Print Report
M179 North American Northern Boreal Woodland Macrogroup
Type Concept Sentence: Open-canopy, short-statured woodlands in subalpine and subarctic North America on cool, dry sites on well-drained to excessively well-drained substrates. Canopies are sparse to open and dominated by Picea glauca and Pinus banksiana, and codominated by Picea mariana. Isolated stands of Populus tremuloides or Populus balsamifera ssp. balsamifera that occur above conifer treeline are included.
Common (Translated Scientific) Name: North American Northern Boreal Woodland Macrogroup
Colloquial Name: North American Northern Boreal Woodland
Hierarchy Level: Macrogroup
Type Concept: This macrogroup occurs through northern Manitoba, northeastern Saskatchewan, southern Nunavut, the Northwest Territories, northern Alberta, northeastern British Columbia, northern Yukon Territory and interior Alaska. It is characterized by the prevalence of open-canopied stands of short-statured Picea mariana and Picea glauca. The latter species is more common west of the Canadian Shield on the relatively nutrient-rich glacial deposits of northern Northwest Territories and Yukon Territory. Near the northern limit of the range, woodlands become even more sparse and are interspersed with tundra toward latitudinal and elevational treeline. Permafrost-affected terrain, developed in thick moss layers and dominated by stunted black spruce stands, is widespread on level landscapes and on northern aspects of upland slopes; active (i.e., freeze/thaw) permafrost layers are typically less than a meter deep. The understory is usually low in stature, sparse and shrubby, under which lichens often form nearly continuous carpets. Vascular understory species include dwarf Salix spp. and Betula nana, as well as ericaceous species such as Ledum groenlandicum, Ledum palustre, Vaccinium uliginosum, Vaccinium vitis-idaea, and Empetrum nigrum. Important terricolous lichens include Cladonia spp., Stereocaulon spp., Nephroma arcticum, Peltigera spp., and Cetraria spp. This macrogroup is influenced by continental and cordilleran climates with extremely cold winters and short cool summers that limit tree growth and understory development; less precipitation towards the north also reduces the extent and depth of organic terrain. The eastern portion of the described range (i.e., between Hudson Bay and Great Slave Lake) is underlain by the Canadian Shield; west of Great Slave Lake the lithology is sedimentary, providing greater nutrient status to soils. All portions of the range were glaciated, except a small Beringean area along the Yukon - Alaska border. This macrogroup is differentiated from ~West-Central North American Boreal Forest & Woodland Macrogroup (M496)$$ to the south by the lack of broad-leaved deciduous trees and the prevalence of spruce woodlands on well-drained sites, as well as the significant occurrence of diagnostic indicator species such as Ledum palustre, Vaccinium uliginosum, and Nephroma arcticum.
Diagnostic Characteristics: Woodland featuring a short-statured canopy dominated by Picea glauca or Picea mariana with dwarf ericaceous shrubs. Another important species is Betula nana. Lichens are often an important component of the understory.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: CNVC is not yet satisfied that the range of woodland conditions in the boreal subalpine and the boreal subarctic are identical. For the time-being, we are proposing to treat these as separate ecological entities. The boreal subalpine is waiting for completion of the Yukon bioclimatic work before it can be comprehensively characterized for Canada.
The position of the subarctic woodland in western Alaska towards the Bering Sea has a stronger maritime influence that differs from the arctic timberline. Picea mariana is absent. The western timberline stretches from the vicinity of Kotzebue Sound (at the Arctic Circle) to Katmai National Monument at the base of the Alaska Peninsula (58°N). Well-developed forests extend westward along the floodplains of the major rivers, perhaps encouraged by the lack of permafrost in the active floodplain area (Viereck 1979, Arno 1984). We will call this "Alaskan-Yukon Boreal Forest" pending completion of the Canadian analysis: Subarctic may be split into western and eastern North American.
The position of the subarctic woodland in western Alaska towards the Bering Sea has a stronger maritime influence that differs from the arctic timberline. Picea mariana is absent. The western timberline stretches from the vicinity of Kotzebue Sound (at the Arctic Circle) to Katmai National Monument at the base of the Alaska Peninsula (58°N). Well-developed forests extend westward along the floodplains of the major rivers, perhaps encouraged by the lack of permafrost in the active floodplain area (Viereck 1979, Arno 1984). We will call this "Alaskan-Yukon Boreal Forest" pending completion of the Canadian analysis: Subarctic may be split into western and eastern North American.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This macrogroup is defined as a needle-leaved evergreen woodland with a widely-spaced and stunted canopy. A minor component of this group includes open to closed canopied stands of stunted broad-leaved deciduous forest that occur beyond the coniferous treeline transitioning to low 2-m tall krummholz. Subarctic woodland may form large expanses 10 or more kilometers wide, whereas the subalpine woodland may be a narrow elevational band (Arno 1984).
Floristics: Subarctic woodlands are characterized by a sparse to open canopy dominated by Picea glauca and/or Picea mariana. Isolated stands of Populus balsamifera ssp. balsamifera occurring on southerly aspects above or beyond coniferous treeline are included in this macrogroup. The shrub layer is composed of low shrubs and dwarf-shrubs, including Arctostaphylos rubra, Betula nana, Betula glandulosa, Empetrum nigrum, Ledum palustre ssp. decumbens, Ledum groenlandicum, Rosa acicularis, Vaccinium uliginosum, Vaccinium vitis-idaea, and Viburnum edule. Scattered stands of Alnus viridis ssp. fruticosa (in the continental boreal), Alnus viridis ssp. sinuata (sub-continental boreal), Salix pulchra, or Salix glauca may be common. Tussock-forming graminoids, including Carex bigelowii or Eriophorum vaginatum, may be abundant on some sites. Common mosses include Hylocomium splendens and Sphagnum species, with lichens, primarily Cladonia spp., Stereocaulon spp., Nephroma arcticum, Peltigera spp., and Cetraria spp., becoming an important component of the understory in mature stands.
Dynamics: Fire, climate and permafrost contribute to successional processes and vegetation patterns in subarctic woodlands. Fire is a primary disturbance factor in this region (Johnson and Miyanishi 1999). Most fires are lightning caused, and they are more frequent in the subarctic than high subarctic woodland. In the low subarctic, current fire cycles (the number of years required to burn an area equal in size to the study area) are estimated at about 100 years (Bergeron and Fenton 2012), but in the high subarctic this may be greatly reduced, and the areas burned may decrease by a 100-fold (Johnson and Miyanishi 1999).
Based on the fire cycle, old-growth forests are expected to be relatively uncommon in subarctic woodlands, but Bergeron and Fenton (2012) used a variety of sources and modeling to estimate the percent of old growth across the Canadian boreal and subarctic woodland ecozones. In the western low subarctic woodlands, stands >200 years occupied 15-25% of the landscape, in the eastern woodlands, they occupied 30%, and in the Hudson plains 78%). In the west, stands >300 years occupied 5-15%, in the east 15-20%, and in the Hudson plains 69%. In the western Canadian cordilleran region, forests of >200 years could occupy 45-50% of the landscape, and forests of >300 years could occupy 30-35% of the area, suggesting montane subalpine woodlands burned much less often. These levels of old growth are present because fires largely act independent of stand age, so some stands are burned twice within a fire cycle, and others are never burned.
Insect disturbance can also be substantial, but more information is needed on the insect pests in subarctic woodlands.
The northern limit of subarctic woodland can be defined by the limit of tree growth, which can itself be defined in various ways: by physiognomy (vegetatively reproducing trees forming woodlands), the tree species line (limits of species that normally grow as trees), and the historic tree line (Scott 1995b, Johnson and Miyanishi 1999). Here we use the physiognomic treeline.
Based on the fire cycle, old-growth forests are expected to be relatively uncommon in subarctic woodlands, but Bergeron and Fenton (2012) used a variety of sources and modeling to estimate the percent of old growth across the Canadian boreal and subarctic woodland ecozones. In the western low subarctic woodlands, stands >200 years occupied 15-25% of the landscape, in the eastern woodlands, they occupied 30%, and in the Hudson plains 78%). In the west, stands >300 years occupied 5-15%, in the east 15-20%, and in the Hudson plains 69%. In the western Canadian cordilleran region, forests of >200 years could occupy 45-50% of the landscape, and forests of >300 years could occupy 30-35% of the area, suggesting montane subalpine woodlands burned much less often. These levels of old growth are present because fires largely act independent of stand age, so some stands are burned twice within a fire cycle, and others are never burned.
Insect disturbance can also be substantial, but more information is needed on the insect pests in subarctic woodlands.
The northern limit of subarctic woodland can be defined by the limit of tree growth, which can itself be defined in various ways: by physiognomy (vegetatively reproducing trees forming woodlands), the tree species line (limits of species that normally grow as trees), and the historic tree line (Scott 1995b, Johnson and Miyanishi 1999). Here we use the physiognomic treeline.
Environmental Description: Climate: This macrogroup occupies a subarctic climate which is characterized by long, usually very cold winters, and short, cool to mild summers with a mean July temperature of 10°C. Sites can be high-elevation in the sub-continental and continental cold boreal bioclimatic zones. Summers are short and cool, with precipitation between 50 and 100 cm. Winters are very cold and windy, with moderate to deep snow accumulation.
Soils/substrate: In the eastern interior subarctic woodlands, soils are uniformly immature and largely Inceptisols and Entisols. Associated landforms include gentle sideslopes, rolling hills, rounded summits and inactive alluvial surfaces. In the west, soils are thin and well-drained to somewhat poorly drained and develop on gravels, loess, or residual bedrock or hillside colluvium. The surface organic layer is typically 10-30 cm thick. Sites are underlain by continuous permafrost or generally absent in the sub-continental boreal, to discontinuous to the north in the continental boreal. Elevations are as high as 1000 m in parts of central Alaska.
Soils/substrate: In the eastern interior subarctic woodlands, soils are uniformly immature and largely Inceptisols and Entisols. Associated landforms include gentle sideslopes, rolling hills, rounded summits and inactive alluvial surfaces. In the west, soils are thin and well-drained to somewhat poorly drained and develop on gravels, loess, or residual bedrock or hillside colluvium. The surface organic layer is typically 10-30 cm thick. Sites are underlain by continuous permafrost or generally absent in the sub-continental boreal, to discontinuous to the north in the continental boreal. Elevations are as high as 1000 m in parts of central Alaska.
Geographic Range: West of Hudson Bay, this macrogroup occupies a narrow band trending west to northwest through the plains and uplands of northern Manitoba, extreme northeastern Saskatchewan and southern Nunavut, and the northeastern Northwest Territories (NWT), with small isolated islands on high-elevation hill systems in northern Alberta, the southern NWT and extreme northeastern British Columbia. From there it continues west of Great Slave Lake and widens to include about 40% of the mainland Northwest Territories and a significant part of northern Yukon Territory, and it continues into the mid- and upper-elevation boreal and sub-boreal regions of Alaska. It does not extend to the west coast of Alaska.
Nations: CA,US
States/Provinces: AB, AK, LB, MB, NT, NU, ON, QC, SK, YT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860664
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.4 Boreal Forest & Woodland Formation | F001 | 1.B.4 |
| Division | 1.B.4.Na North American Boreal Forest & Woodland Division | D014 | 1.B.4.Na |
| Macrogroup | 1.B.4.Na.4 North American Northern Boreal Woodland Macrogroup | M179 | 1.B.4.Na.4 |
| Group | 1.B.4.Na.4.e White Spruce Northern Boreal Mesic Woodland Group | G859 | 1.B.4.Na.4.e |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Forest-tundra ecotone (Elliott-Fisk 2000) [The forest islands are part of this macrogroup.]
> Lichen woodland (Elliott-Fisk 2000) [This type includes the more-or-less continuous zone of this macrogroup.]
= Spruce-Willow-Birch Zone (Prince Rupert Forest Region) (Banner et al. 1993) [This zone is very similar to the system concept of ~Western North American Boreal Treeline White Spruce Woodland (CES105.137)$$.]
= Subarctic lichen woodlands (Johnston and Miyanishi 1999)
> Lichen woodland (Elliott-Fisk 2000) [This type includes the more-or-less continuous zone of this macrogroup.]
= Spruce-Willow-Birch Zone (Prince Rupert Forest Region) (Banner et al. 1993) [This zone is very similar to the system concept of ~Western North American Boreal Treeline White Spruce Woodland (CES105.137)$$.]
= Subarctic lichen woodlands (Johnston and Miyanishi 1999)
- Arno, S. 1984. Timberline: Mountain and arctic forest frontiers. The Mountaineers, Seattle. 304 pp.
- Banner, A., W. MacKenzie, S. Haeussler, S. Thomson, J. Pojar, and R. Trowbridge. 1993. A field guide to site identification and interpretation for the Prince Rupert Forest Region. Ministry of Forests Research Program. Victoria, BC. Parts 1 and 2. Land Management Handbook Number 26.
- Belleau, A., Y. Bergeron, A. Leduc, S. Gauthier, and A. Fall. 2007. Using spatially explicit simulations to explore size distribution and spacing of regenerating areas produced by wildfires: Recommendations for designing harvest agglomerations for the Canadian boreal forest. Forestry Chronicles 83:72-83.
- Bergeron, Y., and N. J. Fenton. 2012. Boreal forests of eastern Canada revisited: Old growth, nonfire disturbances, forest succession, and biodiversity. Botany 90:509-523.
- Boggs, K., A. Garibaldi, J. Stevens, J. Grunblatt, and T. Helt. 2001. Denali National Park and Preserve landcover mapping project. Volume 2: Landcover classes and plant associations. Natural Resource Technical Report NPS/DENA/NRTR--2001/002. National Park Service, Fort Collins, CO. 164 pp.
- Boggs, K., T. Boucher, et al. 2011. List of plant associations for Alaska. 2011 draft. Alaska Natural Heritage Program, Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage.
- CCFM [Canadian Council of Forest Ministers]. 2000. Criteria and indicators of sustainable forest management in Canada, National Status 2000. Canadian Council of Forest Ministers (CCFM), Ottawa, ON.
- Callaghan, C., S. Virc, and J. Duffe. 2011. Woodland caribou, boreal population, trends in Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 11. Canadian Councils of Resource Ministers, Ottawa, ON. iv plus 36 pp.
- Chapin, F. S., III, A. D. McGuire, R. W. Ruess, T. N. Hollingsworth, M. C. Mack, J. F. Johnstone, E. S. Kasischke, E. S. Euskirchen, J. B. Jones, M. T. Jorgenson, K. Kielland, G. P. Kofinas, M. R.Turetsky, J. Yarie, A. H. Lloyd, and D. L. Taylor. 2010. Resilience of Alaska''s boreal forest to climatic change. Canadian Journal of Forest Research 40:1360-1370.
- Drapeau, P., A. Leduc, D. Kneeshaw, and S. Gauthier. 2009. An adaptive framework for monitoring ecosystem management in the boreal black spruce forest. Pages 343-372 in: S. Gauthier, M-A. Vaillancourt, A. Leduc, L. De Grandpré, D. Kneeshaw, H. Morin, P. Drapeau, and Y. Bergeron. Ecosystem management in the boreal forest. Presses de l''Université de Québec, Québec City.
- Elliott-Fisk, D. L. 2000. The taiga and boreal forest. Pages 41-73 in: M. G. Barbour and W. D. Billings, editors. North American terrestrial vegetation. Second edition. Cambridge University Press, New York.
- Environment Canada. 2008. Scientific review for the identification of critical habitat for woodland caribou (Rangifer tarandus caribou), boreal population, in Canada. August 2008.Environment Canada, Ottawa. 72 pp. plus 180 pp. appendices.
- Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.
- Faber-Langendoen, D., C. Hedge, M. Kost, S. Thomas, L. Smart, R. Smyth, J. Drake, and S. Menard. 2012. Assessment of wetland ecosystem condition across landscape regions: A multi-metric approach. Part A. Ecological Integrity Assessment overview and field study in Michigan and Indiana. EPA/600/R-12/021a. U.S. Environmental Protection Agency Office of Research and Development, Washington, DC.
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Foote, M. J. 1983. Classification, description, and dynamics of plant communities after fire in the taiga of interior Alaska. Research Paper PNW-307. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. 108 pp.
- Girardin, M. P., M. D. Flannigan, J. C. Tardif, and Y. Bergeron. 2009. Climate, weather, and forest fires. Pages 79-102 in: S. Gauthier, M-A. Vaillancourt, A. Leduc, L. De Grandpré, D. Kneeshaw, H. Morin, P. Drapeau, and Y. Bergeron. Ecosystem management in the boreal forest. Presses de l''Université de Québec, Québec City.
- Jasinski, P.,and S. Payette. 2005. The creation of alternative stable states in the southeastern boreal forest, Québec, Canada. Ecological Monographs 75(4):561-583.
- Johnston, E. A., and K. Miyanishi. 1999. Subarctic lichen woodlands. Pages 421-436 in: R. C. Anderson, J. S. Fralish, and J. M. Baskin. Savannas, barrens, and rock outcrop plant communities of North America. Cambridge University Press, NY.
- Johnstone, J. F., F. S. Chapin, III, T. N. Hollingsworth, M. C. Mack, V. Romanovsky, and M. Turetsky. 2010. Fire, climate change, and forest resilience in interior Alaska. Canadian Journal of Forest Research 40:1302-1312.
- Jorgenson, M. T., J. E. Roth, S. F. Schlentner, E. R. Pullman, and M. Macander. 2003. An ecological land survey for Fort Richardson, Alaska. ERDC/CRREL TR-03019. U.S. Army Cold Regions Research and Engineering Laboratory, Hanover, NH.
- Jorgenson, T., V. Romanovsky, J. Harden, Y. Shur, J. O''Donnell, E. A. G. Schuur, M. Kanevskiy, and S. Marchenko. 2010. Resilience and vulnerability of permafrost to climate change. Canadian Journal of Forest Research 40:1219-1236.
- Klein, D. R. 1982. Fire, lichens, and caribou. Journal of Range Management 35(3):390-395.
- Scott, G. A. J. 1995b. Canada''s vegetation: A world perspective. McGill-Queen''s Press.
- Shiflet, T. N., editor. 1994. Rangeland cover types of the United States. Society for Range Management. Denver, CO. 152 pp.
- Viereck, L. A. 1979. Characteristics of treeline plant communities in Alaska. Holarctic Ecology 2:228-238.
- Viereck, L. A., C. T. Dyrness, A. R. Batten, and K. J. Wenzlick. 1992. The Alaska vegetation classification. General Technical Report PNW-GTR286. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. 278 pp.
- Weber, M. G., and M. D. Flannigan. 1997. Canadian boreal forest ecosystem structure and function in a changing climate: Impact on fire regimes. Environmental Reviews 5:145-166.