• Scale: Production of an ecosystem-level plan.
• Complexity: Development of a priority-setting plan using science-based metrics.

Mission and Objectives

The purpose of the Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment is to identify priority areas for conserving the biodiversity of the Willamette Valley-Puget Trough-Georgia Basin ecoregion.

The assessment is a resource and guide for planners and others interested in the status or conservation of the biological diversity of this ecoregion.

Lead Organizations

Federal-U.S.

• U.S. Fish and Wildlife Service

State

• Oregon State Natural Heritage Information Center
• Washington Department of Natural Resources

Provincial

• British Columbia Conservation Data Centre

The Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment was developed through the following process:

Technical Teams

Five expert technical teams collaborated on a series of analyses based on methods developed by The Nature Conservancy and other scientists. Three teams covered the terrestrial environment’s plants, animals and ecological systems. A fourth assessed the nearshore marine environment within the Puget Sound and Georgia Strait. A fifth team studied the ecoregion’s freshwater systems.

Core Team

All the technical teams were coordinated and directed by an oversight group called the Core Team, made up of technical team leads and other scientists and conservation professionals from British Columbia, Washington, and Oregon. Staff from The Nature Conservancy in Washington led data compilation, analysis, and portfolio development for terrestrial, marine, and freshwater conservation targets.

The Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment was produced by a partnership initiated in 1998 to identify priority conservation areas in this ecoregion.

The assessment was proposed in a Charter Agreement of the Willamette Valley-Puget Trough-Georgia Basin among The Nature Conservancy, The Nature Conservancy of Canada, and the Washington Department of Fish and Wildlife.

The priority-setting plan was developed to balance natural resource demands with the conservation of natural heritage while creating the fewest conflicts with the legitimate use of natural resources.

The Ecosystem

The Willamette Valley-Puget Trough-Georgia Basin ecoregion is a long ribbon of broad valley lowlands and inland sea flanked by the rugged Cascade and coastal mountain ranges of British Columbia, Washington, and Oregon.

The ecoregion encompasses 21,431 square miles of Pacific inlet, coastal lowlands, islands, and intermontane lowland. It includes the Sunshine Coast and eastern lowland of Vancouver Island in Canada along the Georgia Strait. It also includes the region to the south through Puget Sound and the extensive plains and river floodplains in the Willamette Valley.

The average elevation of the ecoregion is 445 feet above sea level. But the presence of mountains, ocean intrusions and glaciation cause dramatic and localized differences in climate, soils and geology. Distinctive combinations of these factors lead to an array of ecological communities such as coniferous forests, open prairies, rocky balds, and oak savannas.

The ecoregion includes nearshore areas, namely the Puget Sound and Strait of Georgia, which feature a variety of deepwater and nearshore habitats. These habitats include coastal lagoons, kelp and seagrass beds, rocky shores, sandy beaches and spits, and salt marsh wetlands. Steep underwater slopes result in narrow strips of shallow water habitats near the shore. Puget Sound is home to marine mammals including harbor seals, orcas, porpoises, and California sea lions.

Threats

Threats to the ecoregion include:

• Invasive species such as English Ivy and introduced shellfish species.
• Terrestrial land use changes and habitat conversion; more than 40 percent of the ecoregion has been converted to urban or tilled agricultural uses, and most of the remainder is used in forestry.
• Rapid population growth that has included a doubling of the population between the 1960s and 1999, and the anticipation that the population will increase to five million people by 2020.
• Declines in important species, such as wild salmon and orca.

Development of a Priority-Setting Plan

The Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment can be used by planners and conservation organizations to prioritize their efforts.

The five technical teams each proposed conservation targets -- the species, communities, and ecological systems that should be included in priority conservation areas.

If these areas are conserved, they will provide protection for both the identified target and an array of interdependent ecosystem elements

For each target, records of location and status were gathered and goals were developed to identify how many populations (for species targets) or how much area (for system targets) the portfolio should include to adequately represent each target.

Next, the SITES computer program was used to select the optimal portfolio of sites. This is the set of sites which met the goals of the most targets at the lowest cost.

Because of the preponderance of data and experience in the terrestrial arena, the terrestrial portfolio was used as the foundation for the combination of terrestrial, nearshore marine, and freshwater priorities.

Marine sites were added with an emphasis on capturing those places where high-priority terrestrial and marine areas were ecologically connected.

The Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment has realized the following accomplishments or impacts:

• Provision of Common Information: The assessment provides information on the region’s natural systems and species.
• Identification of Shared Priorities: The Nature Conservancy, the Nature Conservancy of Canada, and the Washington Department of Fish and Wildlife will use the results of the assessment to guide their prioritization of projects and funding. Governments, land trusts, and others are encouraged to use the assessment as a supplementary resource to other planning information.

The Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment encountered the following challenges:

• Ownership: Eighty percent of the land in included in the portfolio is privately owned. A wide range of federal, tribal, state, provincial and local government lands make up the remainder. The state of Washington is the largest landowner among government entities. Less than one percent of the land is owned by non-profit conservation groups such as The Nature Conservancy. Approximately six percent of the portfolio lies within areas already designated for biodiversity conservation. A large proportion of the portfolio is managed for timber production. Ownership was not summarized for nearshore marine sites.

• Lack of Authority: This assessment has no regulatory authority. It is a guide for prioritizing work on the conservation of habitats that support the ecoregion’s extraordinary biological diversity.

• Scale: Users are advised to be aware of the large scale of the assessment. The portfolio does not include some sites that are locally significant for biodiversity conservation, such as small wetlands and small, high-quality patches of common habitat types. Mapped site boundaries are approximate and may include areas unsuitable for conservation. Local planners equipped with more complete information and finer resolution data are expected to refine the boundaries for these sites.

• Salmon Fishery Management: Salmon, though considered critical components in the freshwater ecological systems of the region, were not addressed in this assessment. Government and other organizations are developing salmon conservation strategies based on analyses which this assessment cannot replace. The authors of the assessment chose not to address salmon, given the ecological and political complexities. However, this assessment should provide a helpful context for people planning for the conservation of salmon or any other focal group.

• Imbalance of Biodiversity Data: Terrestrial species and habitats are more fully documented than marine or freshwater biodiversity in terms of their identification, location and relative condition. The assessment recognizes the lack of comprehensive data for benthic habitats and the offshore environment. This mostly limited the analysis to the nearshore area, and several shoals for which data was available. Within the nearshore area, finer-scale data is not available, compared to terrestrial areas. The marine portfolio is a representative sample of habitats that can determine which sites are higher priorities for conservation.

• Nearshore-Offshore Dynamics: The marine analysis does not include deepwater environments, allowing for a gap in management of mobile species and system dynamics.

Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment: http://www.ecotrust.org/placematters/assessment.html