Sphagnum moss - Creeping sedge
Sphagnum spp. - Carex chordorrhiza
n = 10
III.A.3.j.(-k.) Subarctic Lowland Sedge (-Moss) Bog
Ecosystem: Relict Lakebed / Drainageway, Depression

The sphagnum moss (Sphagnum spp.) - creeping sedge (Carex chordorrhiza) community found on the Kenai Lowlands is similar to the creeping sedge – buckbean (Menyanthes trifoliata) community described by Scheirel and Meyer (1977) for the Copper River delta, and the mud sedge (Carex limosa) – creeping sedge community described by Calmes (1976 in Viereck et. al., 1992) and Drury (1956), for interior Alaska, but lacks those other associates (buckbean and mud sedge, respectively).  Both on Chugach National Forest (DeVelice et. al., 1999) and on the Copper River Delta (Boggs, 2000) “under-represented” creeping sedge types are named.

Sphagnum moss – creeping sedge often occurs on the lowest, wettest positions of various level relict glacial landforms including drainageways, lakebeds and depressions on recessional moraines.  

A sparse to "woodland" density of creeping sedge occupies a sphagnum mat, often with standing water. 

The organic mat is thick, often greater than 2 meters; it is always an organic soil (histosol).  The water table is at or near the surface.  pH ranges from very strongly acid to slightly acid depending on groundwater flow proximity to mineral soil contact.  All 10 sites visited are jurisdictional 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


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

        Wetland Indicator Status



 Average Cover

  Alaska National
Salix1 fuscescens   0.7 2.7 FACW FACW
Chamaedaphne calyculata   0.6 0.6 FAC FAC
Betula nana 0.6 0.4 FAC FAC, OBL
Dwarf shrubs
Andromeda polifolia 0.9 2.0 OBL OBL
Vaccinium oxycoccos 0.9 0.5 OBL OBL
Carex chordorrhiza 1.0 15.7 OBL OBL
Comarum palustre 0.7 8.2 OBL OBL
Equisetum fluviatile 0.7 3.1 OBL OBL
Carex aquatilis   0.6 2.1 OBL OBL
Calamagrostis canadensis   0.6 1.8 FAC FAC, OBL
Carex magellanica 0.6 0.6 OBL OBL
Sphagnum spp. 0.9 66.0
Open water 1.0 2.0
1 Plant with known morphological adaptation for occurrence in wetlands (USACE, 1987)


 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 10:02