Climax Forests of the Upper Peninsula of Michigan

Abstract

Examination of literature reveals that ecologists are not entirely in agreement concerning the origin and climax characteristics of the pine-hemlock-hardwood forests of the Great Lakes region. Most of these differences may be attributed to lack of information, and, therefore, before they can be harmonized, more facts concerning conditions in various habitats must be collected. This paper attempts to describe and interpret conditions existing in one of the habitat types in the region. It is a by-product of an investigation concerned chiefly with hemlock and is limited to conditions existing on the clay and sandy clay soils in the Ottawa National Forest near the western end of the Upper Peninsula of Michigan. The hemlock-hardwood forests of this locality are usually designated by foresters as mixed hardwoods; the ecologist calls them the northern hardwood climax or the yellow birch-maple climax; and the layman speaks of them as the virgin hardwoods of the Upper Peninsula. Certainly these forests are not virgin, because they were lumbered 45 or 50 years ago. The forester is surely correct in calling them mixed hardwoods because they consist largely of hardwood species and are so mixed in composition that even present-day forest management requires the indication of predominant 1