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D016 Picea mariana - Larix laricina - Populus balsamifera Boreal Flooded & Swamp Forest Division
Type Concept Sentence: This division includes conifer-treed poor peat swamps and broad-leaved cold-deciduous (hardwood) riparian forests and rich swamps of the boreal region of North America, characterized by Abies balsamea, Fraxinus nigra, Larix laricina, Picea mariana, Populus balsamifera, and Thuja occidentalis.
Common (Translated Scientific) Name: Black Spruce - Tamarack - Balsam Poplar Boreal Flooded & Swamp Forest Division
Colloquial Name: North American Boreal Flooded & Swamp Forest
Hierarchy Level: Division
Type Concept: This division is found on moist to wet sites across the boreal region of North America. It encompasses forested peat swamps dominated by the conifers Larix laricina or Picea mariana, and floodplain forests and swamps dominated by the broad-leaved cold-deciduous tree species Fraxinus nigra and Populus balsamifera, or the conifers Abies balsamea and Thuja occidentalis. Betula papyrifera, Picea glauca, Populus tremuloides, or Ulmus americana may also occur in boreal floodplain forests. Forested peatlands mostly occur on poorly-drained, low-lying landscape positions with shallow to deep organic deposits, and a nutrient status ranging from richly to mildly minerotrophic (intermediate to rich swamps) to somewhat ombrotrophic (poor swamp) conditions. Floodplain forests occur along medium-sized to large rivers, on medium- to coarse-textured mineral soils, and are generally flooded each spring. Ericaceous shrubs and peatmosses (Sphagnum spp.) dominate the understory of the more nutrient-poor sites. Richer peatland sites are characterized by shrub birches (Betula spp.) and willows (Salix spp.), a greater abundance of graminoids (e.g., Calamagrostis canadensis) and horsetails (Equisetum spp.) and a well-developed moss layer that includes Hylocomium splendens, Pleurozium schreberi, brown mosses (e.g., Aulacomnium palustre, Tomentypnum nitens), and leafy mosses (Mniaceae). Floodplain forests generally have species-rich understories, including Alnus incana, Calamagrostis canadensis, Cornus sericea, Matteuccia struthiopteris, and various Salix spp.
Diagnostic Characteristics: Strong diagnostic tree species are Abies balsamea, Betula papyrifera, Larix laricina, Picea glauca, Picea mariana, and Populus balsamifera. Fraxinus nigra, Thuja occidentalis, and Ulmus americana are moderate diagnostic species that are more prevalent in the temperate region. Populus tremuloides is a moderate diagnostic species also found in the eastern cool-temperate region and in the Rocky Mountains. Some understory species with strong to moderate diagnostic value are Alnus incana and Calamagrostis canadensis.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The concept for this division was developed by the CNVC Technical Committee (Ken Baldwin, chair). The forested poor peat swamps of this division have similar floristics to treed bogs and fens, where the trees are of lower stature. The treed bogs and fens are included with open bogs and fens within 2.C.2.Na ~North American Bog & Fen Division (D029)$$. Bogs and fens of D029 can contain trees up to 5 m tall (and scattered trees >5 m), although they are generally shorter. But height criteria may need to be more flexible, and linked to floristics and ecology, as Harris et al. (1996), MacKenzie and Moran (2004), Banton et al. (2008) and Rydin and Jeglum (2013) all put the height criteria closer to 10 m and 25% cover to distinguish treed bogs and fens from forested poor swamps.
Riparian/floodplain forests of higher "benches" have limited flooding and deeper subsurface waters and are floristically similar to moist upland forests. As such, forests of this type, e.g., riparian forests dominated by Picea glauca, are included in the upland 1.B.4.Na ~North American Boreal Forest & Woodland Division (D014)$$.
Subarctic woodlands on upland sites may have similar structure and vascular species composition to treed peatlands of subarctic regions. They differ in the soil conditions and understory dominance of wetland species such as Rubus chamaemorus, Eriophorum spp., Sphagnum spp., Tomentypnum nitens, and/or Aulacomnium palustre.
Riparian/floodplain forests of higher "benches" have limited flooding and deeper subsurface waters and are floristically similar to moist upland forests. As such, forests of this type, e.g., riparian forests dominated by Picea glauca, are included in the upland 1.B.4.Na ~North American Boreal Forest & Woodland Division (D014)$$.
Subarctic woodlands on upland sites may have similar structure and vascular species composition to treed peatlands of subarctic regions. They differ in the soil conditions and understory dominance of wetland species such as Rubus chamaemorus, Eriophorum spp., Sphagnum spp., Tomentypnum nitens, and/or Aulacomnium palustre.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This division includes forested peat swamps dominated by needle-leaved evergreen or deciduous conifer tree species, and swamps and riparian forests dominated by broad-leaved cold-deciduous and/or needle- or scale-leaved evergreen tree species, typically greater than 5 m tall. Stand density is highly variable, ranging from closed, moderately productive forests to open stands of poor productivity. Age structure ranges from single-aged, e.g., young riparian stands, to multi-aged. Conifer swamps generally have a well-developed shrub understory and a nearly continuous cover of mosses. Riparian stands usually have a well-developed shrub understory but low to no cover of mosses due to flooding and/or broadleaf litter.
Floristics: Picea mariana is the predominant tree species of peatlands of this division. Larix laricina can dominate in both nutrient-poor and nutrient-enriched (minerotrophic) peatlands. Abies balsamea (eastern range) or Picea glauca (western range) may occur on nutrient-rich organic sites. The understory is dominated by ericaceous shrubs, especially on the more nutrient-poor sites. Ledum groenlandicum (= Rhododendron groenlandicum) and Vaccinium vitis-idaea occur across the range, except in Atlantic Canada where Kalmia angustifolia and Rhododendron canadense replace Ledum groenlandicum. On richer sites, Alnus incana, Betula glandulosa, or Salix spp. are prevalent, as are graminoids, and, in the west, Equisetum spp. is prevalent. Sphagnum spp. characterize the ground layer of these peatland forests and woodlands although feathermosses (Hylocomium splendens, Pleurozium schreberi) are also present. On peatlands with higher nutrient status, Aulacomnium palustre and Tomentypnum nitens are common.
Throughout the range, Populus balsamifera is a dominant tree species in floodplain and richer swamp forests. In eastern Canada, Fraxinus nigra, Abies balsamea, or Thuja occidentalis are also dominant or codominant species. In various parts of the range, Betula papyrifera, Picea glauca, Populus tremuloides, Acer negundo, or Ulmus americana may also occur in boreal floodplain forests. Common understory species include Alnus incana, Calamagrostis canadensis, Cornus sericea (= Cornus stolonifera), Equisetum arvense, Equisetum palustre, Equisetum pratense, Matteuccia struthiopteris, and Salix spp. The understory can be highly species-rich and diverse in the shrub and herb layers; mosses are generally of low cover due to frequent flooding and volume of broadleaf litter.
Throughout the range, Populus balsamifera is a dominant tree species in floodplain and richer swamp forests. In eastern Canada, Fraxinus nigra, Abies balsamea, or Thuja occidentalis are also dominant or codominant species. In various parts of the range, Betula papyrifera, Picea glauca, Populus tremuloides, Acer negundo, or Ulmus americana may also occur in boreal floodplain forests. Common understory species include Alnus incana, Calamagrostis canadensis, Cornus sericea (= Cornus stolonifera), Equisetum arvense, Equisetum palustre, Equisetum pratense, Matteuccia struthiopteris, and Salix spp. The understory can be highly species-rich and diverse in the shrub and herb layers; mosses are generally of low cover due to frequent flooding and volume of broadleaf litter.
Dynamics: Boreal flooded and swamp forests are generally stable ecosystems that are maintained by persistently high water tables. Local hydrology is the main ecological determinant of vegetation characteristics, and changes in water chemistry or level of the permanent water table affect nutrient status, degree of aeration, and soil temperature in the rooting zone. Hydrological changes are usually the result of alterations in local drainage patterns by natural (e.g., beaver activity) or anthropogenic (e.g., road-building, ditching) modifications. Paludification can also occur with higher water tables in cold or wet climates, resulting in the expansion of peatlands onto adjacent upland sites. Although fires can occur on peatlands, they are infrequent because these sites are so wet.
Riparian forests are subject to regular flooding. Erosional dynamics of rivers, including cutting of banks and upstream benches, and downstream deposition of sediments alter growing site conditions by affecting the stability of rooting zones and changing the depth of subsurface seepage. The riparian communities of this division are primarily "mid-bench," i.e., they occur on intermediate height floodplain sites that experience flooding most years, with some deposition of sediment. The "mid" benches are generally characterized by broad-leaved cold-deciduous or mixed broad-leaved and conifer stands, where conifers will replace the broad-leaved tree species over time as the height of the floodplain rises and the conifers outlive the broad-leaved trees. Fires are not common in these communities as they are usually dominated by broad-leaved deciduous trees on relatively moist sites.
Riparian forests are subject to regular flooding. Erosional dynamics of rivers, including cutting of banks and upstream benches, and downstream deposition of sediments alter growing site conditions by affecting the stability of rooting zones and changing the depth of subsurface seepage. The riparian communities of this division are primarily "mid-bench," i.e., they occur on intermediate height floodplain sites that experience flooding most years, with some deposition of sediment. The "mid" benches are generally characterized by broad-leaved cold-deciduous or mixed broad-leaved and conifer stands, where conifers will replace the broad-leaved tree species over time as the height of the floodplain rises and the conifers outlive the broad-leaved trees. Fires are not common in these communities as they are usually dominated by broad-leaved deciduous trees on relatively moist sites.
Environmental Description: Forested poor swamps occur in poorly drained areas with persistently high water tables and limited waterflow. Under such nutrient-poor conditions in the cold boreal climate, growth rates of Sphagnum mosses and some graminoids exceed rates of decomposition and peatlands develop with the accumulation of organic materials. Permafrost is a factor in subarctic and some northern boreal peatlands, and in the high subarctic classic permafrost features such as palsa and plateau bogs and ice-wedge polygons develop. Forested poor swamps have at least some minerotrophic influence and slightly better drainage than lower-statured treed bogs and fens. But it may be very difficult to observe differences in vegetation response between poor swamps and treed bogs or poor fens.
Riparian forests occur along watercourses, adjacent to medium and large rivers where annual flooding takes place and a subsurface water table or seepage supplies nutrient-rich water to the mineral substrate of the site. Boreal swamps occur on floodplains or in landscape depressions where poor drainage maintains high water tables but there is subsurface water movement that provides nutrients and oxygen to the rooting zone.
Climate: This division occurs in a boreal climate. Summers are short; winters long; and there can be a large difference between the coldest and warmest temperatures. Precipitation regimes also vary: the driest areas in the western parts of the range receive as low as 165 mm annually, while the wettest areas in the south and east can receive as much as 1200 mm. Higher elevations and northern regions have cooler temperatures overall. In the western Cordillera, continental effects are modified where higher elevations and mountainous terrain produce cooler summers, warmer winters and more precipitation than is characteristic of areas in the Interior Plains. The Atlantic boreal has a strong maritime influence, with more moderate temperature extremes and high annual precipitation, including considerable snowfall (up to 400 cm). Decreasing temperatures reduce the amount of evapotranspiration, consequently wetland frequency and areal extent generally increase northward on sites with poor drainage. Southward, treed peatlands may be limited by warming temperatures, where decomposition exceeds accumulation.
Soils/substrate: Forested poor swamps have organic soils with shallow to deep, poorly to moderately decomposed peat, generally over finer-textured parent materials or in bedrock depressions. Richer swamps have a surface layer of well-decomposed peat over mineral parent materials and generally show evidence of a shallow or fluctuating water table. Riparian soils comprise fine- to coarse-textured mineral sediments, with little to no humus development and often show evidence of past flooding.
Biogeography: The primary tree species (Larix laricina, Picea mariana, Populus balsamifera) are fairly consistent across the range of this type. Betula papyrifera and Populus tremuloides occur infrequently across the range. Abies balsamea occurs in the central and eastern range, whereas Picea glauca is more prevalent in the west. In the southern part of the range, Acer negundo is found in the central region, and Fraxinus nigra, Thuja occidentalis, and Ulmus americana occur in the east.
Riparian forests occur along watercourses, adjacent to medium and large rivers where annual flooding takes place and a subsurface water table or seepage supplies nutrient-rich water to the mineral substrate of the site. Boreal swamps occur on floodplains or in landscape depressions where poor drainage maintains high water tables but there is subsurface water movement that provides nutrients and oxygen to the rooting zone.
Climate: This division occurs in a boreal climate. Summers are short; winters long; and there can be a large difference between the coldest and warmest temperatures. Precipitation regimes also vary: the driest areas in the western parts of the range receive as low as 165 mm annually, while the wettest areas in the south and east can receive as much as 1200 mm. Higher elevations and northern regions have cooler temperatures overall. In the western Cordillera, continental effects are modified where higher elevations and mountainous terrain produce cooler summers, warmer winters and more precipitation than is characteristic of areas in the Interior Plains. The Atlantic boreal has a strong maritime influence, with more moderate temperature extremes and high annual precipitation, including considerable snowfall (up to 400 cm). Decreasing temperatures reduce the amount of evapotranspiration, consequently wetland frequency and areal extent generally increase northward on sites with poor drainage. Southward, treed peatlands may be limited by warming temperatures, where decomposition exceeds accumulation.
Soils/substrate: Forested poor swamps have organic soils with shallow to deep, poorly to moderately decomposed peat, generally over finer-textured parent materials or in bedrock depressions. Richer swamps have a surface layer of well-decomposed peat over mineral parent materials and generally show evidence of a shallow or fluctuating water table. Riparian soils comprise fine- to coarse-textured mineral sediments, with little to no humus development and often show evidence of past flooding.
Biogeography: The primary tree species (Larix laricina, Picea mariana, Populus balsamifera) are fairly consistent across the range of this type. Betula papyrifera and Populus tremuloides occur infrequently across the range. Abies balsamea occurs in the central and eastern range, whereas Picea glauca is more prevalent in the west. In the southern part of the range, Acer negundo is found in the central region, and Fraxinus nigra, Thuja occidentalis, and Ulmus americana occur in the east.
Geographic Range: This division occurs across the boreal regions of Canada and Alaska extending into parts of the northern Great Lakes states and glaciated areas of the northeastern U.S.
Nations: CA,US
States/Provinces: AB, AK, BC, LB, MB, ME?, MI?, MN?, NB?, NH?, NS?, NT, NU, NY?, ON, PE?, QC, SK, VT?, WI?, YT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860279
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.5 Boreal Flooded & Swamp Forest Formation | F036 | 1.B.5 |
| Division | 1.B.5.Na North American Boreal Flooded & Swamp Forest Division | D016 | 1.B.5.Na |
| Macrogroup | 1.B.5.Na.1 North American Boreal Conifer Poor Swamp Macrogroup | M299 | 1.B.5.Na.1 |
| Macrogroup | 1.B.5.Na.2 North American Boreal Flooded & Rich Swamp Forest Macrogroup | M300 | 1.B.5.Na.2 |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: < Swamp (National Wetlands Working Group 1997) [The definition of swamp in this publication includes all of the types included in this division, but also extends to non-boreal swamp types.]
- Banton, E., H. Lee, G. Racey, P. Uhlig, and M. Wester. 2008. Ecosystems of Ontario: Provincial ecosites. Draft April 29, 2008. Ecological Land Classifications Working Group. Ontario Ministry of Natural Resources.
- 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]
- Harris, A. G., S. C. McMurray, P. W. C. Uhlig, J. K. Jeglum, R. F. Foster, and G. D. Racey. 1996. Field guide to the wetland ecosystem classification for northwestern Ontario. Ontario Ministry of Natural Resources, Northwest Science and Technology, Thunder Bay, Ontario. Field guide FG-01. 74 pp. plus appendix.
- MacKenzie, W. H., and J. R. Moran. 2004. Wetlands of British Columbia: A guide to identification. Land Management Handbook No. 52. Research Branch, British Columbia Ministry of Forests and Lands, Victoria, BC. 287 pp.
- National Wetlands Working Group. 1997. Wetlands of Canada. C. D. A. Rubec, editor. Ecological Land Classification Series No. 24. Environment Canada, Ottawa, and Polyscience Publications, Inc., Montreal. 452 pp.
- Rydin, H., and J. K. Jeglum. 2013. The biology of peatlands. Second edition. Oxford University Press, Inc., New York. 382 pp.