Biodiversity Guide - The Intertwine

egional conservation strategybiodiversity guideAppendix I Watershedsflow from Henry Hagg Lake, Barney Reservoir, communities and species across a spectrum ofof sensitive amphibians and reptiles are known,and wastewater treatment plant effluent. Stored mountain forests, valley woodlands, grasslands,including northern red-legged frogs, westernwater is now managed to maintain minimum and floodplains, and these present excellentpainted turtles, and western pond turtle. In themonthly mean flow of 120 cubic feet per second conservation opportunities. Despite many threats,absence of trapping during the last decade, beaver(cfs) from June to August and 150 cfs for Septemberthe basin still harbors many significant popula-have made rapid gains and recolonized many ofto November at RM 33.3. The river is now tions of special-status and sensitive species inthe basin’s creeks, to the benefit of many species.intensively managed, but its water quality is vastly aquatic, wetland, and upland habitats. One of theAlthough old-growth forests are scarce, the basinimproved.most significant features of the basin is the river’sis host to several sensitive late-successional forestThe watershed’s land uses today are approximately58-mile-long floodplain, which is consistentlywildlife species, including northern spotted owl,50 percent forest, 30 percent agriculture, noted as a regionally significant biodiversityTownsends big-eared bat, marbled murrelet, andand 20 percent urban. Most of the working forestlandsresource. (For example, in the Oregon Con-northern flying squirrel. The basin also supportsare found in the Coast Range, in the upper servation Strategy, it is included as Willamettenumerous elk, deer, muskrat, otter, cougar, andportion of the watershed, while the rest of the rim Valley Conservation Opportunity Area 5.) Thebobcat, along with a variety of other wildlife.contains urban, rural residential, and agricultural floodplain and associated valley wetlands containApproximately 55,000 acres (12 percent) ofareas. The lower watershed’s broad alluvial valley vitally important waterfowl habitats in the Pacificthe Tualatin Basin is held by public entities forencompasses both the residential, commercial, Flyway. Moving west from Wapato Lake, Pattonnatural resource, open space, and park purposes,and industrial urban core and diverse, productive Valley and the area upstream to Cherry Grovebut only a small fraction of these properties isacres of Tualatin River floodplain and wetlands atagricultural lands.have been noted as an important conservationmanaged primarily for biodiversity conservation.Jackson Bottom and Fern Hill wetlands.Since the nineteenth century, humans have opportunity.More than three-quarters of the basin’s naturalThe Coast Range portion of the basin alsovastly altered ecosystems in the Tualatin River Migrating birds routinely number in the thousandsat several key sites. Species include tundrathe largest owners being the Oregon Departmentresource land is located outside urban areas, withhas some large public holdings in addition towatershed. More than half its area has beenTillamook State Forest and the BLM parcels.converted from the original forest and floodplainhabitat to urban or agricultural use, and geese; northern pintail; canvasbacks; blue-wingedmook State Forest) and Bureau of Land Manage-swans; cackling, Canada, and dusky Canadaof Forestry (approximately 25,000 acres in Tilla-There are patches of high-quality mixed coniferousforest at Stub Stewart State Park (approximately1,700 acres) and in City of Forest Grovethe remaining forest is now intensively managed.Water retention on the landscape has been birds also are plentiful in the valley’s wetlands,ments, including cities and the Tualatin Hills Parkand green-winged teal; and buffleheads. Shorement(approximately 10,000 acres). Local govern-watershed lands (approximately 3,800 acres).reduced while water use exceeds the basin’s supplyfrom May into November in an average year. bittern and greater yellowlegs. Several large heroncomponent of park and natural resource lands—where there are healthy populations of Americanand Recreation District, collectively own a largeWashington County manages about 2,500 acres ofU.S. Bureau of Reclamation lands at Henry HaggThe abundance and diversity of fish and wildlife rookeries in the basin host high numbers of greatabout 10,000 acres. These local government landsReservoir. Although a majority of Hagg Lake Parkpopulations have been threatened by shrinking blue herons and also the black-crowned nightare typically near creeks and floodplains, butis inundated by Scoggins Dam, the surroundinghabitat and human impacts on aquatic and terrestrialcommunities. Without action, these trends Neotropical migratory birds.habitat tracts are isolated.heron. Remnant forests and prairie also supporttheir distribution is fragmented and many of theuplands contain a diverse assemblage of foresttypes, including oak habitats and prairies thatare likely to worsen because Washington County Despite well-chronicled declines, native coldwaterfish species such as cutthroat trout and theowned conservation lands across the TualatinThere are several noteworthy tracts of publiclyhave several rare species, including the federallyis expected to gain nearly one-half million peopleendangered Fender’s blue butterfly and federallyover the next few decades. 8 Within the urban ESA-listed threatened winter steelhead are stillBasin. Recent acquisitions by the U.S. Fish andthreatened Kincaid’s lupine.growth boundary of the Tualatin Basin there are present in the Tualatin River and its tributaries.Wildlife Service have enlarged the Tualatin RiverThere are only a few private land holdingsapproximately 20,000 acres of impervious cover Although not historically present in the Tualatin,National Wildlife Refuge to about 3,000 acresdedicated to conservation purposes in the TualatinBasin, but several significant urban wetlandsconnected to a separate storm sewer system. coho salmon totaled record numbers in recentof mainstem floodplain, wetlands, and relatedTwelve urban streams in the basin are listed by surveys, and the basin’s abundance of slow-wateruplands.are owned and managed by The Wetlands Conservancy;these include Cedar Mill Wetlands andDEQ as water-quality impaired for biological criteria.Temperature, toxics, nutrients, bacteria, and a population stronghold in the future. Westernnatural areas since 1995, representing a variety ofhabitat appears to provide ample opportunity forMetro has added more than 3,500 acres ofHedges Creek. A variety of easements and managementagreements exist for riparian, floodplain,impaired flow regime are all contributing factors brook lamprey and Pacific lamprey are alsohabitat types across the basin. The Metro naturalto this biological impairment.present in the Tualatin River and tributaries,areas have some large landscapes, such as 1,200and water resource protection throughout bothBecause of its varied geography and size, the but very little is known about their distributionacres of mixed forest on Chehalem Ridge, as wellurban and rural portions of the basin. Homeowners’associations own more than 2,500 acres ofTualatin Basin has a wide diversity of natural or population status. Several large populationsas some unique sites with rare habitats, such asthe peat bogs of Killin Wetlands. Clean Waterdedicated open spaces in the urban area but often8 http://www.oregon.gov/DAS/OEA/Pages/demographic.aspxServices and the cities of Hillsboro and Forestlack funds for management.Grove cooperatively manage more than 1,500306 307