Patterns of oak regeneration in central Appalachian forest
Abstract
This research examined the characteristics of oak regeneration and species composition changes in a central Appalachian forest in West Virginia. The first phase of the work examined the diversity of woody species with respect to both time and different disturbance regimes from 1787 to 1997. Diversity declined from a high in 1922 to a low in 1997. This was correlated with a reduction in evenness, which was significantly correlated with the increasing importance of sugar maple for all disturbance regimes. Reconstructing the understory characteristics of an old-growth forest just prior to initial logging (ca. 1906–07) was the next focus. Prior to old-growth harvesting, oak recruitment appeared to be continuous from an ephemeral pool of small seedling-size stems less than about 20 years of age which led to an uneven-aged stand structure at a patch-level spatial scale. Immediately following old-growth harvesting, this cohort of small oak seedlings was released and converted the stand to an even-aged structure. The median standwide canopy disturbance interval was 33.8 years during the period 1738 to 1994. The final phase of this research was more applied in character and assessed the utility of releasing northern red oak that were planted and sheltered in a new forest opening. Different levels of release were applied in the spring of 1996—six growing seasons after planting 2–0 seedlings that were protected with 1.5 m corrugated plastic shelters. After two years, average height growth was 1.25 m and 1.21 m for the minimal release and the control group, respectively, and 0.85 m for the full release. Height of the competing vegetation also differed by treatment and was 4.91 m in the minimal release, 5.45 m in the control, and 6.34 m in the full release. In the control group, 26% of the trees were newly classified as overtopped in two growing seasons; 5% were overtopped in the minimal release; and none were overtopped in the minimal release. Early results indicate release operations that leave a moderate level of woody competition may prove to be the most effective at retaining a favorable competitive status of sapling red oak.
Degree
Ph.D.
Advisors
Gillespie, Purdue University.
Subject Area
Forestry|Ecology|Botany
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