Ecoregions of Oregon 124° 123° 122° 121° 120° 119° 118° 117° 1 15 Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity Astoria 2 of environmental resources; they are designed to serve as a spatial framework for the research, Pasco 10 1a Richland assessment, management, and monitoring of ecosystems and ecosystem components. By Longview Kennewick 10 recognizing the spatial differences in the capacities and potentials of ecosystems, ecoregions 46° 1d Walla Walla 11 stratify the environment by its probable response to disturbance (Bryce and others, 1999). 1f 10 11 46° iver Ecoregions are directly applicable to the immediate needs of state agencies, including the R em development of biological criteria and water quality standards and the establishment of 1b al 1f h Milton- e 4 10e management goals for nonpoint-source pollution (Omernik and Griffith, 1991; Hughes and N 10g Freewater 11c 1d Saint 9 Umatilla others, 1990; Whittier and others, 1988). They are also relevant to integrated ecosystem Helens management, an ultimate goal of many federal and state resource management agencies. Hermiston 11l 11f n Um r 3 a e The approach used to compile this map is based on the premise that ecological regions can be 1a 1f t r il 10i W v e 10e i a N l a iv a a 11f identified through the analysis of the spatial patterns and the composition of biotic and abiotic TO bi R Pendleton G l R IN Hood Colum River l ow phenomena that affect or reflect differences in ecosystem quality and integrity (Wiken, 1986; H a e Vancouver S A River 11l R Imnaha W i e Omernik, 1987, 1995). These phenomena include geology, physiography, vegetation, climate, 3a ve c Portland r k soils, land use, wildlife distributions, and hydrology. The relative importance of each Tillamook Hillsboro 3c The 11k a 1d Gresham 4b Dalles n characteristic varies from one ecological region to another regardless of the hierarchical level. A 1a Beaverton S 10c Enterprise r O 11g e v Roman numeral hierarchical scheme has been adopted for different levels of ecological regions. Moro i Hells R 1b Level I is the coarsest level, dividing North America into 15 ecological regions. Level II divides Canyon Heppner 11l hon Rive 1d 4d R de r 10c NRA the continent into 52 regions (Commission for Environmental Cooperation Working Group, 3c Oregon 9c e 1b d 3d n 9b 10k a 11f 10n 1997). At level III, the continental United States contains 104 ecoregions and the conterminous City C r La Grande 11l l M a ac G ka Condon 11l in h United States has 84 ecoregions (United States Environmental Protection Agency [USEPA], c 3d m a a McMinnville m n as 10c 11k 2003). Level IV is a further subdivision of level III ecoregions. Explanations of the methods used 1g 3d 4b 11c R 11m i 10k i m v r I 11o e R to define the USEPA’s ecoregions are given in Omernik (1995), Omernik and others (2000), f 11l 3c i 45° 1b v 10k e 11l Griffith and others (1994), and Gallant and others (1989). i 11l Lincoln r 4c 11o 45° City c 11b 11e Oregon is ecologically diverse. The west side of the state has a marine-influenced climate and Dallas 11d Salem P Fossil o receives plentiful precipitation three seasons of the year. In contrast, eastern Oregon lies in the a 11b r w e d rain shadow of the Cascades and is much drier. The climatic gradient is evident in the state's Si v 11a er le i R t R 3d 11m iv P z 4b 11k er Halfway landscapes: forested mountains, glaciated peaks, shrub- and grass-covered plains, agricultural Santiam River 11d 1b rth ay No R Detroit D 11l valleys, beaches, desert playas, and wetlands. There are 9 level III ecoregions and 65 level IV iver hn Lake r 9d Jo 11m Baker City ecoregions in Oregon and many continue into ecologically similar parts of adjacent states (Bryce S e Newport o 11a 11d u 11o Albany t v and others, 2003; McGrath and others, 2002; Pater and others, 1998). h 4d i 11 r 11b S 4b e 11d a3c R n v Madras nt i ur R 11d This level III and IV ecoregion map was compiled at a scale of 1:250,000. The western part was Corvallis t Lake 11o B iv Lebenon i R 11l 11l a e r m s Billy e originally published as part of Pater and others (1998). The level IV lines in the Columbia Plateau u i 1d R 4b Chinook k 3c l 11l and Blue Mountains were originally published in Clarke and Bryce (1997). Ecoregion boundaries W i 3c v o a Als r e t 11d ea e i r e 9b n in the remainder of Oregon depict revisions and subdivisions of earlier level III ecoregions that v l i D 11l l John Day 11l S R Green M a e m were originally compiled at a coarser scale (Omernik, 1987; USEPA, 2003). Peter Lake s 1d c e h 11l t 4c Crooked 11o t 3b u 11l e Prineville This poster is the product of a collaborative effort primarily between the USEPA Region X, the t e Sisters s 11b R 1d 4d 11m USEPA National Health and Environmental Effects Research Laboratory (Corvallis, Oregon), the i R 1g v R Redmond Weiser i e i 11i v Oregon Natural Heritage Program, the United States Department of Agriculture–Forest Service v 12j r 3c 4a e e enzi r 11n r 11o cK e Riv r (USFS), the United States Department of Agriculture–Natural Resources Conservation Service M e Prineville 11o Payette 44 1a Sius 12a (NRCS) (formerly the Soil Conservation Service), and the United States Department of the ° 1b l Reservoir Florence a Eugene Bend w Fern 44° Interior–Geological Survey (USGS)–Earth Resources Observation Systems (EROS) Data Center. 11b Ontario Ridge Reservior Ri The Oregon ecoregion project is part of an interagency effort to develop a common framework of ver r 12j ecological regions for the United States. Reaching that objective requires recognition of the ve 3d s Ri 12 1b 11h ie 11o differences in the conceptual approaches and mapping methodologies applied to develop the most v Crane Prairie l Waldo i ver common ecoregion-type frameworks, including those developed by the USFS (Bailey and others, Reedsport Reservoir S i Oakridge Lake R 80d 1994), the USEPA (Omernik, 1987, 1995), and the NRCS (U.S. Department of Agriculture–Soil m 80d U pqu Hills 4c r Caldwell a u Conservation Service, 1981). As each of these frameworks is further refined, their differences are 1b Creek e h l becoming less discernible. Regional collaborative projects, such as this one in Oregon, where Res. a R Wickiup LaPine M i agreement has been reached among multiple resource management agencies, are a step toward v Reservoir e 4b Burns r attaining consensus and consistency in ecoregion frameworks for the entire nation. 1a 4d 80j Lake 1b 80f Owyhee 9f 80e Coos Bay Literature Cited: I 80d D 1b 4d A Bailey, R.G., Avers, P.E., King, T., and McNab, W.H., eds., 1994, Ecoregions and subregions of the United 78c R Malheur 80f H No h Um iv rt a e 80j O p qu r Lake States (map) (supplementary table of map unit descriptions compiled and edited by McNab, W.H. and 80d 1b Roseburg Bailey, R.G.): Washington, D.C., USFS, scale 1:7,500,000. 9e Christmas 80d Coquille D 4d Valley Bryce, S.A., Omernik, J.M., and Larsen, D.P., 1999, Ecoregions – a geographic framework to guide risk o n characterization and ecosystem management: Environmental Practice, v. 1, no. 3, p. 141-155. 80g n 1a 4b 80e e r Bryce, S.A., Woods A.J., Morefield, J.D., Omernik, J.M., McKay, T.R., Brackley, G.K., Hall, R.K., Higgins, 1b r 43° e 80m iv R D.K., McMorran, D.C., Vargas, K.E., Petersen, E.B., Zamudio, D.C., and Comstock, J.A., 2003, a 43° u q p 4e a Jordan Valley Ecoregions of Nevada: Reston, Virginia, U.S. Geological Survey, map scale 1:1,350,000. m Crater n S 80g d ou U 80e th Lake Clarke, S.E., and Bryce, S.A., eds., 1997, Hierarchical subdivisions of the Columbia Plateau and Blue 80m Mountains Ecoregions, Oregon and Washington: Portland, Oregon, USFS, Pacific Northwest Research 1h 9f 4f Crater Lake NP Station, General Technical Report PNW-GTR-395. 4d r ve 78e i R 80f Burns O B wy 9f Summer he Commission for Environmental Cooperation Working Group, 1997, Ecological regions of North America – l Junction e R 78d 4d i i t v Lake z er toward a common perspective: Montreal, Commission for Environmental Cooperation, 71 p. n e 80 o Frenchglen n Rogue s Gallant, A.L., Whittier, T.R., Larsen, D.P., Omernik, J.M., and Hughes, R.M., 1989, Regionalization as a R m i R a Warner 80k v Lake i i tool for managing environmental resources: Corvallis, Oregon, U.S. Environmental Protection Agency, e l 80e v l Lakes e r a Abert i pr g S ue r 80a EPA/600/3-89/060, 152 p. W R 9g iv 80d 78b e Griffith, G.E., Omernik, J.M., Wilton, T.F., and Pierson, S.M., 1994, Ecoregions and subregions of Iowa – a 1b Grants 4d Chiloquin r 78b Pass 80m 80j framework for water quality assessment and management: Journal of the Iowa Academy of Science, v.