Ecoregions of the United States
(Note: This map brought to you courtesy of your taxpayer dollars and the USDA Forest Service. There is mention of species that existed prior to "white settlement" throughout this document, just in case you may be thinking that your part of America is a place where you'll still be 'allowed' by the benevolent/malevolent folks in charge. Nope, I did not make that up. It's right here, in the text of this huge amassing of misinformation and language deception. It's high time to stand on your hind legs and stop feeling guilty about your ancestors having been part of "European settlement"!)
100 Polar Domain
120 Tundra Division
125 Bering Tundra (Norther) Province
126 Bering Tundra (Southern) Province
M120 Tundra Regime Mountains
M125 Sewared Peninsula Tundra - Meadow Province
M126 Bering Ahklun Mountains Tundra - Meadow Province
M127 Aleutian Oceanic Meadow - Health Province
M130 Subarctic Division
M135 Coastal Trough Humid Tayga - Tundra
M139 Upper Yukon Tayga Province
M130 Subarctic Regime Mountains
M135 Alaska Range Humid Tayga- Tundra - Meadow Province
M139 Upper Yukon Tayga - Meadow Province
200 Humid Temperate Domain
210 Warm Continental Division
M210 Warm Continental Regime Mountains
220 Hot Continental Division
222 Eastern Broadleaf Forest (Continental) Province
M220 Hot Continental Regime Mountains
M222 Ozark Broadleaf Forest - Meadow Province
230 Subtropical Division
232 Outer Coastal Plain Mixed Forest Province
234 Lower Mississippi Riverine Forest Province
M230 Subtropical Regime Mountains
240 Marine Division
M240 Marine Regime Mountains
M244 Pacific Coastal Mountains Forest - Meadow Province
M245 Pacific Gulf Coastal Forest - Meadow Province
250 Prairie Division
255 Prairie Parkland (Subtropical) Province
260 Mediterranean Regime Mountains
262 California Dry Steppe Province
263 California Coastal Steppe, Mixed Forest, and Redwood Forest Province
M260 Mediterranean Regime Mountains
M262 California Coastal Range Open Woodland - Shrub - Coniferous Forest - Meadow Province
300 Dry Domain
310 Tropical/Subtropical Steppe Division
313 Colorado Plateau Semi-Desert Province
315 Southwest Plateau and Plains Dry Steppe and Shrub Province
M310 Tropical/Subtropical Steppe Regime Mountains
320 Tropical/Subtropical Desert Division
322 American Semi-Desert and Desert Province
M330 Temperate Steppe Division
332 Great Plains Steppe Province
M330 Temperate Steppe Division
M332 Middle Rocky Mountains Steppe - Coniferous Forest - Alpline Meadow Province
M333 Northern Rocky Mountains Forest - Steppe - Coniferous - Forest - Alpine Meadow Province
M334 Black Hills Coniferous Forest Province
340 Temperate Desert Division
342 Intermountain Semi-Desert Province
M340 Temperate Desert Regime Mountains
400 Humid Tropical Domain
410 Savanna Division
M410 Savanna Regime Mountains
M420 Rainforest Regime Mountains
Source: R.G. Bailey [Ecoregions of the United States, USDA Forest Service (scale 1:7,500,000, revised 1994)]
Table of Contents: Ecological Subregions of the United States
1 -- Province 124\lf 1-1
2 -- Province 125\lf 2-1
Section 125B--Yukon-Kuskokwim Delta \lf 2-1
3 -- Province 126\lf 3-1
4 -- Province M121\lf 4-1
Section M121B--Mountains \lf 4-1
5 -- Province M125\lf 5-1
6 -- Province M126\lf 6-1
Chapter 7 -- Province M127 \lf 7-1
Section M127B--Aleutian Islands \lf 7-2
Section M127C--West Kodiak Island \lf 7-3
8 -- Province 131\lf 8-1
Section 131B--Yukon-Kuskokwim Bottomlands \lf 8-1
9 -- Province 135\lf 9-1
Section 135B--Copper River Basin \lf 9-1
10 -- Province 139\lf 10-1
Chapter 11 -- Province M131\lf 11-1
Section M131B--Kuskokwim Mountains \lf 11-2
Section M131C--Nushagak-Lime Hills \lf 11-3
12 -- Province M135 Province\lf 12-1
Section M135B--Wrangell Mountains \lf 12-2
13 -- Province M139\lf 13-1
14 -- Province 212\lf 14-1
Section 212B--Maine and New Brunswick Foothills and Eastern Lowlands \lf 14-2
Section 212C--Fundy Coastal and Interior \lf 14-4
Section 212D--Central Maine Coastal and Interior \lf 14-6
Section 212E--St. Lawrence and Champlain Valley \lf 14-7
Section 212F--Northern Glaciated Allegheny Plateau \lf 14-8
Section 212G--Northern Unglaciated Allegheny Plateau \lf 14-10
Section 212H--Northern Great Lakes \lf 14-11
Section 212J--Southern Superior Uplands \lf 14-12
Section 212K--Western Superior \lf 14-13
Section 212L--Northern Superior Uplands \lf 14-14
Section 212M--Northern Minnesota and Ontario \lf 14-16
Section 212N--Northern Minnesota Draft and Lake Plains \lf 14-17
15 -- Province M212\lf 15-1
Section M212B--New England Piedmont \lf 15-3
Section M212C--Green, Taconic, Berkshire Mountains \lf 15-4
Section M212D--Adirondack Highlands \lf 15-6
Section M212E--Catskill Mountains \lf 15-7
16 -- Province 221\lf 16-1
Section 221B--Hudson Valley \lf 16-2
Section 221C--Upper Atlantic Coastal Plain \lf 16-3
Section 221D--Northern Appalachian Piedmont \lf 16-4
Section 221E--Southern Unglaciated Allegheny Plateau \lf 16-5
Section 221F--Western Glaciated Allegheny Plateau \lf 16-7
Section 221H--Northern Cumberland Plateau \lf 16-8
Section 221I--Southern Cumberland Mountains \lf 16-9
Section 221J--Central Ridge and Valley \lf 16-10
17 -- Province 222\lf 17-1
Section 222C--Upper Gulf Coastal Plain \lf 17-3
Section 222D--Interior Low Plateau, Shawnee Hills \lf 17-3
Section 222E--Interior Low Plateau, Highland Rim \lf 17-5
Section 222F--Interior Low Plateau, Bluegrass \lf 17-6
Section 222G--Central Till Plains, Oak-Hickory \lf 17-7
Section 222H--Central Till Plains, Beech-Maple \lf 17-8
Section 222I--Erie and Ontario Lake Plain \lf 17-9
Section 222J--South Central Great Lakes \lf 17-11
Section 222K--Southwestern Great Lakes Morainal \lf 17-12
Section 222L--North-Central U.S. Driftless and Escarpment \lf 17-13
Section 222M--Minnesota and Northeastern Iowa, Morainal \lf 17-15
Section 222N--Lake Agassiz, Aspen Parklands \lf 17-16
18 -- Province M221\lf 18-1
Section M221B--Allegheny Mountains \lf 18-2
Section M221C--Northern Cumberland Mountains \lf 18-4
Section M221D--Blue Ridge Mountains \lf 18-4
19 -- Province M222\lf 19-1
20 -- Province 231\lf 20-1
Section 231B--Coastal Plains, Middle \lf 20-2
Section 231C--Southern Cumberland Plateau \lf 20-3
Section 231D--Southern Ridge and Valley \lf 20-3
Section 231E--Mid Coastal Plains, Western \lf 20-4
Section 231F--Eastern Gulf Prairies and Marshes \lf 20-5
Section 231G--Arkansas Valley \lf 20-5
Chapter 21 -- Province 232\lf 21-1
Section 232B--Coastal Plains and Flatwoods, Lower \lf 21-2
Section 232C--Atlantic Coastal Flatlands \lf 21-3
Section 232D--Florida Coastal Lowlands (Western) \lf 21-5
Section 232E--Louisiana Coast Prairies and Marshes \lf 21-6
Section 232F--Coastal Plains and Flatwoods, Western Gulf \lf 21-6
Section 232G--Florida Coastal Lowlands (Eastern) \lf 21-7
22 -- Province 234\lf 22-1
23 -- Province M231\lf 23-1
24 -- Province 242\lf 24-1
25 -- Province M242\lf 25-1
Section M242B--Western Cascades \lf 25-3
Section M242C--Eastern Cascades \lf 25-5
-- Province M244\lf 26-1
Section M244B--Lynn Canal \lf 26-2
Section M244C--Boundary Range \lf 26-2
27 -- Province M245\lf 27-1
Section M245B--Northern Alexander Archipelago \lf 27-1
Section M245C--Southern Alexander Archipelago \lf 27-3
28 -- Province 251\lf 28-1
Section 251B--North-Central Glaciated Plains \lf 28-2
Section 251C--Central Dissected Till Plains \lf 28-3
Section 251D--Central Till Plains \lf 28-4
Section 251E--Osage Plains \lf 28-6
Section 251F--Flint Hills \lf 28-7
Section 251G--Central Loess Plains \lf 28-7
29 -- Province 255\lf 29-1
Section 255B--Blackland Prairies \lf 29-2
Section 255C--Oak Woods and Prairies \lf 29-3
Section 255D--Central Gulf Prairies and Marshes \lf 29-3
30 -- Province 261\lf 30-1
Section 261B--Southern California Coast \lf 30-1
31 -- Province 262\lf 31-1
32 -- Province 263\lf 32-1
33 -- Province M261\lf 33-1
Section M261B--Northern California Coast Ranges \lf 33-2
Section M261C--Northern California Interior Coast Ranges \lf 33-3
Section M261D--Southern Cascades \lf 33-4
Section M261E--Sierra Nevada \lf 33-5
Section M261F--Sierra Nevada Foothills \lf 33-5
Section M261G--Modoc Plateau \lf 33-6
34 -- Province M262\lf 34-1
Section M262B--Southern California Mountains and Valleys \lf 34-2
35 -- Province 311\lf 35-1
36 -- Province 313\lf 36-1
Section 313B--Navajo Canyonlands \lf 36-2
Section 313C--Tonto Transition \lf 36-3
Section 313D--Painted Desert \lf 36-5
Section 313E--Central Rio Grande Intermontane \lf 36-6
37 -- Province 315\lf 37-1
Section 315B--Texas High Plains \lf 37-2
Section 315C--Rolling Plains \lf 37-3
Section 315D--Edwards Plateau \lf 37-4
Section 315E--Rio Grande Plain \lf 37-4
Section 315F--Southern Gulf Prairies and Marshes \lf 37-5
38 -- Province M313\lf 38-1
Section M313B--Sacramento-Manzano Mountain \lf 38-2
39 -- Province 321\lf 39-1
Section 321B--Stockton Plateau \lf 39-2
40 -- Province 322\lf 40-1
Section 322B--Sonoran Desert \lf 40-1
Section 322C--Colorado Desert \lf 40-3
41 -- Province 331\lf 41-1
Section 331B--Southern High Plains \lf 41-1
Section 331C--Central High Tablelands \lf 41-2
Section 331D--Northwestern Glaciated Plains \lf 41-3
Section 331E--Northern Glaciated Plains \lf 41-4
Section 331F--Northwestern Great Plains \lf 41-4
Section 331G--Powder River Basin \lf 41-5
Section 331H--Central High Plains \lf 41-5
Section 331I--Arkansas Tablelands \lf 41-6
Section 331J--Northern Rio Grande Basin \lf 41-7
42 -- Province 332\lf 42-1
Section 332B--Western Glaciated Plains \lf 42-1
Section 332C--Nebraska Sand Hills \lf 42-2
Section 332D--North-Central Great Plains \lf 42-3
Section 332E--South-Central Great Plains \lf 42-4
43 -- Province M331\lf 43-1
Section M331B--Bighorn Mountains \lf 43-2
Section M331D--Overthrust Mountains \lf 43-4
Section M331E--Uinta Mountains \lf 43-6
Section M331F--Southern Parks and Rocky Mountain Ranges \lf 43-7
Section M331G--South-Central Highlands \lf 43-8
Section M331H--North-Central Highlands and Rocky Mountain \lf 43-9
Section M331I--Northern Parks and Ranges \lf 43-10
Section M331J--Wind River Mountain \lf 43-11
44 -- Province M332\lf 44-1
Section M332B--Bitterroot Valley \lf 44-1
Section M332C--Rocky Mountain Front \lf 44-3
Section M332D--Belt Mountains \lf 44-3
Section M332E--Beaverhead Mountains \lf 44-4
Section M332F--Challis Volcanics \lf 44-5
Section M332G--Blue Mountains \lf 44-6
45 -- Province M333\lf 45-1
Section M333B--Flathead Valley \lf 45-3
Section M333C--Northern Rockies \lf 45-4
Section M333D--Bitterroot Mountains \lf 45-4
46 -- Province M334\lf 46-1
47 -- Province 341\lf 47-1
Section 341B--Northern Canyon Lands \lf 47-2
Section 341C--Uinta Basin \lf 47-3
Section 341D--Mono \lf 47-4
Section 341E--Lahontan Basin \lf 47-4
Section 341F--Southeastern Great Basin \lf 47-5
Section 341G--Northeastern Great Basin \lf 47-6
48 -- Province 342\lf 48-1
Section 342B--Northwestern Basin and Range \lf 48-1
Section 342C--Owyhee Uplands \lf 48-2
Section 342D--Snake River Basalts \lf 48-2
Section 342E--Bear Lake \lf 48-3
Section 342F--Central Basin and Hills \lf 48-4
Section 342G--Green River Basin \lf 48-5
Section 342H--High Lava Plains \lf 48-6
Section 342I--Columbia Basin \lf 48-7
49 -- Province M341\lf 49-1
Section M341B--Tavaputs Plateau \lf 49-1
Section M341C--Utah High Plateaus and Mountains \lf 49-3
50 -- Province 411\lf 50-1
51 -- Province M411\lf 51-1
52 -- Province M423\lf 52-1
A: Bibliography\lf A-1
Introduction - Ecological Subregions of the United States
The USDA Forest Service adopted a policy of ecosystem management on June 4, 1992, that applied to national forests, grasslands and research programs. By July, an Ecological Classification and Mapping Task Team (ECOMAP) was formed in the Washington Office to develop a consistent approach to ecosystem classification and mapping at multiple geographic scales. This was identified by the Chief as a critical first step in providing field units with an essential tool and scientific basis to plan for and implement ecosystem management. Soon afterwards a subgroup of ECOMAP was formed with representatives from all Forest Service Regions, two Research Stations, the USDA Soil Conservation Service, and The Nature Conservancy. They met in September in Lincoln, NE, to begin development of a land classification system. The structure of the National Hierarchical Framework of Ecological Units (Table 1) was formulated at this meeting and was adopted by the Forest Service on November 5, 1993 (ECOMAP 1993).
Figure 1.--The upper four levels of ecological units in the Forest Service National Hierarchical Framework consist of Domain , Division, Province, and Section. Selected ecological units of the Humid Temperate Domain, in the eastern United States, are progressively revealed to the Section level to illustrate the hierarchical structure, the identification system, and relative sizes of map units at the ecoregion and subregion planning and analysis scales. (Hierarchy of ecoregions at a range of scales, R.G. Bailey, 1994).
Map Unit Descriptions
This text is organized following the national hierarchy structure. Provinces, the lowest hierarchical level at the ecoregion scale (Figure 2), are the basis for chapters. Each chapter consists of the Sections that the Province comprises. Each Section is described by the predominant environmental and biological features used in its delineation, along with other pertinent or characteristic factors. The abbreviated format of this national text necessitated that only a limited amount of information be presented. This information provides the user with a brief description of environmental features that characterize Sections for broad planning and assessment and are useful for comparing landscape characteristics among Sections. Section map unit descriptions were prepared by compilers in each Region following a standard format consisting of 11 elements.
Geomorphology. Geomorphology is the classification, description, nature, origin, and development of present landforms. This element describes the predominant geomorphic processes active in the Section that resulted in formation of the characteristic landforms. The geomorphic province and general landform features may also be described. The range of elevation in ft above mean sea level (m in parentheses) is described. Local relief prevalent in a radius of several miles may be presented.
Lithology and Stratigraphy. Lithology is the description of rocks on the basis of such physical characteristics as manner of origin, composition, and texture. Stratigraphy is the arrangement of rocks as classified by geographic position and chronological order. Classifications by the U.S. Geological Survey were used to provide a consistent national basis for this element (King 1976, King and Beikman 1976, 1978) provide more information on lithology and stratigraphy of the conterminous States; Wahrhaftig (1965) is a source of information for Alaska. Soil Taxa. Soils were characterized by phases of orders, suborders, or great groups that typify the map unit. Soil moisture and temperature regimes are included to help characterize some map units. The soil taxonomy developed by the USDA Soil Conservation Service (Soil Survey Staff 1992) was the basis of information in this element.
Potential Natural Vegetation. This element presents the potential natural vegetative communities, defined by K\"uchler (1964), that typify the map unit. Other more specific information on natural vegetation may also be presented, such as potential natural communities, historic vegetation, or existing communities. Sources of information vary by Region.
Fauna. Characteristic mammals, birds, reptiles, and amphibians of the map unit are named. Some historic, common, and characteristic species are usually listed. Threatened species are provided for some Sections.
Climate. Prevailing climate is characterized in terms of mean annual precipitation in inches (mm in parentheses) and mean annual temperature in degrees Fahrenheit (oC in parentheses). Seasonality of precipitation and relative amount that occurs as snow may also be presented. The growing season is presented as a measure of the length of time during which plant growth may occur, if soil moisture is adequate, and is defined as the mean annual range of days between the last spring and first fall minimum temperatures of 32 oF (0 oC). Additional information is presented by the USDA Soil Conservation Service (1981).
Surface Water Characteristics. Relative occurrence and distinguishing characteristics of rivers, streams, lakes, and wetlands are presented. Some major rivers may be identified.
Disturbance Regimes. This element lists the natural factors and forces that significantly influence ecosystem dynamics within a planning period.
Land Use. This element identifies the predominant changes to natural vegetative communities caused by human uses of land and water resources.
Cultural Ecology. Examples demonstrate how the historical relationship between humans and the natural environment has resulted in modified landscapes.
Compiled by the Forest Service administrative unit primarily responsible for summarizing information pertaining to the Section.
In some instances time was not available to obtain information for one or more elements in the Section description. These elements will be developed more fully when this text of map unit descriptions is revised. The description of some Sections is supplemented with a photograph that illustrates typical landforms, predominant vegetation, and, occasionally, fauna. Information in these Section map unit descriptions is presented in consistent national format. Map unit descriptions were edited for style, but not for technical accuracy. Compilers are responsible for information presented in each Section map unit description. \null \endtwocol
Figure 2 --Ecological units delineated at the Province level (Ecoregions of the United States, R.G. Bailey, 1994) are the basis for organization of this document. Each chapter consists of a Province and its components---Sections.
Five appendices present information to supplement the Section map unit descriptions. Appendix A includes references specifically cited in the Introduction and Glossary and lists selected references that provide general information about elements of map unit descriptions for some Provinces and Sections. Appendix B provides the area of each Section and Province. Appendix C is a selected glossary of terms used in map unit descriptions, and Appendix D lists the common and scientific names of selected flora and fauna. Appendix E lists addresses of Regional contacts to whom comments and suggestions regarding specific map unit descriptions should be addressed.
Many potential uses exist for the descriptions of ecosystems presented in this text. Perhaps the most important use is to provide a means for comparison and contrast of environmental conditions among Sections as a basis for region-wide assessment and monitoring programs. Material in this text will provide a common basis for communication and coordination among public agencies and groups at the international, national, state, and local levels of planning and evaluation. Researchers, land managers, and other users of research findings will have a common basis for suggesting limits of applicability of results from experimental studies. Another potential use of information in this document will be to provide a uniform basis for planning areas of coordinated work, especially among a wide range of resource disciplines. When used with the accompanying map, and perhaps paired with the companion text that describes ecoregions (Bailey In Press), information in this document can be used to illustrate the nested relationship of ecosystems, ranging from global to local levels. A single resource classification, such as a soils or existing vegetation map, may not satisfy all the needs of all users, but an ecological classification will come very close.
The development and completion of this national document in a relatively short time period is a direct result of the coordination, persistent efforts, and diligent teamwork of many persons. Principal compilers were responsible for map unit delineations, developed the overall framework of the Section map unit descriptions, compiled map unit descriptions, and guided overall coordination and completion of tasks associated with this text in their Regions. Assistant compilers aided some principal compilers by locating and organizing resource information pertaining to broad geographical areas, synthesizing general information into succinct summaries, and reviewing map unit descriptions for accuracy. Other assistant compilers made contributions such as developing specific elements of the map unit descriptions or providing technical knowledge and support. Associate compilers participated by serving as subject-matter experts, summarizing information for specific geographical areas, reviewing descriptions for accuracy, and performing other tasks that contributed to the production of this text. Other individuals undoubtedly contributed to this document, but, unfortunately, will remain unknown. This text was produced through the collective, dilligent efforts of the following individuals.
Alaska Region \lf Terry Brock
Alaska Region \lf Greg Nowacki
Alaska Region. R. Dipold, L. Suring.
Pacific Northwest Region.
Pacific Southwest Region.
Rocky Mountain Region.
State and Private Forestry:
Many photographers also made important contributions to this document by providing pictures that illustrate the physical, biological, and cultural characteristics of the subregion ecological map units. Unless otherwise noted, photographers are employees of the USDA Forest Service. When the photograph was obtained from Forest Service files and the photographer is unknown, the person providing the photograph is noted. Credits for photographs are arranged by Region and Section.
Alaska Region. 125B -- USDI Fish and Wildlife Service; M121B -- USDI National Park Service; M125A -- USDI National Park Service; M126A -- USDA Soil Conservation Service; M127A -- USDI National Park Service; M131A -- USDI Bureau of Land Management; M131B -- USDI Geological Survey; M135A, M139A, M244A -- USDI National Park Service; M245B -- USDA Forest Service.
Eastern Region. 212A -- Don Collins, USDA Soil Conservation Service; 212B -- L. Safford; 212C -- M. Torsello; 212D -- Richard Hallett, University of New Hampshire; 212F -- C. Carpenter; 212K -- Bryan Hargrave, Minnesota Department of Natural Resources; 212L -- from B. Leuelling; M212A -- from M. Smith; M212B -- from M. Smith; M212C -- M. Smith; M212E -- P. Rudge; 221E -- James Omernik USEPA; 222A -- Donald R. Kurz, Missouri Conservation Department; 222D -- Ned Trovillion, independent photographer; 222I (upper) -- James Omernik USEPA; 222I (lower) -- M. Keister; 222L -- James Omernik USEPA; M221A, M221B -- from T. DeMeo; 251C -- Donald R. Kurz, Missouri Conservation Department; 251D -- Joel Dexter, Illinois State Geological Survey; 251E -- Donald R. Kurz, Missouri Conservation Department.
Intermountain Region. M331D -- from USDA Forest Service; M331D -- J. Lott; M332F, 341B -- J. Lott; M341C (first) -- J. Lott; M341C (second) -- P. Johnson.
Northern Region. M332B -- K. McBride; M332E -- A. Greene; M333B -- J. Nesser.
Pacific Northwest Region. 242A, M242A (both), M242B (both), M242C (both), M332G, M333A, 342H -- R. Meurisse.
Pacific Southwest Region. M261A, M261B, M261D, M261G -- S. Miles; M262A, M262B, M423A -- D. Diaz. Rocky Mountain Region. 251G -- J. Freeouf; 331B -- K. Grove; 331I -- from J. Freeouf; 331J -- from J. Freeouf; 332C -- K. Grove; 332D -- D. Steinke; M331A -- K. Houston; M331B (upper) -- J. Nesser; M331B (lower) -- F. Lloyd; M331G -- J. Freeouf; M331H -- from J. Freeouf; M331I -- from J. Freeouf; M331J -- M. Holm; M334A -- K. Grove; 342F -- J. Freeouf; 342G -- from J. Freeouf.
Southern Region. 221H -- H. McNab; 221J -- Glendon W. Smalley, retired, Southern Forest Experiment Station; M221D -- Christine Coulter McNab, volunteer, USDA Forest Service; M222A -- from C. Minehart; 231A -- H. McNab; 231D -- J. King; 231E -- D. Bradbury; 231G -- from C. Minehart; 232B (upper and lower) -- H. McNab; 232C -- B. Kaylor; 232D -- from P. Beyer; 232F, 234A -- J. Caldwell; M231A -- from W. Pell; 255A, 315B, 315C -- H. McNab; 411A -- Mr. and Mrs. W. H. McNab, Jr., independent photographers; M411A (both) -- from USDA Forest Service.
Southwestern Region. 313A, 313B, 313C, 313D, M313A, 321A, 322B, M331F -- W. Robbie.
The Southeastern Forest Experiment Station provided funding for editing the Section map unit descriptions compiled by each Region and preparing the document for printing using the \TeX typesetting program. Several persons volunteered all or a significant portion of their services: William A. Hamilton, retired, USDA Forest Service, WO-PAO, designed the document format and typography; John H. Currie, retired, advertising art director, assisted with page design and photograph layout; and Christine Coulter McNab, volunteer, USDA Forest Service, assisted with proofreading and produced Appendixes A and D.
Appendix C: Selected Glossary
(Note: This is a "selected" glossary and does not even begin to define all the words/phrases that make up the intent and agenda of this "PLAN".)
Glossary of selected terms
Included are definitions of selected terms that may not be commonly known to the user of this document. This abbreviated glossary does not include the many, specialized terms used to describe taxa of geologic and soil classifications. Some of the more general geology and soil terms are defined in the glossary of the table that supplements the map of ecoregions and subregions of the U.S. For other definitions the user is directed to references such as Bates and Jackson (1980) for geologic terms and Soil Survey Staff (1992) for soil terminology.
ALLUVIUM---A general term for clay, silt, sand, gravel, or similar unconsolidated detrital material deposited during comparatively recent geologic time by a stream or other body of running water as a sorted or semisorted sediment in the bed of the stream. (Bates and Jackson 1980.)
CIRQUE---A deep steep-walled half-bowl-like recess or hollow situated high on the side of a mountain and commonly a thte head of a glacial valley, and produced by the erosive activity of a mountain glacier. (Bates and Jackson 1980.)
COLD-DECIDUOUS BROADLEAF---Woody angiosperms with wide, flat leaves (e.g., paper birch) that are shed by plants during the dormant season (that portion of the year when frosts occur).
COLLUVIUM---A general term applied to any loose, heterogeneous, and incoherent mass of soil material and/or rock fragments deposited by rainwash, sheetwash, or slow continuous downslope creep, usually collecting at the base of gentle slopes or hillsides. (Bates and Jackson 1980.)
CUESTA---A hill or ridge with a gentle slope on one side and a steep slope on the other; formed by uplifted rock outcrop consisting of strata having different restances to erosion. (Bates and Jackson 1980.)
DIVISION---An ecological unit in the ecoregion planning and analysis scale of the National Hierarchical Framework corresponding to subdivisions of a Domain that have the same regional climate. (ECOMAP 1993.)
DOMAIN---An ecological unit in the ecoregion planning and analysis scale of the National Hierarchical Framework corresponding to subcontinental divisions of broad climatic similarity that are affected by latitude and global atmospheric conditions. (ECOMAP 1993.)
DRUMLIN---An elongated hill or ridge of glacial drift.
DRY---A classification of climate based on the K\"oppen System for regions where evaporation exceeds precipitation. (Bailey 1980.)
ECOREGION---A scale of planning and analysis in the National Hierarchical Framework that has broad applicability for modeling and sampling, strategic planning and assessment, and international planning. Ecoregions include Domain, Division, and Province ecological units.
ECOSYSTEM---A complete interacting system of organisms and their environment. (FSM 2060.)
FLOODPLAIN---The surface or strip of relatively smooth land adjacent to a river channel, constructed by the present riven in its existing regimen and covered with water when the river overflows its banks. (Bates and Jackson 1980.)
LIFE ZONES---A classification of macroclimatic conditions based on temperature and precipitation that has been widely applied in tropical environments to delineate zones dominated by vegetative communities of characteristic physiognomy and composition. (Holdridge 1967.)
MARINE AND ESTUARINE PROVINCE---Regionalizations at the System level of the wetland classification system developed by Cowardin and others (1979) consisting of the open ocean overlying the continental shelf and adjacent areas of coastlines that are influenced by tidal activity.
MORAINE---A mound, ridge, or other distinct accumulation of unsorted, unstratified glacial drift, predominantly till, deposited chiefly by direct action of glacier ice, in a variety of topographic landforms that are independent of control by the surface on which the drift lies. (Bates and Jackson 1980.)
NEEDLE-LEAVED EVERGREEN---Woody gymnosperms with green, needle-shaped, or scale-like leaves (e.g., black spruce) that are retained by plants throughout the year. (Cowardin and others 1979.)
PLANT ASSOCIATION---A potential natural plant community of definite floristic composition and uniform appearance. (FSM 2060.)
PLANT COMMUNITY---A group of one or more populations of plants in a common spatial arrangement. (FSM 2060)
PLAYA--- A term used in the southwestern U.S. for a dry, vegetation-free, flat area at the lowest part of an undrained desert basin, underlain by stratified clay, silt, or sand, and commonly by soluble salts. (Bates and Jackson 1980.)
POLAR---A classification of climate based on the K\"oppen System for regions where the warmest month is colder than 50oF (10oC). (Bailey 1980.)
POTENTIAL NATURAL COMMUNITY---The biotic community that would be established if all successional sequences of its ecosystem were completed without additional human-caused disturbance under present environmental conditions. Grazing by native fauna, natural disturbances, such as drought, floods, fire, insects, and disease, are inherent in the development of potential natural communities which may include naturalized exotic species. (FSM 2060.)
POTENTIAL NATURAL VEGETATION---The vegetation that would exist today if man were removed from the scene and if the plant succession after his removal were telescoped into a single moment. The time compression eliminates the effects of future climatic fluctuations, while the effects of man's earlier activities are permitted to stand. The maps and descriptions of potential natural vegetation developed by K\"uchler (1964) for the 48 conterminous States are among the most widely used.
POTHOLE---A shallow depression, generally less than 10 acres in area, occurring between dunes on a prairie, often containing an intermittent pond or marsh and serving as a nesting place for waterfowl. (Bates and Jackson 1980.)
PROVINCE---An ecological unit in the ecoregion planning and analysis scale of the National Hierarchical Framework corresponding to subdivisions of a Division that conform to climatic subzones controlled mainly by continental weather patterns. (ECOMAP 1993.)
REGIONALIZATION---A mapping procedure in which a set of criteria are used to subdivide the earth's surface into smaller, more homogeneous units that display spatial patterns related to ecosystem structure, composition, and function. (ECOMAP 1993.)
SCALE---The degree of resolution at which ecological processes, structures, and changes across space and time are observed and measured. (ECOMAP 1993.)
SECTION---An ecological unit in the subregion planning and analysis scale of the National Hierarchical Framework corresponding to subdivisions of a Province having broad areas of similar geomorphic process, stratigraphy, geologic origin, drainage networks, topography, and regional climate. Such areas are often inferred by relating geologic maps to potential natural vegetation groupings as mapped by K\"uchler (1964). (ECOMAP 1993.)
SUBENVELOP---The general altitude of the drainage network that portrays differences in stream gradient from one geomorphic unit to another.
SUBREGION---A scale of planning and analysis in the National Hierarchical Framework that has applicability for strategic, multi-forest, statewide, and multi-agency analysis and assessment. Subregions include Section and Subsection ecological units.
SUBSECTION---An ecological unit in the subregion planning and analysis scale of the National Hierarchical Framework corresponding to subdivisions of a Section into areas with similar surficial geology, lithology, geomorphic process, soil groups, subregional climate, and potential natural communities. (ECOMAP 1993.)
SUBTROPICAL---A classification of climate based on the K\"oppen System for regions where there are eight months or more warmer than 50oF (10oC) and the coolest month is warmer than 32oF (0oC) but colder than 65oF (18oC). (Bailey 1980.)
TEMPERATE---A classification of climate based on the K\"oppen System for regions where there are four to eight months warmer than 50oF (10oC) and the coldest month is cooler than 32oF (0oC). (Bailey 1980.)
TROPICAL---A classification of climate based on the K\"oppen System for regions where the coolest month is warmer than 65oF (18oC) (Bailey 1980).
TUNDRA---A classification of climate based on the K\"oppen System for regions where the warmest month is colder than 50oF (10oC) but warmer than 32oF (0oC). (Bailey 1980.)