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.




 William Seaman
 Assistant Professor of Forest Resources
 and Conservation


This dissertation was submitted to the Graduate Faculty of the College
of Agriculture and to the Graduate Council, and was accepted as partial
fulfillment of the requriements for the degree of Doctor of Philosophy.

December, 1980




 Dean, lege of Agricultu


Dean, Graduate School