Designing Pre- and Post-Fire Restoration Strategies For Recovery of Salmonid
Habitats in a Period of Climate Change and Increased Forest Fire Disturbance
Lee Benda and Daniel Miller, Earth Systems Institute, Seattle, WA
Gordon Reeves, U.S. Forest Service, Pacific Northwest Research Station
Cameron Thomas, Wenatchee National Forest
A. Abstract/Statement of Innovation
We propose to apply new watershed analysis tools to identify critical pre-fire and
post-fire restoration and management strategies for enhancing recovery of Chinook,
steelhead, and bull trout habitats in a period of climate change and increasing natural
disturbance.
There is increased emphasis by federal and state resource management agencies
and conservation organizations to restore fish habitats across the Columbia River basin.
Natural disturbances such as fires, however, can pose a significant threat to recovery of
salmonids, including directly impacting NWPCC’s restoration efforts, particularly in the
context of climate change and increased fire activity across the inner mountain west. In
post-fire environments, accelerated influxes of sediment and wood can have negative
habitat impacts; yet, with the right conditions, these same punctuated inputs of sediment
and woody debris interact over time to produce productive and diverse aquatic and
riparian habitats. The natural disturbance-recovery cycle through which fires, storms, and
floods rejuvenate aquatic habitats over decadal time frames can be impeded by existing
land use infrastructure (road networks, road crossings) and by vegetation patterns
reflecting past timber management (young forests, fuel loading). The consequences of
disturbance on aquatic systems vary in a predictable fashion depending on specific
landscape attributes. Thus, using new watershed analysis tools, it has become feasible to
identify those portions of a basin and river network where processes of habitat
destruction and natural recovery are most susceptible to manipulation by watershed
management, including restoration activities. Despite the threat that natural disturbances,
particularly fire, pose to ongoing salmonid recovery efforts, there is a lack of pre- and
post-fire watershed management strategies explicitly designed to maintain natural
disturbance-recovery processes aimed at restoration of salmonid habitats following
episodic, habitat altering events.
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The innovative aspect of this proposal is the application of new watershed tools to
design watershed restoration strategies for promoting recovery of Chinook, steelhead, and
bull trout habitats following disturbances, such as fires. The target landscape is the
Methow watershed (4,300 km2, 1,050,000 acres) and the analysis will be provided to the
Okanogan and Wenatchee National Forests and to other conservation groups to inform
pre-fire forest management planning for maintaining natural disturbance-recovery cycles.
In addition, within three recent fire areas in the Methow basin, new watershed tools will
identify potential fire restoration projects to remove impediments to natural habitat
recovery (i.e., road treatments, small tree thinning that leaves the largest most vigorous
trees in place) and to limit negative impacts on existing quality habitats (i.e., leave trees
on slide prone areas, prioritization of erosion control).
The new watershed tools, along with the digital watershed database developed
during the project, will be made available to NWPCC stakeholders. Work will be
performed by Drs. Lee Benda and Daniel Miller (Earth Systems Institute), Cameron
Thomas (Fish Biologist, Wenatchee N.F.), and Dr. Gordon Reeves (Pacific Northwest
Experiment Station, USFS). NWPCC funding can provide a critical ‘jump start’ and
demonstration of unique basin wide restoration planning that can protect and underpin
other, more local restoration projects.
B. Technical Background
The technical background of this proposal covers three areas relevant to designing
pre- and post-fire watershed management for enhancing recovery and restoration of
salmonid habitats following natural disturbances: 1) the scientific basis of natural
disturbance and habitat recovery, 2) pre- and post-fire management in the context of
natural processes of habitat recovery following disturbances, and 3) new watershed tools
that can identify projects and opportunities in pre- and post-fire management planning.
B.1 Natural Disturbance, Recovery and Aquatic Habitats
The raw materials that provide the building blocks for aquatic and riparian
habitats in mountain environments are often released by disturbances, such as fires,
storms, and floods (Swanson et al. 1988, Benda and Dunne 1997). Much of the sediment
and large wood routed to fish-bearing streams is temporarily stored in headwater
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channels (comprising 70% of the channel network) and its mobilization often requires
landslides, debris flows and gully erosion in mountain landscapes (Swanson and
Lienkaemper 1978, Miller et al. 2003, May and Gresswell 2003, Bigelow et al. 2007).
Large influxes of sediment and woody debris supplied to stream channels can
have immediate negative impacts on aquatic habitats and can threaten isolated
populations of fish with extinction (Rieman et al. 2003). Over decades, however,
influxes of materials can create habitats of high complexity within certain channels of
high heterogeneity (or roughness) characterized by tributary confluences, bedrock
outcrops, alternating floodplain-canyons, fluctuating channel gradients, and log and
boulder accumulations. Such heterogeneity creates diversity in transport and storage of
sediment and organic materials that forms pools, riffles, bars, terraces, undercut banks,
and log jams, in other words complex and abundance habitats (Everest and Meehan 1981,
Sedell and Dahm 1984, Swanson et al. 1988, Reeves et al. 1995, Nakamura and Swanson
2002, Benda et al. 2003, Bigelow et al. 2007). The natural cycle of disturbance and
habitat recovery, however, require that specific upslope-channel linkages and other
watershed attributes remain intact, despite pervasive human land uses across the
landscape (Reeves et al. 2006). This is becoming increasingly important in the context of
climate change in which an enhanced forest fire inducing climate will increase the
frequency and severity of natural disturbances.
B.2 Pre- and Post-Fire Management in the Context of Natural Processes of Habitat
Recovery Following Disturbances
The legacy of past forest management, including timber harvest, fire suppression
and roads can impede habitat recovery following natural disturbances, such as fires,
storms, and floods. For instance, fire suppression has led to higher fuel loads in certain
areas that can increase fire intensity, that when coupled with sensitive terrain, can lead to
increased erosion. Road networks can constrain channel movement in certain valley
types, contribute to slope instability, and impede the transfer of sediment and woody
debris from headwater streams to lower gradient channels by floods, debris flows, and
gullies. Timber harvest can eliminate or reduce the supply of large woody debris by
forest mortality, bank erosion, landsides, debris flows, and post fire toppling
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Future watershed management, including pre-fire treatments and post-fire
rehabilitation, can promote the goal of fish habitat recovery by considering the
relationship among physical watershed attributes, forest and wildfire (burn severity)
characteristics, and aquatic habitats. Specific focus areas include: 1) designing future
timber harvest and road construction to maintain critical upslope-channel linkages, 2)
targeting fuels treatments and road abandonment (temporary or permanent) to promote
natural restoration trajectories, and 3) identifying post-fire rehabilitation measures to
reinforce the role of natural disturbance (fires, storms, and floods) as an agent of
restoration. Specific examples of 1-3 are described below.
B.3 New Watershed Tools for Identifying Projects in Pre- and Post Fire Watershed
Planning
Natural disturbance and variation in watershed attributes are fundamental
characteristics of aquatic systems as represented in stream ecological theory and
documented by numerous field studies. Development of computer-based models that
identify important aspects of natural disturbance and physical features of watersheds has
increased over the last decade; examples include fire and forest growth (Wimberly et al.
2000), landslides (Montgomery and Dietrich 1994, Miller and Burnett 2007), debris
flows (Lancaster et al. 2001), wood recruitment and transport (Benda et al. 2003a),
tributary confluence effects (Benda et al. 2004, and salmonid habitats (Burnett et al.
2003). Despite the development of new watershed tools that could be harnessed to design
watershed restoration strategies for promoting recovery of salmonid habitats at basin
scales, they are not widely available to field practitioners and thus remain underutilized
by stakeholders ranging from agencies to watershed councils.
To simplify the use of new watershed tools for supporting watershed management
and restoration in the face of changing climate, Earth Systems Institute (ESI) has
developed NetMap (Benda et al. 2007), a suite of numerical models and analysis tools
(designed to work within ArcGIS) that is designed for three purposes: 1) increase the
spatial resolution of watershed features and processes, including aspects of natural
disturbance and recovery cycles, 2) automate numerous kinds of watershed analyses in
support of designing restoration strategies for recovery of salmonid species, and 3)
develop regional scale generic watershed terrain databases (e.g., Pacific Northwest,
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including Columbia River basin) to support restoration and management efforts by a
range of stakeholders. Twenty-five automated tools address erosion processes and risk,
habitat indices (Chinook, steelhead, bull trout habitat intrinsic potential), channel
classification, habitat core areas, and sediment and wood supply, among others. Auto
search functions identify overlaps between specific hillslope and channel conditions, such
as areas of fire risk, burn severity, erosion potential and sensitive habitats. To facilitate its
use, NetMap contains hyperlinked users manuals, including a library of 50 watershed
parameters.
In the proposed work, NetMap will be used to identify critical upslope-channel
linkages, including erosion processes, wood recruitment (including by landsliding and
debris flows), and relevant channel and valley attributes focused on the abundance and
diversity of Chinook, steelhead, and bull trout habitats. Such information, coupled with
forest ages, burn severities (in recently burned areas), and road networks, will be used to
develop pre- and post-fire watershed-scale restoration strategies for promoting recovery
of salmonid habitats in an enhanced forest fire environment.
C. Rationale and Significance to the Council’s Fish and Wildlife Program
The Methow Subbasin Plan (WRIA 48) identified several broad limiting factors
for most Assessment Units. The review of limiting factors for focal species of fish was
carried out using EDT (Ecosystem Diagnosis and Treatment) that showed, for the
Methow basin, that habitat losses have resulted from artificial and natural fish passage
barriers, alteration and reduction of riparian habitat, loss of habitat connectivity, instream
and floodplain habitat degradation, low flows and dewatering, and extreme water
temperatures (Methow Subbasin Plan, p. 203). EDT does not identify strategies for
specific restoration, including basin scale management in the face of increasing fire risk.
This proposal is consistent with the Council’s Fish and Wildlife Program and the
Methow Subbasin plan. The use of new watershed tools (NetMap) will be used to craft
basin-wide forest management-related restoration strategies designed to address the
habitat limiting factors listed above (e.g., alteration and reduction of riparian habitat, loss
of habitat connectivity, and in-stream and floodplain habitat degradation), particularly in
the context of increasing fire disturbances. Moreover, NetMap’s basin analysis will
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improve NWPCC’s ability to evaluate and prioritize restoration projects within the
Methow basin overall. Netmap’s analysis will help land managers and land owners
improve restoration site selection
(http://www.nwcouncil.org/fw/subbasinplanning/methow/plan/).
D. Relationship to Other Projects
This proposal has the potential to provide critical information to a variety of land
managers and other stakeholders interested in fish and wildlife habitat improvement.
There are numerous parties involved in collaborative efforts in the Methow Subbasin that
are either directly involved in salmon recovery, or practice land management that could
potentially influence salmon and their habitat. Active Participants include Okanogan
County, Methow Restoration Council, the Upper Columbia Salmon Recovery Board, the
U.S. Forest Service, the Bureau of Reclamation, the USFWS, Washington Department of
Natural Resources, the Colville Confederated Tribes, the Yakama Nation, the Upper
Columbia Salmon Recovery Board Implementation Team, and others. Analysis products
from this proposal could be used by any of these groups singly or in combination for
activities ranging from upland fuel reduction, to improved road management, to active instream restoration.
E. Proposal Objectives, work elements, methods, and monitoring and evaluation
Objective #1: We propose to apply NetMap (Benda et al. 2007) to the Methow
watershed (4,300 km2; 1, 050,000 acres) to identify critical pre-fire upland and riparian
management opportunities and post-fire rehabilitation projects to restore habitats of
Chinook, steelhead, and bull trout habitat, in the context of fire-related disturbances.
The analysis and restoration strategies will be made available to appropriate land owners
and land managers including the Upper Columbia Salmon Recovery Board
Implementation Team, Methow Salmon Conservancy, the Bureau of Reclamation, the
U.S. Forest Service (Methow Valley Ranger District, Okanogan and Wenatchee National
Forest), and other identified groups. A value added component is that the digital
watershed database, in conjunction with new analysis software, could provide the basis
for development of a regional monitoring and evaluation framework.
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Work Element 1.1: Apply NetMap analysis tools across the entire Methow watershed.
NetMap consists of two components: 1) a set of base parameters and 2) an ArcGIS
analysis tool kit. The base parameters are created using digital data, including US
Geological Survey (USGS) 10-m DEMs (or LIDAR when available), climate data from
PRISM (1998), and USGS river gauge data, in conjunction with existing software (Miller
2003, Burnett and Miller 2007) and published studies on relationships between watershed
attributes and aquatic environments (see citations in Benda et al. 2007).
Work Element 1.2 Pre-fire management strategies can be designed to maintain natural
disturbance-recovery cycles to enhance recovery of Chinnok, steelhead, and bull trout
habitats in the context of identified limiting factors (in the Methow basin plan) including
alteration and reduction of riparian habitat, loss of habitat connectivity, and in-stream and
floodplain habitat degradation. Watershed parameters in NetMap that support this
include: 1) landslide potential, 2) debris flow susceptibility and runout, 3) gully erosion
potential and runout, 4) sediment connectivity of tributaries with mainstem channels, 5)
mass wasting deposit types, 6) erosional significance, 7) woody debris delivery by debris
flows, 8) confluence environments, 9) valley morphology, 10) channel morphology, 11)
woody debris accumulation types, 12) habitat intrinsic potential (e.g., Burnett et al. 2003)
for Chinook, and steelhead, 13) channel sedimentation zones, 14) wood recruitment by
chronic mortality, post-fire toppling, bank erosion, and landsliding, and 15) biological
hotspots. Refer to Benda et al. (2007) and www.earthsystems.net for a comprehensive
listing of available parameters and watershed analysis tools in NetMap. These and other
watershed attributes will be used to design pre- and post-fire watershed restoration
strategies for promoting recovery of salmonid habitats in an enhanced forest fire-inducing
climate.
Not all areas in watersheds are equally sensitive to timber harvest, fires, or
salvage logging. In the context of pre-fire planning, maps of debris flow or gully potential
could be overlaid with maps of fire risk indices (fuel loading). Fuels treatment could be
targeted in areas that have overall combinations of high fire risk and high erosion
potential (Figure 1A-B). Riparian buffers in which timber harvest activities are excluded
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Figure 1. Panels A – D show examples of NetMap watershed parameters and tools. Fuel
loading or fire burn severity maps (A) are combined with predicted erosion sources (B);
the overlap between high fuel loading or burn severity and erosion potential can be used
to help direct pre-fire thinning or post fire salvage logging. (C) Certain headwater basins
that have high connectivity to mainstem channels may be important sources of habitat
forming materials and their headwater streams may need to be protected, either during
pre fire management or post fire rehabilitation. (D) Certain road crossings may pose
higher risk either in pre- or post fire environments and NetMap can be used to create a
prioritization system to rapidly evaluate hundreds to thousands of road crossings in large
watersheds.
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or limited could be targeted along headwater streams that have significant influences on
the function of larger, fish-bearing channels (Figure 1C). Road construction may be
identified for potential exclusion from certain areas because of concerns about increase in
landslides. Segments of existing roads would be evaluated for risk and could be identified
for temporary or permanent removal to allow natural transfers of sediment and large
wood (triggered by fires, storms, and floods) to downstream areas, supplying the building
blocks for fish habitats (Figure 1D). For example, some headwater channels may be
important sources of large wood to fish-bearing streams (by debris flows and gully
erosion) and the sources of such wood could be protected (see Burnett and Miller 2007).
In addition, NetMap can be used to search for juxtapositions among fuels risk (or burn
severity), erosion potential, and quality fish habitat (Figure 2). Larger streamside buffers
(and other fire related restrictions) could target the identified areas. In addition, upslope
and riparian management can also reflect risks to lives, private property, and other
engineered structures (roads and bridges) according to terrain attributes such as
landslides, debris flows, tributary-mainstem connectivity and transport of woody debris.
Work Element 1.3: Post fire rehabilitation will target land use impediments to natural
recovery and focus on reducing impacts from accelerated erosion and runoff. To support
this restoration goal, NetMap will be used to identify river network locations within the
Thirty Mile (2001), Farewell (2003), and Tripod (2006) fires that encompass almost 25%
of the Methow basin (Figure 3). Areas where disturbance-recovery cycles can enhance
aquatic habitats include the intersections between gully erosion and debris flow
depositional zones (and post fire toppling of riparian trees) and areas of high physical
heterogeneity in river networks such as tributary confluences, valley width transitions,
high near-stream topographic roughness (ridge controlled channel hard points), and
channel gradient transitions. NetMap can be used to identify specific projects and
opportunities to remove impediments to natural restoration and to limit negative impacts
on existing habitats (e.g., Figures 1- 2).
In a post-fire restoration environment, NetMap’s predictions will be integrated
with burn severity maps (e.g., Figure 3) and vegetation types to support various
restoration opportunities including: 1) limit salvage logging in upland areas (and along
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Figure 2. NetMap’s tool bar in ArcGIS indicates the various watershed and forest
management tools that are readily available to practitioners and planners. One of
NetMap’s tools is used to rapidly search for juxtapositions among high fire risk, high
erosion potential, and high quality fish habitat (tool shown in dialogue box). Areas of
concern are identified within watersheds (red areas indicated on the map) that can be used
to inform pre- upland and riparian forest management planning or post-fire rehabilitation.
Example from the Trinity River Basin in northern California.
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Figure 3. Large wildfires have impacted large portions of the Methow basin (4,300 km2)
including in areas home to Chinook, steelhead, and bull trout fisheries. New watershed
analysis tools can identify critical upslope-channel linkages that can inform pre-fire and
post-fire restoration strategies designed to enhance disturbance-recovery cycles for
restoring and protecting salmonid populations and existing smaller scale restoration
efforts (e.g., Figures 1 and 2).
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headwater swales and channels) that are predicted to have a high potential for landsliding
or debris flows that can contribute large wood to streams (e.g., Figure A-B), 2)
identifying network areas that have a high potential for disturbance-mediated habitats to
form (e.g., Figure 1C), 3) identify areas for salvage logging with minimal downstream
consequences, 4) limiting or eliminating new road construction in areas predicted to have
a high potential for post-fire erosion, 5) limiting or eliminating salvage logging in
riparian areas that are located near predicted biological hotspots (e.g., Figure 1D), 6)
focusing erosion control efforts (straw bales, grass seeding, etc.) in areas predicted to
have both a high erosion potential and a proximity to quality and sensitive aquatic
habitats (e.g., Figure 2), 7) identifying and removing road crossings that present a risk to
drainage diversion or slope instability, of that would impede the transport of woody
debris and sediment pulses downstream (e.g., Figure 1C), and 8) altering upslope, road,
and riparian restoration measures in accordance with the risk they pose to lives, private
property, and other engineered structures (roads and bridges) based on terrain attributes
that would include landslide potential, debris flow susceptibility, tributary-mainstem
connectivity and transport of woody debris.
F. Facilities and Equipment
No special facilities and equipment are needed.
G. Literature Cited
Benda, L. E., and T. Dunne. 1997. Stochastic forcing of sediment routing and storage in
channel networks. Water Resources Research 33:2865-2880.
Benda, L. E., D. J. Miller, P. Bigelow, and K. Andras. 2003a. Effects of post-wildlife
erosion on channel environments Boise River, Idaho. Forest Ecology and Management
178:105-119.
Benda, L., D. Miller, J. Sias, D. Martin, B. Bilby, C. Veldhuisen, and T. Dunne. 2003b.
Wood Recruitment Processes and Wood Budgeting. Pages 49 - 73 in S. V. Gregory, K.
Boyer, and A. M. Gurnell, editors. The Ecology and Management of Wood in World
Rivers. American Fisheries Society.
Benda, L., D. Miller, T. Dunne, L. Poff, G. Reeves, M. Pollock, and G. Pess. 2004.
Network dynamics hypothesis: spatial and temporal organization of physical
heterogeneity in rivers. BioScience 54:413-427.
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Benda, L., D. J. Miller, K. Andras, P. Bigelow, G. Reeves, and D. Michael. 2007.
NetMap: A new tool in support of watershed science and resource management. Forest
Science 52:206-219.
Bigelow, P., L. Benda, D. J. Miller, and K. M. Burnett. 2007. On debris flows, river
networks, and the spatial structure of channel morphology. Forest Science 52:220-238.
Burnett, K., G.H. Reeves, D. Miller, S. Clarke, K. Christiansen, and K. Van-Borland..
2003. A first step toward broad-scale identification of freshwater protected areas for
Pacific salmon and trout in Oregon, U.S.A. T. 144-154. In Beumer, J.P., A. Grant, and
D.C. Smith, editors. Aquatic protected areas: what works best and how do we know?
Proceedings of the World Congress on Aquatic Protected Areas, Cairns, Australia.
August 2002. Australian Society for Fish Biology, North Beach, WA, Australia.
Burnett, K. M., and D. J. Miller. 2007. Streamside Policies for Headwater Channels: An
Example Considering Debris Flows in the Oregon Coast Range Province. Forest Science
53.
Everest, F. H., and W. R. Meehan. 1981. Some effects of debris torrents on habitat of
anadromous salmonids. Technical Bulletin National Council for the Paper Industry for
Air and Stream Improvement.
Lancaster, S. T., S. K. Hayes, and G. E. Grant. 2001. Modeling Sediment and Wood
Storage and Dynamics in Small Mountainous Watersheds. Geomorphic Processes and
Riverine Habitat Water Science and Application: Water Science and Application 4:85102.
May, C. L., and R. E. Gresswell. 2003. Spatial and temporal patterns of debris-flow
deposition in the Oregon Coast Range, USA. Geomorphology 1362:1-15.
Miller, D. J. 2003. Programs for DEM Analysis,
http://www.fsl.orst.edu/clams/prj_wtr_millerprg.html, 38pp. Earth Systems Institute,
Seattle, WA
Miller, D. J., C. H. Luce, and L. E. Benda. 2003. Time, space, and episodicity of physical
disturbance in streams. Forest Ecology and Management 178:121-140.
Miller, D. J., and K. M. Burnett 2007. Topographic and forest-cover controls on debrisflow landslide density in the Oregon Coast Range, Water Resources Research
Montgomery, D. R., and W. E. Dietrich. 1994. A physically based model for the
topographic control on shallow landsliding. Water Resources Research 30:1153-1171.
Nakamura, F., F. J. Swanson, and S. M. Wondzell. 2000. Disurbance regimes of stream
and riparian systems - a disturbance-cascade perspective. Hydrological Processes
14:2849-2860.
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Reeves, G.H., L. Benda, K.M. Burnett, P.A. Bisson, and J R. Sedell.1995. A disturbancebased ecosystem approach to maintaining and restoring freshwater habitats of
evolutionary significant units of anadromous salmonids in the Pacific Northwest. P. 334349 in Symposium on Evolution and the Aquatic System: Defining Unique Units in
Population Conservation, American Fisheries Society.
Reeves, G., B. Peter, B. Rieman, and L. Benda. 2006. Postfire logging in riparian areas.
Conservation Biology 20:994-1004.
Rieman, B., D. Lee, D. A. Burns, R. E. Gresswell, M. K. Young, R. Stowell, J. N. Rinne,
and D. G. Howell. 2003. Status of native fishes in the western United States and issues
for fire and fuels management. Forest Ecology and Management 178:197-211.
Sedell, J. R., and C. N. Dahm. 1984. Catastrophic disturbances to stream ecosystems:
volcanism and clear-cut logging. Pages 531-539 in M. J. Klug and C. A. Reddy, editors.
Current perspectives in microbial ecology. East Lansing and American Society of
Microbiology, Washington, D.C.
Swanson, F. J., and G. W. Lienkaemper. 1978. Physical consequences of large organic
debris in pacific northwest streams. General Technical Report PNW-69, USDA Forest
Service, Portland, Oregon.
Swanson, F. J., T. K. Kratz, N. Caine, and R. G. Woodmansee. 1988. Landform Effects
on Ecosystem Patterns and Processes. BioScience 38:92-98.
Wimberly, M. C. 2002. Spatial simulation of historical landscape patterns in coastal
forests of the Pacific Northwest. Canadian Journal of Forest Resources 32:1316-1328.
H. Key Personnel
Drs. Lee Benda and Daniel Miller, Earth Systems Institute, 310 N. Mt. Shasta Blvd.,
Suite 6, Mt. Shasta, CA 96067 (530 926-1066/206 633-1792)
Dr. Gordon Reeves, Pacific Southwest Experiment Station, U.S.F.S., 3200 Jefferson
Way, Corvallis, OR 97331 (541 750-7314)
Cameron Thomas, Okanagan/Wenatchee National Forest Fish Biologist, Wenatchee
National Forest, Wenatchee, WA (509.664.9361)
I. Budget $88,300
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