United States
Department of
Agriculture
Silviculture: From the
Forest Service
Cradle of Forestry to
Ecosystem Management
Southeastern Forest
Experiment Station
General Technical
Report SE-88
Proceedings of the National
Silviculture Workshop
. . .
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COVER PHOTO: The Biltmore School, built in 1898, was the first forestry
school in America. Several forestry students are pictured in front of the school
with its founder, Dr: Carl Schenck (white shirt, black bow tie). Many of the
school's 367 alumni became practicing professional foresters throughout the
United States. The school was located at what is now known as the Cradle of
Forestry.
In 1968, Congress passed legislation establishing the Cradle of Forestry on 6,400
acres of the Pisgah National Forest. The Cradle preserves the birthplace of
forestry and forestry education in America for the public. It also promotes the
develop
ent of forestry and modern forest management practices.
BACK COVER PHOTO: Dr. Carl Schenck. a German Forester, succeeded
Gifford Pinchot as manager of Pisgah Forest. Dr. Schenck established the first
forestry school in America.
The use of trade or firm names in this publication is for reader information and does not imply
endorsement of any product or service by the U.S. Department of Agriculture or other organizations
represented here.
September 1994
Southeastern Forest Experiment Station P.O. Box 2680 Asheville, North Carolina 28802 Silviculture:
From the Cradle of Forestry
to Ecosystem Management
Proceedings of the National Silviculture Workshop
Hendersonville, NC
November 1-4, 1993
Compiler
Louise H. Foley, Writer-Editor USDA Forest Service Southeastern Forest Experiment Station Asheville, N C Publisher
USDA Forest Service Southeastern Forest Experiment Station Asheville, N C Demonstration of Ecosystem Management .Options ( D.E.M.O.)
A Cooperative Effort Between NFS and Research in the Pacific Northwest James D. White, Dean DeBell Mike Amaranthus, and Brenda Wo dard Abstract
The D.E.M.O. project is a demonstration and administrative
study of silvicultural options for maintaining, enhancing,
or re-creating late-successional characteristics in managed
forests in the Douglas-fir region of the Pacific Northwest.
ix trea ments will be applied in each of eight blocks, four
m
Washington and four in Oregon. These blocks will be
established primarily in the Gifford Pinchot National Forest
in Washington and the Umpqua National Forest in Oregon.
Responses of vegetation, wildlife, soils, fungi, special forest
products, hydrology, economics, and social perceptions will be
investigated over time. The project is in the planning and
early implementation stages.
Introduction and Background
normal practice from the 1930's until the mid to late
1940's. The system used from 1950 through the
late 1980's consisted of staggered-setting harvests,
generally clearcuts, followed by slash burning
and planting. More recently, the preservation and
restoration of late-successional forest ecosystem
characteristics have become a major concern and
have led to retention of green trees in various
amounts and patterns in each cutting unit. These
may range from a few "wildlife" trees to a stand
density approximating that of a shelterwood. Each
approach met a specific need when adopted and
tended to be applied extensively, to the near
exclusion of other methods.
At the same time, it has become increasingly
apparent that our knowledge base for such
management changes is very limited. Most past
forest management research has focused on wood
production, while most basic ecology and wildlife
research has occurred in unmanaged stands.
We know very little about a full range of forest
management options. Many questions need
answering. How will a given practice influence
wildlife habitat, regeneration, nutrient storage,
resistance to fire, wind pathogens, insects? What
are the impacts on watershed and special forest
products? W hat are the economics of these activities
for a full range of forest values? Are activities
socially acceptable?
Forest resource managers and other interested
members of society need information about the
biological, economic, and social consequences
associated with different strategies for managing
forest ecosystems in the Douglas-fir region of the
Pacific Northwest. Professional and lay opinions
about forest management practices have become
polarized, caused partly by ideological differences
but also by inadequate information about effects of
management on many resources and values in the
ecosystem.
Forests can be managed under widely differing
approaches.
Historically, management systems employed in the
Pacific Northwest have changed with changing
societal desires, changing resource problems, and
changing environments. Selective cutting was the
Forester, USDA Forest Service, Gifford Pinchot National
Forest, Vancouver, WA; Team Leader, Silviculture, USDA
Forest Service, Pacific Northwest Research Station, Olympia,
In the past few years, various ideas have been
proposed for gathering sound information on
various silvicultural treatments and their effects
on late-successional forest characteristics. In early
1992, several of these efforts were combined, and
Congress allocated $1.5 million to Region 6 for
FY 93 to establish a New Perspectives Partners
demonstration program, consisting of alternative
harvesting experiments in Oregon and Washington.
WA; Team Leader, Long-Term Ecosystem Productivity, USDA
Forest Service, Pacific Northwest Research Station, Portland
OR; Assistant Timber Staff, USDA Forest Service, Umpqua
.
NatJOnal
Forest, Roseburg, OR respectively ) .
(
1
The study was to be implemented on National
Forest System lands in association with the Pacific
Northwest Research Station and New Perspectives
Partners. The Douglas Project in southern Oregon
and the Olympic Natural Resources Center at the
University of Washington were instrumental in
conceptual and supporting activities for the study;
they have been joined by Oregon State University,
the University of Oregon, and the Washington State
Department of Natural Resources.
During late 1992 and early 1993, several meetings
occurred for initial planning of the study. These
meetings involved the National Forests, Pacific
Northwest Research Station, New Perspectives
Partners, and various science committees composed
of agency an university scientists. The general
consensus of the meetings led to a decision to design
and establish one comprehensive administrative study
of silvicultural options, with installations in the
Umpqua National Forest in Oregon and the Gifford
Pinchot National Forest in Washington, rather than
separate studies at the two Forests. This unified
pproach increases cost-effectiveness and soundness
of scientific evaluations. Also, general trends and
findings can be applied with greater confidence to
other west-side cascade forests. The study was
named Demonstration of Ecosystem Management
Options (D.E.M.O. ) .
D.E.M.O. Design
The D.E.M.O. project will focus on regeneration
harvests and will be installed primarily in mature
forest stands. Different methods of regeneration
harvest cutting will be examined, all intended to
foster the health and productivity of multiple-use
forests. The project will focus on attributes
and species associated with old-growth or
late-successional forests. Within constraints imposed
by each regeneration harvesting option, individual
silvicultural practices will be selected to retain or
accelerate the establishment (or re-establishment) of
late-successional features.
The Treatments
The project will evaluate six treatments, which
include even-aged, two-aged, and uneven-aged
management systems (fig. 1). The systems, differing
primarily in the density and arrangement of residual
trees for an initial regeneration harvest cut, will
create a broad range of biophysical environments.
They are defined in relation to the percentage of
basal area retained after harvest:
D.E.M.O. will focus on attributes and species
associated with old-growth or late-successional
forests. There are many reasons for emphasizing
late-successional characteristics, including the fact
that it is the major driver of current controversies
and changes in public and private forest land policy
today. Although late-successional features will be
emphasized in the study, assessments will extend to
other resources and values and to many practical
considerations in forest ecosystem management.
The D.E.M.O. project will evaluate a wide range
of silvicultural treatments for managing forest
ecosystems and provide an opportunity to proactively
develop information on a range of management
options, all of which seem biologically and
operationally feasible and each of which may have its
time and place in managed forest landscapes. Thus,
the proposed design provides for long-term evaluation
of effects of treatments on multiple resources and
biological, social, and economic values. There will
be many near-term benefits and products associated
with D.E.M.O., but a long-term study is needed to
evaluate sustainability of the various options for
regeneration and management of trees, stands, and
habitats.
Figure 1-D.E.M.O. treatments.
1. 100 Percent Retention-Uncut, unmanaged
"control" stand. This treatment will provide
a baseline for judging the effectiveness of other
treatments in maintaining, re-creating, or accelerating
the development of late-successional features.
2. 80 Percent Retention-Initial harvest will occur
in small patch cuttings (e.g., about 2 acres or width
equal to two times the height attained by dominant
trees during the conversion period). Such patches
will be dispersed throughout the stand and will
occupy about 20 percent of the area. The intent
is to develop over time a multiaged (three to five
age classes), multistoried stand by means of the
group selection system. Future regeneration cuttings
will probably occur on 20- to 30-year cycles; some
thinnings may be done at the same time.
3. 60 Percent Retention-Initial harvest will be a
combination of small patch cuttings, as with the 80
percent treatment, and some thinning dispersed
throughout the remainder of the stand. Patches will
occupy about 20 percent of the area. The intent is
similar to the previous treatment: group selection
will result in multiple age classes, with cutting cycles
of 20 to 30 years.
4. 40 Percent Retention-Half of the residual trees
will be grouped throughout the unit in patches
of about 2 acres. No cutting will occur within
the patches. The other half of the residual trees
will be dispersed throughout the unit and will
consist of diverse species and size classes. The
intent of the patches is to provide an undisturbed
reservoir of biological material that may lead to
rapid recolonization and recovery of species in the
disturbed area. The intent of the scattered residual
trees is to develop a two-aged, multistoried stand.
In future entries, trees in younger age classes will be
thinned and some of the large trees of the original
stand may be harvested. Other large trees will be
retained for structure, some eventually becoming
large snags for cavity-nesting wildlife.
5. 20 Percent Retention-Specifications and intent
of this treatment are the same as for the 40 Percent
Retention treatment, except that fewer 2-acre patches
and dispersed trees will be retained.
6. 0 Percent Retention-This involves a complete
clearcut, "control" area. No green trees (wildlife
trees) will be left because the intent of this treatment
is to complete the disturbance or retention spectrum.
126
More importantly, this treatment will provide a
baseline for judging the effectiveness of some of
the other treatments in accelerating recovery and
recolonization of selected features in managed forests.
Various silvicultural practices will be implemented
as appropriate to secure regeneration and foster
the principal goal of maintaining or accelerating
the development of late-successional characteristics.
These practices may include slash burning, other
site preparation, planting, control of understory
competition, thinning, pruning, and fertilization.
Snags, coarse woody debris, and advanced
reproduction will be retained to the extent
practicable and appropriate.
Some of these practices also may enhance wood
production as they accelerate stand development and
associated habitat. In most cases, applications will
differ in some respects from those normally used
when wood production is the primary objective.
Basic Design or Layout
Treatments will be established in blocks, four each in
the Gifford Pinchot and Umpqua National Forests.
If suitable blocks cannot be found within these
National Forests, we will attempt to locate blocks
on other ownerships in the two States. At this
time, it seems that one block in Washington. will be
located on limds managed by the Washington State
Department of Natural Resources. Each block will
consist of one each of the six treatments, with all
treatments within a block applied in stands having
similar age and species composition, environment,
and surrounding landscapes. Implementation of
some treatments at some sites will require variances
or release from current or changing constraints,
such as Forest Plan Standards and Guidelines,
Late-Successional Reserve boundaries, and streamside
buffer zones.
·
The six treatments will be imposed on units of at
least 13 hectares (32 acres); this minimum size
constraint is needed to assess effects of treatments
on small mammal and bird species. Previous work
has indicated that a square to slightly rectangular
(length:width :$1.5) grid consisting of at least 63
or 64 points, spaced 40 meters (...., 130 feet) apart,
and surrounded by a 40-meter buffer is essential
(see fig. 2). Ideally, the units should be at least 20
hectares (50 acres) and contain a grid of 100 points,
but reconnaissance of sites to date has indicated that
0% Retention 20% Retention
·
60% Retention
40% Retention
80% Retention
Figure 2-D.E.M.O. sampling grid on the landscape.
1 r
we are unlikely to find enough number of stands
of this size that would also meet the other site
selection criteria. Sites are constrained by roads,
existing harvest units in the fragmented landscape,
management allocations, and other constraints, such
as streamside buffers. It would seem, at first glance,
that 32-acre patches of ground should be relatively
easy to find. Unfortunately, existing clearcuts, roads,
streams, and differing stand types severely limit
opportunities.
Ongoing efforts to locate suitable treatment units
have yielded blocks composed of a diversity of forest
zones and stand age classes for the study. Blocks
will be located in the Western Hemlock, Western
Hemlock/White Fir, and Pacific Silver F ir Zones;
age classes represented by the blocks range from
about 70 to 200'years or more. Douglas-fir is the
major tree species in all blocks. The majority of
conditions faced by resource managers in west-side
forests will be represented; thus, basic findings
should have general applicability. At the same time,
the wide range in conditions increases the need to
collect adequate data on pretreatment conditions and
wildlife populations. For some of the study variables,
such as wildlife, 2 years of preharvest baseline data
collection are planned.
Major Areas of Investigation
The D.E.M.O. project provides an opportunity
to examine the effects of the treatments on many
ecosystem characteristics and in relation to other
management considerations, including public
expectations and economics. Given limited time
and financial or human resources, decisions are
now being made regarding which subjects to study.
Some of the high-priority items are given below for
six general subject categories. Plans have been
drafted for trees and snags, understory vegetation
(including regeneration and down trees), wildlife, soil,
mycorrhizal fungi and other special forest products,
hydrology, and social perceptions.
Vegetation
Vegetation assessments will include the survival,
damage, and growth of residual trees, advanced tree
reproduction, and other woody and herbaceous
vegetation; "survival" and dynamics (decay) of snags
and down trees; and the establishment and growth of
tree seedling regeneration.
Wildlife
W ildlife assessments will determine population
densities and habitat use by several species of small
mammals, birds, amphibians, and reptiles. For the
most part, D.E.M.O. will focus on wildlife species
with home ranges at the stand level. The size of
the sampling grid, for instance, was driven by the
home range size of the flying squirrel. D.E.M.O. also
may provide some information about habitat use by
ungulates and other farther ranging mammals and
birds.
Soils, Fungi, and Other Special Forest
Products
Work on soils, fungi, and special forest products will
evaluate disturbance and compaction of the forest
floor and will determine the abundance, community
structure, and dynamics of fungi and special forest
products. Mushrooms and other special forest
products have greatly increased in demand in the
Pacific Northwest during the past few years and· are
both economically and ecologically important. Fungi
also are critically important components of food webs
associated with wildlife species of late-successional
forests. We find that we know very little, however,
about the effect of different management regimes on
these increasingly important organisms.
Hydrology
Hydrologic investigations will focus on quantity and
quality of water moving along surface and subsurface
flow paths, snow accumulation, rain-on-snow events,
and potential for cumulative watershed impacts.
Social Perceptions
D.E.M.O. will include investigation of social
perceptions of the treatments. Perceptions will be
categorized by attitudes and policies, and in relation
to the amount of information people have about
management objectives.
Economics
Economic investigations will focus on financial
evaluation of harvesting costs, stumpage values,
future stand growth, and economic values of
residual trees, and a wide range of commodity and
noncommodity values.
Supporting Studies
The D.E.M.O. installations and data sets developed
will provide many opportunities for supporting
studies concerning all the above as well as other
ecosystem components and values. Examples include
(1) the relation of original stand characteristics and
thinning and harvesting levels to residual canopy
coverage; (2) performance and contributions of
genetically selected stock in the diverse environments
created by various silvicultural regimes; and (3)
depredation of bird nests by corvids (ravens, crows,
and jays) and other predators in the different
regimes; and (4) effects of treatments on insects,
disease, and lichen occurrence and composition.
Some of this work may be conducted with D.E.M.O.
funds, if resources are sufficient. If not, the fact that
such studies can be incorporated into an already
established network should make them attractive to
other funding organizations.
Challenges and Opportunities
National Forest Managers and Research
Scientists
treatments and involve the public in ways that diffe,
from those currently deemed most appropriate or
desirable.
The "Catch-22" of Ecosystem Management
Most forest land managers and much of the
public realize that ecosystem science is in its
infancy, particularly with regard to intentional
management of specific ecosystem components
other than trees. Considerable information,
much of it based on research, will be needed to
place such management on a sound foundation.
Ongoing management, however, necessitates the
establishment of various standards and guidelines
in individual forest plans and other management
plans (such as the Forest Ecosystem Management
Assessment Team report). Such guidelines common!:
represent first approximations based on differing
proportions and amounts of data, professional
judgment, and prevailing philosophies. In many
cases, they have not been validated and in most case
they can be improved. Their existence, however,
may pose significant obstacles to stand-level and
landscape-level research. In order to implement
D.E.M.O., some of the standards and guidelines
in existing and proposed plans will have to be
relaxed for the study. These include those associated
with green tree retention, stream buffer width on
intermittent and some small perennial streams,
limitations on opening size, and visual quality
objectives. The potential impacts associated with
departure from current standards will be quite small,
and thus, we are hopeful that the essential variances
will be obtained.
The planning of D.E.M.O. has required close
interactions between managers and scientists and
has led to better understanding of their respective
roles and contributions in management of forested
ecosystems. Previously unrecognized opportunities
for scientific research and for alternative management
approaches have become evident. The interactions
surrounding D.E.M.O. also have presented some
challenging hurdles, due in large measure to different
objectives and working protocols in most scientific
and management activities. Researchers must be
Optimism and Opportunities
concerned with being able to evaluate treatment
effects and doing so in an objective, unbiased fashion. Although implementing any project on National
Forest System lands in the Pacific Northwest today
These concerns have required harvest units larger
and more extreme treatments than managers would
is problematic, we believe the D.E.M.O. project has
sufficient strength and potential value to overcome
currently implement; moreover, treatments must be
the hurdles. Smaller scale efforts, whether designed
randomly assigned to experimental units to avoid
studies or simply demonstrations, will not, in and
bias, or the appearance thereof, rather than be
of themselves, provide the kind of data needed for
assigned in some manner considered optimum for
valid assessments of treatment responses and the
current land management objectives. Managers may
development of sound management guidelines. This
desire to minimize or mitigate impacts, whereas the
effort, and others of similar magnitude, will be
purpose of the research is to evaluate those impacts.
In the case of D.E.M.O., goodwill and understanding needed to develop the science and art of ecosystem
management. We expect the D.E.M.O. project to
have led to acceptable compromises in resolving
provide excellent opportunities far into the future
conflicting objectives. Scientific objectives were
for training ecosystem managers and for public
modified so that harvest area size and number of
involvement
in many aspects of forest resource
treatments were reduced, thus decreasing impacts on
management.
the land. Managers have been willing to impose
D.E.M.O. Up date
July 1994
During winter and spring of 1994, the initial
D.E.M.O. design was modified, partly to include a
retention level similar to that recommended in the
new Pacific Northwest Forest Plan for managing
late-successional and old-growth forests within the
range of the northern spotted owl (the President's
Forest Plan). The revised plan will compare dispersed
and aggregate tree retention at the 15 Percent
Retention level (the level prescribed in the President's
Forest Plan) and at the 40 Percent Retention level. It
will include one high retention treatment (75 percent),
but will not include a complete clearcut (see revised
fig. 2). The six treatments are as follows:
1. 100 Percent Retention-Uncut, unmanaged
"control" stand. This treatment will provide a
baseline for judging the effectiveness of other
treatments in maintaining, re-creating, or accelerating
the development of late-successional features.
2. 75 Percent Retention-Initial harvest will occur
in small patch cuttings, approximately 1 hectare (2.5
acres) in size. Patches will be dispersed throughout
the stand and will occupy about 25 percent of the
area. Future regeneration cuttings will probably occur
on 20- to 30-year cycles; some thinnings may be done
at the same time.
3. 40 Percent Retention (Dispersed)-Residual trees
will be dispersed throughout the harvested stand, and
will consist primarily of dominant and codominant
130
size classes. The intent is to provide a test of a
moderate level of tree retention, with retained trees
dispersed throughout the unit.
4. 40 Percent Retention (Aggregated)-Residual trees
will be clumped in patches approximately 1 hectare in
size. No cutting will occur within the patches. The
intent of the patches is to provide an undisturbed
reservoir of biological material that may lead to rapid
recolonization and recovery of species in the disturbed
areas. The treatment provides a test of a moderate
level of tree retention, with retained trees aggregated
in patches.
5. 15 Percent Retention (Dispersed)-Specifications
and intent of this treatment are the same as for the
40 Percent Retention (Dispersed) treatment, except
that fewer trees will be retained. Fifteen Percent
Retention provides a similar level of forest retention
to that recommended in the President's Forest Plan,
and provides a comparison with the 40 Percent
Retention treatment.
6. 15 Percent Retention (Aggregated)-Specifications
and intent of this treatment are similar to those for
the 40 Percent Retention (Aggregated) treatment,
except that fewer 1-hectare patches will be retained.
As with the 15 Percent Retention (Dispersed)
treatment, this treatment provides a similar level
of forest retention to that recommended in the
President's Forest Plan.
75% Retention
100% Retention
40% Retention, Aggregated
40% Retention, Dispersed
15% Retention, Aggregated
15% Retention, Dispersed
Figure
2-D.E.M.O.
treatments (revised drawing
of
treatments, July 1994).