forests, lands, natural resource operations and rural ...shrub layer (10 - 35 - 95) salix barclayi...

Chapter 5.2

Fens79

.. Distribution of Fen Site Associations by biogeoclimatic zone

BG BWBS SBPSPP SWB ESSF ICH IDF MS SBS CDF CWH MH

Wf01 Water sedge – Beaked sedge xx x xx xxx xxx xxx xi

Wf02 Scrub birch – Water sedge xxx x xx xx xx xxWf03 Water sedge – Peat-moss xx xWf04 Barclay’s willow – Water sedge – Glow mosss x xxx x xWf05 Slender sedge – Common hook-moss x xx xx xx xxWf06 Slender sedge – Buckbean x x x xWf07 Scrub birch – Buckbean – Shore sedge x x x xWf08 Shore sedge – Buckbean – Hook-moss x x x x xWf09 Few-flowered spike-rush – Hook-moss x x xWf10 Hudson Bay clubrush – Red hook-moss xWf11 Tufted clubrush – Star moss x x x x xWf12 Narrow-leaved cotton-grass – Marsh-marigold xxxWf13 Narrow-leaved cotton-grass – Shore sedge xx xWf50 Narrow-leaved cotton-grass – Peat-moss x xxxWf51 Sitka sedge – Peat-moss x xx xxWf52 Sweet gale – Sitka sedge xx xxs

Wf53 Slender sedge – White beak-rush x xxs

x = incidental; < 5% of wetlands xx = minor; 5–25% of wetlands xxx = major; >25% of wetlands

i = inland areas only s = southern subzones only

Source publicationLMH 52

80 Wetlands of British Columbia: A Field Guide to Identification

.. Fen Species Importance Table

Species Wf01 Wf02 Wf03 Wf04 Wf05 Wf06 Wf07 Wf08

Shrubs Betula nana x xyzzz x xy x x xyzzz xSalix barclayi x x xyzzzz

Salix pedicellaris x xyz xy xy xyzz xySpiraea douglasii x x x x

Myrica gale

Herbs Carex utriculata xyzzz xyz xy xy xyz x x xand Carex aquatilis xyzzz xyzz xyzzz xyzz xyz x xyz xDwarf Comarum palustre xy xyz xy xy xy xyzz xyShrubs Calamagrostis canadensis x xy x xyzz x x x x

Carex lasiocarpa x xyzzzz xyzzzz xy xMenyanthes trifoliata x x x xyzzz xyzzz xyzz

Carex limosa x x x x xy xyzz xyzzzCarex chordorrhiza x x xy xyz xy

Eleocharis quinqueflora x xTrichophorum alpinum x

Trichophorum cespitosumEriophorum angustifolium x xy xy x x xy xy

Caltha leptosepala xy xyCarex anthoxantheaEquisetum fluviatile x x xy xy xy xy

Carex magellanica x xCarex sitchensis xy xy xyz xyz x x

Rhynchospora alba xCarex livida x x x x

Eriophorum chamissonis x x xVahlodea atropurpurea x

Drosera anglica x x xyHypericum anagalloides

Triantha glutinosa x x xySchoenoplectus tabernaemontani

Fauria crista-galliSenecio triangularis x x xyz xy

Andromeda polifolia x xy xyKalmia microphylla x x xOxycoccus oxycoccos x x x x xy xTriglochin maritima x x x xy xyDrosera rotundifolia x x x

Leptarrhena pyrolifolia xy xPlatanthera dilatata x xy x x x

Sanguisorba canadensis x xyUtricularia intermedia x x x xy

Viola palustris x x x

Lichens Sphagnum Group I xy xyz xyzz x x xyz xand Aulacomnium palustre x xyz xyz xyzz x x x xMosses Drepanocladus spp. xyz x xy xyzz xyz xyz xyz

Sphagnum Group II x xyz x x xyz xyTomentypnum nitens x xyzz xyz xy x xyz xy

Philonotis fontana xy xyzCalliergon stramineum x x x x x

Scorpidium spp. x xy xyzz xyCampylium stellatum x x xy xy x x

Warnstorfia spp. x xy x x xyz x xyMeesia triquetra x x xy xy

General Description

Barclay’s willow – Water sedge – Glow moss fen/swamps arecommon at subalpine elevations of the Sub-Boreal Interior,Southern Interior Mountains, and Northern Boreal Moun-tains. They occur on subalpineseepage slopes, along glacier-fedcreeks, and in frost-prone basins.

Salix barclayi dominates the shrublayer with a scattering of other low shrubspecies. Carex aquatilis dominates the herblayer but is often accompanied by scatteredhigh-elevation species such as Caltha lep-tosepala, Eriophorum angustifolium, andLeptarrhena pyrolifolia. The moss layer can be absent or moderately well developed.

Continuous (often copious) groundwater or snowmelt seepage is typical,and soils are cold. Peat is often shallow because of low biomass produc-tion but occasionally deep sedge peat deposits are encountered.Common soil types include terric Mesisols, Humisols, and Fibrisols

Characteristic Vegetation

Tree layer (0 - .5 - 3)Shrub layer (10 - 35 - 95)Salix barclayiHerb layer (26 - 65 - 99)Calamagrostis canadensis, Carex aquatilis,C. sitchensisMoss layer (0 - 15 - 95)Aulacomnium palustre, Mnium spp.,Philonotis fontana

Comments

Wf 04 can occur alone or surrounding sedgeor cotton-grass fens (Wf 03 or Wf12), or inwet depressions within forb-rich subalpinemeadows or carrs.The similar Sc03 is alsocommon at high elevations in the Interior.However, the Sc03’s low shrub physiognomyis the result of cold-air drainage not wet soils,and it is characterized by subalpine forbs with few hydrophytes.

Chapter 5.2 Fens 85

Barclay’s willow – Water sedge – Glow moss Wf 04

Salix barclayi – Carex aquatilis – Aulacomnium palustre

Wetland Edatopic Grid

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Soil Nutrient Regime

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Chapter 5.2

Fens79














Myrica gale






















General Description

Slender sedge – Common hook-moss fens are commonthroughout the Interior at elevations below 1400 m. Thesefens occur on peat flats surrounding small lakes and ponds or

in infilled palustrine basins. Pro-longed shallow surface flooding andcontinual surface peat saturation are typical.

Carex lasiocarpa and Drepanocladus aduncusare constant dominants. Other large watersedges, such as C. aquatilis and C. utriculata,are also common. There can be a very sparseshrub cover of Salix pedicellaris, S. candida, orBetula nana. The moss layer is usually well developed but is occasionally absent. Hook-

mosses usually dominate with occasional inclusions of other brownmosses.

Deep peat deposits are common but some sites may occur on thin or-ganic veneers. Mesisols are the most common soil type but Humisolsand Fibrisols also occur.


Tree layer (0 - 0 - 0)Shrub layer (0 - 3 - 10)Herb layer (13 - 60 - 100)Carex aquatilis, C. lasiocarpa, C. utriculataMoss layer (0 - 55 - 100)Drepanocladus aduncus

Comments

Some Wf 05 sites are marsh-like with deepflooding, low diversity, and virtually no mosslayer.The related Wf 06 occurs on floatingmats with a more equable water regime andhummock/hollow topography. Slender-sedge fens (Wf 05, Wf 06) occur in locationssimilar to the Wf 01 but seem to representsites with longer surface saturation and morebasic soil water. Similar sites in coastal areasare described by the Wf53.


Wf 05 Slender sedge – Common hook-moss

Carex lasiocarpa – Drepanocladus aduncus


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Chapter 5.3

Marshes

105

.. Distribution of Marsh Site Associations by biogeoclimatic zone


Wm01 Beaked sedge – Water sedge x xx x xxx xxx xx xx xWm02 Swamp horsetail – Beaked sedge x x x x xxWm03 Awned sedge x xWm04 Common spike-rush x x xx x x xx xWm05 Cattail xxx x xx xx x xx xx xs

Wm06 Great bulrush xxx x x xx xx x x xWm07 Baltic rush x xxWm50 Sitka sedge – Hemlock-parsley xx xxWm51 Three-way sedge x x x


s = southern subzones only



.. Marsh Species Importance Table

Species Wm01 Wm02 Wm03 Wm04 Wm05

Herbs Carex utriculata xyzzz xyzzz x xyand Carex aquatilis xyzz xy xDwarf Equisetum fluviatile x xyzzzz xShrubs Comarum palustre xy xy x

Sium suave x xyCarex exsiccata x

Carex atherodes xyzzzzPolygonum amphibium x x xy x x

Eleocharis palustris x xyzzzz xPotamogeton richardsonii xyz

Typha latifolia x xyzzzzSchoenoplectus acutus xMenyanthes trifoliata

Utricularia macrorhiza x x x x xJuncus balticus x x

Hordeum jubatum xPotentilla anserina x

Calamagrostis canadensis xy x xy xCicuta douglasii x x

Lysichiton americanus xOenanthe sarmentosa x

Galium trifidum xSpiraea douglasii x

Carex sitchensisNuphar lutea ssp. polysepala x x

Dulichium arundinaceum

Mosses Drepanocladus spp. xy xy xy x xWarnstorfia spp. x x x x x

General Description

Beaked sedge – Water sedge marshes constitute the most common and widespread Marsh Site Association in theprovince. The Wm01 occurs in all subzones from low to sub-alpine elevations on sites that are inundated by shallow,

low-energy floodwaters and that experiencesome late-season drawdown. These marshes arefound in a wide variety of landscape positionsincluding flooded beaver ponds, lake margins,floodplains, and palustrine basins.

Species diversity is low and plant cover isstrongly dominated by Carex utriculata and C. aquatiliswith scattered forbs, aquatics, and mosses. On sites experi-encing significant surface drying, species diversity increasesand sites become more meadow-like. Species such as Cala-magrostis canadensis, Geum macrophyllum, or Deschampsiacespitosa can become prominent.

The Wm01 occurs over a wide range of site conditions onmineral substrates with thin peat veneers. Common soil

types include Gleysols and Terric Humisols.


Tree layer (0 - 0 - 0)Shrub layer (0 - 0 - 5)Herb layer (13 - 80 - 100)Carex aquatilis, C. utriculataMoss layer (0 - 5 - 100)

Comments

The Wf 01 and Wm01 have similar plant com-munities, but, because these units arespecies-poor and the two dominant sedgespecies have a wide ecological amplitude, theplant community poorly differentiates betweensites on peat (Wf 01) and those on mineral soil(Wm01). In general, the Wm01 is more deeplyflooded, has more dynamic hydrology, and has a higher cover of C. utriculata.

The Wm02 is another similar community that occurs on more hydrologically dynamic loca-tions such as lake margins or floodplains. In cooler climates the Wm01 frequently develops intoWf 01 on sites with less dynamic hydrology.

Some Wm01 sites have scattered tall shrubs; those sites supporting > 10% shrub cover are de-scribed by Swamp Site Associations (Section 5.4).



Wm01 Beaked sedge – Water sedge

Carex utriculata – Carex aquatilis

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Chapter 5.2

Fens79














Myrica gale






















General Description

The Shore sedge – Buckbean – Hook-moss is an uncommon,rich Fen Site Association that occurs mainly at higher eleva-tions throughout the Interior (700–1800 m) in coldersubzones. These fens occur on pond-side floating mats or inflarks of patterned fens where there is prolonged shallowflooding to no more than severalcentimetres.

Carex limosa rooted in shallowwater is the constant dominant on these sites.Menyanthes trifoliata occurs on most sites butcan be very sparse or absent on some. A diversity of species tolerant of permanent sat-uration such as Carex chordorrhiza, Equisetumfluviatile, and Andromeda polifolia commonlyoccur with low cover.

Peat deposits are shallow (0.5 m) to very deep (> 6 m), fibric or mesic,and derived from fine sedges and brown mosses. Fibrisols are the mostcommon soil type.


Tree layer (0 - 0 - 0)Shrub layer (0 - .5 - 10)Herb layer (14 - 35 - 100)C. limosa, Menyanthes trifoliataMoss layer (1 - 85 - 100)Drepanocladus spp.

Comments

This is the most common and dominant SiteAssociation in patterned fens. In weakly pat-terned fens, the Wf 08 occurs over ribs andflarks. Where there is a more pronouncedrib/flark pattern, the Wf 08 will typicallyoccur in flarks and the floristically similar,shrubby Wf 07 on elevated ribs.

The Wf 06 occurs on wetter and more hydrologically dynamic sites than the Wf 08. Similarlystagnant sites with acidic soil water are occupied by the Wb13.The Wf 08 has similar hydrolo-gy to the Wf 09 and Wf10, but with more mobile groundwater and greater degree of surfaceflooding. Wf 08 sites may become Wb13 sites in some circumstances.Peat deposits are often consistent throughout the profile, and peat core contents of fine sedgeand brown mosses are readily identifiable.This suggests that these ecosystems can be stableand long-lived.

Chapter 5.2 Fens 89

Shore sedge – Buckbean – Hook-moss Wf 08

Carex limosa – Menyanthes trifoliata – Drepanocladus


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Chapter 5.3

Marshes

105

.. Distribution of Marsh Site Associations by biogeoclimatic zone


Wm01 Beaked sedge – Water sedge x xx x xxx xxx xx xx xWm02 Swamp horsetail – Beaked sedge x x x x xxWm03 Awned sedge x xWm04 Common spike-rush x x xx x x xx xWm05 Cattail xxx x xx xx x xx xx xs

Wm06 Great bulrush xxx x x xx xx x x xWm07 Baltic rush x xxWm50 Sitka sedge – Hemlock-parsley xx xxWm51 Three-way sedge x x x


s = southern subzones only



.. Marsh Species Importance Table

Species Wm01 Wm02 Wm03 Wm04 Wm05

Herbs Carex utriculata xyzzz xyzzz x xyand Carex aquatilis xyzz xy xDwarf Equisetum fluviatile x xyzzzz xShrubs Comarum palustre xy xy x

Sium suave x xyCarex exsiccata x

Carex atherodes xyzzzzPolygonum amphibium x x xy x x

Eleocharis palustris x xyzzzz xPotamogeton richardsonii xyz

Typha latifolia x xyzzzzSchoenoplectus acutus xMenyanthes trifoliata

Utricularia macrorhiza x x x x xJuncus balticus x x

Hordeum jubatum xPotentilla anserina x

Calamagrostis canadensis xy x xy xCicuta douglasii x x

Lysichiton americanus xOenanthe sarmentosa x

Galium trifidum xSpiraea douglasii x

Carex sitchensisNuphar lutea ssp. polysepala x x

Dulichium arundinaceum

Mosses Drepanocladus spp. xy xy xy x xWarnstorfia spp. x x x x x

General Description

The Swamp horsetail – Beaked sedge Marsh Site Association isuncommon at lower elevations throughout the Interior. Com-mon locations are in back-levee depressions along sediment-laden, low-gradient streams, protected bays of large lakes, orhydrologically modified (flooded) fens. The Wm02 also oc-curs along the Coast in tidal reaches of large rivers abovesaltwater influence.

Plant diversity is low. Sites are dom-inated by Equisetum fluviatile with Carexutriculata sometimes co-dominating; oftenthere are scattered aquatics such as Potamoge-ton and Myriophyllum spp. The Wm02 issimilar to the Wm01 but is distinguished by itshigher hydrodynamic index and by the domi-nance of E. fluviatile.

Soils are derived from silty or fine-sandy fluvi-um, deep limnic deposits at open margins of lakes, or recently floodedpeat. Rego Gleysols and Terric Humisols are common soil types.


Tree layer (0 - 0 - 0)Shrub layer (0 - 0 - 4)Herb layer (18 - 85 - 100)C. utriculata, Equisetum fluviatileMoss layer (0 - 0 - 90)

Comments

E. fluviatile is tolerant of extreme variationsin water depth and high rates of sedimenta-tion and can colonize exposed mineral orpeat soils. It has been used to revegetate theextreme environment of the drawdown zonein reservoirs.

On fluvial sites, the Wm02 is usually adjacentto tall-willow swamps or low bench commu-nities. In lake systems, Wm02 commonlyadjoins open water and other marsh commu-nities.

Chapter 5.3 Marshes 109

Swamp horsetail – Beaked sedge Wm02

Equisetum fluviatile – Carex utriculata


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