This file was created by scanning the printed publication. Text errors identified by the software have been corrected; however, some errors may remain. Editors SHARON E. CLARKE is a geographer and GIS analyst, Department of Forest Science, Oregon State University, Corvallis, OR 97331; and SANDRA A. BRYCE is a biogeographer, Dynamac Corporation, Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Western Ecology Division, Corvallis, OR 97333. This document is a product of cooperative research between the U.S. Department of Agriculture, Forest Service; the Forest Science De- partment, Oregon State University; and the U.S. Environmental Protection Agency. Cover Artwork Cover artwork was designed and produced by John Ivie. Abstract Clarke, Sharon E.; Bryce, Sandra A., eds. 1997. Hierarchical subdivisions of the Columbia Plateau and Blue Mountains ecoregions, Oregon and Washington. Gen. Tech. Rep. PNW-GTR-395. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 114 p. This document presents two spatial scales of a hierarchical, ecoregional framework and provides a connection to both larger and smaller scale ecological classifications. The two spatial scales are subregions (1:250,000) and landscape-level ecoregions (1:100,000), or Level IV and Level V ecoregions. Level IV ecoregions were developed by the Environmental Protection Agency because the resolution of national-scale ecoregions provided insufficient detail to meet the needs of state agencies for estab- lishing biocriteria, reference sites, and attainability goals for water-quality regulation. For this project, two ecoregions—the Columbia Plateau and the Blue Mountains— were subdivided into more detailed Level IV ecoregions. Similarly, the finer scale landscape-level ecoregions (Level V) were developed to address local land manage- ment issues. The landscape-level ecoregions for northeast Oregon and southeast Washington were created specifically to address the issue of anadromous fish habi- tat. Their delineation, however, employed landscape information similar to that used in other levels of the ecoregion hierarchy, thereby indicating the potential for general application of these regions to both terrestrial and aquatic research questions. The study area for the landscape-level ecoregions was defined by contiguous watersheds within the ecoregions of the Columbia Plateau and Blue Mountains to merge the ecoregional information with units corresponding to fish distribution. Keywords: Ecoregions, anadromous fish habitat, fish habitat, watershed classification, landscape ecology, water quality, environmental mapping, classification. Contents 10 Section 1—Level IV Ecoregipns of the Columbia Plateau Ecoregion of Oregon, Washington, and Idaho by Sandra A. Bryce and James M. Omernik 10 Columbia Plateau Ecoregion-Subregion Project 10 Description of the Columbia Plateau Ecoregion 12 Materials 13 Ecoregion Boundary Decisions 14 Description of the Columbia Plateau Subregions 20 Water Resource Issues of the Columbia Plateau Ecoregion 22 Literature Cited 24 Section 2—Level IV Ecoregions of the Blue Mountains Ecoregion of Oregon, Washington, and Idaho by Sandra A. Bryce and James M. Omernik 24 Climate 25 Geology—The Birth of the Blues 27 Blue Mountains Soils 28 Blue Mountains Vegetation 34 Descriptions of the Blue Mountains Subregions 52 Literature Cited 56 Section 3—Landscape-Level Ecoregions for Seven Contiguous Watersheds, Northeast Oregon and Southeast Washington by Sharon E. Clarke, Mark W. Garner, Bruce A. Mclntosh, and James R. Sedell 56 Introduction 58 Objectives of the Project 59 Connection to Other Approaches 61 Rationale for Delineating Landscape-Level Ecoregions 68 Delineation of Landscape-Level Ecoregions 99 Conclusion 101 Literature Cited 114 Acknowledgments Introduction Much of our disagreement about the proper role and function of regions, models and other generalizations probably should be attributed to basic and inherent differences between humans and their need for order, in which case it cannot be resolved by rational discussion. Most of us are probably some- where on a continuum between two polar extremes. At one extreme are those tidy-minded souls whose instincts tell them that the world should move with all the precision of a finely tuned watch,. .that our inability to detect regularity and order reflects our own weak analytical skills rather than the possibility that it may not exist. At the other extreme are those rambunctious types who perceive the world as a massive stochastic process, who glory in its disorder, chaos, and complexity, and who revel in the thought that every leaf on every tree is different. This battered old planet has quite enough evidence to keep both extremes happily convinced that they are right. John Fraser Hart, 1982 Background The condition of the ecosystems of the Columbia Plateau and Blue Mountains is pres- ently the focus of several Federal and State agencies. One hundred and fifty years of intensive land use—logging, road building, mining, grazing, and fire suppression— have transformed forests and grasslands, threatening the existence and long-term productivity of native ecosystems (Johnson and others 1994). Plans for restoration include more holistic management of forest, range, and water resources. Although the concept of ecosystem management has gained acceptance among land management agencies, implementing it can be a challenge. It is difficult for resource managers to apply the results of many individual studies to broad areas. Different agencies have conflicting missions, overlapping jurisdictions, and administrative boundaries that restrict an ecosystem focus overall. Resource managers in Canada have experienced the same difficulties; they have stressed the importance of an eco- system perspective, arguing that the bulk of environmental research is concentrated on single-issue and single-medium subjects (Omernik 1995). How do we move spatially and conceptually from single-issue research to consider cumulative stresses and ecosystem response? To coordinate ecosystem manage- ment in environmental research, Federal land management agencies formed an inter- agency task force to draft a memorandum of agreement that promotes the use of a common, hierarchical ecosystem framework. Existing ecoregion frameworks (Bailey 1983; Bailey and others 1994; Omernik 1987, 1995) provide the template for a com- mon framework by delineating areas of similar landscape characteristics that reflect the similarities in ecosystem type. By using a scheme that divides the landscape ecologically rather than administratively, agencies will be better able to develop strategies that are focused, ecologically significant, and thus, more cost-efficient. Federal agencies already have invested much time and effort in developing their own frameworks for particular objectives. It will be an arduous process to agree on a common scheme; but if successful, it will be an important step toward coordinating research efforts. 1 Recent movement toward ecosystem management within Federal land management agencies has been prompted in large part by biological-diversity issues in forests of the Pacific Northwest. After President Clinton’s April 1993 Forest Conference in Portland, Oregon, various Federal agencies proposed initiatives to address problems with endangered species, remnant old-growth forests, poor forest health, and de- clining anadromous fish runs. The Eastside Forest Ecosystem Health Assessment and the Eastside Scientific Panel have addressed similar forest problems in eastern Washington, Oregon, Idaho, Montana, and northern California (Everett and others 1993, Henjum and others 1994). The interagency Forest Ecosystem Management Assessment Team (FEMAT) report (FEMAT 1993) lists four components of an Aquatic Conservation Strategy: the estab- lishment of riparian reserves and watershed refugia, and watershed analysis as a foundation for watershed restoration. Ecoregion classifications at state and landscape scales will contribute to all the components of the Aquatic Conservation Strategy by identifying groups of watersheds that are similar in ecosystem structure and by describing their expected condition. A possible point of interagency contention is the tendency to consider watershed and ecosystem frameworks as mutually exclusive approaches. As a framework for re- search and planning, ecoregions provide a natural complement to watersheds. Spatial patterns in ecosystems or environmental resources continue across topographic divides (Omernik and Griffith 1991). In addition, streams may pass through multiple ecoregions, and their watersheds often change dramatically in character from head- waters to midstem to lowland sections. Figure 1 is an example of the interplay be- tween ecoregions and watersheds (Bryce and Clarke 1996). Because streams B and C are within the same ecoregion, they will have more in common than stream B has with stream A. Although streams A and B are located within the same watershed, they flow through distinctly different landscape types. Data that offer no particular patterns when stratified by watershed may show patterns when stratified by ecoregion. Both frameworks should be applied for a full exploration of spatial patterns and management options; however, neither framework should be stretched beyond its ability to explain variability and patterns in the data (Bryce and Clarke 1996). In this document, we report on the development and application