A Subjective Tribute to the Work of Robert P. McIntosh

Abstract

A prominent ecologist named R.H. Whittaker once noted the possibility of an ecology of ecologists, their preferences being regionally or culturally determined. Whether or not this is true of one particular ecologist, Robert P. McIntosh (Mac), has yet to be seen. He would say that his career and his ecology were shaped predominantly by chance. In order to understand his contribution to ecology and The American Midland Naturalist, it is crucial to note the wide variety of work he completed, jobs he had, along with a bit of his character and personal history. In the following pages I will attempt to give a bit of insight into the career of an ecologist from the perspective of a completely biased granddaughter. The subsequent information has been gathered from the articles mentioned and several interviews with my grandfather Dr. McIntosh (Mac). At one point, I asked Mac how he came to study ecology. He knew exactly how to answer this question, as if he had answered a hundred times and knew just how to begin. It was mostly a matter of chance he told me. It all started when he was a freshman at Lawrence College. A friend of Mac's worked as Albert Fuller's right-hand man, to use his own words. By this time Mac had taken one botany class. Fuller, as the Curator of Botany at the Milwaukee Public Museum, was conducting a summer project to gather, press and send plants to high schools as learning tools. Mac's friend was put in charge of overseeing the project and hiring someone to identify the plants. Mac was hired for the job, worked for Fuller and very quickly learned which plants were which. After this experience Mac took more botany classes, graduated from Lawrence College and promptly joined the army in 1942. He was discharged in 1946 and wondered what to do next. To answer this question he talked to Albert Fuller and heard that biology laboratory teachers were needed. He was hired and taught in Milwaukee, Wisconsin until the head of the biology department there suggested that Mac go to Madison to get a graduate degree in biology from the University of Wisconsin. At first he took biology classes until he ran into the ecology department, met John Curtis and eventually became one of five students in Curtis' first graduating class. In 1951 Mac wrote a groundbreaking paper with his teacher and friend John Curtis. The study was based on the analysis of a large sampling of the prairie-forest border of Wisconsin. The data was used to determine if plant communities exist in discrete, neatly ordered units or if they exist as a continuous series of overlapping species. Mac considers the real contribution of the study to be the large sampling technique and the density-frequency dominance index that assigned weighted numbers to each species. It was in this paper that the continuum concept was named. As Mac has told me many times, the ideas of this paper were based on those of an earlier ecologist named Henry A. Gleason. It was Gleason who suggested an idea to rival that of Frederick Clements' original community-unit concept. Mac's unfailing and continued interest in the history of ecology meant he was able to illustrate for me the full story of Gleason and his initially defeated individualistic concept. In the first half of the 20th century, community ideas provided by Clements dominated the field of ecology and all ecology textbooks. Clements proposed that communities of organisms in nature are organized in very distinct units defined by identifiable boundaries. In contrast to Clements' ideas, Gleason offered the view that communities exist as a series of species that are distributed individually from one another. The widespread acceptance of well-delineated communities prevented other ideas such as Gleason's from being