Igniting Change: measuring prescribed fire effects in a central Pennsylvania hardwood forest
Open Access
- Author:
- Dems, Cody
- Graduate Program:
- Forest Resources
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- October 02, 2019
- Committee Members:
- Margot Wilkinson Kaye, Thesis Advisor/Co-Advisor
Erica A H Smithwick, Committee Member
Alan H Taylor, Committee Member
Jesse K Kreye, Committee Member
David Eissenstat, Program Head/Chair - Keywords:
- prescribed fire
fire management
structure
composition
forest fuels
quercus
acer
eastern deciduous forests - Abstract:
- Prescribed fire in eastern deciduous forests has been understudied relative to other regions in the United States yet is increasingly being used for management purposes. Particularly in Pennsylvania where prescribed fire use has increased by more than five times since 2009, the localized forest response has not been extensively studied. Given the feedback system between vegetation and fire, Pennsylvania deciduous forests will both burn and respond differently than forests across the Eastern U.S. due to variations in pre-fire land use and forest composition. This study broadens the understanding of increased fire disturbance by asking how prescribed fire affects mid-Atlantic deciduous forests over time. We measured changes in forest structure, composition, and fuel loadings up to eight years after prescribed fire in the ridge and valley region of the Appalachian Mountains in central Pennsylvania. Research was conducted on Pennsylvania State Game Lands 176 from 2009-2018. Within five years after prescribed fire, tree seedling density increased by more than 72% while sapling density decreased by 90%, midstory density dropped 46%, and depending on pre-fire conditions, overstory densities either increased or decreased to about 200 stems per hectare. However, not all tree species responded similarly and post-fire shifts in relative abundance occurred in the sapling and seedling size classes. Red maple and cherry abundance decreased while sassafras, quaking aspen, hickory, and black oak increased. Compositional shifts were most pronounced where pre-fire overstory thinning and two prescribed fires were applied. Other prescribed fire effects include litter depth increases, sustained duff losses, accumulation of coarse woody debris, and variability in fine woody debris over time. Forest response to prescribed fire is highly dependent upon pre-fire land use, management, weather, and vegetation. In context with other studies throughout eastern forests, we found post-fire structural changes are more consistent than compositional shifts. As scarce resources and burn windows limit prescribed fire use, management goals focused on forest structure can be achieved more readily and goals focused on forest composition will require a combination of long-term fire use and steady monitoring.