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. / Master of Science / Prescribed fire is a cultural land management practice used historically and currently in many locations around the world. These burns have been and are currently conducted for many reasons, including wildlife habitat management, hazardous fuel reduction, and vegetation control. Trees have innate characteristics that increase potential resistance and resilience to fire damage, however, these characteristics can vary depending on tree species and tree age. These characteristics may include, but are not limited to, bark thickness and texture, litter chemistry, leaf shape, and a species' resprouting strategy.
Prescribed fire is often used in conjunction with other forest management techniques (i.e. herbicides, thinning) in locations where timber value is a management priority, therefore it is important to understand how prescribed fire may affect the growth and quality of merchantable timber species. Few studies have focused on potential wood quality issues posed by the use of prescribed fire in the Appalachian Mountains. Determining if prescribed fires affect wood quality may provide land managers, in many locations, with information that may aid their selection of desired management practices and priorities.
To help address this knowledge gap, a research study was designed and conducted to investigate these issues for the following merchantable timber species in six burned and adjacent, unburned locations of the Monongahela National Forest, West Virginia: red maple (Acer rubrum), white oak (Quercus alba), chestnut oak (Q. montana), and northern red oak (Q. rubra). The results show that one or two mixed intensity and severity prescribed fires, implemented since 2012, resulted in an overall volume loss of 3% from the bottommost 4.9 m log, therefore prescribed fire did not cause a significant reduction in total volume. Two main species, A. rubrum and Q. rubra, comprised 93% of the trees with wounds resulting in volume loss. However, Q. rubra alone constituted 60% of trees with volume loss wounds. The results also show that A. rubrum was the most commonly wounded tree with 43.5% having at least one wound. Additional research is warranted to more fully understand these dynamics, including sampling locations that have experienced more prescribed fires and fires with different intensities and milling wounded trees and charred trees located in burned locations.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/111097 |
| Date | 01 July 2022 |
| Creators | Sharpe, Caroline Marie |
| Contributors | Forest Resources and Environmental Conservation, Coates, Thomas Adam, Carter, David Robert James, Thomas-Van Gundy, Melissa A. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Coverage | West Virginia, United States |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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