The Vegetation of Sodon Lake

Abstract

In 1947 a program of limnological studies was commenced by the scientific staff of Cranbrook Institute of Science. The season's activities were concentrated largely on Sodon Lake, Sec. 20, Bloomfield Township, Oakland County, Michigan. Sodon Lake is a pond of 5.7 acres lying in the Outer Defiance moraine (Stanley, 1936). It is apparently a kettlehole or ice-block lake surrounded by morainal hills and reaching a maximum depth of slightly less than 60 feet, with about 10 per cent of its area deeper than 50 feet. It has a small inlet bringing surface drainage from a few acres, but it is apparently supplied most of its water by subterranean sources. A small outlet, flowing at wetter seasons, connects to the east with Echo Lake. The original lake, in early postglacial time, covered approximately twice the present area. Whatever the details of its history, preliminary pollen studies indicate that the ice block had melted, the lake formed, and sedimentation commenced before the close of the pre-boreal spruce-fir period of the region, for the marly clays of the deepest sediments sampled (24 feet) contain a dominance of species of the Canadian forest (Cain, 1948; Cain and Cain, 1948). In the present study the vegetation of Sodon Lake is considered in its broadest aspect, including not only that within the area of open water, but also that occupying the sedimentary soils within the basin of the original lake. Only brief mention is made in this paper of the character of the upland vegetation. Of minor importance in themselves, these descriptions should play a useful role as background material for the chemical-physical and biological studies of the contemporary pond (Newcombe and Slater, 1948, 1949), and in the interpretation of the history of this body of water and its vegetation as it is being worked out by stratigraphic and pollen analyses (Cain and Slater, 1948). In the following outline of the communities which we have recognized at Sodon a polyphase classification is attempted which combines life-form, ecological, successional, and floristic relationships in the arrangement. These are natural areas of small order (Cain, 1947). Whether certain of them are valid communities is a question which deserves more study. It is certainly impossible to state, only on the basis of the local study, that several of these so-called communities are examples of associations in the sense that they are representative of widespread types of vegetation. In the absence of comparative data from intensive studies over a wide area, or on a regional