Author ORCID Identifier

https://orcid.org/0000-0001-7639-7401

Year of Publication

2020

Degree Name

Master of Science in Forest and Natural Resource Sciences (MSFNRS)

Document Type

Master's Thesis

College

Agriculture, Food and Environment

Department

Forestry and Natural Resources

First Advisor

Dr. Mary Arthur

Abstract

The decline of upland oak (Quercus spp.) communities in our eastern forests has been attributed to the loss of periodic disturbance after decades of fire suppression. As land managers have begun to reintroduce fire, effects on oak regeneration and species composition have varied widely, making it apparent that our understanding of how fire can aid in oak forest management needs refinement. Restoring upland oak communities requires decreasing stand density and opening of the canopy to release shade-intolerant oaks in the understory. This necessitates an extended fire-free interval to allow these oaks to be recruited into larger size classes and develop resistance to future fires. The ability of prescribed fire alone to create these structural changes is uncertain due to the low intensity of prescribed burns which for the most part do not kill larger diameter trees. In this work, I examined the utility of a fire-free interval following repeated fire alone as a management tool, as well as the combined effects of fire and mechanical removal in the form of midstory mastication. Where forest structure is significantly reduced by fire or mechanical removal, restoration of oak communities is complicated by both prolific sprouting and ingrowth of competitor species and the introduction of invasive species. The results of this study suggest that, in the absence of mechanical removals, reductions in stem density necessary to restore conditions for oak regeneration might be limited to sites that experience higher fire severity and/or drier landscape positions. Additionally, the rapid response of competing non-oak stems such as maple (Acer spp.), yellow-poplar (Liriodendron tulipifera) and sassafras (Sassafras albidum) during the fire-free interval and the increasingly severe invasion of Japanese stiltgrass (Microstegium vimineum) following disturbance are severe hindrances to successful restoration of upland oak ecosystems. Despite these management concerns, results of the research reported in this thesis indicate that restoring disturbance regimes slows the process of mesophication, improves size and stature of oak regeneration, and increases community diversity across the landscape.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2020.116

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