An Upland Forest Continuum in the Prairie‐Forest Border Region of Wisconsin

It has been said that the desirable order of ecological research in a given region is first, the study of communities, second, the study of the individual species, and last, the study of the habitat (Yapp 1922). Sociological investigations of constituent species and their numerical relations should precede autecological studies if the latter are to have maximum meaning. This sequence should lead to a greater efficiency in research, in that an initial knowledge of any natural groupings of species may enable the autecology of the groups to be studied simultaneously, with a resultant saving in time and travel expenses. The grossly inadequate state of autecological knowledge of even our most common species indicates that the current haphazard method of attack is faulty; if aggregations of species occur together under similar environmental conditions in nature, they could be studied in a systematic program. A long-term investigation of the communities of Wisconsin has been underway since 1946 with a view to determining the existence and the floristic nature of such aggregations (Curtis and Greene 1949). The present paper deals with the upland hardwood forests of the p)rairie-forest border region of the state and their interrelations with each other and with certain physical factors of the environment. Deep appreciation is expresse(l to Professor P. B. Whitford, hlio