Sphagnum moss / Tall cottongrass  
Sphagnum spp. - Eriophorum angustifolium  
n = 8
III.A.3.k (III.A.3.a.) Subarctic Lowland Sedge-Moss Bog Meadow (Wet Sedge Meadow Tundra)
Ecosystem: Relict Lakebed / Drainageway, Kettle, Depression

This is a well known and widely documented community in Alaska (Craighead, et. al., 1988; Holowaychuk and Smeck, 1979, Viereck, 1963, White, et. al., 1975 and Murray, 1974 in Viereck, et. al., 1992; Racine, 1976; Racine and Anderson, 1979Boggs, 2000 and DeVelice, et. al., 1999).  Viereck, et. al. (1992), describe the majority of tall cottongrass (Eriophorum angustifolium) dominated communities as interior Alaska tundra types, i.e. underlain by permafrostHowever, tall cottongrass communities are common on the Kenai lowlands, where permafrost is absent and the climate is maritime.

Sphagnum moss (Sphagnum spp.) tall cottongrass is widespread and somewhat common on well-developed peat in wetter areas of relict glacial lakebeds.  

In these communities, sparse to open tall cottongrass plants push up through a thick sphagnum mat sometimes with open dwarf birch (Betula nana) cover.  Two dwarf shrubs, bog rosemary (Andromeda polifolia) and bog cranberry (Vaccinium oxycoccos) are usually present in trace amounts.  

The organic mat is often over 1.5 m thick and the water table is usually at or very near the surface.  pH is extremely to strongly acid (5.1) at the four sites measured.  All sites visited are wetlands.

Table 1. Frequency of soil series occurrence and hydric status at NRCS holes.  Bold type indicates soils on the NRCS Alaska hydric soils list.

   Soil Series n

Hydric Criteria Number

STARICHKOF 2 1, 2B2, 3

Table 2.  Summary of plant frequency and average cover for plants occurring in more than 50% of plots.

        Wetland Indicator Status


f  Average Cover   Alaska National
Betula nana 1.0 5.6 FAC FAC, OBL
Empetrum nigrum 0.6 10.0 FAC FACU, FACW
Vaccinium uliginosum 0.6 7.2 FAC FACU+, FACW
Ledum palustre ssp. decumbens   0.8 2.6 FACW FACW
Dwarf shrubs
Vaccinium oxycoccos 0.9 1.0 OBL OBL
Andromeda polifolia 0.9 0.7 OBL OBL
Eriophorum angustifolium   1.0 22.1 OBL OBL
Drosera rotundifolia 0.8 1.1 OBL OBL
Carex rotundata   0.6 0.4   OBL OBL


 Introduction and Key to Plant Communities  

Introduction and Key to Ecosystems

    Kenai Hydric Soils    Map Unit Summary    Methods   Glossary

Contact: Mike Gracz
Kenai Watershed Forum 
PO Box 15301
Fritz Creek, AK  99603
The Alaska Natural Heritage Program
Environment and Natural Resource Institute
University of Alaska, Anchorage
707 A Street, Suite 101
Anchorage, Alaska  99501

04 May 2007 10:03