Common (Translated Scientific) Name: Small Cranberry - Bog-rosemary / Peatmoss species Shrub Bog Alliance

Colloquial Name: Western Boreal Ericaceous Shrub Bog

Hierarchy Level:  Alliance

Type Concept: This bog and poor fen acidic peatland occurs in the boreal and boreal transition regions of western North America. The vegetation is dominated by low ericaceous shrubs, including Betula glandulosa, Chamaedaphne calyculata, Empetrum nigrum, Kalmia polifolia, Ledum groenlandicum, Ledum palustre ssp. decumbens, Rubus chamaemorus, Vaccinium oxycoccos, and Vaccinium uliginosum, along with patches of graminoids and bryophyte lawns. Sedge species include Carex chordorrhiza, Carex lasiocarpa, Carex limosa, Carex livida, Carex membranacea, Carex microglochin, Carex pluriflora, Carex pauciflora, Carex rariflora, Carex rotundata, Carex stylosa, Eriophorum brachyantherum, and Eriophorum angustifolium. Sphagnum species are characteristic, including Sphagnum capillifolium, Sphagnum magellanicum, Sphagnum fuscum, Sphagnum papillosum, and Sphagnum cuspidatum. Conifers sometimes occur (Picea mariana or Larix laricina). In this acidic peatland there is little to no groundwater inputs, and there are thick (>40 cm) peat deposits. Permafrost processes may also occur. This peatland forms where the rate of sphagnum peat accumulation exceeds its decomposition, resulting in ombrotrophic and acidic peatlands in which, under the most acidic conditions, the peat surface is raised above the water table (i.e., a raised bog). These peatlands are typically formed as lake-filled basins or depressions. The surface morphology of the peatland may be more-or-less level, domed, or eccentric. Secondary bog pools may be present. While the raised portion defines these bogs, boreal fen systems may occupy some portion of the same basin, due to localized groundwater input.

Diagnostic Characteristics: The vegetation is dominated by low ericaceous shrubs, including Betula glandulosa, Chamaedaphne calyculata, Empetrum nigrum, Kalmia polifolia, Ledum groenlandicum, Ledum palustre ssp. decumbens, Vaccinium oxycoccos, and Vaccinium uliginosum, along with patches of graminoids and bryophyte lawns. Andromeda polifolia and Carex oligosperma are absent from western boreal acidic peatlands. Conifers sometimes occur (Picea mariana or Larix laricina). In this acidic peatland there is little to no groundwater inputs, and there are thick (>40 cm) peat deposits.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Adapted from ecological systems ~Western North American Boreal Sedge-Dwarf-Shrub Bog (CES105.138)$$ and ~Boreal Depressional Shrub Bog (CES103.871)$$. See references there. String bogs and ribbed fens are included in this system. Blanket bogs may also be included here. This a broad-based alliance, and several patterns of variation may be worthy of alliance distinctions: (1) shrub versus graminoid; (2) "shrub and graminoid bog" versus "shrub and graminoid poor fen"; and (3) "subboreal" versus "boreal." Further distinctions are challenging because the type is often species-poor. Kalmia microphylla may be a good indicator of subboreal floristics. Vaccinium oxycoccos, Chamaedaphne calyculata, and Ledum groenlandicum are common across the boreal peatland, but are absent from the Rocky Mountains. Andromeda polifolia and Carex oligosperma are absent from western boreal acidic peatlands. All the sedges are common across North American boreal peatlands, except Carex membranacea is more of a high arctic sedge, Carex rariflora and Carex rotundata are northern boreal, and Carex pluriflora is found in Alaska, British Columbia and Washington (and eastern Russia).

Similar NVC Types: No Data Available

note: No Data Available