W. S. Cooper As I Knew Him: Teacher, Mentor and Friend

Abstract

William Skinner Cooper played an important role in shaping American “dynamic ecology” during the first quarter of the twentieth century. A student of Henry Chandler Cowles, he became a prominent proponent of physiographic ecology and geobotanical research. In the following essay, I present my professional and personal views of Cooper as his only female PhD student, his last PhD student, and the only one still living. I focus my reflections on the latter part of his career (mid 1940s through the 1950s) through a student's eyes but point out some relevant experiences from his earlier life as well as reflect on his continuing impacts on ecology today. I discuss aspects not well known about him, derived from many letters that were exchanged not only in his capacity as my mentor, but as a friend over many post-student years. Cooper is best known today for his long-term plant succession research on Isle Royale, Lake Superior (1913;1928), and especially for initiating studies of the complicated chronosequences following the retreat of tidewater glaciers at Glacier Bay, Alaska (Cooper, 1923, 1931, 1937, 1939). Some of these studies led to his significant philosophical publication, The Fundamentals of Vegetational Change (Cooper 1926b). The Ecological Society of America (ESA) recognized Cooper for these and other achievements as an Eminent Ecologist in 1963, as well as by establishing an award for geobotanical and physiographic ecology studies in his name (the W. S. Cooper Award) in 1985. He played active roles in the Society, such as leading a vigorous national campaign that convinced President Calvin Coolidge to establish Glacier Bay as a National Monument in 1925 (in 1978 President Jimmy Carter elevated it to National Park and Preserve status). Both for his efforts to preserve the area, and to establish it as a natural laboratory for science, a mountain in the Park was named Mount Cooper in 1980. Cooper, a charter member of ESA, also served in its early and critical years as Vice President in 1927 and as President in 1936. Less well known by ecologists are his more geobotanical studies. He investigated the influence of the past glacial environment on contemporary plant communities of the Upper Mississippi Basin (Cooper 1935) as a prelude to his later Glacier Bay successional research. He pursued extensive plant geographic (Cooper 1936) and geomorphic analyses directed toward understanding the development of Pacific coastal sand dunes and its relationship to glaciations and climate history (Cooper 1958,1967). His first Geological Society of America Memoir of dunes in Oregon and Washington (Cooper 1958) was nominated for the Penrose Medal, the highest award given by that society. He received the Charles P. Daly Medal from the Geographical Society (1965) for outstanding geographical studies, especially his research relating to post-Pleistocene climate history (Cooper 1942a). Furthermore, he has been credited with development of the subdiscipline of glacial ecology as a result of his interdisciplinary studies relating ecology and glaciology. Aside from this broad recognition of the impact of Cooper's research, however, other aspects that enable a better understanding of this multifaceted man have been little discussed or even ignored. His early concerns about advanced training of women in ecology and efforts to help them overcome hurdles of restrictions and low expectations have generally not been recognized. The effectiveness of his teaching has been recognized mainly in the context of the impact of his early doctoral students and their academic lineage on the field of ecology (Sprugel 1980), and merits further discussion. Furthermore, his mentoring role for students' research has not been addressed. And few ecologists know about his deep interests in the arts and his perception of their relationship to science. I shall address each of these facets chronologically within the frame of my experiences with Cooper, but will extend my student years to a post-student period. During this latter time Cooper had retired to Colorado and focused on completing the publication of his Pacific coast dune research. I now was associated with the University of California at Berkeley during an exciting period of development of new directions in ecological thinking. Completing the writing of my dissertation, discussion of some of my interactions with Herbert Mason via letters continued to reveal Cooper's interest in new ideas and his non-ideological perspectives. It also reveals his interest in maintaining a friendship with a former student, actually a geobotanical team, during his retirement. I begin the discussion of this facet to show that how I became Cooper's doctoral student reflects his background, interests, and personal attitudes. He spent most of his academic career (1915 to1951) in the Botany Department at the University of Minnesota, which had a general policy of restricting women to Master's degrees. The prevailing attitude there, as in many institutions at this time, was that women would not be able to utilize the advanced training a doctorate provided, but could use a master's degree in teaching. Cooper was supportive of women being educated in ecology and sponsored nine women for MS degrees and sent one of them to pursue a PhD degree with H. C. Cowles. I, however, was the only one for whom he went against departmental policy to sponsor as a PhD. Cooper's thinking about women's professional contributions may have been influenced as a student in the Botany Department at the University of Chicago doing his doctorate with Cowles (1907–1911). This department was noted for its progressive attitude in enabling numerous women to obtain PhD degrees in various areas of botany early in the 20th century. This was despite most such women having subsequent difficulty finding employment and research opportunities. This situation related to the tendency of the women to become married and traditional societal values of the times that dictated a relatively restricted life of caretakers for husband and children. Cowles, nonetheless, was amenable to having women doctoral students, in spite of the additional challenges imposed by field research in physiographic ecology. Perhaps he had been influenced that women could deal with field conditions as part of their research because his wife, Elizabeth, accompanied him as a field assistant on many of his treks. Cooper had been particularly impressed, as indicated from discussions in our history of ecology seminar, with several married women ecologists who were also educated at the turn of the century, such as Edith Shreve and Edith Clements. They were able to make successful contributions in field ecology with strong support of their well known ecologist husbands, albeit in different ways (Langenheim 1996). Cooper also was known among his colleagues for supporting women who accompanied their husbands as field assistants, such as Libby Lawrence, the wife of his colleague Donald Lawrence. Cooper sent Harriet George, after she took her MS at Minnesota in 1924 under his sponsorship, to the University of Chicago to pursue a PhD with Cowles. She had been an outstanding and enthusiastic student whom he thought would probably find a way to continue with the field studies she loved. At Chicago she met B. D. Barclay, a doctoral candidate in plant morphology, whom she married after obtaining her PhD in 1928. Her new husband strongly supported her professorship at the University of Tulsa, where they taught together in the Biology Department, as well as her field activities in Oklahoma and at the Rocky Mountain Biological Laboratory (RMBL). Cooper remained in active contact with Harriet throughout her career. Such examples may have encouraged Cooper in the early to mid-1930s to aid the research of Helen Foot (Cooper and Foot 1932), who had married Murray Buell during graduate school at Minnesota. The Buells became part of an inspirational duo working together with their numerous ecology graduate students at Rutgers University. Although they were sponsored by other faculty at Minnesota, Cooper was the one who mentored them in ecology during their student days and subsequently greatly influenced their ecological future through a long professional association. Especially in field ecological research, Cooper reasoned that if the husband was supportive or the two worked together, the trained woman had more chance in utilizing her advanced education to make significant contributions. It was in this context that my relationship with Cooper began to develop. A series of serendipitous events led to my becoming Cooper's last and only woman PhD. In 1943 I entered the University of Tulsa (TU) as an undergraduate hoping to major in geology; I soon learned, however, that women could take geology courses but not major in it (Langenheim 2010). A summer field-camp type course was required for the major that women were not allowed to take (a common issue for women at universities across the country). Cooper's former student, Harriet George Barclay, by then a botany professor at TU, encouraged me to take courses in geology and botany at TU and then apply to Minnesota to study geobotany and physiographic ecology with Cooper. During my senior year (1946), the University of Minnesota Botany Department accepted me as a MS graduate student with Cooper as my sponsor. Barclay also suggested that I take Field Ecology and Field Botany courses at RMBL in Colorado (appropriate living arrangements were available there for women) during the summer after graduation, as well as do some initial research on a prominent earthflow near the lab. I could begin to study plant succession initiating from a bare surface, and investigate the possibility of doing research on physiographic ecology there for a MS thesis. In the fall of 1946, I joined a large group of ecology graduate students in the U. of Minnesota Botany Department, divided between Cooper and D. B. Lawrence. I was the only one, however, with strong interests in pursuing physiographic ecology/geobotany in the Cowlesian tradition. Cooper thus advised me to expand my background in geomorphology and paleobotany. Because of significant intellectual impacts that the glacial geologist T. C. Chamberlain and geographic geologist R. D. Salisbury had on him during his student days at Chicago, Cooper thought similar relationships with geologists in my areas of interest would be important for me. As a result of Cooper's special efforts to establish these relationships, I had enthusiastic support from Robert Sharpe in geomorphology and Harlan Banks in paleobotany, which provided me with exceptional plant ecology—paleobotany and geomorphology interdisciplinary thinking—a perspective I would follow throughout my career. I had married a young geologist, Ralph Langenheim, at the end of 1946, and was separated from my new husband for the first part of 1947 while he completed his MS degree at the University of Colorado. He wanted to continue to do research in the Colorado mountains, hopefully in joint research with me, but had not committed to any university. Cooper then took the unusual step of asking Ralph if he would consider doing his doctoral studies at the University of Minnesota. Cooper had become very interested in seeing both of us do doctoral research on the western slope of the Colorado Rockies, where he had made first ascents of several peaks in the San Juan Mountains in 1908 and had become one of the “big figures in Colorado mountaineering” (Bueler 2000 and Borneman 2011). However, he had developed a heart condition shortly thereafter, in 1909, that prevented him from continuing vigorous high altitude activity. He thus channeled his love of learning about these mountains vicariously through the activities of other researchers. With a positive answer from Ralph, Cooper contacted colleagues in the Geology Department about considering Ralph's application; the department was sufficiently impressed to offer him a fellowship, which he accepted. As a result of Cooper's endeavors, and my husband agreeing to doing our doctoral studies in tandem, a research plan was worked out in which Ralph and I would jointly map about 100 square miles of the geology and vegetation in the Crested Butte area in western Colorado, ranging in altitude from 9,500 to 13,500 feet. Ralph would cover the total geology of the area, spanning PreCambrian to Pleistocene rocks, but focus on the stratigraphy and paleontology of the Carboniferous redbeds. I would describe the plant communities and their environments influenced in part by this geological diversity. Describing plant communities and determining their successional status constituted mainline plant ecological research during the 1940s and 1950s. Many areas, particularly western ones, had not been described. These descriptions of pristine vegetation were also considered valuable in aiding management decisions over the large areas of forest and grazing land increasingly being utilized. I think our research plan also intrigued Cooper because he could test his reasoning that women were more able to make significant contributions to ecological research, especially in the field, if they worked together in some way with their husbands. Geology faculty with whom Ralph and I had contact confirmed that this was a point they had discussed with Cooper. (He also convinced them that Ralph would benefit from my assistance.) Cooper was at least partially correct, as the record of successful field research of single women with PhD degrees during the 1940s and 1950s often depended upon cooperation with other women or relatives (Langenheim 1988, 1996). For example, two women (Catherine Keever and Elsie Quarterman) who obtained their PhD in 1949 from one of Cooper's early doctorates, H.J. Oosting, did their dissertation and later research together in the southern mixed hardwood forest. E. Lucy Braun, who had gotten her PhD in 1911, lived with and did research throughout the eastern deciduous forest with her older sister, a distinguished entomologist. Cooper was a remarkable teacher. I discuss two of his courses and the weekly graduate meetings he held at his home that influenced me most. In Ecological Plant Geography of North America and Field Ecology, his meticulous preparation, including presentation of striking photographs and scientifically effective illustrations, was impressive. His lectures and discussion sections were appreciated not only by ecologists within the Botany Department but were often crowded with enthusiastic students in Zoology as well as applied fields such as agriculture, forestry, range management, and wildlife from the university's St Paul campus. Before my discussion of the specific aspects of these courses, it is helpful to understand the development of Cooper's attitudes toward Frederic Clements, a dominant figure in ecology at the time (Kingsland 2005). Cooper had been influenced to disagree with Clements' rigid ideas as well as some of his perceived arrogant ways by Edgar Transeau, another well-known ecologist who taught Cooper as an undergraduate student at Alma College. After obtaining his PhD in 1911 under the sponsorship of Cowles (who also had misgiving about some of Clements' central ecological concepts; Cassidy 2007), and four years of conducting research in California, Cooper accepted the opportunity in 1915 to have direct contact with Clements and his ideas by becoming his assistant at the University of Minnesota. Although Cooper came to admire and perhaps understand Clements in some ways (and did not speak of him personally in a negative way, as numerous ecologists of the time did), he was at odds with most of Clements' fundamental ecological concepts. Overall, Cooper thought that Clements had burdened the development of clear thinking in ecology with conceptual dogmatism that lacked supporting evidence and with overwhelming jargon in his prolific writing. Specific criticisms came out in Cooper's courses in which he contrasted his own views supported with evidence from his own research. Plant geography was still an integral part of ecology in the 1940s and 1950s and different philosophies were presented in courses and books, to which Cooper added his own perspectives and helped his students understand the issues in context. I was fascinated with Cooper's historical approach to understanding the development of plant ecologic concepts from a geographic perspective in his Ecological Plant Geography of North America course. He discussed how plant geography emerged from the worldwide travels of 19th century geographers such as Alexander von Humboldt (Humboldt and Bonpland 1807). Cooper deliberated about Clements' philosophical orientation having been strongly influenced by floristically and systematically oriented German geographers such as Oscar Drude (1890) as well as by August Grisebach (1872), who followed Humboldt in emphasizing the important role of climate controlling the distribution of groups of species. Clements (1905) presented a new concept of vegetation as a complex organism that arises, grows, and matures with climate being the overall cause of its progressive change (i.e., its “development”). Clements deplored the “chaotic and unsystematized state of ecology” and decided to address this by devising a hierarchical classification of vegetation (often using new Greek-derived terms). Cooper disavowed this organismal concept of vegetation, and avoided the rigid, complicated classification system formulated and advocated by Clements. Cooper did agree with Clements in recognizing the importance of Andreas Schimper's Plant Geography on a Physiological Basis, which was based on the marriage of plant physiology and ecology. Along with Cowles, however, Cooper emphasized the philosophical position of the Danish botanist Eugenius Warming, author of the first textbook in ecology Plantesamfund (1895), which Cowles had learned Danish to read. Its German translation Lehrbuch der Okologishchen Pflazengeographie (1896) had led to wide development of courses called Ecological Plant Geography. Warming had created a new perspective regarding plant distribution by shifting plant geography from largely descriptive and floristic studies to consideration of evolutionary change and plant adaptation to the environment that might lead to better explanation of their distribution (Coleman 1986). Cooper's use of lantern and Kodachrome slides of his own photography in his Ecological Plant Geography of North America course was outstanding. He often said that viewing nature was an inspiring pleasure similar to viewing a great work of art. He referred to the impact on his thinking of Humboldt's incorporation of aesthetics along with scientific aspects of natural history in his publication Views of Nature (Humboldt 1850). Cooper captured some of this feeling in his photographs while demonstrating their utility in describing the plant communities and discussing environmental factors that control their distribution across most of North America. I often heard students exclaiming over how much they learned from the strikingly beautiful slides used in his lectures. Such descriptive courses are rarely part of ecology curricula today; I feel privileged that I had the opportunity to attend Cooper's course. William Cooper with climbing companion John Hubbard outside Long's Peak Inn 1906. Cooper made first Long's Peak ascent in 1904. Permission from Colorado Mountain Club Press. In his Field Ecology course, Cooper used continental glaciation, which strongly influences the Minneapolis–St Paul landscape, to demonstrate interrelationships of geomorphic and successional processes in plant communities. From his classic study of the past glacial environment of the Upper Mississippi Basin (Cooper 1935, 1938) he introduced students to glacial drift, glacial lake bogs and sand dunes developed from glacial outwash. At least during my student days, teaching assistants were taken on a small plane flight to view the area where they would assist students on field trips. Cooper was among the first ecologists to recognize the value of aerial views in understanding the ecology of an area. He also could point out its use resulting in discovery of Cedar Creek Bog, which later became Cedar Creek Natural History Area, a teaching and research facility administered by the University of Minnesota and Minnesota Academy of Sciences. Cooper's Field Ecology course was demanding and time-consuming, but a particularly valuable course for graduate students. It was divided into three parts. Students first accumulated data based on careful observation and description from 13 field trips. Although Cooper did not accompany students in the field when I took the course, he had done so in the past (Daubenmire, R. letter to Cooper, 1951). However, he did discuss with the class as a group their field data, helping to organize them for a complete report to be written by each student. He encouraged thinking about historical explanations, using information from other courses in which we were learning techniques of dendrochronology and palynology. As an example, my field report (Langenheim 1947) was 95 pages long and included numerous diagrams, tables and plant lists. Regular reading assignments included a few review chapters from the Weaver and Clements Plant Ecology text (still the only one available at that time), which also enabled direct discussion of Clements' viewpoints. A relatively long list of related research literature, some of which students were required to investigate, augmented the text reading. Cooper used an inductive approach in working from observable field data, to then testing multiple working hypotheses to explain the phenomena that would change through time. He had agreed with Cowles in thinking that laws of succession could be induced from exhaustive field research (later, however, finding difficulties in so doing during his Glacier Bay studies), but emphasized the need in all cases to subject the deductive process of theorizing to continued careful scrutiny from field data. He referred us to his 1926 classic paper, Fundamentals of Vegetative Change, where he urged a “fluent mode of thought,” emphasizing “that the mode of thought is more fundamental than the result thereof.” This became an overarching fundamental idea for his students. With regard to succession, Cooper had concluded “The fundamental concept is that change is a universal law governing vegetation. Succession is change regardless of causes.” He developed this conclusion doing doctoral studies on Isle Royale (1913) followed by a 17-year study there of mapped plants in quadrats, as well as by some early research progress at Glacier Bay (1923) that resulted in the aforementioned Fundamentals of Vegetative Change (1926b). In contrast to the common image promoted by Clements (1905 and 1916) of an essentially homogeneous “organismal” community ever developing toward stability, Cooper described the Isle Royale forest as a mosaic or patchwork of different ages that was in a state of constant change. His well documented exposition of the importance of small-scale disturbance in the community has gone largely unrecognized—attention having been given instead to A.S. Watt's gap-phase description (Watt 1947) of the phenomenon. Robert MacIntosh (1985), an historian of ecology, has noted that long-term recognition of a phenomenon often follows presentation of a descriptive term, which seems to have happened in this case.) Additionally, his Isle Royale study led Cooper to depart from Clements' generally accepted concept of linear succession to a stable (climax) community controlled by climate to a more complex view using the metaphor of a flowing braided stream. Here he integrated his paleoecological perspective, indicating that constituent elements (produced by glaciation in our case), branch, interweave, disappear, and reappear through time, and that the vegetation we see today is the advancing front of this stream. He also pointed out that successional processes on alluvial fans he had studied in California were controlled more by physiographic factors, including terrain, rock type, and geologic structure, than by biotic and climatic factors (Cooper 1926a). Thus, all successions did not necessarily follow the developmental pattern inherent in Clements' organismal view of the community. Cooper also warned us about predetermined classification systems of vegetation that perhaps inadvertently perpetuated static thinking, which thereby obscured dynamic processes. Cooper compared the local glacial phenomena the class had studied with some of his research on tidal glacial succession at Glacier Bay, Alaska (Cooper 1923, 1931, 1939). It had been this local Minnesota glaciated landscape that had stimulated Cooper to wonder how it was revegetated during glacial recession and led him to seek clues from the current glacial retreats at Glacier Bay. Here he saw the opportunity to view changes directly through time, thus not being dependent upon indirect (inferential spatial) comparisons, as other successional studies did at that time. However, during the 19 years of his own field work at Glacier Bay, Cooper found his approach in establishing permanent quadrats to view changes over time to be much more complicated than he initially thought it would be. He had discovered intermingled stages of succession that were not determined by age since deglaciation as he had originally hypothesized, but by various environmental conditions (Cooper 1939). Furthermore, although he valued the data he collected at Glacier Bay, by the end of his final scientific visit to Alaska he had realized that viewing Glacier Bay in isolation would not result in universal laws of succession (Cooper 1937). This conclusion was made even more evident by his work in Prince William Sound (Cooper 1942). He told my class that it would take more than his lifetime to understand the complexities of successional changes following the retreat of these tidewater glaciers. By the time of this course, he had turned the continued field studies over to his colleague, D. B. Lawrence (e.g., Lawrence 1950, 1953), and begun to focus on his long interest in the development of Pacific coast sand dunes. An important aspect of the Field Ecology course was Cooper's careful editing of the students' reports, making clear his high expectations for careful analysis of data and clarity in presenting it. He emphasized simplicity and directness in ecological exposition and strongly advised against using the unwieldy terminology and logic with which he thought Clements had burdened ecology. Some students, however, had low tolerance for this kind of “tough” treatment and remembered it with some distaste. Cooper's careful editing was often a topic of conversation among his former students at national meetings. In contrast to Frederic Clements who emphasized writing books, Cooper was especially interested in training graduate students; this included 24 masters and 13 doctoral students. The largest number of his doctorates came during the economically difficult Great Depression but the students managed to fund research throughout North America. Furthermore, they spread to institutions across the United States to teach, write textbooks and do research, thus disseminating ecology from the early primarily Midwestern universities. Important in this training were weekly meetings, often accompanied by spirited discussions held at Cooper's home. During my period as a student, D. B. Lawrence and his graduate students generally joined the group of students Cooper was supervising. One year, a term was devoted to the conceptual history of ecology; one of the students edited our presentations and put them together as a little monograph (Allison, H. 1948). We often focused discussion on recent books such as Stanley Cain's Plant Geography (1944) with new approaches to thinking about plant geography. We compared major monographs, such as Herbert Mason's (1947) and Ralph Chaney's (1938) different interpretations of Tertiary paleobotany, which expanded our views of vegetation history beyond the Pleistocene. We examined Clausen, Keck and Hiesey's monograph (1940) on experimental studies of the nature of species that led to the critical ecological concept of ecotypic differentiation, among others. These discussions of challenging ideas from the literature were especially important, because in this immediate postwar period, weekly seminars with distinguished visitors that we know so well today were not yet common events for graduate students. These stimulating sessions were highly valued and often attended by students from other departments. Numerous former students have acknowledged these sessions in their own later work. Cooper's influence on Raymond Lindeman's research on energy flow at Cedar Creek Bog (Lindeman 1942) is often cited. About his classic paper on the “trophic–dynamic concept in ecology,” Lindeman wrote to Cooper: “Many of the good parts of the paper were due to the stimuli given by yourself and spirited discussions out at your home” (Cook 1977, Rumore 2009). These meetings displayed Cooper's strikingly non-ideological and open-minded viewpoints regarding a wide range of research, and emphasized that he did not impose his own ideas on his students. He wanted students to make up their own minds but to be able to adequately defend their positions. Cooper never published a textbook, although he started writing one in the 1940s for his Introduction to Plant Ecology course (William Skinner Cooper papers, UMN Archives). His well designed and equally well received courses, however, inspired some of his students to do so (Hoffman 1996). Their eight textbooks span the late 1940s to late 1970s and cover both basic and applied fields. R.F. Daubenmire's Plants and