Ecoregions of Yukon Territory
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~(OIl~610"'1 Of WIJI(OI'l IIIIIIIIOIIW E.T. OSWALD AND J.P. SENYK CANADIAN FORESTRY SERVICE • Enworonment Environoement • Co.'" .......C'"'" ......canadie<l des Canada Front (X)ver photographs Top' Kathleen Lake south of Haines Junction Middle' Kaskawulsh Glacier in St. Elias Mountains Bottom' Valley wetlands and Itsi Mountain Range. lat_ l)JOOS'N, long. 1300 12'W BC-X-l64 June 1977 ABSTRACT RESUME A reconnaissance level biophysical survey of On eu recours ades envolees de reconnaissance the Yukon Territory was conducted during 1975. pour effectuer un releve biophysique sur Ie Territoire Twenty-two ecoregions were recognized and described du Yukon au coors de I'annee 1975. L'on roconnalt in terms of the biophysical data available, either 22 erorfigions, decrites en termes de donnees bio collected during the surveyor from literature physiques disponibles, provenant du releve ou de la reviewed. The primary feature used to segregate and linerature specialisee qu'on a consultee. La premiere describe the ecoregions was the vegetation on different caraeteristique utilisee pour differencier et decrire les landforms under a regional climate. This was aug' ~coregions fut la vegetation selon la physiographie mented by describing the distribution and extent of et les climats regionauK. On accentua davantage en permafrost, geological history and terrain features. decrivant la distribution et I'etendue du pergelisol, j'historique geologique et les paysages. The lower elevation terrain in southern Yukon Territory is mostly forested with a variety Le terrain a plus basse altitude dans la partie of boreal coniferous and hardwood tree species. sud du Territoire du Yukon est SUl100t peuple d'une With increasing elevation and latitude, the tree density varihe de resineuK et de feuillus boreauK. A mesure declines and the dominant vegetation becomes arctic qu'augmentent I'altitude et la latitude, la densite des and alpine tundra. Shrub communities have a high amres decroit et la vegetation dominante est remplacee frequency and cover, especially across the ecotone par la toundra arctique et alpine. Les amustes sont from forest to tundra. Ground vegetation, primarily frequents et tooffus, particulierement dans I'ecozone mos.s cover, plays a significant role in the development situe entre la foret et la toundra. La vegiitation au sol, and persistence of permafrost. sunout formee d'une couverture de mousse, joue un rale imponant dans Ie devefoppement et la persistance The relationship among several biophysical du pergelisol. parameters is discussed in light of available informa· tion. Research of a more intensive nature is necessary Les auteurs dissertent sur la correlation entre to establish more detailed correlations. plusieurs parametres biophysiques a la lumiilre des renseignements disponibles. Des recherches de nature plus intensive seront n~cessaires a I'ihablissement de nouvelles correlations plus detaillees. ACKNOWLEDGMENTS Appreciation is eKtended to personnel of the Yukon Lands and Forest Service for providing fiKed'winged aircraft and helicoPter time, making aa:ommodation reservations, providing storage and office space and participating in discussions about various aspects and locations of the Yukon Territory. Other personnel of the Department of Indian and Nonhern Affairs offered constructive guidance during the planning phase. Dr. S. Kojima and Mr. S.C. Zoltai of the Northern Forest Research Centre, Edmonton, Alberta assisted in plant identification, especially with the lichens. Dr. T.G. Honer, Program Manager, Pacific Forest Research Centre, was helpful during all phases of the project. Field assistance by B.N. Brown and H. Hirvonen was appreciated. J.C. Wiens drew the final figures, designed the cover and layout of the teKt. 2 TABLE OF CONTENTS Page Abstract .........•.......••......••......•.....••...... _ •..•....••.. Resume. .......... .• .......•..... ••• ..... ••• ... .•• .•... .•••• •• •••••• 1 AcknO\Vledgments .........••......••.••...•..•.••••••••••••••••••••••• 1 Introduction.........••...•.••....••••....•.• , ...•.......•............ 5 Methods of Survey .................••.•...••••••.••.•••• , ••••••• , • • . • • . 6 Description of the Yukon Territory. .....••••••••.••••••••••.•••.••.•••.••..• 6 1. GeographicSetting............. ..•••••.. •••••.•. •••.... ••••.•.. 6 2. Physiography and Geology. .........•.....•.•.....••......•••..... 8 3. Watersheds................................................... 8 4. Climate..................................................... 14 S. Glacial History ..........••......•..•....••.....•••... ,....•.•. 14 6. Soils....................................................... 18 7. Permafrost................................................... 19 8. Vegetation................................................... 19 Ecoregions of the Yukon Territory. .....•....•......•..... .. •.......•......•. 22 1. 8eaverRiver................ ..•......•.......•..•... ••••...•.. 24 2. Liard River. ................. .• ......•..... •. ...... •• ...... .• . 26 3. Logan Mountains. .....................•..............•.......•. 28 4. Pelly Mountains. ......••......•......•......••......••......•. 30 5. Lake Laberge. ........•.•..••••.••.••.••...••..•....•.•••.•.•. 33 6. Coast Mountains .......•......•........•....•.......•.. '.' ...••. 35 7. St. Elias Mountains. .........• •• ..... •• ...... •• ......•.......•.. 38 8. Ruby Range. ...............••.....••.............•......••... 40 9. Wellesley Lake. ......••.•..•••••....••.....•••....•.•....•••.. 42 10. Dawson Range. .... .. ..... .• •••• ... •• ..... ••• •....•... .• . ••• •. 45 11. Klondike River .............••.....•••....•••.....••......... _. 47 12. Pelly River. ...............••.....••.....••......•.......••... 49 13. Mayo Lake-Ross Riyer .....•.•••.....••••...•••••...••••....•••.. 52 14. Itsi Range ................••••...•••.....••. '" . •• •••• •• •••• . 54 15. Wernecke Mountains. .......• ••• .... ••. .... ••. ..... ••. ....•..... 56 16. South OgilYie Mountains......•......••......••............ _•..... 58 17. North Ogilvie Mountains. .....• •. • .. •• .••... ••• .. ...•......•..... 61 18. Eagle Plain , •.••....•.•....•••... , ••••....•.•. ,. 63 19. Peel Riyer ...................... •• .....• •. .....•..... .• •..... 65 20. Berry Creek. .....................•......•......•......••..... 67 21. Old Crow Basin.................................••.... _. •...... 68 22. Northern Mountains and Coastal Plain. .....••.•••••••...••••.•••••.... 71 Terrain Interrelationships. ..........................•......•......•....... 73 References _.......•••..•••.•.•...•••....• • •••••.•...•..•••.•.. 94 3 Appendices A. Species List .•..........•• • ......•......••......•.......•.... 98 B. Glossary of Terms. .••......••.... ••••... .••..... •••.... 101 C. Soil Analyses. .........•.•...•.•.•••..•.•.••..•••..•...•••... 106 D. Forest Statistics .........••••....••.....••......••.... ,.•..... 113 List of Tables Table 1. Climatic data ,,. 15 List of Figures Figure 1. Geographic location of the Yukon Territory . 7 Figure 2. Place·names in the Yukon Territory . 9 Figure 3. Extent and approximate dePth of volcanic ash deposits ........•••..•. 10 Figure 4. Physiographic subdivisions .. ............••.. 11 Figure 5. Generalized geology _ ............•••......• 12 Figure 6. Majordrainage systems......................•......•......• 13 Figure 7. Annual mean precipitation isohyets . 16 Figure 8. Ice sources, glacial limits and flow patterns . 17 Figure 9. Permafrost zones and subzones and mean annual air temperature isotherms .. 20 Figure 10. Forest regions. ...... .. 21 Figure 11. Ecoregions of Yukon Territory . 23 List of Plates Plate I Beaver River Ecoregion. .. .••......•.•.. ..•....•.. 25 Plate II liard River Ec:oregion _ ..••.....••.....•......••.. 27 Plate II r logan Mountains Ecoregion .......•••......••............•.. 29 Plate IV Pefly Mountains Ecoregion .........•.••..•.•.••....••......• 31 Plate V lake Laberge Ecoregion ...........•......••.•......•...••.• 34 Plate VI Coast Mountains Ecoregion ........•......•.......•. .. .•... 36 Plate VII St. Elias Mountains Ecoregion ......•......•......• 39 Plate VIII Ruby Range Ecoregion ...........•..•...........•......••.. 41 Plate IX Wellesley lake Ec:oregion ........•••••...••••..••.•••.•••.•• 43 Plate X Dawson Range Ecoregion ........••.....••......••.....••... 46 Plate XI Klondike Alver Ecoregion . 48 Plate XII Pe!ly River Ecoregion. ............••.....•.•... 50 Plate XIII Mayo lake-Ross River Ecoregion. .. ••..•.••..•..........••.• 53 Plate XIV ltsi Range Ecoregion .................•••......•......•.... 55 Plate XV Wernecke Mountains Ecoregion ...........•........ ...••.. 57 Plate XVI South Ogilvie Mountains Ecoregion........••......••.....••.... 59 Plate XVII North Ogilvie Mountains Ecoregion........•••...•.••.....••.... 62 Plate XVIII Eagle Plain Ecoregion. ...... .. .. ..••...•..•.....•••... 64 Plate XIX Peel River Ecoregion ...............••......••.... 66 Plate XX Old Crow Basin Ecoregion............................••.... 69 Plate XXI Northern Mountains and Coastal Plain Ecoregion.......••....•••.. 72 Plate XXII Earth stripes. blanket bog and nonsorted circle ......•...•.....•.•.. 77 Plate XXlll String fen. paisa and drumlins ..................•. 78 Plate XXIV Fluvial deposit. frost sorting and peat mound . 79 4 TABLE OF CONTENTS (Con't) Plate XXV Fluvial deposit. meltwater channels and dunes .........••.....•.... so Plate XXVI Colluvial and morainal material and valley glaciers ......•..••.•••.••. 8t Plate XXVII Lapilli. bog·fen