variable retention harvest
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Mezger
To: Kim Titus, Salem District Manager
From: Tracy Mezger
Date: May 30, 2014
Subject: Decision of variable retention harvest
Description of the action and prescription
A variable retention harvest is the best method to create diverse early seral ecosystems
while providing viable timber and revenue. A variable retention harvest is the best method for
restoring forest structures by emulating a natural disturbance. Disturbances are important for the
forest by allowing regeneration and developing complex forest structures. They are also key for
creating early seral conditions. Maintaining forest structures can help meet the demands of
habitat opportunity through ecological and structural diversity. Ecological and structural
diversity can be established
by retaining legacies and
course woody debris on the
harvest site and replanting
after the harvest. Replanting
the areas also allows for
profitable regeneration for
future harvests. Creating
structural diversity can be
created either through Figure 1: Variable Retention Harvest (Johnson, 2014)
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aggregated retention or dispersed retention, leaving at least 25% of the stand remaining. The
legacy trees are left until the next harvest rotation. Both surviving and dead trees offer habitat
with cavities and stumps that help maintain species diversity. A variable retention harvest will
also avoid building logging roads by primarily utilizing skyline extraction of the harvested
timber, which decreases erosion and sedimentation. A visual of what a variable retention harvest
looks like is shown above as Figure 1.
Landscape context
The project area for this harvest lies on Bureau of
Land Management (BLM) forested land in the Salem
District. It is also part of Mary's Peak resource area, an area
abundant with natural resources. Mary's Peak is the highest
point in Oregon's Coast Range reaching 4,097 ft. The Salem
district lies northwest in Oregon, highlighted in Figure 2.
The specific harvest area in Mary's Peak resource area is
dominated by young conifers of about 60 years of Figure 2: Salem District (BLM, 2014)
age with little structural complexity and diversity. The Mary's Peak resource area also retains
late successional forest stands, which adds complexity to the area's overall structure. It is also an
area managed for riparian reserves and critical habitat to the endangered Marbled Murrelets,
Coho Salmon, and Northern Spotted owl (Wimberly, 2002). The critical habitat of these species
range throughout the Pacific Northwest (Johnson, 2014). Our proposed harvest area is not
located in critical habitat.
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Reason for the action
The variable retention harvest method meets the goals of the Northwest Forest Plan
(NWFP) and the goals of the O&C Act. The NWFP helps to guide forest practices towards
sustainability. The NWFP also aims to integrate agencies in an effort to make better decisions
regarding long term forest management.The plan was established not only to sustain timber
supplies in the Northwest, but to protect fish and wildlife habitat for those federal forests. The
O&C Act was created to provide a permanent forest production to help local economic stability
while protecting and regulating watersheds (USDI BLM, n.d.(b)).
The chosen action of variable retention harvest balances the societal need for economic
stability and the biological need for ecosystem services to the forest structure. The NWFP and
the O&C Act have similar goals for the management of federal forests in the Northwest. A major
reason the NWFP was implemented was to protect endangered species. The Mary's Peak
resource area contains portions of critical habitat for murrelets, salmon, and the spotted owl; this
method of harvest helps retain a buffer zone that meets the goals for protecting endangered
species who rely on ecologic functions under the NWFP. Revenue from the timber will help
O&C counties' economies which is a priority of the act (USDI BLM, n.d.(b)).
Under the 1937 O&C Act, this BLM land is to be managed for sustained permanent
forest production (USDI BLM, n.d.(a)). As a moist forest type, the Mary's Peak Resource Area
rarely experiences wildfire; historically only experiencing a severe fire every 100 to 200 years
(Spies, et. al., 2007). When wildfires occur today, they are often suppressed, adding to a major
decline of early seral habitat from the historical rate of 16% to the current 3% in the Oregon
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Coast Range. This means a decrease in habitat for species who are specialized for early seral
ecosystem structures and a decrease in biodiversity. The open space after a severe disturbance
offers new conditions for rapid growth with little competition; this rapid growth is shown in
Figure 3. This phase of forest structure is also the only time when conifers and overstory cover
does not dominate the site. The variable retention harvest method replicates a natural event like
wildfire in an area that lacks this type of stand diversity and species complexity. Immediate
growth in these areas offer future conditions for sustainable harvest. This form of ecological
forestry helps to maintain ecosystem services for species as well as a profitable yield of timber.
The estimated revenue generated from the variable retention harvest at this site is
calculated below. The total harvest volume is calculated to be: 60,000*.75*91= 4,095,000 board
ft; the total stumpage value comes out at : 4,050*$300= $1,215,000. This revenue is important
for O&C land
revenue to
compensate
counties. This will
help stabilize local
economies.
Figure 3: Early seral rapid growth(Johnson, 2014).
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Other effects
Positive effects may reach farther than providing habitat for specialized species and
healthier forest regeneration. Variable retention harvest can also be positively impacting complex
food webs across the entire forest. By emulating a natural disturbance that is spatially variable,
we are encouraging historical conditions that makes the forest most efficient. People can also
benefit from this system by incorporating ecosystem values into their management; timber
production is reliable and adaptive.
Negative affects are still present as the land is still manipulated by humans. Although
management incorporates the entire system, some consequences may not be accounted for. This
stand is only 20 years away from becoming old growth. Cutting the stand takes away the
opportunity for future Northern Spotted owl habitat. As atmospheric changes like climate
change, this stand will contribute less than it could have for carbon sequestration once it is
harvested. Other problems like invasive species pose a threat to specialized species relying on
certain climate and habitat conditions. This may lead to further protection of forest areas
stopping timber harvest which can lead to economic deficiency.
Compliance with the Endangered Species Act
The Endangered Species Act (ESA) lists a species as endangered if it is at risk of
extinction in a portion or all of its range. The purpose of the ESA is to protect and recover listed
species and the ecosystems they depend on (Brown & Shogren, 1998). The ESA ustilizes legal
tools to assess whether and action may result in a taking and will consult the organizer about
alternatives. This area is not in critical habitat range, as shown in Figure 4 and 5, and a variable
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retention harvest will not conflict with the ESA and will not result in a taking of endangered
species. Although the harvest area is not critical habitat now, it has the potential to become old
growth in a short time which could contribute to the recovery of these species through added
habitat. Addition features of ecological forestry does not conflict with landscape conditions
endangered species may rely on. For example, buffering riparian zones with old growth ensures
riparian health and water quality through provided shade microclimate and reduced
sedimentation from erosion. Limited matrix gaps and connectivity of legacy trees ensures that
species can move across the harvest without leaving a moderately complex forest structure
(MacDonald, et. al., 2003).
Fig. 4 (above left): Critical habitat of N. Spotted Owl Fig. 5 (above right): Critical habitat of C. Salmon
and M. Murrelet (Johnson, 2014). (Johnson, 2014).
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Keys to increase public acceptability
The public feels very strongly against clearcutting on federal lands. Opposition is socially
constructed based on values and normative science, which is essentially advocacy for a
particular view (Bliss, 2000). People should understand that variable retention is different from
clear cutting as it retains part of the forest structure that is essential for diversity and stand
complexity; ecological concerns are addressed and managed for. This prescription also allows
for early seral ecosystems, whereas clear cutting usually skips this phase by spraying herbicides
on the area where shrubs and hardwoods might grow. Education is key here. Misleading science,
has confused the public.
This type of harvest method accommodates to people's values by supporting biodiversity,
which is easier to relate to people than the science behind harvest methods. The public needs to
not only understand the difference between harvesting methods but be able to see the difference,
which is more personal and valuable. There are similar features between variable retention and
clear cuts that may be confusing so showing people the difference may be a positive approach to
education. Socially, people are still going to be concerned about harvesting timber on federal
lands because the public is most interested in the aesthetic qualities and recreation. Informing the
public about harvests and of the opportunities to get involved in the decision making process
will help the acceptance of variable retention harvesting.
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References
Bliss, J. 2000. Public perceptions of clearcutting. Journal of Forestry. 98(12), 4-9.
Brown, G. M., & Shogren, J. F. (1998). Economics of the Endangered Species Act. Journal of
Economic Perspectives, 12, 3-20.
Franklin, J.F., Mitchell, R.J., Palik, B.J.. 2007. Natural disturbance and stand development.
USDA Forest Service General Tech, 19, 1-2.
Johnson, N. May 22, 2014. Variable retention harvest/ early seral. FOR 460 class. Lecture
conducted from Corvallis, Oregon.
Macdonald, J. S., MacIsaac, E. A., & Herunter, H. E. (2003). The effect of variable-retention
riparian buffer zones on water temperatures in small headwater streams in sub-boreal
forest ecosystems of British Columbia.Canadian Journal of Forest Research, 33(8),
1371-1382.
Spies, T.A., Johnson, K.N., Burnett, K., Ohmann, J.L., McComb, B.C, Reeves, G.H., Bettinger,
P., Kline, J.D., & Garber-Yonts, B. 2007. Cumulative ecological and socioeconomic
effects of forest policies In Coastal Oregon. Ecological Applications 88(1): p. 5-17.
Swanson, M. J., F. Franklin, R. L Beschta, C. M. Crisafulli, D. A. DellaSala, R. L. Hutto, D.
B. Lindenmayer, and F. J. Swanson. 2011. The forgotten stage of forest succession: early
successional ecosystems on forest sites. Frontiers in Ecology Environment. 9:117–125.
USDI BLM. No date (a). O&C Sustained Yield Act. The land, the law, and the legacy: 1937-
1987. http://www.blm.gov/or/files/OC_History.pdf
USDI BLM. No date (b). Overview of the Oregon and California (O&C) Lands Act of 1937.
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http://www.blm.gov/or/rac/files/Oregon%20Flyer.pdf
Wimberly, M. 2002. Spatial simulation of historical landscape patterns in coastal forests of the
Pacific Northwest. Can. J. For. Res. 32:1316-1328.
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