Site relationships and black walnut height growth in natural stands in eastern Kansas

Prediction of forestland productivity is needed for proper species selection in tree planting. By relating site quality to site and soil characteristics, potential productivity can be estimated for non-forested areas. Our study measured the growth potential of black walnut in natural stands in southeastern Kansas. We looked at over 200 stands on unglaciated soils. Numerous environmental factors were evaluated within the following broad categories: site, soil chemical, and soil physical. These environmental factors were related to tree height at the age of 50 years. Simple correlation and multiple regression analyses were run against site index using over 60 variables of soil and topographic characteristics. Depth to a restrictive layer explained 74% of the variation in height.