations, such as regeneration harvests, can reduce hazardous fuel loads and alter fuel structure, potentially minimizing extreme wildfire conditions while maintaining ecosystem services, such as wildlife habitat and water quality. Regeneration harvests of differing intensities (clearcut, high-retention shelterwood, and low-retention shelterwood) were first applied between 1995 and 1996 to three sites on the George Washington-Jefferson National Forest in the Ridge and Valley Province of Virginia, USA. Over two decades after the clearcut was conducted and 11–12 years after the overwood was removed in the shelterwood stands, woody debris, litter, and duff masses and depths were quantified. One-hour fuel loads were greater in clearcut units than in high-retention shelterwood, low-retention shelterwood, or control units. Ten-hour fuel loads were greater in clearcut and low-retention shelterwood units than in high-retention shelterwood and control units. No significant differences in 100-hour fuels were observed between treatments. Control units contained more rotten and total 1000-hour fuels than all other treatments. The total woody debris load was less in the clearcut and high-retention shelterwood than in the low-retention shelterwood and control. High-retention shelterwood woody fuel depth was greater than clearcut woody fuel depth. Litter and duff loads were less in treated units than in the control units. Total fuel load (woody fuel load + litter load + duff load) was greater in the control than the silvicultural treatments. Litter depth did not differ between treatments, while duff depth was greater in the control than in the treated units. Using the computer modeling software, BehavePlus 6.0.0, these alterations to fuel loads and depths led to increased values in the control units for six fire behavior parameters. Predicted surface flame length in the low-retention shelterwood was the only modeled value that was not less than control values. Overall, these results indicated that harvest intensity and timing may have long-term effects on down and dead woody fuels, forest floor depth, and potential fire behavior. Clearcutting reduced fire behavior most, followed by the high-retention shelterwood system. The potential differences in slash and debris generated by varying shelterwood systems may impact long-term fuel and fire dynamics.
  • Thumbnail Image
    Prescribed Fire Effects on Tree Grades and Wounds on the Monongahela National Forest, WV
    Sharpe, Caroline Marie (Virginia Tech, 2022-07-01)
    Species traits, including but not exclusive to bark thickness and texture, sprouting ability, and litter bulk density and chemistry, may be related to a stem's potential to withstand potential heating from wildland fire. Trees exhibiting similarities for these properties and others may be classified into two broad functional groups: pyrophytes and pyrophobes. To our knowledge, few research studies have been conducted to determine how prescribed fires may affect wood quality of merchantable tree species in the Appalachian Mountains. Understanding potential relationships between wounding and fire tolerance may assist prescribed fire managers as they seek to promote and expand the use of prescribed fire for management purposes. To investigate this issue, six locations on the Monongahela National Forest, West Virginia, that had been subjected to one or two mixed intensity and severity prescribed fires since 2012 were selected for stand inventory in 2021. Overstory trees within these burned locations and adjacent, unburned locations were measured and graded using variable radius sampling, and additional landscape features and physiographic factors, such as aspect, elevation, and slope percentage, were also recorded at each variable radius sampling location. The most common, commercially valuable deciduous species encountered were red maple (Acer rubrum) (17.5%), white oak (Quercus alba) (9.8%), chestnut oak (Quercus montana) (32.8%), and northern red oak (Quercus rubra) (39.9%). Using field measurements and tree grades, the total number and types of wounds, potential volume loss, charring, basal area, and diameters at breast height (DBH) were compared by species, burn status (burn or control), and the number of burns. Overall, A. rubrum and Q. rubra comprised 93% of the total trees exhibiting volume loss from wounds in the burned locations. However, total volume loss only constituted about 3% of the bottommost 4.9 m log. Trees in the burned locations experiencing volume loss differed significantly between species (p=0.0294) with Q. rubra constituting 60% of volume loss trees. In burned and control plots, A. rubrum was the most commonly wounded tree with 43.5% of trees having at least one wound. Cat face and oval wounds were the only wound types resulting in volume loss. Felling and milling stems identified in this study as having potential volume loss from any fire-influenced wounds would be valuable. Furthermore, assessing the potential impact of outer bark char resulting from prescribed fires would be desired to better understand if charring constitutes any potential internal damage to stems. Deploying a similar, field-scale experiment on areas with varying fire frequencies and intensities would be useful to determine how wood quality may be affected after several prescribed burns.  
  • Thumbnail Image
    Wildfire and Prescribed Fire Effects on Forest Floor Properties and Erosion Potential in the Central Appalachian Region, USA
    Thompson, Emma Georgia; Coates, T. Adam; Aust, W. Michael; Thomas-Van Gundy, Melissa A. (MDPI, 2019-06-08)
    Short- and long-term impacts of wildland fires on forest floor properties and erosion potential were examined at three locations in the Central Appalachian region, U.S.A. In 2018, two wildfires were investigated within six months of burning on the George Washington–Jefferson National Forest (GWJNF) in Bland County, Virginia and the Monongahela National Forest (MNF) in Grant County, West Virginia. An additional wildfire was studied eight years post-fire on the Fishburn Forest (FF) in Montgomery County, Virginia. A 2018 prescribed fire was also studied within six months of burning on the MNF in Pendleton County, West Virginia. Litter and duff consumption were examined to evaluate fire severity and char heights were measured to better understand fire intensity. The Universal Soil Loss Equation for forestlands (USLE-Forest) was utilized to estimate potential erosion values. For the 2018 comparisons, litter depth was least as a result of the wildfires on both the MNF and GWJNF (p < 0.001). Wildfire burned duff depths in 2018 did not differ from unburned duff depths on either the MNF or GWJNF. Eight years after the FF wildfire, post-fire litter depth was less than that of an adjacent non-burned forest (p = 0.29) and duff depth was greater than that of an adjacent non-burned forest (p = 0.76). Mean GWJNF wildfire char heights were greatest of all disturbance regimes at 10.0 m, indicating high fire intensity, followed by the MNF wildfire and then the MNF prescribed fire. USLE-Forest potential erosion estimates were greatest on the MNF wildfire at 21.6 Mg soil ha−1 year−1 due to slope steepness. The next largest USLE-Forest value was 6.9 Mg soil ha−1 year−1 on the GWJNF wildfire. Both the prescribed fire and the 2010 wildfire USLE-Forest values were approximately 0.00 Mg soil ha−1 year−1. Implications for potential long-term soil erosion resulting from similar wildfires in Central Appalachian forests appeared to be minimal given the 2010 wildfire results.
  • Thumbnail Image
    Wildland Fire in the Central Appalachian Mountains: Impacts on Above- and Belowground Resources
    Hahn, George Eugene, III (Virginia Tech, 2021-03-03)
    Prescribed fire use in Virginia and West Virginia has increased over the past ten years as forest managers on public lands have increasingly used prescribed fire to meet management goals. These goals include hazardous fuel reduction, wildlife habitat restoration and management, and control of less desired vegetation. Research is needed to better understand the effects of wildland fire on forest ecosystems. In this study, we addressed wildland fire's effects on water, vegetation, and soil resources in the central Appalachian Region. Moreover, the long-term efficacy of various types of timber harvests on forest fuel reduction was analyzed. Over fifty peer-reviewed articles were evaluated to characterize the effects of prescribed fire on physical, chemical, and biological water quality parameters throughout the eastern United States. It was determined that fires of low to moderate intensity and severity may cause short-term sediment and nutrient increases in nearby waterbodies, but these effects often dissipate within 2-3 years. Effects on biological organisms are more transient, frequently lasting from a few weeks to a few months. Regeneration following wildfires at three sites in Virginia and West Virginia varied due to fire behavior and time since fire. Preferred and undesired species responded differently at each site. Follow-up treatments and continued monitoring are needed to obtain desired vegetative compositions post-fire. Two dormant season prescribed fires on the Fishburn Forest near Blacksburg, Virginia were studied for mineral soil chemistry effects. Both treatment and time affected macronutrient levels, but no differences were present 6 and 14 months post-fire between burned and unburned locations. Forest fuels were quantified approximately 20 years following different silvicultural harvests on the George Washington-Jefferson National Forest. Fuels of different size classes responded differently to different harvests as fine fuels were reduced by the high-leave shelterwood treatment, and coarse woody fuels were reduced by the clearcut and low-leave shelterwood treatments. Overall, low intensity and low severity fires induce minimal, potentially negative changes in water and soil quality. In contrast, wildfires of high intensity and severity may potentially contribute to changes in species composition and forest floor properties. Furthermore, varying levels of overstory removal may reduce extreme wildfire risk for decades. The findings of this study reinforce the need for continued research and monitoring of both wildfire effects and prescribed fire use in the central Appalachian Region.