Northern red oak regeneration in oak and pine stands : long-term effects of mechanical competitor removal and short-term effects of prescribed fire

Author

Jason Paul Hartman

Date of Award

5-2003

Degree Type

Thesis

Degree Name

Master of Science

Major

Forestry

Major Professor

David S. Buckley

Committee Members

Run Hay, Jack Ranney

Abstract

Northern red oak (Quercus rubra) stands in northern lower Michigan are maturing on intermediate quality sites formerly dominated by mixed red pine (Pinus resinosa) and white pine (Finns strobus) forests. White pine and red maple (Acer rubrum) regeneration has been more prevalent than oak regeneration in oak stands throughout several forest regions of eastern North America. It has been hypothesized that the absence of wildland fire is supporting greater components of red maple in the present oak/pine stand type than in presettlement stands.

Maintaining the current oak resource has become a priority for forest managers, in Michigan and elsewhere, due to the high wildlife and timber values oak provides. Factors such as canopy composition, cover, and fire may influence oak regeneration by affecting red maple competition, late spring frosts, and deer browsing. Questions need to be addressed regarding effects of specific treatments on oak regeneration success in regions where hardwoods did not dominate historically.

Objectives included: 1) Testing the hypothesis that prescribed burning will reduce the abundance and cover of red maple and other competitors relative to oak, 2) Testing the hypothesis that oak seedling pre-hum height and/or basal diameter can be used to predict post-hum sprout growth, and 3) Investigating effects of interactions between prescribed fire and forest cover type (oak vs. pine), canopy cover, and deer browsing on oak and competitors of oak.

Study sites consisted of three natural northern red oak stands and three red pine plantations. Overstory removal treatments and understory manipulations were completed in 1991, when northern red oak acorns and nursery seedlings were planted with and without protection from browsing. Natural regeneration and planted oaks were measured and evaluated for growth and mortality July through August, in 2001 and 2002, before and after prescribed burning.

One decade after initial treatment, before prescribed burning, red maple density was already significantly less abundant in pine stands compared to oak stands. Mortality of planted oak seedlings was greatest in pine clearcuts and lowest in plots originally thinned to 75% canopy cover plots within pine stands. Caged seedlings exhibited greater survival in pine stands while uncaged seedling survival was nearly equal between cover types. Natural oak regeneration was significantly most abundant in plots originally thinned to 25% canopy cover plots within oak stands.

Prescribed fire was applied across all replicates in May, 2002. Following burning, the 25% canopy treatment within oak stands maintained significantly more oak stems than all other treatments. Post-bum oak sprout growth was greatest in clear-cut and 25% cover plots. Nearly all red maple < 2m tall were top-killed, while many larger maple sustained bark damage and infection by pathogenic fungi. These stressed stems sprouted prolifically even though the main stem survived. A noticeable increase in deer browsing of red maple compared to previous years was documented. Following burning, the percentage of uncaged oak seedlings browsed decreased in all plots within oak stands and increased in pine shelterwood plots. Results indicated that, on intermediate sites, a pine canopy had more negative effects on red maple development than did a single prescribed fire. Therefore, prescribed burning to control understory competitors was less critical in pine than in oak stands on these sites. The results also suggested that prescribed fire use is most successful for maximizing oak regeneration in oak shelterwood stands with 25-50% canopy cover, where oak regeneration was present before buming. First year fire effects indicated that red maple control was most successful in uncut plots. Future sampling will be needed to determine the effect fire had on larger red maple saplings in clear-cuts and 25-50% canopy cover treatments.

Recommended Citation

Hartman, Jason Paul, "Northern red oak regeneration in oak and pine stands : long-term effects of mechanical competitor removal and short-term effects of prescribed fire. " Master's Thesis, University of Tennessee, 2003.
https://trace.tennessee.edu/utk_gradthes/6585