Tallgrass prairie range assessment techniques.

Abstract

A scorecard method r determining range condition was developed for the tallgrass prairie of east central Kansas. It was designed for use primarily by non-professional range managers. Data was collected by the step-loop method of determining vegetation composition and density. The step-loop data was entered into both a vegetation scorecard and a soil stability scorecard to determine overall condition classification of a range site. To assure that the data obtained by the steploop method was a reliable index to vegetation composition and density, plots were clipped by the frame-point method and estimates of basal density were made. It was shown that as the number of step-loop hits on decreaser species and increaser species increased, so did the lbs/ acre dry-weight production and the basal density. This seemed to indicate that the step-loop method was a reliable index to vegetation composition and density. Because range condition is closely related to range utilization, stubble height curves for determining the utilization of Andropogon gerardi Vitman.,S. scoparius Michx., Sorghastrum nutans (L.) Nash., and Panicum virgatum L. were formulated. Since native grasses have two mature forms, those that produce seedstalks and those that do not produce seedstalks, two stubble height curves were formulated for each species. One curve was for use during a year in which seedstalks dominate (normal or favorable year) and the other curve was for use during a year in which seedstalks do not dominate (unfavorable year). Finally, the relative growth rates (RGR) of A. gerardi, A. scoparius, A. nutans, and f. virgatum were measured as a possible indication of density dependant growth rates between range condition classes. No significant difference in RGR was found between almost all comparisons of condition classes or between the mean total heights, mean dry weights, or leaf area ratios of the various species at the two major study sites.