Evaluation of site quality of an upland hardwood forest at Scott County, Tennessee

Management of upland hardwood forests involves many problems and is still at an early stage of development. A better understanding of the inherent complexity of these forests will be required before better schemes of forest management can be planned. Site evaluation is a management problem of high priority. Large numbers of species forming many-aged stands which are frequently abnormally stocked characterize upland hardwood forests. Under such conditions neither growth nor site index methodology can be directly applied to assess forest productivity.

This study was conducted to determine the feasibility of the site index methodology for evaluating site productivity of a tract of the Cumberland Forest Station of the University of Tennessee in Scott County.

By stepwise multiple regression analysis it was found that:

– Site index of chestnut oak can be estimated (r² = 0. 50) using logarithm of langleys/basal area ratio, total basal area growth (10-year periodic growth) and slope position as independent variables.

– Site index of white oak can be estimated (r² = 0. 45) using azimuth, slope position, white oak basal area growth (10-year periodic growth) and total basal area growth (10-year periodic growth) of the study plot as independent variables.

– Yellow poplar site index can be estimated (r² = 0.35) using azimuth and effect of surrounding landmasses, arctangent exposure, as independent variables.

– Total basal area growth (ten-year periodic growth) of the study plots can be estimated (r = 0. 58) using chestnut oak basal area growth (10-year periodic growth) and chestnut oak site index as independent variables.

– Basal area growth of yellow poplar (10-year periodic growth) can be estimated (r² = 0. 35) using altitude, exposure percent, and logarithm of langleys/basal area ratio as independent variables.

The most useful variables for estimating site productivity were azimuth, slope position, logarithm of langley s/basal area ratio, basal area of the plot, and total basal area growth (10-year periodic growth).