Invalid Unit Specified
M063 Pinus contorta var. contorta / Ledum groenlandicum / Carex cusickii North Pacific Bog & Fen Macrogroup

The U.S. National
Vegetation Classification
Type Concept Sentence: This macrogroup contains alkaline, acidic, and neutral peatlands (fens and bogs) that occur throughout southern Alaska (including the Aleutian Islands), maritime British Columbia, Washington, Oregon, and northern California. The vegetation is low-shrub or graminoid physiognomy, or stunted coastal Pacific tree species, and nearly all examples have a moss-dominated ground layer.
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Common (Translated Scientific) Name: Beach Pine / Bog Labrador-tea / Cusick's Sedge North Pacific Bog & Fen Macrogroup
Colloquial Name: North Pacific Bog & Fen
Hierarchy Level: Macrogroup
Type Concept: This macrogroup contains acidic to alkaline peatlands (bogs and fens) with low-growing shrubs, stunted trees, or dense herbaceous structure, or a mosaic of physiognomic types; nearly all have a moss-dominated ground layer. Indicator shrub and herbaceous species include Betula nana, Carex aquatilis, Carex cusickii, Carex limosa, Carex livida, Carex utriculata, Comarum palustre, Kalmia microphylla, Ledum spp., Menyanthes trifoliata, Myrica gale, Salix pulchra, Spiraea douglasii, and many others. The ground layer is usually very thick with Sphagnum moss or "brown mosses" such as Campylium, Drepanocladus, Scorpidium, Tomentypnum, and Warnstorfia. Stunted tree species present may include Callitropsis nootkatensis, Pinus contorta var. contorta, Picea sitchensis, Thuja plicata, and/or Tsuga heterophylla. This macrogroup occurs throughout southern Alaska (including the Aleutian Islands), maritime British Columbia, Washington, Oregon, and northern California. This includes lowlands such as the Puget Sound lowlands and higher montane and subalpine elevations in the coastal mountains, the Sierra Nevada, and the Klamath-Siskiyou mountains. The macrogroup is not limited to coastal/maritime areas. Elevations are mostly under 457 m (1500 feet). The macrogroup includes well-developed bogs, raised bogs, "poor" (aka acidic) and "rich" (aka alkaline), as well as neutral fens. Soils are deep (>40 cm) organic, and are usually saturated throughout the growing season. Sites include serpentine- and ultramafic-influenced peatlands in northern California. Water sources include mineral-rich groundwater (fens) to only that of precipitation (bogs).
Diagnostic Characteristics: Saturated organic soils >40 cm deep; ground layer dominated by Sphagnum spp., brown mosses or liverworts. Dominance by indicator species, including Betula nana, Carex aquatilis, Carex cusickii, Carex limosa, Carex livida, Carex utriculata, Comarum palustre, Kalmia polifolia, Ledum spp., Menyanthes trifoliata, Myrica gale, Salix pulchra, and Spiraea douglasii. The distinctive scrubby tree species present may include Callitropsis nootkatensis, Pinus contorta var. contorta, Picea sitchensis, Thuja plicata, and/or Tsuga heterophylla.
Rationale for Nominal Species or Physiognomic Features: Ledum groenlandicum helps to distinguish this type from Rocky Mountain fens in ~Rocky Mountain Fen Macrogroup (M064)$$, though it is common across boreal peatlands of ~North American Boreal & Sub-Boreal Acidic Bog & Fen Macrogroup (M876)$$. Carex cusickii was suggested by Joe Rocchio (pers. comm. 2014). Pinus contorta var. contorta is a distinctive Pacific coastal scrub tree species.
Classification Comments: These peatlands are distinguished from boreal and interior continental bogs and fens by the presence of Pacific coastal species and a maritime-moderated climate. Its primary distinctiveness relative to boreal peatlands and Rocky Mountain peatlands appears to be from the distinctive tree composition of the scrub layer. Further review is needed. Its occurrence in western Nevada should be checked, as sites may be more similar to Rocky Mountain fens (J. Rocchio pers. comm. 2014). If this macrogroups is accepted as distinct from former Rocky Mountain Fen Macrogroup (M064) [subsequently split into North American Boreal & Subboreal Bog & Acidic Fen Macrogroup (M876) and North American Boreal & Subboreal Alkaline Fen Macrogroup (M877)], then it may need to be listed for northwestern Montana and parts of northern Idaho (L. Vance pers. comm. 2014).

Some ecologists would have liked to lump North Pacific Bog & Fen Macrogroup (M063) with former Rocky Mountain Fen Macrogroup (M064), as the species composition can be very similar. There are several reasons to keep them separate: (a) the bogs and fens of M063 have a warmer climate, with maritime influences in some areas, and therefore have higher rates of growth and decomposition, and M063 is a more dynamic macrogroup than this colder Rocky Mountain counterpart; (b) montane fens in the North Pacific may have more floristic overlap with M064, but the lowlands of M063 are floristically distinct due to maritime climate and occurrence of ombrotrophic bogs which are not found in M064; and (c) Sierra Nevada fens in California should be placed here in M064.

Within the macrogroup, there are three main types of fens by water chemistry: (1) alkaline or "rich" fens (pH >6.5 or 7.0), generally associated with calcareous bedrock; (2) intermediate fens (pH 5.0-6.5), generally associated with granitic bedrock, which represent the majority of our fens; and (3) acidic fens (pH <5.0). The acidic fens have sometimes been called poor fens, but that doesn't quite fit because they can have very high ionic concentrations. Our most acidic fens are associated with geologic sources of acid, either from iron pyrite (iron fens) or geothermal venting (geothermal fens). The fens that are most similar to classic "poor" fens are best considered as the low pH end of the intermediate fen category and are most often basin fens in granite landscapes where there is little input of ions (J. Lemly pers. comm. 2014).

This is a reasonable macrogroup to be separated from boreal/subboreal and Vancouverian fens and bogs. However, the species of these fens can be wide-ranging, at least in the Pacific Northwest. It is true, as noted, that the coastal fens are under a milder climate--if you look at MacKenzie and Moran (2004), the Wf associations between coastal and interior areas are mostly a difference in Carex aquatilis var. dives (= Carex sitchensis) (Kartesz 1999) versus Carex aquatilis, which are combined by some. However, the acidic fens for the Pacific maritime areas include some of the British Columbia "bogs" and here there are additional species to characterize the Pacific area--and in the hypermaritime, the acidic fen-bogs are extensive, and can occur on quite steep slopes and in unusual slope positions (crests). They are unique in a global perspective and likely warrant recognition at a high level of the classification. As noted, the environmental drivers are also quite different between these extensive coastal bog-fens and fens of the interior (D. Meidinger pers. comm. 2014).
Similar NVC Types:
M876 North American Boreal & Subboreal Bog & Acidic Fen, note: "includes acidic peatlands (bogs and poor fens) that occur in much colder climates of the north and interior relative to members of M063, which have a more moderate maritime-influenced climate, but M876 currently includes Atlantic maritime climates."
M877 North American Boreal & Subboreal Alkaline Fen, note: "includes alkaline peatlands (circumneutral to alkaline fens) that occur in much colder climates of the north and interior, relative to members of M063, which have a more moderate maritime-influenced climate, but M877 currently includes Atlantic maritime climates."
Physiognomy and Structure: Vegetation is predominantly dwarf-shrubs or herbaceous (vascular or nonvascular) plants with a moss-dominated ground layer. Stunted trees may be present or a mosaic of patches of stunted trees amongst the mostly herbaceous area.
Floristics: Acidic fen herbaceous species include Carex anthoxanthea, Carex aquatilis var. dives (= Carex sitchensis), Carex limosa, Carex pauciflora, Carex pluriflora, Comarum palustre, Cornus canadensis, Dodecatheon pulchellum, Drosera rotundifolia, Geum calthifolium, Nephrophyllidium crista-galli, Parnassia kotzebuei, Rubus chamaemorus, and Sanguisorba menziesii. Moss species include Sphagnum fuscum, Sphagnum austinii, Sphagnum henryense, Sphagnum pacificum, Sphagnum papillosum, Sphagnum rubellum, Sphagnum mendocinum, and Philonotis fontana var. americana. Liverworts include species of Nardia, Marsupella, and Scapania. Shrub species include Andromeda polifolia, Betula nana, Empetrum nigrum, Kalmia microphylla, Ledum groenlandicum, Ledum palustre ssp. decumbens, Myrica gale, Salix pulchra, Vaccinium cespitosum, Vaccinium oxycoccos, and Vaccinium uliginosum. Stunted (<5 m) tree species, if present, include Callitropsis nootkatensis (= Cupressus nootkatensis), Picea sitchensis, Pinus contorta var. contorta, Pinus monticola, Thuja plicata, Tsuga heterophylla, or Tsuga mertensiana.

Neutral to alkaline fens may have brown mosses such as Campylium, Drepanocladus, Scorpidium, Tomentypnum, and Warnstorfia. Indicator species include Betula nana, Carex aquatilis, Carex cusickii, Carex lasiocarpa, Carex livida, Carex utriculata, Comarum palustre, Menyanthes trifoliata, Myrica gale, Spiraea douglasii. Trees may be present at the edges or on raised hummocks where soils are not anoxic and include Tsuga heterophylla, Thuja plicata, Callitropsis nootkatensis, Pinus contorta var. contorta, and/or Picea sitchensis.

Along the coast, Pinus contorta does not occur north of Juneau in southeastern Alaska; however, further inland it does occur much farther north in the Yukon Territory. Treed bogs in the Pacific Northwest have mostly Pinus contorta var. contorta or Callitropsis nootkatensis but can include some Tsuga heterophylla, Tsuga mertensiana, or Thuja plicata. Ledum groenlandicum is generally the dominant shrub understory species; other shrubs include Vaccinium uliginosum, Juniperus communis, Myrica gale, or Gaultheria shallon. Low-shrub species include Empetrum nigrum, Kalmia microphylla, and Rubus chamaemorus. Herbaceous species include sedges such as Eriophorum angustifolium, Trichophorum cespitosum, Carex livida, or herbs such as Sanguisorba officinalis, Triantha glutinosa, or Drosera rotundifolia. Dominant bryophytes include Sphagnum spp. and Racomitrium lanuginosum.

Floristic information was summarized from the following sources: Shacklette et al. (1969), Knight et al. (1970), Thorne (1976), Sawyer et al. (1978), Slack (1979), Eyre (1980), Kruckeberg (1984), Banner et al. (1986, 1988, 1993), Keeler-Wolf (1986), Sawyer (1986), DeMeo et al. (1992), Viereck et al. (1992), Kunze (1994), Talbot and Talbot (1994), Jimerson et al. (1995), Martin et al. (1995), Shephard (1995), DeVelice et al. (1999), Boggs et al. (2003, 2008a, 2008b), Kagan et al. (2004), MacKenzie and Moran (2004), Talbot et al. (2006), and Fleming and Spencer (2007).
Dynamics: Natural disturbance events along north coastal peatlands play an important role in slowing and reducing organic matter accumulation on specific types of sites. The main types of natural disturbance are landslides, windthrow, and fluvial activity (Banner et al. 2005). Peatlands on steep slopes experience landslides and windthrow events which tend to mix soil and slow the buildup of organic layers. On more gentle terrain, disturbance is less frequent, which allows for a deep accumulation of organic matter. Disturbance here is of small and localized scale. Large-scale disturbance such as major blowdown or severe fire are infrequent (>1000 years).

Fire, when it does occur, stimulates growth of mosses that prefer bare substrates, and starts the successional sequence of different mosses and vascular plants. Fires also increase nutrient availability and may temporarily create a carbon sink. Fire scars on stumps within herbaceous bogs and fens have been observed, pointing to a need for more study (Banner et al. 2005, J. Rocchio pers. comm. 2013). It has been documented that Native Americans burned herbaceous wetlands of the Olympic Peninsula annually to keep trees from invading wetland openings (Anderson 2009).

In addition to disturbance, there are natural cycles and interplay between the advancement and retreat of peat levels (the buildup of peat that alters depth of rooting zone relative to groundwater, or decrease in peat depth from an increase decomposition due to drought) and encroachment peat into surrounding uplands (paludification) or the reverse, surrounding upland species that may shade out moss species. Generally, the greatest (annually measurable) change generally occurs on the edges of fens and bogs and at the tops of hummocks. These small-scale dynamics depend on the type of wetland and specific local site characteristics that cannot be generalized in a group description. Some examples are given here. In Alaska, species that dominate the early stages of succession in newly formed ponded basins include Equisetum variegatum, Equisetum fluviatile, and Comarum palustre, while Sphagnum species invade the surface and help in forming peat. Acidic and nutrient-poor-tolerant vascular species eventually dominate such sites, including Myrica gale, Empetrum nigrum, Vaccinium uliginosum, Andromeda polifolia, and Vaccinium oxycoccos. The late-successional stage of a peatland supports various community types, depending on the pH, waterflow, and nutrient status of a site, such as Myrica gale / Empetrum nigrum and Picea sitchensis / Sphagnum plant associations. Peat buildup, patterned ground, and changes in water table are recurrent aspects of peatland development rather than unidirectional successional events. For this reason it is unlikely that any of the late-seral peatland communities are stable in the sense of climax vegetation (K. Boggs and T. Boucher pers. comm. 2008). In Washington, some fens can be indefinitely maintained by groundwater discharge; sometimes succession from rich fen to poor fen/bog may occur in these situations but often is dependent on water chemistry and level of discharge and fire (J. Rocchio pers. comm. 2012).

Treed bogs of the Pacific Northwest represent forests with soils that have taken hundreds to thousands of years to develop, a topoedaphic climax that is relatively stable over time. Tree regeneration frequently occurs on raised organic microsites on the remains of previous trees. Tree growth is very slow. Longer-term succession is probably influenced by paludification and climatic patterns that dictate drainage, either favoring poorer drainage, increased tree mortality, and more open canopy; or improved drainage, greater tree growth, and a more closed canopy. These patterns can also favor individual tree species based on their tolerance or intolerance of wet soils. The widespread yellow-cedar decline, which covers 200,000 ha in southeastern Alaska, is an example of a climate-induced tree death that has resulted in a composition shift away from yellow-cedar due to this mortality (Hennon et al. 2008). Windthrow can cause soil mixing that reverses the paludification processes on a small scale, where productivity may be increased (Banner et al. 2005).
Environmental Description: Soils are deep (>40 cm), organic, and are usually saturated throughout the growing season. Organic soil may overlay mineral soils and may be floating or submerged. Fens are alkaline, neutral and acidic. This macrogroup also includes bogs, deep peatlands that do not interact with groundwater. Peatland elevations are mostly under 457 m (1500 feet), and annual precipitation ranges from 890-3050 mm (35-120 inches); however, some types occur higher than 500 m (1650 feet). Within Washington, they are prominent within areas affected by continental and alpine glaciation, especially in the Puget Basin where glaciation has left kettle and glacial scours that currently support bogs and basin fens (J. Rocchio pers. comm. 2014). In Alaska hypermaritime site organic soils are characterized by an abundance of sodium cations from oceanic spray. Soils are deep (>40 cm), organic, acidic (pH <5.5) and are usually saturated throughout the growing season. Organic soil may overlay mineral soils and may be floating or submerged. Alkaline and acidic fens can be intermixed with bogs. California fens have a more Mediterranean climate of hot summers and mild, cool winters. Some fens occur on serpentine and ultramafic soils. Fens occur in river valleys, in basins, around lakes and marshes, or on gentle to steep slopes. These wetlands are relatively abundant in Alaska and British Columbia but diminish rapidly in size and number farther south. They occur in river valleys, around lakes and marshes or on slopes. Treed bogs and poor fens may grade into drier upland forest on mineral soil, or adjacent shrubland or herbaceous poor fen and bogs, or grade into wetter non-treed fens, which have richer soil water (higher pH).

Environmental information was summarized from the following sources: Shacklette et al. (1969), Knight et al. (1970), Thorne (1976), Sawyer et al. (1978), Slack (1979), Eyre (1980), Kruckeberg (1984), Banner et al. (1986, 1988, 1993), Keeler-Wolf (1986), Sawyer (1986), DeMeo et al. (1992), Viereck et al. (1992), Kunze (1994), Talbot and Talbot (1994), Jimerson et al. (1995), Martin et al. (1995), Shephard (1995), DeVelice et al. (1999), Boggs et al. (2003, 2008a, 2008b), Kagan et al. (2004), MacKenzie and Moran (2004), Cooper and Wolf (2006), Talbot et al. (2006), and Fleming and Spencer (2007).
Geographic Range: This wetland type is relatively abundant in southeastern Alaska and maritime British Columbia but diminishes rapidly in size and number farther south. It includes peatlands along the Pacific coast from the Aleutian Islands, Alaska Peninsula, Kodiak Islands, southern and southeastern coastal Alaska, coastal British Columbia south to northern California. It also includes peatlands found in the Puget Sound lowlands, in the coastal mountains and montane to subalpine elevations of the Cascades and the Klamath-Siskiyou mountains.
Nations: CA, US
States/Provinces: AK, BC, CA, OR, WA
US Forest Service Ecoregions (2007)
Domain Name:
Division Name:
Province Name: Sierran Steppe - Mixed Forest - Coniferous Forest - Alpine Meadow Province
Province Code: M261    Occurrence Status: Confident or certain
Section Name: Willamette Valley Section
Section Code: 242B     Occurrence Status: Confident or certain
Omernik Ecoregions:
Plot Analysis Summary:
Confidence Level: High
Confidence Level Comments:
Grank: GNR
Greasons:
Name:Database Code:Classification Code:
Class 2 Shrub & Herb Vegetation C02 2
Subclass 2.C Shrub & Herb Wetland S44 2.C
Formation 2.C.2 Temperate to Polar Bog & Fen F016 2.C.2
Division 2.C.2.Na North American Bog & Fen D029 2.C.2.Na
Macrogroup M063 North Pacific Bog & Fen M063 2.C.2.Na.3
Group G610 North Pacific Maritime Wooded Bog & Poor Fen G610 2.C.2.Na.3.c
Group G285 North Pacific Alkaline Open Fen G285 2.C.2.Na.3.a
Group G284 North Pacific Acidic Open Bog & Fen G284 2.C.2.Na.3.b
Concept Lineage:
Predecessors:
Obsolete Names:
Obsolete Parents:
Synonomy: < Peatlands (Mitsch and Gosselink 2000) [Discusses only boreal peatlands, but concept is the same, on a smaller scale for Pacific coast lowlands and montane bogs and fens with floristics that are similar but also with regional differences.]
< Peatlands (Barbour and Billings 2000) [Discusses only boreal peatlands, but concept is the same, on a smaller scale for Pacific coast lowlands and montane bogs and fens with floristics that are similar but also with regional differences.]
Concept Author(s): Kittel, M. Reid, K. Boggs, and T. Boucher, in Faber-Langendoen et al. (2014)
Author of Description: G. Kittel and D. Meidinger
Acknowledgements: We have incorporated significant descriptive information previously compiled by K. Boggs, T. Boucher, and T. Keeler-Wolf.
Version Date: 29Mar2017
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