Stabilization of Midwestern Grassland

INTRODUCTION After three years with good precipitation (1941 to 1943), which followed the eight years of drought in the mid-continental grasslands, an extended study was made of the nature and degree of recovery of vegetation (Weaver & Albertson 1944). It was realized at that time that the mosaic of grassland patterns that crystallized out of a mass of recovering vegetation was merely one phase of a long developmental process (Fig. 1). The prairies had suffered a terrible catastrophe. At this time, largely by the tremendous increase of its most drought evading and drought resisting perennial species, mid or true prairie had merely succeeded in repopulating most of the bared soil. Many changes in the plant populations were still to occur. These included the increase of former dominants, then of small abundance; the suppression of drought dominants under the wetter phase of the climatic cycle; the disappearance or reduction to normal numbers of other relicts of drought populations; the increase of drought-depleted forb populations; and a new development of societies.