Date of Award


Degree Name

Biological Sciences


College of Science

Type of Degree


Document Type


First Advisor

Frank S. Gilliam

Second Advisor

Jayme Waldron

Third Advisor

Shane Welch


This thesis contributes to on-going research at Marshall University on effects of excess nitrogen (N) deposition on hardwood forests. Excess N can decrease plant biodiversity and enhance loss of nutrients (e.g., Ca++). Preliminary results have suggested that excess N has increased cover of Rubus (blackberry) in the herbaceous layer. The purpose of this study was to quantify the response of Rubus to the N treatment, relating Rubus cover to species richness and using foliar analysis to examine effects on nutrient availability. It is expected that increased Rubus will decrease biodiversity by eliminating N-efficient species, and that added N will simultaneously increase foliar N and decrease foliar cations. Species richness decreased significantly with Nmediated increases in Rubus cover. Foliar tissue contained higher N and lower Ca++ from added N, suggesting loss via leaching with NO3 - . Observed increases of Rubus cover under a closed canopy is novel, considering its intolerance of shade


Forest ecology - Appalachian Region.

Hardwoods - Ecology.

Fernow Experimental Forest (Tucker County, W. Va.)