Agronomy and Horticulture, Department of


Document Type


Date of this Version



Published in Ecology, Vol. 28, No. 2 (Apr., 1947), pp. 146-162. Copyright 1947 Ecological Society of America. Used by permission.


After several years of intensive study of midwestern prairies, their degeneration under grazing was given careful consideration (Weaver and Fitzpatrick, '32, '34; Weaver and Hansen, '41). It was ascertained that the intelligent use or careless abuse of these grasslands had resulted in pastures and ranges which could logically be grouped into four classes. These were excellent, good, medium, and poor. The first consisted almost entirely of climax grasses and an abundance of nutritious forbs which, as is almost universally found, were of the highest grazing value (Bews, '29: 298). In good pastures many of these persisted, but there was a strong trend toward loss of vigor and decrease in abundance of the best grasses and forbs. About half of the vegetation consisted of the less productive Kentucky bluegrass (Poa pratensis) or short grasses. In pastures of medium grade, climax grasses and the most palatable forbs had all but disappeared. Here bluegrass, blue grama (Bouteloua gracilis) or buffalo grass (Buchloe dactyloides) were the dominants. Usually bluegrass alone was in control east of the Missouri river and the short grasses westward, but in the transitional area it was not unusual for both types to occur in alternes. Poor pastures were characterized by broken cover, more or less isolated patches of bluegrass or short grasses, much bare soil or soil supporting a stand of various, mostly annual, weeds. Since the great drought, medium and poor pastures of sand dropseed (Sporobolus cryptandrus) and western wheat grass (Agropyron smithii) also occur.