1. Department of Ecology and Evolutionary Biology University of Michigan 2059 Kraus Natural Science Building Ann Arbor MI 48109 USA
2. Kellogg Biological Station and Department of Plant Biology Michigan State University 3700 East Gull Lake Drive Hickory Corners MI 49060 USA
3. Department of Biological Sciences University of Cincinnati 724 Rieveschl Hall Cincinnati OH 45221 USA