Sphagnum moss - Ericaceous shrub
Sphagnum spp. - Ericaceae   
 n = 26
II.C.2.e. Ericaceous Shrub Bog
Ecosystem: Relict Lakebed / Drainageway, Kettle, Depression

Ericaceous bogs (fens) are well documented in Alaska, but the particular combination of co-dominants found on Kenai Lowlands fens are not.  Usually ericaceous communities are described as alpine (DeVelice et. al., 1999), or with less dwarf birch (Betula nana) and more Labrador tea (Ledum palustre ssp. decumbens) (Bos, 1967; Cooper, 1942, Rigg, 1914 and Viereck, 1970, in Viereck, et. al., 1992) and/or bog blueberry (Vaccinium uliginosum(Boggs, 2000; Stiegers, et. al., 1983, in Viereck, et. al. 1992; Shephard, 1995) than is found on Kenai peatlands. Although these two ericads occur here, crowberry typically dominates with dwarf birch.

This common, widespread type is found on small relict glacial lakebed fens, or at the edges of larger lakebed fens where the peat is thicker and the water table a little deeper.  

Sphagnum (Sphagnum spp.) - ericaceous shrub communities are characterized by a continuous sphagnum mat (sometimes other mosses dominate) with low to dwarf crowberry (Empetrum nigrum) cover dominating the shrub layer, and with dwarf birch and Labrador tea both usually present at woodland densities.  Cloudberry (Rubus chamaemorus) and bog blueberry are usually present, and sometimes common.  Bog cranberry (Vaccinium oxycoccos) is usually present, but at low abundance.  

Peat is usually greater than a meter thick, though a few sites visited lacked even a histic epipedon (20 cm, or 8 of organic horizon).  The water table is almost always less than 30 cm (one foot) below the surface, though at three sites it was deeper.  At the three sites measured, pH was extremely acid (4.2).  Of the 26 sites examined, all but one qualify as a jurisdictional wetland.   

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 7 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
Shrubs/Stunted tree
stunted Picea X lutzii   0.6 2.9 np
Empetrum nigrum 1.0 23.4 FAC FACU, FACW
Betula nana 1.0 14.3 FAC FAC, OBL
Ledum palustre ssp. decumbens   1.0 9.8 FACW FACW
Vaccinium uliginosum 0.9 10.2 FAC FACU+, FACW
Vaccinium vitis-idaea 0.5 1.9 FAC FAC
Dwarf shrubs
Vaccinium oxycoccos 0.8 0.5 OBL OBL
Andromeda polifolia 0.6 2.0 OBL OBL
Salix1 fuscescens   0.5 2.5 FACW FACW
Rubus chamaemorus 0.9 12.0 FACW FACW
Carex pluriflora 0.6 11.4 OBL OBL
Equisetum arvense 0.6 4.0 FAC* FAC*, FACW-
Moss 0.9 97.5
np- not present on the wetland indicator status list
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 10:03