Ecoregions of Alaska U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1567 Prepared in cooperation with Colorado State University and the Environmental Protection Agency &i^^ •n. * Ecoregions of Alaska By Alisa L. Gallant, Emily F. Binnian, James M. Omernik, and Mark B. Shasby U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1567 Prepared in cooperation with Colorado State University and the Environmental Protection Agency A spatial analysis of regional ecological patterns in Alaska using analog and digital maps and descriptive information UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1995 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director For sale by U.S. Geological Survey, Information Services Box 25286, Federal Center Denver, CO 80225 Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government CONTENTS Abstract......................................................................................................................... 1 Introduction................................................................................................................... 1 Background................................................................................................................... 1 Methods......................................................................................................................... 3 Materials........................................................................................................................ 5 Ecoregion Descriptions................................................................................................. 7 Arctic Coastal Plain................................................................................................ 8 Arctic Foothills....................................................................................................... 11 Brooks Range.......................................................................................................... 15 Interior Forested Lowlands and Uplands................................................................ 17 Interior Highlands................................................................................................... 20 Interior Bottomlands............................................................................................... 23 Yukon Flats............................................................................................................. 25 Ogilvie Mountains .................................................................................................. 28 Subarctic Coastal Plains.......................................................................................... 30 Seward Peninsula.................................................................................................... 32 Ahklun and Kilbuck Mountains.............................................................................. 34 Bristol Bay-Nushagak Lowlands ........................................................................... 38 Alaska Peninsula Mountains................................................................................... 41 Aleutian Islands...................................................................................................... 43 Cook Inlet................................................................................................................ 45 Alaska Range.......................................................................................................... 48 Copper Plateau........................................................................................................ 51 Wrangell Mountains................................................................................................ 53 Pacific Coastal Mountains...................................................................................... 55 Coastal Western Hemlock-Sitka Spruce Forests.................................................... 56 Summary....................................................................................................................... 59 Acknowledgments......................................................................................................... 59 References..................................................................................................................... 60 Appendix 1.................................................................................................................... 64 Appendix 2.................................................................................................................... 70 Appendix 3.................................................................................................................... 71 PLATES 1. Ecoregions of Alaska........................................................................................................................................... In pocket ffl IV CONTENTS ILLUSTRATIONS 1. Map of Alaska................................................................_ 9 2. Arctic Coastal Plain thaw lakes.................................................................................................................................... 9 3. Arctic Coastal Plain vegetation .................................................................................................................................... 10 4. Arctic Coastal Plain vegetation .................................................................................................................................... 10 5. Arctic Foothills physiography and drainage pattern..................................................................................................... 13 6. Arctic Foothills beaded stream drainage ...................................................................................................................... 13 7. Arctic Foothills vegetation............................................................................................................................................ 14 8. Brooks Range physiography......................................................................................................................................... 14 9. Brooks Range unstable slopes...................................................................................................................................... 16 10. Brooks Range vegetation.............................................................................................................................................. 16 11. Interior Forested Lowlands and Uplands forest vegetation ......................................................................................... 18 12. Interior Forested Lowlands and Uplands burned area ................................................................................................. 18 13. Interior Highlands physiography.................................................................................................................................. 22 14. Interior Bottomlands physiography, surface water, and vegetation............................................................................. 22 15. Yukon Flats physiography and surface water............................................................................................................... 25 16. Yukon Flats physiography and vegetation.................................................................................................................... 26 17. Yukon Flats vegetation ................................................................................................................................................. 26 18. Ogilvie Mountains physiography and vegetation......................................................................................................... 29 19. Subarctic Coastal Plains physiography, surface water, and vegetation........................................................................ 29 20. Subarctic Coastal Plains forest vegetation ................................................................................................................... 31 21. Seward Peninsula physiography and vegetation .......................................................................................................... 33 22. Seward Peninsula gelifluction lobes............................................................................................................................. 33 23. Seward Peninsula low scrub and dwarf scrub-graminoid communities...................................................................... 35 24. Ahklun and Kilbuck Mountains physiography............................................................................................................. 35 25. Ahklun and Kilbuck Mountains vegetation.................................................................................................................. 36 26. Ahklun and Kilbuck Mountains vegetation.................................................................................................................. 37 27. Bristol Bay-Nushagak Lowlands physiography ......................................................................................................... 37 28. Bristol Bay-Nushagak Lowlands vegetation ............................................................................................................... 40 29. Alaska Peninsula Mountains physiography, soils, and vegetation..............................................................................