A CHARACTERIZATION OF MIXED FOREST STANDS IN THE TANANA VALLEY, ALASKA

Abstract

The objective of this thesis is to define the composition, age structure, volume ranges, and community types present in the Tanana Valley mixed stands.

Sixty-six permanent sample plots were established in 22 forest stands located throughout the Valley. Plots were at least 100 feet from a road. Total height, crown height, diameter breast height were measured and health and vigor were assessed for 5,415 trees. Five tree species and 57 herb and shrub species were found.

White spruce, birch, and aspen numbers are generally less in mixed stands than predicted for pure stands. Stand density index values, a method of assessing species' use of growing space, ranged from 61 to 422 stems per acre with a mean of 269. Existing individual tree volume tables need revision to avoid negative values for small trees. Existing site index curves for pure stands of lnterior species are inadequate for comparing to mixed stands.