An Associational Study of Illinois Sand Prairie

Abstract

The present study is restricted to the grassland associations of sand in the Illinois River valley, and the emphasis is placed upon the animals of the region. The unit of study is here the association, or community of organisms: the social aggregate
of plants and animals, which, living in a common environment, come into various relations one with another. In the sand prairie of the river valley several types of areas may be distinguished, each
characterized by a definite set of physical conditions, by a particular association of plants, and by a particular assemblage of animals. In
this report the plant and animal assemblages are considered together, and inquiry is made into the relations which obtain between them, and between them and the physical environment.