Table 2.1—Hierarchical relations between assessment scales and various types of ecosystem delineation.

Biophysical Environments Existing Conditions Assessment Terrestrial Aquatic Vegetation Social Scale Units1 Units2 Units3 Assessment Units

Global Domain Zoogeographic Region Class Continent Continental Division Zoogeographic Subregion Subclass Nation Regional Province River Basin Group State Subregion Section Subsection Subbasin Formation County Landscape Landtype Association Watershed/Subwatershed Series Community Land Unit Landtype Phase Valley Section/Stream Reach Association Neighborhood Site Ecological Site Channel Unit Individual 'ECO Map 1993 2USDA Forest Service 1994a 3Driscoll and others 1984

Example: ABLA/VASC 107

106

105

Fire Group 7 (0 ABLA Rocky Forests Mountain Subalpine 102 Forest

ABLA Seecf\Snowbank Germination

104 106 108 1010 1012 Meters2 Plot/Stand Landscape i Ecoregion Continent

ABLA=Subalpine Fir PICO=Lodgepole Pine VASC=Grouse Whortleberry

Figure 2.2—An ecosystem characterization example of subalpine fir forests in the Northern Rocky Mountains.

Biophysical 113 Ecological units (Bailey and others 1994a; Cleland » Geologic Environments and others, in press; McNab and Avers 1994), • Geoclimatic Ecological Units \,land units (Zonneveld 1989), ecoregions ^(Omernick 1987), biogeoclimatic ecosystems » Potential Vegetation Settings (Meidinger and Pojar 1991), and land systems * Hydrologic Environments (Christian and Stewart 1968) are examples of mapping systems that » Integrated Ecological Reporting Units delineate ecologically homogeneous environments Ecological pattern and process relations, successional at different spatial scales based primarily on climatic, pathway dynamics, and management potential/ geomorphic, and biotic criteria. Hierarchical hazard ratings were developed for these biophysical watershed/geoclimatic maps are additional examples environment maps to assist various SIT and Envi- of biophysical environment maps that are increas- ronmental Impact Statement (EIS) team efforts. ingly being used in aquatic system assessment Descriptions of these biophysical environments and efforts (Jensen and others 1996, Maxwell and suggestions concerning rJieir use and limitations in others 1995). ecological assessment activities are provided in The ecosystem components used in developing the following discussion. biophysical environment maps (for example, climate, landforms, geology, or soils) do not Geologic Settings change following most management activities; consequently, such maps provide a useful template Despite the fact that the geologic components of a for interpretation of data such as existing vegeta- biophysical environment do not change as a result tion that commonly display change following of management activity, geologic process rates may management treatments. These types of data change dramatically as a result of management. describe the "existing condition" of the landscape Geologic components and processes profoundly and are commonly associated with appropriate influence other ecosystem components and pro- biophysical environment settings in determining cesses, including current and potential vegetation the condition or "" of an area. The effects of patterns and successional processes, as well as management practices on the landscape are most terrestrial and aquatic and productivity, efficiently described by contrasting the "existing and settlement patterns. Changes in condition" of an area with other managed or geologic process rates due to human activity may unmanaged areas of similar biophysical environ- also profoundly affect ecosystems through increased ment settings. This process minimizes the natural erosion, sedimentation, and toxic element release. variability among sites, facilitating more direct Human activity can also improve ecological condi- descriptions of the relations between observed tions through management activities diat preserve or landscape conditions and management treatments. mimic natural processes. From a human perspective, some important geologic processes are catastrophic; Biophysical environment maps may be delineated these include volcanic eruptions and dieir associated at different spatial scales (table 2.1) dependent effects, earthquakes, earth movements such as on assessment needs and the types of ecological landslides and rockfalls, and large floods. The patterns and processes to be predicted. Regional, influence of, and interactions between, geologic subregional, and landscape scales of biophysical processes and other ecosystem processes are environment maps were developed by the Land- described later in this chapter. The geologic scape Staff for use in the assessment of the environments that constrain such processes are Basin. These maps included: described below.

114 Biophysical General Description of the Geologic » Rocks that formed as oceanic crust and have Environments of the Basin since been transported onto continents by plate tectonics. The geologic components of any ecosystem can be subdivided into bedrock and surficial geologic * Flood basalts that cooled from giant lakes of lava. units. Bedrock geologic units are those that are » Volcanic rock formed by the present-day solid and underlie any unconsolidated surficial Cascade volcanos. materials. These two types of units affect and interact with other ecosystem processes at many * Sandstones, shales, and conglomerates that spatial and temporal scales. For example, erosion formed through erosion and deposition of rates for most bedrock types with associated "natural" older rocks. vegetative cover are generally low. Physical erosion * Carbonate rocks formed from animal remains. rates for unconsolidated surficial deposits (such as alluvium, loess, or glacial till) are commonly « Chemically deposited sedimentary rocks. higher than those found on bedrock units. Chemical Additionally, unique physical or chemical properties weathering rates determine the release of rock of lithologies such as serpentinite, some tuffs, and components, such as nutrients and toxic elements, carbonate rocks provide unique habitat for selected into the ecosystem. Disturbance of vegetative species that contributes to the landscape and cover, road building, mining, agriculture, urban- species diversity of the Basin. ization, dam building, and other human activities may profoundly increase the physical and chemical Different geologic processes have affected the weadiering rates of geologic materials. In a similar rocks of the Basin in numerous ways during the manner, such disturbances may also affect water course of geologic history. These processes (for retention or other characteristics of the rocks and example, erosion, deposition, consolidation, uplift, soils of an area in such a way that they no longer metamorphism, volcanism, and geochemical support predisturbance vegetation cover types. changes) have all occurred at different times Increased fluxes of sediment, toxic elements, and throughout the history of the Basin, resulting in nutrients, or decreased water flows caused by the different physiography, erosion characteristics, human activities may irrevocably alter ecosystem nutrient availability, and other landscape parameters processes and must be considered in land manage- present today. It is impossible, for example, to ment planning. An understanding of both the classify granite into a single erosion group or geologic environments and geologic processes of a characteristic. Although much of the granitic planning area are essential components of any rock of the Idaho batholith is crumbly and erodes ecological assessment effort. relatively easily, other granitic units (for example, rocks in the Bighorn Crags or the Sawtooth The lithologic characteristics of rocks within Mountain Range) display wide ranges in natural the Basin are diverse, which in many cases defies erosion rates. simple classification of rock types by ERU. Bed- rock geologic units within the Basin range in age Surficial geologic units may develop directly from Precambrian rocks older than 2.7 billion through physical and chemical weathering of years, to volcanic rocks formed during the Mt. bedrock geologic units, or they may be transported St. Helens eruption of 1980. Rocks include: from elsewhere as glacial till and alluvium, or as wind-blown dust, sand, or volcanic ash. Discus- » Those that crystallized deep within the earth's sion of the surficial geologic units of the Basin and crust from liquids or by metamorphism, and their related soil properties is presented later in which were subsequently exposed at the earth's this chapter. surface by erosion.

Biophysical 115 Approach Used in Geologic Setting ment over the Basin within the next 10 years. The Description longer term metallic mineral potential of the Basin was displayed in maps of permissive or Geologic, hydrologic, and mineral resource data favorable rankings for the occurrence of 29 distinct were compiled, interpreted, and synthesized from mineral deposit types (Box and others, in press). published and unpublished sources and databases. The economic feasibility of development of as yet The earth science themes for the Basin assessment undiscovered mineral deposits in permissive areas were delineated and developed through collabora- was also described (U.S. Bureau of Mines 1995). tion with scientists from all SIT staff disciplines. In addition to their economic applications, such Individual digitized state geologic maps were used types of mineral resource information provided an to create a lithologic group map of the Pacific assessment of likely future disturbance areas resulting Northwest, including all of Washington, Oregon, from mining-related activities (Zientek and others, Idaho, and parts of Montana, Wyoming, Utah, in press a). Mineral resource (Box and others, in Nevada, and California (map 2.2) (Johnson and press) and existing deposit information (Bookstrom Raines in press). These individual state coverages and others, in press b) were used in the assessment were then used to develop the derivative maps of aquatic system integrity; past, current, and required for this study. Derivative map products future economic activity and conditions; and included: biophysical environments. » Areas favorable for sand, gravel, and Data from the National Geochemical database (Bookstrom and others, in press a). (Hoffman and Buttleman 1994) were used to evaluate metal loadings in streams draining areas » Areas favorable for cave-dwelling bats (for with exposed mineral resources (Raines and Smith example, lithologies such as carbonate develop in press). Geochemical data from stream sediment caverns, recent basalt flows contain lava tubes, samples were found to correlate well with and mine portals provide man-made caves) geochemical characteristics delineated on the (Frost and others 1996). lithologic group map (Johnson and Raines, in » Geochemical nutrients (carbonate, potassium, press). Digitized versions of published hazard iron, aluminum, magnesium, and phospho- maps, including earthquake and volcanic hazards rous). (Hoblitt and others 1987), as well as geothermal well and spring coverages were also produced. » Heavy metal distribution maps (Raines and Stream flow, water quality, and aquifer data sets from Smith, in press). the USGS Water Resources Division were utilized in This lithologic group map and the derivative the Economics, Broadscale Assessment of Aquatic geochemical and lithologic maps were used in Species and , and Landscape Dynamics developing maps for soil erosion potential and assessments. Descriptions of the map themes sup- sediment supply, watershed classification, geoclimatic plied and reports generated for the project by the subsections, and potential vegetation. These maps USGS are discussed in Chapter 8, Information were also used to evaluate terrestrial species habitat System Development and Documentation. and "hot spots" of species richness and endemism, as well as aquatic characteristic correlation matrices Uses and Limitations of and aquatic integrity indices. Geologic Information Mineral resource databases of the U.S. Geological The geologic, hydrologic, mineral resource, and Survey (USGS) and U.S. Bureau of Mines (USBM) process data compiled and interpreted in this were queried to provide information on metallic assessment provide important information for mineral deposits and their current production addressing many issues related to ecosystem status and to project possible economic develop-

116 : Biophysical Lithologic Group Map of the Pacific Northwest to kj LEGEND 3- 0_ o H alkalic intrusive era o' HI alluvium H argillite and slate

•O I calc-alkaline meta-volcanic

-O iHI carbonate O "^> H conglomerate 5-It d] dune sand H felsic pyroclastic H glacial drift CH glacial ice Bl granite d3 granite gneiss H interlayered meta-sedimentary d lake sediment and playa I landslide d loess H mafic gneiss H mafic intrusive C3 mafic meta-volcanic HH meta-sandstone CH meta-siltstone H metamorphosed 3 I mixed miogeosynclinal o' Htuff T3 ^< I ultramafic C/5 >V State Boundaries o" 5L A' LCA Boundary A/ Columbia River Basin Assessment Boundary H- (•*

ICBEMP pattern and process relations. The utility of geo- A subsection group map of the Basin (map 2.3) logic information in this, or any other ecosystem was constructed from individual subsection delin- assessment and monitoring program, is limited eations (Nesser and others, in press) to display only by: repeatable ecological units with similar climate, landforms, and surficial materials features. These » Scale of analysis. mapping units were primarily used to develop » Completeness and appropriateness of the watershed classifications, to map probable stream geologic or hydrologic database to the type group distributions, and to describe general questions being asked. hydrologic environments by ecological reporting unit (ERU). Ecoregions, subsections, and sub- « Understanding of the processes or patterns section groups were the primary geoclimatic maps being investigated. used in most of the landscape ecology assessment For regional-scale analysis such as the ICBEMP, work. The following discussion summarizes the generalized geologic and related derivative maps construction, associated information, and general at 1:500,000 scale are appropriate for nutrient use of these various maps in the assessment process. distribution description, mineral resource and mineral impact assessment, regional stream character Ecoregions description, and vegetation pattern analysis, among others. For watershed- or landscape-level Ecoregions represent large regional ecosystems analysis, bedrock and surficial geologic maps at that are uniquely identified (labeled) in geoclimatic scales as large as 1:24,000 or larger are commonly environment mapping. Several maps and descrip- required to address erosion, vegetation pattern, tions of the ecoregions of the United States have species habitat, aquatic integrity, and other been prepared over the last several decades (Bailey important issues. 1978, 1982, 1988; Bailey and others 1994a; Driscoll and others 1984; Omernik 1987). Such Geologic, geochemical, geophysical, and hydro- maps are commonly constructed based on features logic data have many uses in ecosystem assessment such as climate, landforms, geologic materials, and monitoring. Earth science data (especially potential natural vegetation, land use, and soils. when combined with climatic, biologic, landscape ecology, or other data sets) provide important In 1994, a map of the ecoregions and subregions information for addressing many of the issues of the United States was published at a scale of commonly identified in multi-scale ecological 1:7,500,000 (Bailey and others 1994a). This map assessments. delineated terrestrial biophysical environment ecological units at the following four levels of Geoclimatic Settings specificity: domains, divisions, provinces, and sections. Domains are normally defined using Hierarchical, geoclimatic-based ecological unit maps broad climatic zones. Divisions are defined using (Cleland and others, in press) were developed for regional climatic factors. Provinces are defined regional, subregional, and landscape scale assess- using potential vegetation communities, land- ment efforts. Terrestrial environments described by forms, and altitudinal zonations. Sections are these maps include provinces, sections (Bailey and further defined based on physiography (geology others 1994a, McNab and Avers 1994), subsections and topography). A companion publication (Nesser and others in press), and subsection groups. (McNab and Avers 1994) to this map of the Provinces, sections, and subsections were used to identify progressively finer delineations of unique ecoregions with similar climate, landform, and surficial geologic material composition.

±48 Biophysical *ue Geoclimatic Subsection Groups E LEGEND -V State Boundaries N Columbia River Basin Assessment Boundary A' LCA Boundary

' [U 33101 • M33101 3 «H CH 33102 H M33102 o d 33103 • M33103 -a O 34201 • M33104 [1134202 • M33105 d 34203 CH M33106 CH 34204 CH M33201 • 34205 C] M33202 • 34206 • M33203 • 34207 • M33204 • M24201• M3320S • M24202• M33206 • M24203• M33207 • M24204 OH M33208 U M24205 • M33209 [13 M26101 M M33301 • M26102• M33302 • M26103• M33303 • M26104C] M33304 • M26105 CD o" en o' CD

P- H> CD ICBEMP Nation's ecoregions and subregions was also subsection map for this project: geologic material, published to provide map unit descriptions for landform, and climate. These ecosystem compo- the sections displayed on the map. Terrestrial nents were considered to be the important driving (geoclimatic-based) biophysical environments of variables (at the 1:500,000 scale) of many finer- the Basin are displayed at the section level in map scale patterns and processes within the Basin. A 2.4. A total of 7 provinces and 23 sections occur complete description of the differentiating criteria within the landscape ecology characterization area and accessory characteristics associated with the displayed in map 2.4. geoclimatic subsections of the Basin is provided by Nesser and others (in press). The following is a Although some of the earlier Land System Inventories general summary of that information: (LSI) and more recent ecoregion mapping were done at several scales, a standardized framework In development of the geoclimatic subsection map for their construction did not exist until recently. of the Basin, geologic materials were first separated In 1994, a National Hierarchical Framework of by major groups of bedrock types (for example, Ecological Units (Cleland and others, in press) was intrusive igneous, carbonate sedimentary, and established that defined different levels of terrestrial metasedimentary) and surficial materials (for biophysical environment mapping appropriate to example, alluvium, glacial till, and residuum). multi-scale ecological assessment efforts (table These classes of geologic materials could not be 2.1). To provide a basic overview of this mapping more specific than the state geology maps used in system, the mapping scales associated with this subsection map construction. Broad landform hierarchy are displayed in table 2.2 and the principal types (for example, glaciated mountains, plateaus, criteria used in map unit design are described in and plains) were the second important differentia table 2.3. used in map construction. General climate zones, which were inferred from general vegetation patterns, Subsections were also considered in map design (for example, grassland, shrublands, and forest). In some cases, For the assessment of the Basin, a subsection level these vegetation classes were further subdivided map of over 203 million acres was produced that based on knowledge of local vegetation ecology. identified 283 unique geoclimatic environments (Nesser and others, in press). This map was prepared Information concerning numerous other ecosystem at a scale of 1:500,000 because this was the only features (accessory characteristics) was used in the scale where associated base maps, topographic description of each subsection. Examples of this maps, and geologic maps were available for the information include soils, mean annual precipita- seven states covered by the map. This map scale tion, mean annual air temperature, surface water was also considered to be the highest resolution characteristics, slope range, elevation range, and that could be mapped in the amount of time disturbance regimes. Summarization of this informa- available that was consistent with recommenda- tion was included in map unit description reports for tions outlined in the National Hierarchy of each subsection (Nesser and others, in press). Ecological Units (Cleland and others, in press). The USGS 1:500,000 Albers Conic Equal-Area Ecosystem components considered in the delineation Projection Maps for the states of Montana, Idaho, of subsection mapping units are the differentiating Washington, Oregon, California, Nevada, Utah, criteria used in map construction. Other compo- and Wyoming were used as subsection base maps. nents used to describe each subsection (but not in Geologic materials were determined from map unit delineation) are referred to as accessory 1:500,000 State geology maps with some minor characteristics. Three primary differentia (differen- refinements based on local knowledge. General tiating criteria) were used in constructing the landforms were determined using 1:500,000 State topographic maps and local knowledge.

Biophysical Map 2.4—Geoclimatic sections.

Biophysical 121 Table 2.2—Typical map scales and polygon sizes of terrestrial biophysical environment ecological units.

Ecological Unit Map Scale Range General Polygon Size

Domain 1:30,000,000 or smaller 1,000,000s of square miles Division 1:30,000,000 to 1:7,500,000 100,000s of square miles Province 1:15,000,000 to 1:5,000,000 10,000s of square miles Section 1:7,500,000 to 1:3,500,000 1,000s of square miles Subsection 1:3,500,000 to 1:250,000 10s to low 1,000 of acres Landtype Association 1:250,000 to 1:60,000 high 10Os to 1,000s acres Landtype 1:60,000 to 1:24,000 10s to 10Os of acres Landtype Phase 1:24,000 or larger Less than 100 acres

Table 2.3—Principal map unit design criteria used in the construction of terrestrial biophysical environment ecological units.

Ecological Unit Principal Map Unit Design Criteria

Domain 1 Broad climatic zones or groups (such as dry, humid, and tropical). Division 1 Regional climatic types (Koppen 1931, Trewartha 1968). 1 Vegetational affinities (such as prairie or forest). • Soil order. Province > Dominant potential natural vegetation (Kuchler 1964). ' Highlands or mountains with complex vertical climate-vegetation-soil zonation. Section 1 Geomorphic province, geologic age, stratigraphy, lithology. ' Regional climatic data. 1 Phases of soil orders, suborders or great groups. 1 Potential natural vegetation. • Potential natural communities (PNC) (FSH 2090). Subsection 1 Geomorphic process, surficial geology, lithology. 1 Phases of soil orders, suborders, or great groups. 1 Subregional climatic data. 1 PNC (formation or series). Landtype Association 1 Geomorphic process, geologic formation, surficial geology, and elevation. 1 Phases of soil subgroups, families, or series. 1 Local climate. 1 PNC (series, subseries, plant associations). Landtype ' Landform and topography (elevation, aspect, slope gradient and position). 1 Phases of soil subgroups, families, or series. 1 Rock type, geomorphic process. 1 PNC (plant associations). Landtype Phase > Phases of soil families or series. > Landform and slope position. • PNC (plant associations or phases).

Biophysical Broad climatic zones were inferred from potential State Library and the Pacific Northwest Regional natural vegetation mapping units of Kuchler Office of the FS in Portland, Oregon. Plots of this (1964) and other regional and local sources of map were constructed at 1:500,000, 1:1,500,000, information. and 1:2,000,000 scales for different assessment effort needs. Characterization of average annual precipitation for map units was achieved using the PRISM model. PRISM (Precipitation-elevation Regressions Subsection Groups on Independent Slopes Model) is an analytical The 283 subsections of the Basin were combined model that distributes point measurements to a into 39 subsection groups for subsequent terres- regular grid on regional to continental scales. trial and aquatic system analysis. Groupings of PRISM uses a Digital Elevation Model (DEM) to subsections were made by province based primarily estimate precipitation at each DEM cell using a on similarities of landform and surficial geologic regression of precipitation versus orographic characteristics. Bedrock geology, average annual elevation. Precipitation maps based on PRISM were precipitation, and slope characteristics were also provided by the U.S. Department of Agriculture considered in subsection group identification. The (USDA) Natural Resources Conservation Service following is a generalized description of the 39 (NRCS). Statewide climatic data and local subsection groups identified within the Basin by knowledge were also used in subsection map province (map 2.3). Only the most extensive types development. of rocks, landforms, geomorphic processes, and Soils were described for each subsection using vegetation types within each subsection group are local survey data and experience where possible. listed in these descriptions. At this level of gener- Other sources of soils information included Major alization, smaller amounts of many other types of Land Resource Areas and State Soil Geographic settings usually occur with a subsection group. DataBases from the NRCS. DEM data and Great Plains-Palouse Dry Steppe Province hydrography coverages were also used in the (Number 331) characterization of subsection map units. Subsection group 33101 consists of breaklands of Subsection maps were constructed during work- Columbia River basalt that have been modified by shops comprised primarily of soil scientists and stream downcutting. The general vegetative types geologists knowledgeable about local areas. include coniferous forest and grassland. Soils are Preliminary subsection maps of parts of the Basin generally coarse- to medium-textured. The subsec- (Arnold 1994, Holdorf 1994) were compiled and tion included in this unit is 331 Af. edited by project coordinators. These maps were then reviewed and modified by soil scientists, Subsection group 33102 consists of foothills and geologists, and ecologists from the USDA Forest plateaus of basalt with a mantle of loess that have Service (FS), NRCS, U.S. Department of Interior been modified by fluvial processes. The general (USDI) Bureau of Land Management (BLM), and vegetative type is grassland. Soils are generally fine- USGS. A list of all the people who assisted with textured. The subsections included in this group construction of the subsection maps for the Basin are 331Aa-d and g. is available in Nesser and others (in press). Subsection group 33103 consists of plateaus of Brief initial descriptions of subsections were basalt with a mantle of loess that occur in areas of provided by Arnold (1994) and Holdorf (1994); high precipitation and have been modified by however, most map unit descriptions were written fluvial processes. The general vegetative type is by the same people who finalized map unit grassland. Soils are generally fine-textured. The delineation. Subsection maps were redrafted, subsection included in this unit is 331 Aa. edited, digitized, and attributed by the Montana

Biophysical 123 Intermountain Semi-Desert Province been modified by fluvial processes. The general (Number 342) vegetative types include shrubland and grassland. Soils are generally coarse- to medium-textured. Subsection group 34201 consists of breaklands The subsections included in this group are 342Ba, and steep foothills of mostly igneous extrusive g, and I; and 342Cg. rocks with lesser amounts of intrusives and sedi- mentary rocks. These materials have been modified Subsection group 34207 consists of foothills by uplifting and downcutting. The general vegetative composed mainly of loess over basalt that have type is grassland with some coniferous forests at been modified by fluvial and aeolian processes. higher elevations. Soils are generally coarse- to The general vegetative type is grassland. Soils are medium-textured. The subsections included in generally fine-textured. The subsection included in this group are 342Bc and 342Ie. this unit is 342Ic. Subsection group 34202 consists of plateaus and Cascade Mixed Forest-Coniferous Forest-Alpine high plains of basalts and tuffs that have been Meadow Province (Number M242) modified by fluvial and aeolian processes. The Subsection group M24201 consists of glaciated general vegetative types include shrubland and mountains and foothills of igneous and sedimentary grassland. Soils are generally coarse- to medium- rocks that have been modified by glacial and textured. The subsections included in this group fluvial processes. The general vegetative type is are 342Cc-e and 342Da-f. coniferous forest. Soils are generally medium- to Subsection group 34203 consists of plateaus and fine-textured. The subsections included in this high plains of fluvial and lacustrine sediments group are M242Ca, b, e, g, m, o-q, and s-u. and ash deposits that have been created by aeolian, Subsection group M24202 consists of plains of fluvial, and lacustrine processes. The general ash and pumice over volcanic rocks, mostly basalt, vegetative types include grassland and shrubland. that have been modified by alluvial and volcanic Soils are generally fine-textured. The subsections processes. The general vegetative type is coniferous included in this group are 342Bd, 342Ca and b, forest. Soils are generally fine-textured. The sub- 342Hc, and 342Ib and d. section included in this unit is M242Cd. Subsection group 34204 consists of intermontane Subsection group M24203 consists of mountains basins and valleys composed mainly of alluvium, covered by ash or pumice and frequently underlain ash, and lacustrine materials over basalt. The by igneous extrusive rocks. These materials have general vegetative types include shrubland and been modified by fluvial, mass wasting, and grassland. Soils are generally medium- to fine- aeolian processes. The general vegetative type textured. Subsections included in this group are is coniferous forest. Soils are generally coarse- 342Bh, 342Hd, and 342Ia. textured. The subsection in this group is M242Cf. Subsection group 34205 consists of plateaus and Subsection group M24204 consists of intermontane foothills composed mainly of tuffs and basalts basins covered by ash, pumice, and alluvium. that have been modified by fluvial and aeolian These materials have been modified by fluvial processes. The general vegetative types include processes. The general vegetative type is coniferous shrubland and grassland. Soils are generally coarse- forest. Soils are generally fine-textured. The sub- to medium-textured. Subsections included in this section in this group is M242Cv. group are 342Bb and j, 342Ch and I, 342Ha and b, and342Ifandg. Subsection group M24205 consists of mountains and foothills covered by ash and pumice and Subsection group 34206 consists of mountains frequently underlain by igneous extrusive rocks. composed mainly of tuffs and basalts that have These materials have been modified by fluvial,

124 Biophysical mass wasting, and aeolian processes. The general Southern Rocky Mountain Steppe-Open Wood- vegetative type is coniferous forest. Soils are generally land-Coniferous Forest-Alpine Meadow Province fine-textured. The subsections included in this (Number M331) group are M242Cc and n. Subsection group M33101 consists of foothills Sierran Steppe-Mixed Forest-Coniferous Forest- and plateaus of volcanic and metamorphic rocks Alpine Meadow Province (Number M26D that have been modified by colluvial, fluvial, glacial, and periglacial processes. The general Subsection group M26101 consists of foothills vegetative types include forest, grassland, and of extrusive igneous rocks and some alluvium that shrubland. Soils are generally medium- to fine- have been modified by fluvial processes. The textured. Subsections included in this group are general vegetative types include shrubland and M331Ab, f, I, andn. grassland with lesser amounts of forest. Soils are generally coarse- to medium-textured. Subsections Subsection group M33102 consists of intermontane included in this group are M26lDa and e. basins and valleys of valley fill, alluvium, and lacustrine materials overlying volcanic and sedi- Subsection group M26102 consists of intermontane mentary rocks. The general vegetative types in- basins, foothills, and plateaus of igneous extrusive clude coniferous forest, grassland, and shrubland. rocks overlain by ash, pumice, and alluvium that Soils are generally medium- to fine-textured. have been modified by fluvial and volcanic Subsections included in this group are M331Aa, processes. The general vegetative types include k, and 1; and M331Da, e, h, j, v, and w. coniferous forest, grassland, and shrubland. Soils are generally coarse- to medium-textured. Sub- Subsection group M33103 consists of glaciated sections included in this group are M26lDb and mountains of volcanic and sedimentary rocks that M26lGaandd. have been modified by colluvial, fluvial, residual glacial, and periglacial processes. The general Subsection group M26103 consists of glaciated vegetative types include coniferous forest, mountains and foothills of volcanic rocks that shrubland, and some alpine tundra. Soils are have been modified by glacial, fluvial, and mass generally coarse-textured. Subsections included in wasting processes. The general vegetative type is this group are M331Dk, m, and t; and M331Ja-e. coniferous forest. Soils are generally coarse- to medium-textured. Subsections included in this Subsection group M33104 consists of glaciated group are M26lDc and d. mountains of volcanic and sedimentary rocks that have been modified by colluvial, fluvial, residual, Subsection group M26104 consists of mountains and glacial processes. The general vegetative types of extrusive igneous rocks that have been modified are coniferous forest with some shrubland. Soils by fluvial processes. The general vegetative type is are generally fine-textured. Subsections included coniferous forest. Soils are generally coarse- to in this group are M331Dd, o, and p. medium-textured. Subsections included in this group are M26lDg and M26lGb. Subsection group M33105 consists of mountains of volcanic rocks that have been modified by Subsection group M26105 consists of mountains colluvial, fluvial, and periglacial processes. The of extrusive igneous rocks that have been modified general vegetative types include coniferous forest, by fluvial processes. The general vegetative type is grassland, and shrubland. Soils are generally coniferous forest. Soils are generally fine-textured. coarse- to medium-textured. Subsections included Subsections included in this group are M26lDf in this group are M331Ac, d, g, h, and j. and h, and M26lGc. Subsection group M33106 consists of mountains of sedimentary and volcanic rocks that have been

Biophysical 125 modified by colluvial, fluvial, residual, glacial, and Subsection group M33205 consists of glaciated periglacial processes. The general vegetative types mountains of granitics and gneiss with lesser include coniferous forest, grassland, and shrubland. amounts of volcanic and sedimentary rocks that Soils are generally fine-textured. Subsections have been modified by glacial, periglacial, fluvial, included in this group are M331Ae, m, o, p and colluvial, and mass wasting processes. General M331Db, c, f, g, I, andu. vegetative types include coniferous forest, grassland, and shrubland. Soils are generally coarse- to Middle Rocky Mountain Steppe-Coniferous medium-textured. Subsections included in this Forest-Alpine Meadow Province (Number M332) group are M332Ae, f, k, m, r, t, v, ii, mm, and nn; Subsection group M33201 consists of breaklands M332Ba and d; M332De, j; M332Eb, h, x, y, and and foothills of granitic rocks that have been ff; M332Fi and t; and M332Gd. modified by fluvial, colluvial, and mass wasting Subsection group M33206 consists of glaciated processes. The general vegetative types include mountains of granitic and sedimentary rocks that coniferous forest, grassland, and shrubland. Soils have been modified by glacial, periglacial, colluvial, are generally coarse- to medium-textured. Sub- and fluvial processes. General vegetative types sections included in this group are M332Aa, o, q, cc an include coniferous forest, grassland, and shrubland. > gg> PP- d x*- Soils are generally fine-textured. Subsections Subsection group M33202 consists of foothills of included in this group are M332Ab; M332Bh; granitic and volcanic rocks with some metamorphics M332Ca-d; M332Ed, I, p, and z; and M332GL and sedimentary rocks that have been modified by Subsection group M33207 is heterogeneous con- glacial, fluvial, and residual processes. The general sisting of mountains of igneous and metamorphic vegetative types include coniferous forest, grass- rocks with lesser amounts of sedimentary rocks. land, and shrubland. Soils are generally medium- These materials have been modified by fluvial, to fine-textured. Subsections included in this colluvial, mass wasting, frost churning and glacial group are M332Au, 11, and qq; M332Da and o; processes. The general vegetative types include M332Fa; and M332Gb, o, r, and u. coniferous forest, grassland, and shrubland. Soils Subsection group M33203 consists of intermontane are generally coarse- to medium-textured. Sub- basins and valleys of sediments that have been sections included in this group are M332Ah, 1,1, modified by fluvial and glacial processes. The n, s, w, x, y, z, aa, ee, hh, jj, yy, and zz; M332Bc, j, general vegetative types include coniferous forest, and 1; M332Df and s; M332Ec, e, f, m, n, s, and grassland, and shrubland. Soils are generally aa; M332Fc, d, e, g, and h; and M332Gf, q, s, and v. coarse- to medium-textured. Subsections included Subsection group M33208 is very heterogeneous in this group are M332AJ, bb, ff, kk, and oo; and consists of mountains of igneous, sedimentary, M332Bm; M332Dk, 1, and t; M332Er, u, v, w, and metamorphic rocks. These materials have been and cc; and M332Gt. modified mainly by fluvial and colluvial processes Subsection group M33204 consists of intermontane with lesser amounts of glaciation, frost churning, basins and valleys of alluvium, lacustrine, and loess and mass wasting. The general vegetative types deposits that have been modified by fluvial, mass include coniferous forest, grassland, and shrubland. wasting, glacial, and aeolian processes. General Soils are generally fine-textured. Subsections vegetative types include coniferous forest, grassland, included in this group are M332Ag; M332Bf, g, k, and shrubland. Soils are generally fine-textured. and n; M332Db-d, g-I, m, n, q, and r; M332Ea, Subsections included in this group are M332Ad; k, 1, t, and dd; M332Fb; and M332Ga, and g-j. M332Bb, e, and I; M332Eg and q; and M332G1.

128,. Biophysical Subsection group M33209 consists of plateaus Potential Vegetation Settings of basalt and granite that have been modified by fluvial and colluvial processes. The general vegetative This section summarizes the approach used to types include forest and grassland. Soils are generally model the distribution of broad-scale potential medium- to fine-textured. Subsections included in vegetation (PV) settings over the assessment area. this group are M332Ap, and rr; and M332Gm, n, Although the specific definitions may change, PV and p. is always understood to be an expression of the biophysical environment of an area regardless of Northern Rocky Mountain Forest-Steppe- the study scale or existing vegetation status Coniferous Forest-Alpine Meadow Province (Eilenberg 1988, Kuchler 1988). The methods (Number M333) used in PV classification and mapping, as well as Subsection group M33301 consists of foothills of descriptions of the PV environments identified granitics and gneisses that have been modified by within the Basin, are outlined in Reid and others fluvial and colluvial processes. The general vegeta- (1996). The following is a summary of that report. tive types include coniferous forest and grassland. Potential vegetation maps are used in conjunction Soils are generally fine-textured. Subsections with other maps of abiotic features, such as land- included in this group are M333Am and forms, to define biophysical environments at M333De. different spatial scales (Zonneveld 1989). Such Subsection group M33302 consists of intermontane maps provide the context for understanding basins, valleys, and till plains of lacustrine, glacial relations between disturbance regimes and other outwash, alluvium, and till. The general vegetative ecological processes and the existing landscape types include forest and grassland with a smaller patterns of an area, such as the existing vegetation. amount of shrubland. Soils are generally medium- Potential vegetation maps are also commonly used to fine-textured. Subsections included in this as input into models of landscape pattern change group are M333Ac, d, r, and s; and M333Bc. under various scenarios such as different manage- ment strategies or global . In this Subsection group M33303 consists of glaciated assessment, PV maps were used for different por- mountains of granitic and metasedimentary rocks tions of the Terrestrial, Aquatic, and Landscape that have been modified by glacial and fluvial Ecology staff assessments see Chapters 5,4, and 3 processes. The general vegetative type is coniferous respectively. For example, PV maps were used as forest. Soils are generally medium- to fine-textured. input to the Columbia River Basin Succession Model Subsections included in this group are M333Aa, b, (CRBSUM) for modeling change in vegetation e, and h-k; M333Ba, b, and e; and M333Ca, b, d, patterns under a doubling of and g. (CO2) scenario. PV maps were also used in the Subsection group M33304 consists of mountains construction of hydrologic subregion maps. and breaklands of granitic and metasedimentary rocks. These materials have been modified mainly Methods Used in Broad-Scale Potential by fluvial and colluvial processes with some frost Vegetation Classification and Mapping churning and alpine glaciation at higher elevations. The dependent variable of the vegetation site model The general vegetative type is coniferous forest. used in broad-scale PV mapping was a vegetation Soils are generally medium- to fine-textured. type. Over large areas such as the Basin, there was Subsections included in this group are M333Af, g, a need to use a standardized and regionalized o, and q; M333Bf; and M333Da-d, and f-j. classification system (Bourgeron 1988 and 1989). In this modeling exercise, The Conservancy's (TNC) Western Regional Vegetation Classification (WRVC) (Bourgeron and Engelking 1994) was

Biophysical 12? • adopted. This classification included the existing Workshop participants were asked to list the natural and semi-natural vegetation in the western PV plant associations within each temperature- United States. (See Reid and others 1996 for moisture setting (for example, cold or wet setting) further discussion of the WRVC and its develop- for each physiognomic class. There were 16 PV ment and use). types for each physiognomic class, for a total of 64 possible PV classes within each geoclimatic section Potential vegetation classifications were generated of the Basin. An example of this classification at three classification scales: section, regional, and system is provided in table 2.4. coarse. Initial classifications were developed by dividing vegetation types into three broad physio- Temperature and moisture gradients were scaled gnomic classes: forest, shrubland, and herbaceous by physiognomic class within each geoclimatic types. Potential vegetation types and their relation- section. For example, within a given section, the ship to temperature-moisture gradients were men cold or wet cell for forests was not necessarily defined for each physiognomic class: (1) for each equivalent to the cold or wet cell for the shrublands. geoclimatic section (section level) and (2) across the Moreover, a given temperature-moisture cell [for entire assessment area (regional level). A coarse-level example, cold (or wet) for forests] was not neces- PV classification was generated by defining 20 PV sarily equivalent among geoclimatic sections (for types in relation to Basin-wide temperature-moisture example, between a high mountain section and gradients, regardless of the physiognomic type. a low desert section). The process of determining the potential vegetation Section-level classifications were aggregated into a classifications and their temperature-moisture regional classification using regional temperature- gradient relations included the generation of a list moisture 4 by 4 matrices for each physiognomic of PV plant associations over the Basin and the class. This process created three regional PV classi- arrangement of the potential plant associations fications, one for each physiognomic class for a into section-level classifications. total of 48 regional PV types (Reid and others 1996). A coarse-level temperature-moisture matrix The general approach used was to consider as PV all of 20 cells was also created. In constructing this plant associations that represented the end point of matrix, the 48 regional PV types were aggregated successional sequences. A master list of such plant into the cells of the coarse-level matrix regardless associations by physiognomic class was generated of their physiognomic class. Descriptions of the from the WRVC for the Basin (Reid and others vegetation types in both the regional and coarse- 1996). This master list was revised as necessary level PV classes are provided by Reid and others before, during, and after all the workshops used in (1996). PV map construction. A total of 807 plant associa- tions were associated with the classifications used The independent variables (related to the vegetation in PV mapping (Reid and others 1996). type dependent variable described above) for the vegetation model were selected on the basis of Section-level PV classifications were built for each of their ability to be derived from the DEM data for the three broad physiognomic classes of vegetation each 1-km2 pixel of the grid covering the entire (forest, shrubland, and herbaceous types) from the Basin. Elevation, slope, and aspect (table 2.5) were master list of PV plant associations. This task was chosen since they are closely related to the direct accomplished in various workshops by staff from ecological factors that define potential vegetation the FS, U.S. Fish and Wildlife Service (USFWS), environments (for example, solar radiation). The BLM, NRCS, and TNC, as well as other profes- assignment of the biophysical settings to section-level sionals with broad regional knowledge of these PV classes (model calibration) was done on a PV plant associations. geoclimatic subsection basis by professionals with Moisture and temperature gradients were divided local field experience (Reid and others 1996). into four coarse segments resulting in 4 by 4 matrices (four temperature settings by four moisture settings).

Biophysical Table 2.4—Forest biome temperature-moisture gradient potential vegetation classifications for section M333C of the Basin (Reid and others 1996).

Moisture: Wet (1) Moist (2) Dry (3) Very Dry (4) Temperature: Cold(1) ABLA/CACA4 ABLA/MEFE ABLA/LUGLH ABLA/VASC LALY/ABLA ABLA-PIALA/ASC PIAL-ABLA Cool (2) PICEA/EQAR ABLA/LIB03 ABLA/VACE PICEA/VACE ABLA/OPHO THPL/GYDR PSME/LIBO3 PSME/VACE THPL7ATFI TSME/CLUN2 ABGR/XETE ABLA/CLUN2 ABLA/XETE PICEA/GATR3 ABLA/VAGL PICEA/CLUN2 Warm (3) THPL7OPHO THPL7CLUN2 PSME/CARU PSME/SYAL ABGR/SETR THPL/ASCA2 PSME/PMA5 PICEA/COGE16 ABGR/LIB03 ABGR/PHMA5 ABGR/CLUN2 PHMEA/AGL Hot (4) POTR5/COSE16 POTR5/OSOC PORT15/COSE1 PICEA/LYAM3 PSME/COSE16

Table 2.5—List of site parameter/GIS rules used in the "vegetation-site" model for broad- scale potential vegetation environment mapping.

Elevation (meters) Aspect Slope

0-304 Northeast Flat 305 -609 Southwest 5 - 29% 610-914 Flat 30 - 59% 915-1,219 Greater than 60% 1,220 -1,523 1,524-1,828 1,829-2,133 2,134-2,438 2,439 -2,743 2,744 -3,047 3,048 -3,352 3,353 -3,657 3,658 -3,962 3,963 -4,267

Biophysical Section-level PV mapping was accomplished pants to dominant valley bottom settings within within each geoclimatic subsection by reading the each of the 48 regional-level PV environments slope, aspect, and elevation values for each pixel described above. This assignment facilitated spatial and using them to index the name of the section- identification of probable riparian PV environments level PV type in the pixel. Inaccuracy in the DEM at a 1-km2 grid throughout the Basin. Descrip- was corrected during a series of workshop sessions tions and methods used in the classification and conducted for quality control of the three scales of mapping of riparian plant association groups are maps produced. provided by Manning and others (in press). Predictive models of coarse-level PV type distribu- tions were constructed based on current and Results of Broad-Scale Potential Vegetation projected future climate data. The coarse-level PV Classification and Mapping map generated for the Basin (map 2.5) was used A map was produced for each geoclimatic section to provide the source of PV data under current using the section-level PV classifications and their climatic conditions. The resulting models were used assigned elevation, aspect, and slope settings by to produce maps of predicted PV environments subsections (Reid and others 1996). These maps under current climate conditions and a doubled were reviewed by TNC, and State Heritage ecolo- CO2 climate change scenario. gists, as well as FS and BLM professionals. Over- Generalized linear models were used to quantify lapping and missing data areas in these maps were PV response to climatic conditions in this study. corrected, and changes in vegetation-site classifica- Nine climate attributes were selected as predictor tions were made as necessary and subjected to variables in the analysis. A map of the distribution further review. of 20 PV types under current climatic conditions Calibration of vegetation-site models was previously generated for the assessment (Reid and performed separately for each PV type by elevation others 1996) provided the source of PV data used. class within each geoclimatic subsection. Once To construct the models, the current climatic vegetation-site models were revised, resulting conditions generated over the Basin at a 2-by-2- attribute matrices were generated section by kilometer scale for a normal climate year (Thornton section to describe the possible ecological range and Running 1996) were associated with the of each section-level PV class. Table 2.6 provides pixels of the base PV map. For a more complete an example of an attribute matrix for the Northern description of the modeling approach and climatic Rockies section (see Reid and others 1996 for a attributes used in this characterization refer to description of all sections). A final map of all Thornton and others (in press). section-level potential vegetation environments was produced at a 1:2,000,000 scale (Reid and Riparian Potential Vegetation Settings others 1996). Riparian plant associations within the Basin were Coarse- and regional-level potential vegetation identified based on the Regional Hierarchical environment maps (maps 2.5 and 2.6) were Classification of Western United States Vegetation produced from section-level maps by establishing (Bourgeron and Engelking 1994) and a series of relations between section-level classes and regional workshops involving local experts. These plant classes and then establishing relations between associations were then aggregated into Riparian regional classes and coarse-level classes (Reid and Plant Association Groups based on climatic zone, others 1996). All maps produced by this process vegetation structure, and moisture status/indicator were reviewed, and as with the section-level PV species criteria. Riparian Plant Association Group map, overlapping and missing data areas and composition was assigned by workshop partici- obvious errors in the maps were corrected.

130 Biophysical u Coarse Level Potential Vegetation Environment Map -a

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