Clements, Frederic E. (1874 – 1945) American Ecologist

views updated

Frederic E. Clements (1874 – 1945)
American ecologist

For Frederick Clements, trained in botany as a plant physiologist, ecology became "the dominant theme in the study of plants, indeed...the central and vital part of botany." He became a leader in the new science, still described as "the leading plant ecologist of the day."

Clements was born in Lincoln, Nebraska, and earned all of his degrees in botany from the University of Nebraska, attaining his Ph.D. under Charles Bessey in 1989. As a student, he participated in Bessey's famous "Botanical Seminar" and helped carry out an ambitious survey of the vegetation of Nebraska, publishing the results—co-authored with a class-mate—in an internationally recognized volume titled The Phytogeography of Nebraska, out in print the same year (1898) that he received his doctorate. He then accepted a faculty position at the university in Lincoln.

Clements married Edith Schwartz in 1899, described (in Ecology in 1945) as a wife and help-mate, who "unsparingly devoted her unusual ability as an illustrator, linguist, and botanist" to become his life-long field assistant and also a collaborator on research and books on flowers, particularly those of the Rocky Mountains. Clements rose through the ranks as a teacher and researcher at Nebraska and then, in 1907, he was appointed as Professor and Head of the department of botany at the University of Minnesota. He stayed there until 1917, when he moved to the Carnegie Institution in Washington, D.C., where he focused full-time on research for the rest of his career. Retired from Carnegie in 1941, he continued a year-round work-load in research, spending summers on Pikes Peak at an alpine laboratory and winters in Santa Barbara at a coastal laboratory. He died in Santa Barbara on July 26, 1945.

Publication of Research Methods in Ecology in 1905 marked his promotion to full professor at the University of Nebraska, but more importantly it marked his turn from taxonomic and phytogeographical work to ecology. It has been called "the earliest how-to book in ecology," and "a manifesto for the emerging field." More broadly, Arthur Tansley, a leading plant ecologist of the time in Great Britain, though critical of some of Clements' views, described him as "by far the greatest individual creator of the modern science of vegetation." Henry a. Gleason, though an early and severe critic of Clements' ideas, also recognized him as "an original ecologist, one inspired by Europeans but developing his ideas entirely de novo from his own fertile brain."

Clements deplored the "chaotic and unsystematized" state of ecology and assumed the task of remedying it. He did bring rigor, standardization, and an early quantitative approach to research processes in plant ecology, especially through his development of sampling procedures at the turn of the century. Robert McIntosh, writing on the background of ecology, argues that Clements was the "pioneer in developing the quadrat as the basis of quantitative community ecology," was "an earnest cheerleader for quantitative plant ecology, and was the notable American developer and advocate of the quadrat method," though he also declares that "Clements did not get beyond simple counting, and more sophisticated statistical considerations were left to others." However, McIntosh still credits Clements' work as a giant step to quantification in ecology, the crux being that Clements methods "were designed to examine and follow change in vegetation, not only to report the status quo."

Clements is often described as rigid and dogmatic, which seems at odds with his importance in emphasizing change in natural systems; that emphasis on what he called "dynamic ecology" became his research trademark. Clements also stressed the importance of process and function. Clements anticipated ecosystem ecology through his concern for changes through time of plant associations, in correspondence to changes in the physical sites where the communities were found. His rudimentary conception of such systems carried his ecological questions beyond the traditional confines of plant ecology to what McIntosh described as "the larger system transcending plants, or even living organisms" to link to the abiotic environment, especially climate. McIntosh also credits him with a definition of paleoecology that antedated major developments that would studies of vegetation and pollen analysis (or palynology). Clements being Clements, he went into print with a book, Methods and Principles of Paleo-Ecology (1924) appropriate to the new topic. Clements even played a role, if not a major one relative to figures like Forbes, toward understanding what ecologists came to call eutrophic changes in lakes, an area of major current consideration in the environmental science of water bodies.

One of the stimulants for botanical, and then plant ecological, research for Clements and other students of Bessey's at Nebraska was their location in a major agricultural area dependent on plants for crops. Problems of agriculture remained one of Clements' interests for all of his life. During his long career, Clements remained continually involved in various ways of applying ecology to problems of land use such as grazing and soil erosion, even the planning of shelter belts. In large part because of the early work by Bessey and Clements and their colleagues and collaborators, the Midwest became a center for the development of grassland ecology and range management. Worster (in Nature's Economy, 1994) suggests that Clements' "dynamic ecology provided much of the scientific authority for the new ecological conservation movement" which, from the 1930's on, relied heavily on his "climax theory as a yardstick by which man's intrusions into nature could be measured." Though considered misguided by some, pleas for wilderness set-asides still argue today that land-use policy should leave "the climax" undisturbed or preserved areas returned to a perceived climax condition. Clements believed early that homesteaders in Nebraska were wrong to destroy the sod covering the sandhills of Nebraska and that the prairies should be grazed and not tilled. Farmers objected early to the implications of climax theory because they feared threats to their livelihoods from calls for cautious use of marginal lands. Even some scientific attempts to discredit the idea of the climax were based on the desire to undermine its importance to the conservation movement.

Clements even anticipated a century of sporadic connections between biological ecology and human ecology in the social sciences, arguing that sociology "is the ecology of a particular species of animal and has, in consequence, a similar close association with plant ecology." That connection was lost in in professional ecology in the early forties and has still not been reestablished, even at the beginning of the twenty-first century. Though Clements' name is still recognized today as one of ecology's foundation thinkers, and though he gained considerable respect and influence among the ecologists of his day, his work from the beginning was controversial. One reason was that ecologists were skeptical that approaches from plant physiology could be transposed directly to ecology. Another reason, and the idea with which Clements is still associated three-quarters of a century later, was his conviction that the successional process was the same as the development of an organism and that the communities emerging as the end-points of succession were in fact super-organisms. Clements believed that succession was a dynamic process of 'progressive' development of the plant formation, that it was controlled absolutely by climate, developed in an absolutely predictable way (and in the same way in all similar climates) and then was absolutely stable for long periods of time. A cautionary note from MacIntosh: "Clements's ideas are notably resilient and persist, often under different names," even "some of his suspect ideas persist in the new ecology under new rubrics." Synonymizing Gaia with a super organism is one frequently cited example.

Clements' fondness for words, and especially for coining his own nonce terms for about every conceivable nuance of his work also got him in trouble with his colleagues in ecology. As McIntosh terms it, Clements was known for his "labyrinthine logic and proliferation of terminology," characterized by others as "chronic logorrhea." This fondness for coining new words to describe his work, e.g., 'the rium' to describe a successional stage caused by animals, added to the fuel for critics who wished to find fault with the substance of his ideas. Unfortunately, Clements also gave further cause to those, then and now, wishing to discount all of his ideas by retaining a belief in Lamarckian evolution, and by doing experiments during retirement at his alpine research station, in which he even claimed he been able to convert "several Linnean species into each other, histologically as well as morphologically."

Kingsland, writing in 1991, in Foundations of Ecology, identified Clements' 1936 article "The Nature and Structure of the Climax" as a classic paper and included its author as among those who defined ecology, but she could still claim that "by the 1950s plant ecologists had abandoned many of the central principles of Clementsian dogma, as well as the more cumbersome features of his classification system, as inappropriate or unproductive." But without the work and thinking of the early ecologists that created a foundation on which to build, ecology might be considerably the lesser today. Missteps certainly were made, but the stones were laid and some of that foundation is based on the dynamics of ecological processes as first conceived by Clements in a considerable body of pioneering work.

[Gerald L. Young Ph.D. ]