Rexford F. Daubenmire

Daubenmire taught botany at the University of Idaho for ten years, from 1936 to 1946.[1] In addition to this job, during summers he taught at the Lake Itasca Field Station of University of Minnesota and at the University of Wyoming.[1] During World War II, he taught chemistry to American military personnel.[1]

In 1947, he moved to Washington State University in Pullman, Washington, where much of his research was undertaken.[1][2] In 1948, only one year after joining WSU's faculty, he created a six-week intensive summer field course for surveying in the Rocky Mountains. He was joined by seven students from universities in Idaho, Michigan, Montana, and Tennessee, as well as his wife Jean Boomer, who was also a botanist. From 1 July through 12 August, the group travelled over 3,000 miles, visiting areas of ecological interest including Palouse Falls, Lookout Pass, Great Falls, Big Timber Canyon, and Glacier National Park.[5] During his tenure, he took trips on his sabbatical years to Costa Rica and Sweden.[1]

He was a member of the Ecological Society of America. He served in positions including chairman and vice-chairman of the Western Section, and was a member of the editorial board, the Survey and Planning Committee, the Committee on Vegetation, and the Committee on Applied Ecology. He served as president of the society for the year of 1967.[2]

Daubenmire taught for twenty-nine years at WSU, retiring in 1975, whereupon he was appointed professor emeritus.[4] Between both Idaho and Washington State, he mentored thirty-five PhD students and eighteen Master's students.[1] Some of his students include F. Herbert Bormann and Tom Tidwell.[3]

After retirement, he and his wife moved to Florida, where they continued studying plant ecology. He studied the plant communities of Florida, and published multiple books and papers. The Daubenmires travelled to multiple locations, including the Amazon rainforest, the Philippines, Malaysia, and Africa, and Rexford led naturalist trips to Ecuador and Costa Rica.[1]

Daubenmire died on 27 August 1995 in Sorrento, Florida.[1]

In the early to mid twentieth century, there was debate among plant ecologists as to whether plant communities were randomly established within a continuum, or if they formed discrete and predictable entities.[3][5] The continuum theory preexisted Daubenmire's community theory, having been championed initially by Henry Allan Gleason, and re-established in the 1950s by University of Wisconsin-Madison professor John Thomas Curtis. It proposed that over an area, a plant species would appear, increase in quantity, then decline, and finally disappear, without distinct communities that could be predictably understood.[3]

Much of Daubenmire's early research was focused on this subject. He criticized Curtis's continuum theory, noting that it was unable to provide any meaningful results because it did not have an organizing principle and could not make predictions. He also argued against their methods — mathematically tabulating the abundance of distribution of plant species — as missing factors beyond just the plants themselves, and that population structures and dynamics were more complex than could be understood just with statistics.[6]

Daubenmire instead proposed the community theory: that all organisms within a community were necessarily ecologically interconnected, though the nature and degree of the interrelations changed depending on context: either obligative or indirect.[6] His work helped pioneer the "ecology of place," understanding how predictions could promote better environmental health and broader ecosystems, while also servicing human needs for natural resources through a scientifically informed process.[6] Decades prior to any fully established understanding of environmentalism, he recognized that an accurate understanding of ecosystems required knowledge of how plant communities operated outside of human economic concerns such as logging and grazing.[3][4]

Some of Daubenmire's contributions to plant ecology were initially seen as subversive and controversial due to providing an ecological lens over a strictly economic, and for diverting from commonly held beliefs and practices.[3] While his criticisms of the continuum theory were accepted by many of his peers, others defended the preexisting paradigm.[3]

In the 1950s, he created a classification scheme for plant communities which emphasized the need to study potential vegetation in an area, not just what is presently available for study after human influence.[3] This was seen as a radical proposition at the time.[4]

In his 1970 book Steppe Vegetation of Washington, he questioned the perceived wisdom of rangeland managers who were in favour of eradicating sagebrush, an economically non-viable plant whose removal provided better growth for valuable grasses in the short-term. He argued instead that a scientifically informed view of managing those systems would recognize the value of all species, not just those that had resource worth, because of how they had impacts, both direct and indirect, on long-term health of the range. He noted that sagebrush protected grasses which would be at risk of overgrazing without it; that its removal would have negative effects on mineral recycling into the soil, making for worse yields of other products in the future; that sagebrush provided habitat for birds that controlled insects; and that it increased soil quality in terms of moisture, by holding snow longer into springtime.[6]

Through decades of fieldwork, Daubenmire was able to classify the plant habitats in the forests and steppes of the Columbia Plateau. He was concerned with the longevity of old-growth forest in the region, fearing that economic concern was driving its destruction: loggers sought younger trees, and would remove older forest in favour of managed plantations more suitable for their work.[3]

As plant sampling for ecological study was in its infancy during Daubenmire's work, he had to pioneer many strategies and adopt others. He was a proponent of Hormay's line interception technique for monitoring changes in plant communities because of its cost-effectiveness. This involves recording the amount of cover of each plant along a set length of rope, then summing by species and converting into a percentage.[6]

Daubenmire created a simple tool for measuring coverage of plant species within a stand: The Daubenmire cover scale or Daubenmire frame.[7] It was originally a 20 cm x 50 cm plot frame, with one corner divided into a 7 cm x 7 cm square. References are marked for 5%, 25%, 50%, and 75% of the frame. If a plant within the frame fills out the 7 cm x 7 cm square, its cover would be 5% of the sampled area.[8] The original design has since been modified to improve cover accuracy for infrequent species within the frame.[8] It allows cover to be assessed by eye, with the researcher standing directly above where it is placed on the ground.[9] For best results, it is placed along a tape on predetermined transects, with results systematically recorded.[10]

Daubenmire studied a range of other subjects within plant ecology and botany, including the effects of fire on vegetation, the effects of soil moisture and temperature on conifer distribution, and lichen.[1] His research was the first to consider fire as an element in ecology.[11]

He discovered a new monotypic genus of Boraginaceae (a family of flowering plants that includes the forget-me-not) which is endemic to only a few square kilometers in northern Idaho.[1][12] Its binomial name, Dasynotus daubenmirei, commemorates him.