Synopsis Of Findings
[as of November, 2007]
Critical Public Perceptions of Forest Successional Pathways
Research Program
Funded by the Demonstration of Ecosystem Management Options
(DEMO) Study
USDA Forest Service Pacific Northwest Research Station
Research Conducted by:
Robert G. Ribe
Institute for a Sustainable Environment
Department of Landscape Architecture
University of Oregon
This is a product of the Demonstration of Ecosystem Management Options (DEMO)
study, a joint effort of the USDA Forest Service Region 6 and Pacific Northwest
Research Station. Research partners include the University of Washington, Oregon
State University, University of Oregon, Gifford Pinchot and Umpqua National
Forests, and the Washington State Department of Natural Resources.
1
Sources of Results in this Synopsis:
1. Ribe, R. 2007. Predicting scenic beauty inside forests and retention harvests: Pattern, basal area, density and
down wood (2007) Report: cooperative research agreement 06-CA--11261992. USDA Pacific Northwest
Research Station, U.S.D.A. Forest Service, Portland, OR
2. Ribe, R. 2006. Perceptions of Forestry Alternatives in the U.S. Pacific Northwest: Information Effects and
Acceptability Distribution Analysis. Journal of Environmental Psychology. 26(2):100-115.
3. Ribe, R. 2005. Perceptions of Green-tree Retention Timber Harvests in Vista Views: How Much do Cut Level,
Pattern and Design Matter? Landscape and Urban Planning. 73(8):277-293.
4. Ribe, R. 2005 Comparing Changes in Scenic Beauty Produced by Green-Tree Retention Harvests, Thinnings and
Clearcuts: Evidence From Three Pacific Northwest Experiments. In: Maguire and others (eds.) Balancing
Ecosystem Values: Innovative Experiments for Sustainable Forestry. USDA Forest Service, General Technical
Report PNW-635. Portland, OR. 137-146.
5. Ribe, R. and M. Matteson. 2002. Views of Old Forestry and New Among Reference Groups in the Pacific
Northwest. Western Journal of Applied Forestry, 17(4):1-10.
6. Ribe, R. 2002. Is Scenic Beauty a Proxy for Acceptable Management? The Influence of Environmental Attitudes
on Landscape Perceptions. Environment and Behavior, 34(6):757-780.
7. Ribe, R., E.T. Armstrong and P.H. Gobster. 2002. Scenic Vistas and the Changing Policy Landscape: Visualizing
and Testing the Role of Visual Resources in Ecosystem Management. Landscape Journal, 21(1): 42-66.
8. Ribe, R and T. Silvaggio. 2002. National forest management in timber and spotted owl country: A survey of
interested people in western Oregon and Washington. Institute for a Sustainable Environment, U. of Oregon.
9. Ribe, R. 2002. Aesthetics and ecosystem policy acceptance. Healthy Ecosystems Healthy People: Linkages
Between Biodiversity, Ecosystem Health and Human Health. Presentation at Conference of the International
Society for Ecosystem health, Washington, DC.
10. Ribe, R. 1998. Acceptability perceptions of landscape ecological patterns prescribed by the Northwest Forest
Plan. Presentation at U.S. International Association for Landscape Ecology Conference, East Lansing, MI.
These reports are cited in parentheses, by their numbers listed above, on the following pages.
2
Contents:
1. Selected general forest attitude
distributions as background
2. How people with different attitudes regard clearcuts and New Forestry
3. Visual cues to acceptable forest management
4. In-stand perceptions of acceptable forest management
5. In-stand perceptions of forest scenic beauty
6. Perceptions of vista views of forest landscapes
3
How much trust do you have in the
federal government to do what is right
concerning public land management
issues?
While the public is as ambivalent toward the Forest Service as they are the federal government in
general, they trust that it to manage national forests more than alternative agencies. (8)
4
National forests should
be a beautiful and
healthy regional setting
for quality of life whether
or not people use them
for economic gain or
recreation.
National forests should
mainly serve those in the
local region near the
forest.
The public in the Pacific Northwest clearly views national forests as a regional
environmental asset as a context for quality of life much more than an economic
resource for neighboring communities. (8)
5
National forests should
provide plenty of timber
industry jobs to make
needed wood products
for people!s homes.
National forests should
provide as much timber
harvest as possible while
keeping the landscape
beautiful and
environmentally healthy
While the regional public does not favor maximizing timber harvests from national
forests for economic purposes, they are receptive to maximizing timber harvests if they
perceive that the forests are healthy and beautiful. (8)
6
National forests should
provide for as much
diversity of animals and
plants as possible.
National forests
should provide
habitat for animals
that are thought to be
rare and threatened
with extinction.
The public has a strong desire for national forests to provide considerable biodiversity. (8)
7
National forests
should be changed
only in ways like
they have naturally
changed in the past.
National forests should
be left to natural
processes with as little
management as possible.
The public does not clearly favor employing a strongly naturalistic management
philosophy in making decisions about national forest management. (8)
8
National forests that
are not old growth
should be harvested
and managed for
jobs and wealth from
forest products.
If they have already
been harvested, forests
should be managed to
maximize the growth
and harvest of trees.
The regional public clearly favors economic management of forests that are not old growth. (8)
9
When forests are harvested…
It upsets the delicate balance of
nature with potentially disastrous
consequences.
People exercise their right to
modify the environment to meet
important human needs.
Can do a good job and live in
harmony with nature so humans
and nature can both thrive.
It is acceptable to harvest an
area of national forest if foresters
expect this will help restore its
health when trees are sick (such
as beetle infestations).
The public is not averse
to timber harvesting. (8)
10
National forests should supply all
the timber needed by existing
mills. Other resources should be
provided as much as possible
only after that goal is met.
(Survey executed in 1995.)
National forests should produce
as much timber as possible now
without impairing the ability of
the forests to produce an
adequate amount of timber and
other resource values that may
be needed in the future.
The public is on board with
the multiple use sustained
yield philosophy. (8)
11
Old growth forests should
NOT be harvested in order
to provide ecosystems for
wildlife like spotted owl and
salmon.
National forests that are
NOT old growth should
NOT be harvested, so
they can be left to natural
processes as much as
possible.
The regional public makes a clear distinction between old growth and non-old-growth forests
with respect to the acceptability of timber harvests. (8)
12
Contents:
1. Selected general forest attitude distributions as background
2. How people with different attitudes
regard clearcuts and New Forestry
3. Visual cues to acceptable forest management
4. In-stand perceptions of acceptable forest management
5. In-stand perceptions of forest scenic beauty
6. Perceptions of vista views of forest landscapes
13
People with all kinds of attitudes towards the use of forests do not favor unregulated
clearcutting. At the opposite extreme, opinions toward a prohibition of clearcutting fall
substantially along ideological lines related to people!s attitudes toward forest use. (5)
14
Very few people strongly trust management professionals to judge when clearcuts are
appropriate. People with attitudes favoring forest protection generally do not even
moderately trust managers to determine when clearcuts are acceptable. People with
attitudes that favor forest production and those with non-aligned attitudes often do have
moderate trust in professionals to decide when to clearcut forests. (5)
15
Few people with any attitude toward forest production or protection find traditional clearcut
mitigation measures (replanting and visual screening) sufficient to justify clearcutting. (5)
16
There is strong general support for New Forestry, as opposed to traditional methods of
national forest management. People who favor forest protection often tend to oppose new
forestry because it still entails timber harvests. Others do not clearly share this viewpoint. (5)
17
People who favor forest protection favor New Forestry more if it avoids old growth forests.
People who favor forest production are more ambivalent but are still more inclined to
pursue New Forestry in old growth forests. Non-aligned people are even more ambivalent
and lean more toward the views of forest protectionists. (5)
18
Contents:
1. Selected general forest attitude distributions as background
2. How people with different attitudes regard clearcuts and New Forestry
3. Visual cues to acceptable forest
management
4. In-stand perceptions of acceptable forest management
5. In-stand perceptions of forest scenic beauty
6. Perceptions of vista views of forest landscapes
19
When people are asked to rate national forest vista scenes! for management acceptability
without information, and other people are asked to rate the same scenes for scenic beauty,
also without information, the two ratings turn out to be highly correlated. People use scenic
beauty as a cue to good management. (6)
20
People with attitudes that favor forest protection have high scenic beauty standards in
judging the management acceptability of forest scenes. For example, scenes with beautiful
mountain topography but with clearcuts are viewed as less acceptable than beautiful. Their
perceptions of the acceptability of scenic beauty levels are not broadly representative. (6)
21
People with attitudes that favor forest production have low scenic beauty standards in
judging the management acceptability of forest scenes. For example, scenes with beautiful
mountain topography but with clearcuts are viewed as more acceptable than beautiful. Their
(6)
perceptions of the acceptability of scenic beauty levels are not broadly representative.
22
People with attitudes not clearly favoring either forest protection or production have more
neutral scenic beauty standards in judging forests! management acceptability, but lean
more toward the standards of forest protectionists. Their perceptions of the acceptability
of scenic beauty levels are most nearly broadly representative.
(6)
23
Contents:
1. Selected general forest attitude distributions as background
2. How people with different attitudes regard clearcuts and New Forestry
3. Visual cues to acceptable forest management
4. In-stand perceptions of acceptable
forest management
5. In-stand perceptions of forest scenic beauty
6. Perceptions of vista views of forest landscapes
24
R e g r es s ion analysis e x plai n i ng r atings of t he
o v e r al l ac ce pta bi lity o f f o r es t tr e atmen t s. a
____________________________________________________________
Standard
Parameterb
Estimate
error
t
value
Prob.
____________________________________________________________
Intercept
0.38c
0.16
2.35
0.019
1.22c
0.05
24.37
<0.001
0 . 6 1c
0.05
11.49
<0.001
- 0 . 2 1c
0.03
-6.25
<0.001
Scenic beauty
0.42c
0.02
19.16
<0.001
Percent retention
0.02c
Wildlife value
Economic and safety value
(Econ. & safety value)2
0.01
3.24
0.001
(Percent retention)2
- 0 . 0 0 0 3c
0.00006
-4.93
<0.001
____________________________________________________________
Regression statistics:
Degrees of freedom R2
Adjusted R2
F-test
Prob.
____________________________________________________________
6/1631
0.62
0.61
434.43
<0.001
____________________________________________________________
Stepwise regression explanation of variance in overall acceptability ratings:
Step Parameter
Added R2
Cumulative
R2
____________________________________________________________
1
W i l d l i fe value
0.47
0.47
2
S c e n ic beauty
0.06
0.53
3
E c o n o m ic and safety quadratic 0.07
0.60
4 Percent retention quadratic
0.02
0.62
____________________________________________________________
a Regression was estimated across all ratings of overall acceptability
across all treatments and respondents.
b Independent variables are each respondent's own ratings of wildife
value, economic and safety value and scenic beauty, and the percent of
green tree retention described in each forest treatment's explanation.
c Statistically significant results at the p = 0.05 level.
People were shown in-stand pictures of
forests with various harvest and thinning
treatments, as well as unmanaged
forests of various ages. They were also
given information about the management
attributes, intentions and resource
outcomes of the corresponding forests.
They rated the forests for how much
scenic beauty, economic and safety
value, and wildlife value they perceived
in each. They then rated the forests for
overall management acceptability.
All the results in the rest of this section
derive from this survey.
This regression model explains those
acceptability perceptions. It shows that
perceived wildlife value tends to be most
influential upon acceptability perceptions.
Perceived scenic beauty tends to be
second most influential, followed by
economic and safety value, and then the
percent of trees retained by a forest
treatment, including 100% for
unmanaged forests. Other factors were
not typically important. (2)
25
The two quadratic factors in the explanation
of average acceptability ratings:
These graphs elaborate the way that two of the influential factors on the last page tend to
affect forest acceptability perceptions.
The graph on the left shows that managers can go too far, past a point of diminishing returns,
in pursuing economic values from forests. The public perceives such strongly, financially
motivated forestry as unacceptably unbalanced.
The graph on the right shows how the public tends to find more acceptable forest treatments
to be those which retain moderate levels of green tree retention, eschewing-- on average-both clearcuts and unmanaged forests, once other perceptions are accounted for. (2)
26
(2)
If you plot the number or percent of people who render different acceptability
ratings, along a gradient of negative to positive approval, the resulting distribution
can be interestingly informative of how the public perceives the forest being rated.
The above illustrative case shows a normal (bell curve), slightly positive distribution.
27
The various graphs to the left show all the
most likely kinds of acceptability distributions
that can be observed for different forest
treatments, and their interpretations.
The average opinion about a forest can be
negative, neutral or positive, corresponding to
the left, center or right columns.
That average opinion can be the product of
consensus, shown on the bottom two rows.
Or, it can arise from public conflict where
there are two “humps” of concentrated
opinion. These two humps may be roughly
equal, creating a balanced or neutral conflict
(center column). Or, one may be bigger than
the other indicating a conflict of public opinion
that is either overall negative (left column) or
overall positive (right column).
Sometimes one or two “humps” of opinion
can be at the extreme edges of the
distribution, indicating lots of people are
strongly opposed (aversion) and/or strongly
favor (exuberance) a policy. (2)
28
Conflicts Over Untreated Forests:
The regional public is clearly conflicted about
whether it is acceptable to leave forests alone
without management. More people think it is
OK to do so than not. But, those who do view
unmanaged forests as unacceptable tend to
have rather strong feelings about it.
This is a positive, conflicted, temperate
distribution, and applies to young, mature and
old growth forests. (2)
29
Clearcuts:
The regional public tends to find clearcutting to be strongly unacceptable, irrespective of
the level of down wood left after harvest. These are negative, consensus, averse
acceptability distributions. (2)
30
Thinnings of Young Forests
The regional public finds thinning of young forests to be acceptable, irrespective of
the intensity of the thinning or the level of down wood left after treatment. Less
intense thinnings garner a bit more approval. (2)
31
15% Green-Tree Retention Harvests
The regional public has a similar distribution of opinion about 15% green-tree retention
harvests as for clearcuts, except with less negative overall opinion due to a clear set of
supporters represented by the positive “humps” in all graphs. The distribution pattern of
retained trees and the level of post-harvest down wood do not matter. (2)
32
40% Green-Tree Retention Harvests
The regional public approves of 40% green-tree retention harvests, with consensus,
irrespective of the pattern of retained trees or the level of post-harvest down wood. (2)
33
15% Green-Tree Retention Harvests of Old Growth
The regional public is clearly conflicted about 15% green-tree retention harvests of old growth,
with aversion, irrespective of the pattern of the retained trees. (2)
34
The order of mean, informed acceptability ratings from the graphs on previous pages falls
into a neat, orderly sequence, revealing the relative acceptability of forest treatments. (2)
35
Contents:
1. Selected general forest attitude distributions as background
2. How people with different attitudes regard clearcuts and New Forestry
3. Visual cues to acceptable forest management
4. In-stand perceptions of acceptable forest management
5. In-stand perceptions of forest scenic
beauty
6. Perceptions of vista views of forest landscapes
36
People were shown pairs of photographs, each of the same view inside forests: one taken
before various forest treatments and the other taken after the treatment. The photos were
randomly mixed so respondents could not discern the matched photos. They rated the photos
for scenic beauty and the average changes were computed for each type of forest treatment.
The two graphs above display the same results in two different ways. Comparative, absolute
changes (left) and actual changes in range (right).
Clearcuts and 15% aggregated-retention harvests of both mature and old growth forests are
perceived to have the greatest reductions in scenic beauty. 15% dispersed-retention and 40%
aggregated-retention harvests of mature forests show the next largest reduction in scenic
beauty. 40% dispersed-retention harvests of mature forests and thinnings of young forest
exhibit the smallest scenic beauty reductions. (4)
37
USFS Scenic
Integrity Level
Regression analysis explaining scenes’ scenic beauty estimates by measures of
forest structure, here including basal area, and New Forestry prescriptions.
_____________________________________________________________________________
Standard
Standard
Parameter
Estimate Coeff.
e r r o r t value Prob.
_____________________________________________________________________________
Intercept
2
Basal area m / h e c t a r e
Basal area squared
1
Down wood indicator
Dispersed retention indicator
2
-80.81
- 8 0.81
9.37
- 8.62
<0.001
2.10
1.54
0.20
10.40
<0.001
-0.007
- 1.21
0.001
- 8.88
<0.001
- 3 9.40
- 0.20
8.61
- 4.58
<0.001
43.28
0.23
8.88
4.87
<0.001
Quadratic mean diam e t e r
0.14
0.04
0.20
0.70
0.48
_____________________________________________________________________________
Regression statistics:
Degrees of freedom R2
Adjusted R2
F-test
Prob.
_____________________________________________________________________________
5/202
0.68
0 . 6 7
86.25
<0.001
_____________________________________________________________________________
Stepwise regression explanation of variance in ratio scenic beauty estimates:
Step Parameter
Added R2
C u m u l a t i v e R2
_____________________________________________________________________________
1 Dispersed retention indicator
0 . 3 3
0.33
2 Basal area quadratic
0.32
0.65
3 Down wood indicator
0.03
0.68
4 Quadratic mean diameter
0.001
0.68
_____________________________________________________________________________
Black points are pre-treatment old growth scenes.
1
The down wood indicator variable took on a value of 1.0 for scenes of high down wood
treatments, and 0 for scenes of low down wood treatments, including all untreated (100%
retention) forests with no down wood produced by timber harvesting.
2
The dispersed retention indicator variable took on a value of 1.0 for scenes of forest
treatments with dispersed patterns of green tree retention, including those with 100%
retention, and 0 for scenes of all other treatments, including those with aggregated
patterns of retention and clearcuts.
People were shown 12 randomly selected and ordered photographs taken inside forests after
various treatments were finished. They also saw 8 photographs from the same forests taken
prior to the treatments. They rated these for scenic beauty.
This regression model and its graph show that dispersing retained trees after harvest is the
strongest predictor of perceived scenic beauty. Basal area approaching 160 m2/ha are next
most important. Reducing down wood after harvest is also important. (1)
The results on this page are preliminary and have not been rechecked and confirmed.
38
USFS Scenic
Integrity Level
Regression analysis explaining scenes’ scenic beauty estimates by means of
basic New Forestry attributes of forest treatments.
_____________________________________________________________________________
Standard Standard
Parameter
Estimate Coeff.
error
t
value Prob.
_____________________________________________________________________________
Intercept
Retention level
1
Down wood indicator
-67.68
- 6 7.68
8.71
- 7.77
<0.001
1.36
0.61
0.13
10.57
<0.001
- 3 1.48
- 0.16
9.37
- 3.36
<0.001
2
Dispersed retention indicator
26.23
0.14
10.18
2 . 5 8 0.011
_____________________________________________________________________________
Regression statistics:
Degrees of freedom R2
Adjusted R2
F-test
Prob.
_____________________________________________________________________________
3/204
0.63
0 . 6 2
116.82
<0.001
_____________________________________________________________________________
1
The down wood indicator variable took on a value of 1.0 for scenes of high down wood
treatments, and 0 for scenes of low down wood treatments, including all untreated (100%
retention) forests with no down wood produced by timber harvesting.
2
The dispersed retention indicator variable took on a value of 1.0 for scenes of forest
treatments with dispersed patterns of green tree retention, including those with 100%
retention, and 0 for scenes of all other treatments, including those with aggregated
patterns of retention and clearcuts.
In the same study as on the previous page, people were shown randomly selected and ordered
photographs taken inside forests after various treatments. They also saw photographs from the
same forests taken prior to the treatments. They rated these for scenic beauty.
This regression model and its graph excludes measures of stand structure. It shows that
retention level is the most important predictor of perceived scenic beauty, followed by two roughly
equal factors: reducing down wood left on the ground and dispersing the trees retained after
harvest. The vertical divisions of the graph are estimated USFS Scenic Integrity Levels.
The graph shows the perceived scenic beauty of the forest treatments included in this study in
relation to green-tree retention levels. The next page offers a better graphical interpretation. (1)
The results on this page are preliminary and have not been rechecked and confirmed.
39
Contents:
1. Selected general forest attitude distributions as background
2. How people with different attitudes regard clearcuts and New Forestry
3. Visual cues to acceptable forest management
4. In-stand perceptions of acceptable forest management
5. In-stand perceptions of forest scenic beauty
6. Perceptions of vista views of forest
landscapes
40
Scenic beauty is a major influence upon informed
perceptions of management acceptability in vista
forest views. But, information about the forests!
management intentions and resource outputs
has significant effects upon perceived
acceptability. (9)
When presented affirmatively,
information about forest vista scenes
have positive effects upon perceived
management acceptability, with the
exception of a description of traditional,
plantation forestry. (10)
41
Example photo taken before the Northwest Forest Plan in the Upper Clackamas Basin, Mount
Hood National Forest of Oregon. This and 14 other such photos were rated for scenic beauty. (7)
42
Example photo simulation after the Northwest Forest Plan corresponding to that on the last
page. This and 14 others were also rated for scenic beauty, along with their partner photos.(7)
43
Before and after photo
pairs, like that shown on
the last two pages were
analyzed to see which
changes in USFS Scenery
Management
characteristics best
predicted the
corresponding changes in
perceived scenic beauty. (7)
44
The most surprising, salient factor in the regression analysis derived from the last page
was the beneficial effect of mitigating harvests! appearance in the middle-ground
distance zone.
This led to the study on the following pages. (7)
45
TRADITIONAL TIMBER HARVEST OPTIONS
Traditional harvest management vista scenes shown to respondents.
(3)
46
GREEN-TREE RETENTION TIMBER HARVEST OPTIONS
Green-tree retention harvest scenes shown to the respondents. (3)
47
This graph shows the perceived scenic beauty levels of the scenes shown on the last two pages.
Any aggregated retention harvest is perceived as ugly, irrespective of retention level, pattern or
visual mitigation design.
Dispersed retention harvests are seen as positively beautiful above about 25% retention level,
irrespective of retention pattern or visual mitigation design. (3)
48