I certify that I have read this study and that in my opinion it conforms 



to acceptable standards of scholarly presentation and is fully adequate, 



in scope and quality, as a dissertation for the degree of Doctor of 

 Philosophy. 



Qd& 



William T. Haller, Chairman 

 Associate Professor of Forest 

 Resources and Conservation 



I certify that I have read this study and that in my opinion it conforms 

 to acceptable standards of scholarly presentation and is fully adequate, 

 in scope and quality, as a dissertation for the degree of Doctor of 

 Philosophy. 



Jerome V." Shi reman 

 Professor of Forest Resources 



and Conservation 



I certify that I have read this study and that in my opinion it conforms 

 to acceptable standards of scholarly presentation and is fully adequate, 

 in scope and quality, as a dissertation for the degree of Doctor of 

 Philosophy. 



tfx<U?.*J~- 



Sherlie H. West 

 Professor of Agronomy 



I certify that I have read this study and that in my opinion it conforms 



to acceptable standards of scholarly presentation and is fully adequate, 



in scope and quality, as a dissertation for the degree of Doctor of 

 Philosophy. 



Leon A. Garrard 

 Associate Professor of 

 Agronomy 



This dissertation was submitted to the Graduate Faculty of the School of 

 Forest Resources and Conservation in the College of Agriculture and to 

 the Graduate Council and was accepted as partial fulfillment of the 

 requirements for the degree of Doctor of Philosophy. 



^a^. 



- 



Daniel E. CanfieTd, Jr, 

 Assistant Professor of Forest 

 Resources and Conservation 



