Density and Age Distributions of Trees in Upland and Lowland Oldfields 60 Years After Abandonment: The Role of Dispersal

I attempted to determine whether the patterns of seedling establishment described in the literature for forests and recently abandoned oldfields are maintained in fields sixty years after abandonment. To determine this distribution pattern, as well as to compare patterns of age and density distribution in upland and lowland oldfields, I conducted research at Mammoth Cave National Park. I studied three species, the seeds of which are dispersed by three different modes: Juniperus virginiana, a predominantly bird-dispersed species; Acer rubrum, a predominantly winddispersed species; and Fagus grandifolia, a predominantly mammal-dispersed species. The establishment patterns observed by others in recently abandoned oldfields were not maintained in the sixty-year-old fields analyzed in this study. Age of Juniperus virginiana individuals did not decrease as distance from the edge increased in either uplands or lowlands. Age of Acer rubrum individuals decreased marginally as distance from the edge increased in the upland sites, but slope of the regression was not significant in the lowlands. Ages of Fagus grandifolia individuals decreased significantly as distance from the edge increased in both uplands and lowlands. Migration rate, however, was more rapid than predicted in the literature. Density distribution of stems of each species was even across all oldfields. Rare, long-distance dispersal events are a possible explanation for the establishment patterns observed in these sixty-year-old fields.

Name thesis:degree_name

Master of Arts

Discipline thesis:degree_discipline

Department of Biology

Year

2000

Author dc:creator

• McDaniel, Virginia

• Medical Sciences

Repository record dc:identifier

https://digitalcommons.wku.edu/theses/727

OAI identifier oai:identifier

oai:digitalcommons.wku.edu:theses-1730