William Clark Denison, 1928–2005

William Clark Denison was born in Rochester, New York, on June 1, 1928, and died April 8, 2005, in Corvallis, Oregon, after a lengthy illness. He was the first of two children born to Glen Morris Denison and Rhoda Taylor Torrance Denison. Bill’s father was a high school administrator and principal of Charlotte High School, which Bill himself attended in grades 7–11. Bill’s mother was an avid naturalist, and her influence may well have turned Bill toward biological sciences and mycology. The family spent a number of summers in Chatauqua County in western New York, primarily in Chatauqua Gorge, where Bill’s mother operated a girls’ camp. During these periods Bill’s father served as registrar of “the Chatauqua” to supplement his meager depression-era salary as aPUBLIC employee.

Throughout his early years Bill was an exceptional student, breezing through exams with little application or formal study. This facility left him time to pursue numerous interests: trombone; stamp collecting; wood-working; hiking and camping; making fireworks; and getting to know people of many cultures and disciplines. Bill was a skilled craftsman, and he worked one summer as a millwright’s assistant at Eastman Kodak, fabricating custom-designed gizmos deemed necessary for the war effort. Throughout Bill’s career his skill and ingenuity with tools and materials afforded him great pleasure and served him in good stead when it came to the manufacture of everything from rainfall collectors to field balances for weighing lichens.

During Bill’s sophomore year he attended summer school and as a consequence graduated from high school at the end of his junior year. Bill applied to Oberlin College, was accepted, and arrived there as a prospective physics major in fall 1945. He soon discovered that the physics labs were closed and locked when scheduled classes were not in session but that the biology laboratories were always open. He quickly shifted his major to biology and together with his roommate Robert Lichtwardt fell under the influence of George T. Jones, a broadly trained field biologist who encouraged the study of all manner of organisms, including fungi. Howard Bigelow and Francis Holmes were also protégés of this gifted educator.

In 1948 Bill was expelled from Oberlin for his marriage to Margaret Mellinger, in defiance of the dean of the college (at that time administrative approval was required for the marriage of Oberlin undergraduates). Bill and Margo promptly moved to Gary, Indiana, where Margo had secured a job at a settlement house in an African-American neighborhood. Bill was employed by Turtox as a biological preparator, triple-injecting dead cats with colored latex for anatomical study; later he collected pig embryos and tapeworms from the Chicago stockyards. In January 1949 the Oberlin Committee of Deans relented and let Bill return to school. Bill received a B.A. in 1950 and stayed on at Oberlin another two years to work with George Jones on the systematics of Scutellinia, a genus of operculate discomycetes.

After their return to Oberlin Bill and Margo signed on as nature counselors at a summer camp in the Catskills specializing in square dancing, folk singing (with Pete Seeger as a frequent visitor) and left-wing politics. Throughout the rest of his life Bill could call square dances on a moment’s notice; he did so at his retirement party, and the memorial celebration of his life concluded with a square dance.

Bill Denison, 1928–2005, in 2002. Photo courtesy of Blaine Baker.

In 1952 Bill entered Cornell University, where he had been accepted for a doctoral program under Prof Richard Korf. Korf had encouraged Bill to undertake a revision of some manageable group of North American discomycetes. Bill had read a report (erroneous, as it turned out) that Scutellinia could be grown and fruited in culture, and he found the prospect of an experimental systematic study on a familiar group of fungi appealing. During Bill’s years in graduate school he collected extensively, primarily operculate discomycetes, for the New York State Museum

In the summer of 1955 Bill left Cornell, degree uncompleted, to take a position as assistant professor of biology at Swarthmore College. He was to occupy that position 11 y and during that tenure developed and taught a wide range of courses for the intellectually gifted and curious bunch of young people then enrolled as biology majors. These offerings included introductory biology, ecology, plant systematics, the morphology of lower plants (including fungi) and genetics. Genetics at the dawn of the era of molecular biology posed particular challenges for Bill, especially because class rosters included the offspring of several eminent molecular biologists. To say that Bill’s courses were well received is an understatement. Students once captured in his orbit often subsequently enrolled in all the courses he offered. He was a superb raconteur; his lectures often were funny and always illuminating. Exams were imaginative, quirky and usually taught as much as they tested. Bill never hesitated to throw out a challenge and let students chew on it; he let students make mistakes and figure out solutions. Laboratories were open-ended and project oriented. In short Bill’s educational philosophy was more attuned to that which prevails in teaching science now than was usual in the 1950s and 1960s.

Bill’s interactions with students extended beyond the classroom. His course in plant systematics became famous for an alternate-year field trip to the Florida Keys and points en route from southern Pennsylvania during spring vacation. He arranged a field trip with upper class botany majors to the USDA Research Center in Beltsville, Maryland, in 1962, and while there I distinctly remember being shown a white inorganic matrix with a faint blue smudge, alleged to be the first sighting of phytochrome. Bill introduced a small group of undergraduates to the arcane beauties of the ascomycetes during an NSF-sponsored summer program at his summer home near Ithaca, New York. In 1962 and again in 1964 Bill led groups of undergraduates on botanical and mycological expeditions to Costa Rica and other countries in Central America. Beyond this he became an unofficial career and personal counselor to many Swarthmore students. As undergraduates many of us thought we faced ambiguous futures, and as our time at Swarthmore grew short, we worried. Bill was nothing if not imaginative, and in his presence anything seemed possible—admission to graduate programs, travel/study in a foreign country, important discoveries, a calling, a career, a life. Just before his retirement Bill sent me a list of close to 100 Swarthmore protégés who had moved on to careers in biology.

At Swarthmore Bill also proved productive as a scholar, at least within the constraints placed on professors by the teaching load at a small liberal arts college. He indeed finished his doctoral thesis on Scutellinia in 1956. Three years later Bill published a companion treatment of the sister genus Cheilymenia. His subsequent work on discomycetes was based on several trips to Central America, where he discovered a number of interesting species and two new genera (Geodina and Nanoscypha) that have stood the test of time.

In 1966 Bill accepted a position as associate professor in the Department of Botany and Plant Pathology at Oregon State University in Corvallis. This move afforded Bill a wider arena for research, let him teach advanced courses in mycology and plant pathology, and for the first time in his career involved him in graduate education. At the same time Bill became curator of the mycological herbarium at OSU.

Although Bill’s academic focus shifted toward research when he moved to OSU, he remained passionate about teaching throughout his career. During Bill’s tenure at OSU he taught upper division courses on the fleshy fungi, microfungi and plant pathogenic fungi as well as a course on the morphology of lower plants. Toward the end of his career Bill took responsibility for teaching one term of general botany. In 1992 OSU presented Bill with the Lloyd Carter award for outstanding and inspirational teaching. Bill also taught a number of seminars on special topics of mycological interest and supervised graduate students; his doctoral students included John Haines, Harold Larsen, Richard Roeper, Amy Rossman and Marcia Wicklow.

During Bill’s first years at OSU he continued to publish on taxonomic discoveries among the Pezizales he had collected in Central America. At the same time his mycological horizons expanded and he succumbed to a real fascination with the lichens, particularly the large foliose and fruticose species dominant in the forests of the Pacific Northwest. In the early 1970s the International Biological Program got under way. Faculty members from various departments at OSU met weekly to discuss the nascent science of ecosystems analysis and the possibility for a multidisciplinary research program centered on sites within the H.J. Andrews Experimental Forest (AEF) in the Oregon Cascades west of Eugene. Bill participated in these discussions enthusiastically and constantly emphasized the importance of fungi in the function of these forest ecosystems. When NSF financial support for work in the AEF materialized Bill claimed a fraction of the money for pilot studies on a possible role for lichens in nutrient cycling in Douglas-fir forests.

In the early 1970s studies of forested ecosystems faced an intractable problem. While the soil, locus of nutrient retention and chemical transformation, lay readily at hand, the arena for primary production rose 100–150 feet above the ground to a patchy and inaccessible forest canopy. In 1971 one of Bill’s undergraduate students, Diane Tracy, suggested that old-growth trees could be rigged with ropes and ascended with conventional rock-climbing techniques. This proved possible, and it enabled detailed studies of nutrient cycling and trophic processes in the forest canopy. Bill was quick to devise a system of wooden spars that could be hoisted into the canopy and affixed to tree trunks to allow horizontal as well as vertical mobility.

What did these preliminary ascents into the canopy show? Most significantly they revealed enormous standing crops of Lobaria oregana and other lichens containing cyanobacteria. Bill’s postdoctoral fellow, Larry Pike, showed that several of these lichens, when moist, did indeed fix nitrogen at high rates. Because nitrogen is the limiting element in most coniferous forests in the Pacific Northwest these results suggested a significant role for lichens in forest health and pointed the way toward more detailed work.

By 1974 the International Biological Program was winding down and financial support for the research it stimulated was transferred to the newly organized NSF program on ecosystems analysis. In fall 1974 Bill and I wrote a joint proposal to NSF for a three-year grant to explore the contribution of arboreal lichens to the nitrogen economy of old-growth Douglas-fir forests. This grant was approved, and for the next three years we pursued a multipronged approach to answering this question. Bill supervised teams of tree-climbers who rigged six trees for canopy access and made detailed observations and measurements to estimate lichen biomass in treetops. I organized a program of litter-fall collections to determine the turnover of lichen biomass in litter. Fred Rhoades, then a doctoral student in my lab, established photographic stations in the canopy and documented growth of Lobaria thalli photographically for 30 mo. Bill, together with Larry Pike and a field technician, made repeated trips to the AEF throughout the rain year to measure N-fixation on lichens retrieved from tree canopies. All these data when combined with readings from micrometeorological stations obtained later suggested an overall contribution of 5 kg/ha of newly fixed N/year, a small but significant annual increment when summed over the 400–500 y lifespan typical of these forests.

In 1978 our canopy grant came up for renewal. Although the research continued another four years, Bill opted out at this point, possibly because the proposed continuation moved far afield from his mycological interests. Parallel to his canopy lichen research Bill had developed an interest in the commercial cultivation of edible mushrooms. Through a family connection Bill met an international entrepreneur with investments in vineyards and other agricultural enterprises and a particular interest in providing seed money for small scale ventures. With the money Bill set up a small laboratory and spawn production facility in Corvallis, incorporated as Northwest Mycological Consultants (NMC) in 1985. Initially the business was conceived broadly as an umbrella mycological consulting firm, but with time NMC concentrated almost exclusively on products and services for shiitake and other specialty mushroom growers, particularly on the production of high quality mushroom spawn. Bill and NMC senior research associate, John Donoghue, carried out research on the production of shiitake in plastic bags and developed bags with special filters that permitted gas exchange but excluded contaminating fungi. This proved an important advance that encouraged the shift from logs to sawdust as a substrate for shiitake production. Thanks to Bill’s efforts NMC has fostered the growth of a shiitake industry in Oregon from its inception to its current standing as the second largest shiitake-producing state in the USA.

During the same period Bill also pursued a low-key research program on the ecophysiology of Lobaria oregana. He maintained a lichen “farm” on his property north of Corvallis. There a large number of thalli growing on nylon monofilament were exposed to a variety of habitats; Bill monitored their growth over a period of years by recording increases in weight at regular intervals. In the early 1990s Bill also joined Nancy Weber and Jim Trappe as co-PI on two consecutive NSF grants to explore the systematics and distribution of the Pezizales in the Pacific Northwest.

In May 1993 Bill officially retired from Oregon State University, an event celebrated in a day-long gala starting with rides in a tethered hot air balloon and concluding with a square dance called by Bill himself. In retirement Bill found time for travel and with Margo made two notable trips to exotic locales, one to Pohnpei, Micronesia, to evaluate the possible contribution of arboreal lichens to aquatic food chains in mangrove-dominated intertidal zones and one to Bhutan (as the guest of the royal family) to provide advice on agricultural development. In the 1990s Bill also made three trips to Russia as a volunteer for a nonprofit international development agency. While there he provided technical assistance on mushroom production to farmers, cooperatives and government agencies. During this time Bill also continued his work with lichens. His lastPUBLICation documented the prevalence of thalli-bearing apothecia in populations of Lobaria oregana and showed that self-inhibitors of germination were present in ascospores of both L. oregana and L. pulmonaria.

In the early 1990s Bill became concerned about the possible importation of pests on green logs from Siberia, pests that might wreak havoc in the Douglas-fir forests of the Pacific Northwest. He provided expert testimony in a lawsuit that resulted in a ban on imports of unprocessed wood from sources outside North America. In 2004 Bill made contact with foresters in Russia who were interested in planting Douglas-fir seedlings in eastern Siberia as bait for possible Asian tree pests. Bill remained passionately interested in this project even during his long terminal illness.

No summing up of Bill’s life would be complete without mention of the numerous social and humanitarian causes he served. Bill engaged in draft counseling during the Vietnam War, helped to found a food co-op in Corvallis, served a term on the Benton County, Oregon, planning commission and cofounded the Willamette Institute for Biological control, which helped convince the Oregon Department of Agriculture to spray BT (Bacillus thuringiensis) spores instead of toxic pesticides during a gypsy moth outbreak in Oregon in the 1980s. Both Bill and Margo were founding members of the Adair Volunteer Fire Department and actively served as “fire-people” for a period of years. Bill and Margo sponsored a family of Russian immigrants during the 1990s. This brief list is incomplete and omits a large number of less enduring commitments. However no list could detail the daily acts of kindness and compassion that were hallmarks of Bill Denison’s life.

I am indebted to these individuals for help with compiling facts for this tribute: Margo Denison, John Donoghue, Richard Korf, Ann Lawrence, Robert Lichtwardt, Phil Sollins and James Trappe.