The Beach Pool‐Leaf Hopper Complex

Abstract

The University of Michigan Biological Station is located at Douglas Lake about twenty miles south of Mackinac. Douglas Lake is one of a number of large and small lakes in the northern part of the Southern Peninsula. This region consists generally of low sandy ridges formerly covered by an extensive pine forest but, owing to repeated cutting and burning, has grown up to a mixed forest of pines and aspens with a sparse ground cover. Douglas Lake itself is roughly fish-shaped with a broad shallow margin, called the shelf, which fringes the shore all around the lake. The shelf averages about twenty feet in width with a depth of six feet at the outer margin. Beyond the shelf the bottom of the lake drops almost, perpendicularly to depths of fifty feet or more.