Silviculture is the science and practice of growing and regenerating forest trees using knowledge of their natural ecology and growth habits. Bob Seymour is a retired scientist who studied silvicultural systems to benefit landowners and communities of the Northern Forest.
Bob is the retired Curtis Hutchins Professor of Forest Resources at the University of Maine, where he joined the faculty in 1981. He used mathematics and computer modeling tools to help Maine's landowners and forest managers make silvicultural and forest management decisions about coniferous forest stands.
"My NSRC-funded research projects focused on improving the management of northern spruce-, fir-, hemlock-, and white pine-dominated forests," explains Bob. In particular, he is well know for rethinking the long-established methods of eastern white pine silviculture and testing an intensive crop-tree method of growing pine to achieve high rates of monetary return on clear-stemmed logs.
His studies at forests throughout eastern and northern Maine demonstrated how to grow white pine at unconventionally low stand densities—as low as 30 trees per acre when they mature. He carefully selected white pine crop trees, often grown in a mixture of more shade tolerant conifers (spruce, fir, and hemlock). He then compared expected growth and lumber yields of his crop trees to that of white pines grown at traditional densities prescribed by the eastern white pine stocking guide developed in the 1960s. (NSRC Project Links: Comparing Two Management Schemes for Eastern White Pine and Growth, Lumber Yields, and Financial Maturity of Isolated White Pine Crop Trees and Recommendations for Using Shelterwood Silviculture to Regenerate Eastern White Pine and Growth, Lumber Yields, and Financial Maturity of Isolated Eastern White Pine Crop Trees)
"By growing pines at lower than conventional stocking levels, you intentionally sacrifice total timber yield," he admits, "for very fast growing, knot-free trees that can be worth as much as $1000 a tree." Bob cautions that to succeed at this venture, a landowner must begin with a population of young, straight-stemmed pines that are worth pruning.
"We liked to use our NSRC funding for practical research projects where we could make rapid progress and deliver our findings to forest landowners and managers," he says. He and co-principal investigators, David Ray and Neal Scott, completed a study that addressed how forests contribute to offsetting carbon dioxide in the atmosphere by sequestering, or storing, carbon in woody tissue. Using decades of forest data to calibrate a computer model, they compared the estimated carbon sequestered by managed stands of northern spruce and hemlock to that of unmanaged stands. Bob continued his work on carbon storage with another NSRC-funded project to study the influence of age on productivity and carbon sequestration of eastern white pine,
"When we look just at the potential for storing carbon in forests, we find that reserving old growth forests may be the best strategy for carbon sequestration even over lightly managing stands. The big picture is more complicated, however, when we include the benefits of wood as a substitute for fossil fuels and other non-renewable resources," Bob suggests. "Looking back at decades of historical data gave us eye-opening results—how foresters and landowners manage forest stands can make huge differences in the amounts of carbon sequestered."
In another NSRC-funded project, Bob compared recently harvested stands with unmanaged second-growth benchmark stands and a nearby old-growth reserve to obtain baseline information for future comparisons between managed and old-growth forests. An on-going NSRC-funded study with University of Maine colleagues involves the Acadian Forest Ecosystem Research Project (AFERP), established on the Penobscot Experiand is part of a 20-year ongoing effort to test an ecologically-based silvicultural system in a mixed-species forest type representative of much of the Northern Forest.
Bob sums up his career as "a cross-fertilization of research and teaching." Winner of an outstanding teaching award in 2004, he taught silviculture, timber management, and forest stand dynamics for more than 22 years and advised more than two dozen graduate student research projects. Bob co-advised (with NSRC researcher Laura Kenefic) doctoral student Justin Waskiewicz, an NSRC Northern Forest Scholar who examined how forest stand structure affects growth and development of mixed red oak-white pine forests in Maine.
Also recipient of an outstanding public service award and selected as a Fellow of the Society of American Foresters (SAF), Bob has actively informed forestry practices and land management decisions in Maine for nearly 30 years. "Ninety percent of Maine is forested and much of that is privately owned," states Bob. "The forest is important to Northern Forest residents, and it has been rewarding to make a difference and contribute to society and our forests."
"Bob has not only been the leader of many formal and high level technical workshops, he has been an active and effective advisor to many organizations involved with the everyday problems associated with...managing natural resources," writes George Ritz, district forester with the Maine Division of Parks and Public Lands, in nominating Bob for SAF Fellow. "His intense professional and personal involvement in the management of Maine's Public Lands has had a direct and positive influence on the management of those resources and the development of the Bureau staff." He adds, "Although Bob is a 'high profile' type of forester, he has never lost touch with the field forester on the ground."
Bob works on the ground in his own Maine woodlot and enjoys the Northern Forest for hiking, fishing, whitewater canoeing, and cross-country skiing.