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Identification Information
Title: Ecological Subsections
Originator: USDA Forest Service, Alaska Region
Publication Date: 20040527
Website URL:
Resource(Server) URL:
Abstract: This geospatially explicit vector-based polygon dataset identifies 85 terrestrial ecological subsection delineations present in Southeast Alaska and the Tongass National Forest. Within each subsection one can expect to find a relatively consistent occurence and distribution of vegetation types. Due to the hydrologically-influenced geomorphology of Southeast Alaska specific key indicators of physiography, lithology, and surface geology were employed to systematically distinguish terrestrial ecosystems.
Purpose: The primary purpose of this dataset is to provide a practical basis for ecosystem management, planning, mapping, and research at the national, regional, and forest level.
Progress: Completed
Frequency: Not planned
Time Period of Content
Single Date
Date: 20120720
Currentness: Unknown
West Bounding Longitude: -153.343078
East Bounding Longitude: -128.080947
North Bounding Latitude: 62.543345
South Bounding Latitude: 53.236724
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Point of Contact
Organization: USDA Forest Service
Person: Barbara Schrader
Contact Position: Regional Ecologist
Address Type: mailing and physical
Address: 709 West 9th Street
City: Juneau
State: AK
Postal Code: 99801
Telephone: 907-586-7863
Browse Graphic
Browse Graphic URL:
Browse Graphic Caption: Regional overview of the dataset.
Browse Graphic Type: JPEG
Access: Unrestricted
Use: Any hardcopy or electronic products utilizing these data sets shall clearly indicate their source. If the user has modified the data in any way, they are obligated to describe the types of modifications they have performed. User specifically agrees not to misrepresent these data sets, nor to imply that the USDA Forest Service, Tongass National Forest approved the changes.
Theme Keywords
Theme Reference: R10-TP-75
Theme Topics: geology, hierarchy, ecological, surficial, domain, subsection, lithology, terrestrial, section, ecological unit, physiography, ecology, division, province
Theme Reference: ISO 19115 Topic Categories
Theme Keywords: geoscientificInformation
Place Keyword Thesaurus: None
Place Keyword: Southeast Alaska, Alaska, SE AK, Tongass, Canada
Data Quality Information
Logical Consistency Report: All polygons checked for accuracy. Data is complete
Completeness Report: Data is complete
Positional Accuracy
Horizontal Positional Accuracy Report: Based on 1:63,360 USGS topographic quadrangle maps with approximate planimetric accuracy of 200 feet.
Vertical Positional Accuracy Report: Based on 1:63,360 USGS topographic quadrangle maps with approximate altimetric accuracy of 200 feet.
Processing Steps
Step 1 Process Description: Data was checked for complete polygons and attributes
Step 1 Process Date: 20040527
Entity And Attribute Information
Overview: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 AREA 8 18 F 5 9 PERIMETER 8 18 F 5 17 ECOSUB# 4 5 B 21 ECOSUB-ID 4 5 B 25 SUBNUMBER 8 10 F 0 33 DOMAIN_CODE 10 10 C 43 DOMAIN_NAME 45 45 C 88 DIVISION_CODE 10 10 C 98 DIVISION_NAME 45 45 C 143 PROVINCE_CODE 10 10 C 153 PROVINCE_NAME 45 45 C 198 SECTION_CODE 10 10 C 208 SECTION_NAME 45 45 C 253 SUBSECTION_CODE 15 15 C 268 SUBSECTION_NAME 45 45 C 313 SE_AK_HIER_CODE 10 10 C 323 RECNUMBER 4 4 B The prefix "M" attached to codes indicates mountainous Sections where soil and vegetational zonation is present. Ecological Unit General size range Characteristics Domain > 70 million acres global climatic patterns Division 10-100 million acres continental climatic patterns Province (ecoregion) 2-40 million acres continental weather and associated broad vegetation patterns Section 100,000-1 million acres physiography, regional climate Subsection 5,000 -100,000 acres bedrock and surficial geology patterns and processes, local vegetation patterns CODE DESCRIPTION DOMAIN_CODE DOMAIN_NAME 100 Polar 200 Humid Temperate DIVISION_CODE DIVISION_NAME M140 Perimarine Regime Mountains M240 Marine Regime Mountains PROVINCE_CODE PROVINCE_NAME M144 Kluane Ranges M244 Chugach-St. Elias Mountains M245 Gulf of Alaska Coast M246 Northern Coast Mountains M247 Alexander Archipelago SECTION_CODE SECTION_NAME M144A Alsek Ranges M244A Kenai Mountains M244B Chugach Mountains M244C St. Elias-Fairweather Mountains M245A Northern Gulf Fjordlands M245B Northern Gulf Forelands M246A Chikat River Complex M246B Boundary Ranges M247A Glacier Bay Fjordlands M247B Baranof-Chihagof Fjordlands M247C Northeast Chichagof Fjordlands M247D Kootznoowoo Fjordlands M247E Inside Passage Fjordlands M247F Kuiu-POW Fjordlands M247G Kupreanof Lowlands M247H Outer Islands Fjordlands M247I Prince of Wales Mountains M247K Coast Mountain Batholith Fjordlands SUBSECTION_CODE SUBSECTION_NAME M144Aa Alsek-Tatshenshine River Valleys M244Aa Turnagain Arm M244Ab Western Kenai Mountains M244Ba Chugach Icefields M244Bb Lowe River M244Bc Tasnuna River M244Ca St.Elias-Fairweather Icefields M244Cb Puget Peninsula Metasediments M244Cc Fairweather Front Range complex M245Aa Kenai Fjordlands M245Ab Prince William Sound Mainland M245Ac Prince William Sound Islands M245Ba Copper River Delta M245Bc Copper River M245Bc Yakutat-Lituya Forelands M246Aa Chilkat Complex M246Ab Chilkat River Valley M246Ba Boundary Ranges Icefields M246Bb Stikine-Taku River Valleys M247Aa Upper West Arm Mountains M247Ab Queen-Tidal Inlet Mountains M247Ac Wachusett-Adams Hills M247Ad Hugh Miller-Geikie Inlet Mountains M247Ae Dundas Bay Granitics M247Af Dundas River Flats M247Ag Berg Bay Complex M247Ah Berg-Beardslee Moraine M247Ai Gustavus Flats M247Aj Salmon river Sediments M247Ak Chilkat Peninsula Carbonates M247Ba Cape Spencer Complex M247Bb North Chichagof Granitics M247Bc Outer coast Wave-cut Terraces M247Bd West Chichagof Complex M247Be Ushk-Patterson Bay Granitics M247Bf Peril Strait Granitics M247Bg North Baranof Complex M247Bh Sitka Sound Complex M247Bi Mount Edgecumbe Volcanics M247Bj Central Baranof Sediments M247Bk Necker Bay Granitics M247Bl South Baranof Sediments M247Ca Point Adolphus Carbonates M247Cb Freshwater Bay Carbonates M247Cc Kook Lake Carbonates M247Da Stephens Passage Glaciomarine Terraces M247Db North Admiralty Complex M247Dc Stephens Passage Volcanics M247Dd Thayer Lake Granitics M247De Mitchell-Hasselborg Till Lowlands M247Df Hood-Gambier Bay Carbonates M247Dg South Admiralty Volcanics M247Ea Holkham Bay Complex M247Eb Cape Fanshaw Complex M247Ec Thomas Bay Outwash Plains M247Ed Wrangell Narrows Metasediments M247Ee Eastern Pass Complex M247Ef Stikine River Delta M247Eg Bell Island Granitics M247Eh Stikine Strait Complex M247Ei Etolin Granitics M247Ej Zimovia Strait Complex M247Ek Clarence Strait Volcanics M247El Ketchikan Mafics/Ultramafics M247Em Vixen Inlet Till Lowlands M247En Traitors Cover Metasediments M247Eo Behm Canal Complex M247Fa Kuiu-POW Granitics M247Fb Rowan Sediments M247Fc North POW-Kuiu Carbonates M247Fd Alvin Bay Sediments M247Fe Affleck Canal Till Lowlands M247Ff North POW Complex M247Fg Elevenmile Till Lowlands M247Fh Gulf of Esquibel Till Lowlands M247Fi Klawock Inlet Till Lowlands M247Fj Soda Bay till Lowlands M247Ga Kake Volcanics M247Gb Duncan Canal Till Lowlands M247Gc Sumner Strait Volcanics M247Gd Central POW Till Lowlands M247Ge Kasaan Peninsula Volcanics M247Gf Skowl Arm Till Lowlands M247Ha Outer Islands Complex M247Hb Dall-Outside Complex M247Ia Central POW Volcanics M247Ib Hetta Inlet Metasediments M247Ic Moira Sound Complex M247Ja South POW Granitics M247Jb Duke Island Till Lowlands M247Jc Thorne Arm Granitics M247Jd Princess Bay Volcanics M247Je Foggy Bay Till Lowlands M247Jf Boca De Quadra Complex M247Ka Misty Fiords Granitics SE_AK_HIER_CODE feature attribute information was created to reflect developmental histories of terrestrial surfaces. Three terrain classes were distinguished at teh first level. Subsections currently affected by glacial processes were classified as active glacial terrains. Older surfaces developing after continental ice retreat (>= 14,000 years ago) are classifed inactive glacial terrain. Subsections resulting from post-glacial processes not relating to glaciation, e.g. volcanism, were classified as post-glacial terrains. These three terrain classes were then divided by physiography. The second level was further subdivided by lithology and surficial geology to form a third hierarchical tier. Hierarchical arrangement of Southeast Alaska Subsections (SE_AK_HIER_CODE) and adjoining portions of Canada based on geomorphic and glacial origin, topography, lithology, and surficial deposits. First, second, and third levels represent terrain classes (Roman numberals), physigraphic classes (capital letters), and geologic classes (numbers): SE_AK_HIER_CODE attribute decode example I=terrain class A=physiographic class 1=geologic class a=??? I. active glacial terrains A. icefields B. recently deglaciated areas 1. exposed bedrock 2. unconsolidated sediments C. mainland rivers 1. valleys 2. deltas II. inactive glacial terrains A. angular mountains 1. granitics 2. sedimentary, noncarbonates 3. sedimentary, carbonates 4. metasedimentary 5. complex sedimentary and volcanics 6. mafics/ultramafics B. rounded mountains 1. granitics 2. sedimentary, carbonates 3. metasedimentary 4. complex sedimentary and volcanics 5. volcanics C. hills 1. granitics 2. sedimentary, noncarbonates 3. complex sedimentary and volcanics 4. volcanics D. lowlands 1. till lowlands 2. outwash plains 3. glaciomarine terraces 4. wave-cut terraces III. post-glacial terrains A. volcanics SE_AK_HIER_CODE IA1 IA2 IB1a IB1b IB1c IB2a IB2b IB2b IB2c IB2d IB2e IC1a IC1b IC1c IC2a IIA1a IIA1b IIA2a IIA3a IIA4a IIA4b IIA5a IIA5b IIA5c IIA5d IIA5e IIA5f IIA5g IIA6a IIB1a IIB1b IIB1c IIB1d IIB1e IIB1f IIB1g IIB1h IIB2a IIB2b IIB2c IIB2d IIB2e IIB3a IIB3b IIB3c IIB4a IIB4b IIB4c IIB4d IIB4e IIB4f IIB4g IIB4h IIB4i IIB4j IIB5a IIB5b IIB5c IIB5d IIC1a IIC1b IIC2a IIC2b IIC2c IIC3a IIC3b IIC4a IIC4b IIC4c IID1a IID1b IID1c IID1d IID1e IID1f IID1g IID1h IID1i IID1j IID1l IID2a IID3a IID4a IIIA1 IIIA2 N/A
Detail Citation: Bailey, R.G. 1980. Descriptions of the Ecoregions of the United States. USDA Forest Service Misc. Publ. No. 1391, Washington, DC.
Spatial Reference Information
Geodetic Model
Horizontal Datum Name: D North American 1983
Ellipsoid Name: GRS 1980
Semi-major Axis: 6378137.0
Denominator of Flattening Ratio: 298.257222101
Metadata Reference Information
Metadata Creation Date: 20140314
Organization: USDA Forest Service, Alaska Region
Person: Barbara Schrader
Contact Position: Regional Ecologist
Address Type: mailing and physical
City: Juneau
State: AK
Postal Code: 99801
Telephone: 907-586-7863
Metadata Standard Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998
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