Agronomy and Horticulture Department


Date of this Version



Published in Ecology, Vol. 25, No. 2 (Apr., 1944), pp. 202-215. Copyright 1944 Ecological Society of America. Used by permission.


Major changes in grassland have now been followed for a decade over a considerable portion of true prairie in Nebraska and Kansas. The replacement of portions of this association by mixed prairie has been described (Weaver, '43). This major change resulted from the enormous increase or invasion of western wheat grass (Agropyron smithii) and the development of an understory of blue grama (Bouteloua gracilis) or buffalo grass (Buchloe dactyloides). But numerous areas of true prairie were only partially occupied by western wheat grass. Nearly all of the original cover of bluestems and associated species, however, was greatly opened if not completely destroyed by successive years of desiccation (1934 to 1940). Some degree of recovery was attained during the best years of the dry cycle and at the end of the drought several types or communities of vegetation formed a veritable mosaic in the prairie landscape. In this paper the vegetation of four representative prairies is described as it appeared at the end of the drought. This study, with the preceding one, gives an authentic record of conditions at the end of the period of great desiccation over the entire central portion of true prairie which has been so greatly damaged.