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 populations, smaller than barren-ground
Barren ground caribou – 650-750K in total, 11 major herds, mostly long migrations between summer/winter range
Muskoxen – range throughout Arctic/high Subarctic, almost all in North America, prefer sedges/grasses.
Caribou distribution North America – 6 of 11 main herds
Source: Gov’t NWT website
Main grazers – Scandinavia
Reindeer – semi-domesticated, estimated at 600,000 in subarctic and Southern Arctic Scandinavia. Migratory, usually tended by herders and used for transportation
Source: International Centre for Reindeer Husbandry website
Main predators – North America and Scandinavia
Bears – barren ground grizzly Wolverine
Tundra wolf – main caribou predator Golden eagle
“Predation by wolf, lynx, eagle and wolverine has a dramatic impact on reindeer herds, directly affecting herders in all areas” (International Centre for Reindeer Husbandry)
Lynx
Range management – North America vs. Scandinavia
• Primary concern is caribou or reindeer in both countries, with secondary focus on muskox in North America
• Reindeer herding contributes significantly to local economies especially in Europe/Asia
Reindeer herds and herders across the northern hemisphere
Source: International Centre for Reindeer Husbandry website
Across the northern hemisphere, caribou/reindeer are important food and clothing sources and are part of the culture of Arctic and Subarctic people.
North America • In NA, caribou and muskox are unconfined wild
populations – These populations fluctuate enormously e.g. Bathurst
herd 186,000 in 2003, 15-22,000 in 2015! – Climate fluctuations are important drivers, so are seasonal
events (e.g. freezing rain that limits access to forage) – Tracking population levels is key to managing – A lot of effort goes toward monitoring and co-managing
harvest levels (governments and local residents form co-management boards) and to research
– 2011-2015 barren ground caribou management strategy.pdf for NWT provides more details
Scandinavia and Asia
• Reindeer herds are actively managed • Herders have hundreds of years of experience
– There are established territories and family groups know their pastures and migration routes intimately
– Groups share resources in response to both ecosystem changes and social needs
– Government policymakers need to take traditional knowledge and views into account
How does regional range (ecosystem) classification help?
• Provides a common information base • Provides insights into how landscapes
influence range production • Helps with predictions of range condition
going forward – focuses monitoring efforts • Mapped ecosystems are benchmarks for
change, which is inevitable and constant.