Green Ash Growth Curves

Abstract

The growth potential of green ash growing in native timber stands in Kansas can be evaluated using newly developed site-index curves. A single guide curve was computed from data gathered in the 1964-1965 Kansas forest inventory and harmonized curves were calculated. Green ash (Fraxinus pennsylvanica L.) is found throughout most of Kansas (Stephens, 1969). It has high commercial importance and ranks second in harvested sawtimber (Raile and Spencer, 1984). It is used principally for containers, tool handles, and furniture. Because it is hardy to climatic extremes, it is found on a variety of sites. Green ash naturally grows best on moist bottomlands and stream banks. Generally, it is not tolerant of forest competition and grows in almost pure stands (Harlow and Harrar, 1950). Evaluation of site productivity (wood-producing potential of an area) is an important aspect of management for attaining maximum benefits from forest lands. The site-index method is the most widely accepted means for determining site quality. It uses tree height/age relationships, which correlate well with timber yields. By definition, site index is the average height at age 50 years of dominant/codominant (overstory) trees in a fully stocked, evenaged stand. Curves or tables have been published for many commercial tree species in the United States. In Kansas, only curves for black walnut (Juglans nigra L.) and hackberry (Celtis occidentalis L.) have been published (Geyer and Lynch, 1987; Lynch and Geyer, 1988). The purpose of this paper is to provide another in a series of site-index equations, curves, and height tables for important tree species growing in natural stands in Kansas. PROCEDURE