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Transcript of Rangelands of Subarctic and Arctic North America and ... Arctic and Subarctic defined • ARCTIC...

  • Rangelands of Subarctic and Arctic North America and Europe:

    ecosystems, wildlife and management

    Dave Downing, X Int’l Range Conf. 2016

  • Outline • Arctic/subarctic rangelands – what they are,

    where they occur • Biophysical characteristics and appearance, with

    examples from the Northwest Territories • Grazing animals and predators in arctic and

    subarctic rangelands • Range management in high latitude ecosystems,

    with reference to North America and Europe. • Present and future value of ecosystem

    classification

  • Rangeland defined • Society for Range Management 1998: “Rangelands are lands …(that are) managed as a

    natural ecosystem…Rangeland includes natural grasslands, savannas, shrublands, many deserts, tundras, alpine communities, marshes and meadows.”

    • Rangelands also include forested ecosystems e.g. forests in boreal and subalpine areas and woodland-shrub ecosystems in the Subarctic.

  • Arctic and Subarctic defined

    • ARCTIC – treeless shrub and graminoid tundra in low arctic, polar deserts in high arctic, continuous permafrost.

    • SUBARCTIC – conifer dominated woodlands, discontinuous tundra, mostly continuous permafrost.

    • Northern Boreal Zone of Europe = the Subarctic of North America.

  • North American Subarctic and Arctic Ecosystems

  • European Subarctic and Arctic Ecosystems

  • Why the big difference between NA and Europe? Global Climates : (1) Gulf Stream

    •Warm waters flow north, cool, and sink: “conveyor belt” •These currents carry warmer water north of Norway

    Source : American Scientist 94(4)

    Scandinavia

  • Source : American Scientist 94(4)

    Global Climates (2) Proximity to ice-free oceans •water stores more heat than land, releases it more slowly •Atmospheric circulation flows southwest to northeast across the Atlantic, transporting warm air eastward. •Oceans bordering the north coasts of North America and Asia are icebound.

    North Am. Eurasia Eurasia

  • Climatic trends Regional climates determine Subarctic and

    Arctic ecosystem distribution • Climate stations are sparsely distributed, but

    permafrost and vegetation patterns are current and historic indicators of climatic influences

    • Insolation, Temperature, Precipitation models indicate overall trends

  • North America – Canada Annual Solar Radiation mJ/m2

    Source: Agriculture Canada

    Subarctic and Arctic rangelands don’t get much solar energy, even in summer (low sun angles)

  • North America – Canada Mean Annual Temperature oC

    Source: Agriculture Canada

    Subarctic and Arctic rangelands are cold

  • North America – Canada Mean Annual Precipitation (mm)

    Source: Agriculture Canada

    Subarctic and Arctic rangelands are dry – polar deserts in the far north

  • Plants and permafrost distribution - indicators of climatic differences

    Polygonal peat plateaus – High Subarctic

    Jackpine – Low Subarctic, Boreal

    Lodgepole pine, alpine fir – Cordilleran- boreal

    Purple saxifrage barrens – High Arctic

    Ice-wedge polygons – continuous permafrost

  • Overall plant productivity is indicative of climatic differences in the Arctic (above treeline)

    Source: Circumpolar Arctic Vegetation Map 2003

  • Rangelands of Subarctic and Arctic Canada

    • Northwest Territories landscapes are generally representative of subarctic and arctic landscapes in Yukon, Alaska and Nunavut

    • The arctic/subarctic ecosystem (=rangeland) delineation in NWT is more comprehensive than elsewhere in Canada

    • A few slides about that classification and how it was done...

  • Northwest Territories ecosystem classification (= regional range inventory)

    • Initiated in 2004; revision to existing inventory needed for resource management

    • Took 9 years to complete and involved – Focused and extensive field programs to collect

    information – GIS mapping – Report preparation

  • Acknowledgements

    • Colleagues Bas Oosenbrug, Bob Decker, Tom Chowns and Charles Tarnocai (all retired now) formed the core, with later assistance from Suzanne Carriere

    • Dozens of people assisted with logistics

  • Classification and mapping concepts • Developed at outset of project and refined for specific

    areas – consistent and explicit.

  • Field program • Provisional ecoregion classifications prior to

    fieldwork aided transect planning. • Almost all of it depended on floatplanes and

    helicopters (1.6 million km2 and few roads) • Aircraft management was a critical part of this

    exercise – fuel availability, load limits, weather • Success = (Political will + technology +

    availability of experts + availability of resources)

  • 125,000 km in fixedwing and helicopter 70,000 oblique aerial/10,000 ground photos, 9 yr.

  • Aerial transects 2011 Arctic Islands

    2009- Southern Arctic

    2007- Cordillera

    2006 – Taiga Shield

    2005 – Taiga Plains

    2010 Arctic Islands

  • Transect detail

    YEAR MTH DAY WAYPOINT LAT LON Photolabel DIRECTION COMMENTS1

    2005 8 14 677 66.0848 -121.911 NWT2005-08-14-001DSC_0677.jpg N Treeline | center of photo Data record with each image captures themes

  • Ground stops About 200 shown, not including ground data from other studies

  • Fieldwork- the agony and the ecstacy

    Blackfly hell... The white flecks are blackflies on the camera lens and in the air around the researcher

    Direct transmission of terrain knowledge from the guru Charles Tarnocai

  • Data analysis • 80,000 photos and the associated descriptive notes

    had to be downloaded, organized and reviewed

    • Linked photos to locations by 1:1 match between waypoints and photo numbers on unique days

    • Comments in the descriptive notes were used to create themes – Used these themes to help detect patterns – Themes were an important part of a multi-part

    landscape analysis

  • Themes developed from aerial and ground records e.g. vegetation and permafrost indicators of climatic differences

    Peat polygons – High Subarctic, organic soils

    Jackpine – Low Subarctic, Boreal indicator

    Lodgepole pine, alpine fir – Cordilleran- boreal indicator

    Purple saxifrage barrens – High Arctic indicator

    Ice-wedge polygons – continuous permafrost

  • Integration DEM,

    hydrology, Landsat

    Field data, themes

    Wildlife – published info, field

    obs.

    Workshops, expert opinion

    Aspatial data

    Climate, vegetation

    Geology, peatlands

    Map, report, geodatabase

  • Further info: Reports and photos

    Search for: • Government of NWT Ecosystem Classification • Government of NWT Ecosystem Photo

  • Quite a few changes from 1996 to 20XX classification

  • A tour of NWT ecosystems: Northern Arctic

  • Northern Arctic: Northern Islands rangelands

    Northernmost NWT land, Borden Island

    Sedge-moss-dwarf shrub tundra – sheltered locales

    Rush-grass-forb- cryptogam tundra – Alopecuris (inset)

    Prostrate dwarf shrub-herb tundra

    Cryptogam-herb barrens

  • Northern Arctic: Banks and Victoria Islands

    Dwarf shrub tundra

    Snow geese on wet sedge tundra

    Mountain avens, territorial flower, common tundra plant

    Tree-sized willows and muskox, sheltered inlet

  • NWT ecosystems: Southern Arctic

  • Southern Arctic rangelands: Tundra Plains/Shield

    Prostrate dwarf shrub-herb tundra – coastlines, higher elevations

    Shrub tundra – moister, warmer sites in southern Arctic Erect dwarf shrub tundra, well

    drained areas on the Shield

    Barren ground caribou on lush sedge-cottongrass tundra, old lakebeds

  • NWT ecosystems: Taiga Shield

  • Taiga Shield: Subarctic rangelands

    Till drumlins and lichen-dwarf shrub tundra, eastern High Subarctic

    Bouldery till and vast tracts of burned forest, eastern Low Subarctic.

    Barren ground caribou and shrub tundra, western High Subarctic

    Open black spruce woodlands in the western Low Subarctic

  • NWT rangelands: Taiga Plains Subarctic

  • Tundra on dry hilltops, spruce woodlands in lowlands, High Subarctic

    Taiga Plains: Subarctic Rangelands

    Spruce woodlands and peat plateaus (organic, perhafrost) High Subarctic

    Typical peat plateau (organic permafrost) and woodland complex, Low Subarctic.

  • Main grazers – North American Arctic/Subarctic

    Peary caribou – restricted to Arctic Islands, small p