Crowberry Bog blueberry
Empetrum nigrum Vaccinium uliginosum   
n = 13
II.C.2.e. Open Low Scrub, Ericaceous Shrub Bog
Ecosystem: Relict Lakebed, Depression, Relict Drainageway

Ericaceous shrub types are common in Alaska in a variety of ecological settings. On the Copper River Delta, Boggs (2000) describes a bog blueberry (Vaccinium uliginosum) - crowberry (Empetrum nigrum) type that is nearly identical.  DeVelice, et. al. (1999) describe a similar type but with manyflower sedge (Carex pluriflora) as an indicator.  The ericads have a bimodal ecological distribution: both in peatlands and on dry subalpine ridges and slopes.  Crowberry occurs more frequently in maritime environments.

Crowberry bog blueberry communities occur on a variety of landforms, but are concentrated on mature peatlands on the southern lowlands (although these dominants can be found on subalpine ridges).  Thick low crowberry dominates, with the sub-dominants bog blueberry, and dwarf birch (Betula nana). Cloudberry (Rubus chamaemorus) cover is often abundant as well.  Labrador tea (Ledum palustre ssp. decumbens) is usually present as a sub-dominant, and fewflower sedge (Carex pauciflora) can be common. Trace amounts of the dwarf shrubs bog rosemary (Andromeda polifolia) and lowbush cranberry (Vaccinium oxycoccos) are typically present. 

The peat mat is generally thicker than one meter, and the water table is always less than 30 cm from the surface.  These sites are always jurisdictional wetlands, unless found on hilltops.  On hilltops and ridges, a few upland plants, such as sweetgrass (Hierochloe alpina) and blackish oxytrope (Oxytropis nigrescens) replace the peat specialists fewflower sedge, lowbush cranberry, bog rosemary and others.   

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

   Soil Series n

Hydric Criteria Number

NIKOLAI    4 1
STARICHKOF 4 1, 2B2, 3

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
Shrubs/Stunted tree        
stunted Picea X lutzii 0.7 2.1 np
Empetrum nigrum 1.0 58.1 FAC FACU, FACW
Vaccinium uliginosum 1.0 22.8 FAC FACU+, FACW
Betula nana 1.0 19.9 FAC FAC, OBL
Ledum palustre ssp. decumbens   0.8 10.3 FACW FACW
Dwarf shrubs
Vaccinium oxycoccos 0.9 0.5 OBL OBL
Andromeda polifolia 0.8 0.6 OBL OBL
Rubus chamaemorus 0.9 16.7 FACW FACW
Carex pauciflora   0.8 9.2 OBL OBL
Equisetum arvense 0.7 16.6 FAC* FAC*, FACW-
Moss 1.0 94.6
Lichen 0.6 1.1
Open water 0.5 0.5
np- not present on the wetland indicator status list


 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 09:39