Case 2 Puget Trough

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In the Puget Trough-Georgia Basin ecoregion, we compared un-integrated and integrated approaches to planning across terrestrial and nearshore marine environments. The entire ecoregion is called the Willamette Valley-Puget Trough-Georgia Basin (WPG). This 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. It encompasses some 5,550,000 ha of ocean inlets, coastal lowlands, islands, and intermontane lowland. It extends from the eastern lowland of Vancouver Island along Georgia Strait, south through Puget Sound and the extensive plains and river floodplains in the Willamette Valley. Although the ecoregion’s elevation averages 445 feet (maximum 4,203 feet), the effect of the adjacent mountains, ocean intrusions, and glaciation in the regions’ northern two-thirds have caused dramatic localized differences in climate, soils, and geology. The marine and estuarine environments of British Columbia and Washington include systems such as kelp forests, eelgrass beds, and saltmarsh as well as many marine mammals, fishes and invertebrates.

The ecoregional assessment identified many terrestrial and marine species and ecosystems in the WPG. Conservation features were not identified in marine waters deeper than 40 meters because little data was available in these deeper waters. There were a total of 108 nearshore marine features and more than 800 terrestrial features distributed throughout the five subregions that accounted for the adequate distribution of conservation priority areas. A single set of 8,107 contiguous planning units, 750-hectare hexagon units, was developed across the terrestrial and marine environments.

In the integrated analysis, all nearshore marine and terrestrial targets were examined together in one analysis; the other analysis separated nearshore marine and terrestrial features but retained the same planning units. Freshwater targets were included in the assessment, but they were examined separately from terrestrial and marine targets using different planning units (i.e. watersheds), and it was not possible to compare their integration analytically. Researchers compared the total area of conservation priorities selected as well as how well each conservation feature met its desired goal or representation level.

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