The
history and legacy of the western United States involve more than just cowboys
and covered wagons. Tangible pieces of our past lay within mixed-conifer
forests that dot the region. Trees not only form a vital part of the
contemporary western U.S. ecological system, but that of the future, as well.
Unfortunately, deforestation and poor management have threatened the benefits
and beauty of these natural resources.
Author
and OSU Professor Emeritus of Forestry John C. Tappeiner II joins us today to
demonstrate the importance of analyzing and understanding silviculture, the
study of forest growth and management. Tappeiner, along with three colleagues,
is co-author of the recently released second edition of Silviculture and Ecology of Western U.S. Forests. Read on for a
sneak peek at the text, introduced by Tappeiner’s commentary.
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This book focuses on the silviculture of western U.S.
forests for two reasons. First, the authors’ careers were spent mainly in the
forests of California, Oregon, Washington, and 
Arizona, with some brief forays
into southeastern Alaska, Montana, the Lake states, New England, and the
Southeast. Most of our research and practical forest management work was done
in Douglas-fir, ponderosa pine, lodgepole pine, true fir, and Sierra Nevada and
southern Oregon mixed-conifer forests. Therefore, many of the examples we use
are derived from either firsthand experience or the experience of colleagues in
these forests. However, many of the species and forest types that we discuss occur
throughout the western U.S., so the principles that we develop are valuable to
the silviculture of western forests. With the help of excellent reviews and by
consulting the literature, we have included considerable information from the
interior west. Therefore our work is of value throughout the West.
The authors believe that silviculture can help resolve
many of today’s forest management controversies. Frequently we hear debates
about forest management that reach an impasse. We think that these impasses are
least partially the result of an incomplete understanding of silviculture and
forest growth and development. We hope that the ideas and information in our
book will reduce the “sharp edges” and controversies in the forest management
debate and lead to more informed, fruitful discussions.
EXCERPT
Uncertainty and the Long-Term Nature of Silviculture
Taken
from Chapter 1: Silviculture, p. 13-14
"Silvicultural systems are by their nature long-term. It is
sobering to remember the length of time required for a forest stand to develop
and mature. This process may span the careers of several forest managers and,
in contemporary society, several changes in forest policy as well. A 50-yr-old
stand is comparatively young by western forest standards. Thus foresters—and
society at large—have only modest “control” over silvicultural systems and
stand and forest development. It is wise to view silvicultural systems as
“working hypotheses” of stand development, as Smith et al. (1997) suggest.
Silvicultural systems will often have to be modified for several reasons.
Natural events such as windthrow, insect and pathogen outbreaks, fire, and
unexpected regeneration of trees or shrubs occur frequently and may alter stand
density and species composition. Shifts in policy, markets for forest products,
landowners’ need for income, and public attitudes often require reevaluation
of, and changes to, systems. Furthermore, new information on silvicultural
practices, plant biology, or forest ecology may provide new insights and
reasons for modifying systems.
"Given the inherent uncertainty in the enterprise of
tending forests, we believe that one important principle is that a
silvicultural system should preserve future options. An example is the shift in
silvicultural theory and practice in response to an outbreak of Swiss needle
cast disease (Phaeocryptopus gaeumannii)
on thousands of acres of Douglas-fir in northwestern Oregon. Stands with
mixtures of western hemlock and other species may come through the episode
better than pure stands of Douglas-fir; these other species probably do not
retard the spread of the disease, but if they are present they can replace
Douglas-fir killed or damaged by it. Silviculturists who worked to produce pure
Douglas-fir stands for economic efficiency and high yield are consequently
reevaluating that practice on sites where needle cast is common As a result, in
disease-prone stands where western redcedar, red alder, and western hemlock can
grow, managers may either plant these species along with Douglas-fir or favor
them where they regenerate naturally. The outcome in terms of species
composition, wildlife habitat, and forest yield is not yet known, but a mixture
of species will minimize the risk of losing an entire stand. Even though some
species in the mix are of less commercial value, this silvicultural strategy
will maintain future options better than continuing to plant only commercially
valuable trees susceptible to the disease.
"Given the present rate of change in public sentiment
toward forestry, and resulting changes in regulations constraining
silvicultural practices, one may start to question whether the concept of a
silvicultural system is even viable (Shindler et al. 2002). The context of the
discussion often changes too rapidly for systems to be fully implemented,
tested, and understood. Environmental issues change rapidly, and new
regulations proliferate must faster than the typical cycle of thinning or
harvest of an even-aged stand. From an even broader perspective, potential
climate change and human population growth almost guarantee that the objectives
guiding the design of current silvicultural systems will be modified.
"Numerous creative solutions have been proposed for meeting
concurrent commodity and amenity objectives, but many of these are
silvicultural treatments designed to produce certain stand structures over a
relatively short term. These innovative treatments are often not well
integrated into comprehensive silvicultural systems. A given treatment may be
designed to produce a certain type of stand or vegetation structure, but the
longevity of that structure and the future dynamics of the stand may be only
superficially considered and understood. For example, it has been proposed that
groups of trees or single trees be left after harvesting of even-aged stands.
These trees are intended to provide structural diversity in the next stand and
help certain organisms survive from one stand to the next. However, it is not
clear how the trees around these groups and individuals should be managed. For
example, should they be thinned or underburned? The practice raises other
questions. Is it necessary to carry over young trees in stands being managed on
short rotations? If so, what species and how many trees should be left?
Finally, it is an open question whether those trees will actually function as
intended for conserving biodiversity."
Tappeiner et al., 2015
REVIEW
“This is a great basic overview of silviculture theory… It
is nice to know there are efforts to infuse the next generation of
silviculturists with a basic knowledge of ecology.”
Goodreads user Gabrielle
on May 24, 2008
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John C.
Tapeiner II is Professor Emeritus in the Department of Forest
Engineering, Resources, and Management at Oregon State University.
Douglas
A. Maguire is the N.B. and Jacqueline Giustina Professor of Forest
Management in the Department of Forest Engineering, Resources, and Management
at Oregon State University.
Timothy
B. Harrington is a Research Forester for the Pacific Northwest Research
Station, USDA Forest Service in Olympia, Washington.
John D.
Bailey is an Associate Professor in the Department of Forest
Engineering, Resources, and Management at Oregon State University.