NATIONAL PARK SERVICE The Impact of Three Exotic Plant Species on a Potomac Island

Many people have aided in the successful completion of this study. Special thanks are extended to Dr. W. D. Billings of Duke University Botany Department for his counsel in selecting this study problem as well as in research methods and procedures. Dr. Boyd Strain of the same department also provided advice on procedures. The statistical consultations with Dr. Roger Chapman of Duke University Forestry School were invaluable in facilitating the research.

The gathering of much of the data would have been impossible or exceedingly slow without field and laboratory help. The following temporary National Park Service personnel were hired at various times specifically to help me: Judith T. Simmons, Margaret E. Oliver, Michael J. Blymyer, and Mary T. Flynn. In addition, other people both in and out of the National Park Service provided or volunteered their help for which I am thankful. Special mention, because of his great assistance in placing and retrieving light meters, is due to William C. Wilkinson, III, who was site supervisor on Theodore Roosevelt Island.

The patience of my wife, Nancy, and my children during this project as well as their help is acknowledged gratefully. All except the youngest child has helped in the field or laboratory at some stage in the project and my daughter, Elizabeth, has helped several times.

LINDSEY KAY THOMAS, JR.
Duke University