Quantitative Study of Degeneration of Mixed Prairie

Introduction The vegetation of great areas of Mixed Prairie has been destroyed by plowing. But even larger ones, still intact , have degenerated far from a climax condition. The almost universal cause for such deterioration, aside from drought, is grazing. The objective of this study has been to ascertain the changes in vegetation that have resulted from 60-70 years of different intensities of grazing by cattle and to express them quantitatively. Since the early work of SAMPSON (7) it has been generally recognized that the forage value and carrying capacity are highest where the vegetation represents a stage close to the herbaceous climax and that they are lowest in the type most remote from the climax. Studies on degeneration of various grasslands are necessary, since responses of vegetation to different intensities of grazing vary with the soil, climate, and climax vegetation. The physiographic region selected for this study is known as the Loess Hills and Plains of central Nebraska. It lies southeast of the great Sandhill Region of west-central Ne-braska. A total of 2255 square miles, about 48(Jo, of the upland loess soils of the four major counties in the region (Buffalo, Custer, Valley, and Sherman) is covered with the native prairie sod (8).