Tufted bulrush Tall cottongrass
Trichophorum caespitosum Eriophorum angustifolium
n = 17
III.A.3.k. Subalpine Lowland Sedge-Moss Bog Meadow
Ecosystem: Relict Lakebed / Drainageway, Kettle

This type is apparently unique to the Kenai.  DeVelice, et. al. (1999) describe a nominally similar type for Chugach National Forest, but with less tufted bulrush (Trichophorum caespitosum) dominance and greater shrub representation (ERIANG - TRICAE).   Dachnowski-Stokes (1941), and Streveler, et. al. (1973) describe a tufted bulrush cottongrass whitebeak sedge / sphagnum moss type; and several authors describe tall cottongrass (Eriophorum angustifolium) types (Boggs, 2000; Craighead, et. al., 1988; Racine and Anderson, 1979; Holowaychuk and Smeck, 1979, in Viereck, et. al., 1992; Racine, 1976), which Viereck, et. al. (1992) list as primarily a tundra (permafrost) type.  

Tufted bulrush tall cottongrass communities occur on kettles and relict glacial lakebeds and drainageways throughout the lowlands.  

Bulrush dominates the community and cottongrass is present at woodland densities.  Dwarf birch (Betula nanaand bog rosemary (Andromeda polifolia) are present, and bog cranberry (Vaccinium oxycoccoss usually present in trace amounts.  A sphagnum mat is typically continuous, though sometimes sedge tussocks alternate with low sphagnum hummocks. 

The organic horizon is usually greater than 1.5 meters thick (60) and the water table is often at the surface or just below it.  The pH was measured at only two sites, a strongly acid 5.4 and 5.5.  All 17 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

STARICHKOF 8 1, 2B2, 3
DOROSHIN  3 1
SALAMATOF 3 1, 3

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

          Wetland Indicator Status

 Plant

f  Average Cover   Alaska National
Shrubs
Betula nana 0.9 4.7 FAC FAC, OBL
Myrica gale1,2 0.6 8.2 OBL OBL
Dwarf shrubs
Andromeda polifolia 0.9 1.3 OBL OBL
Vaccinium oxycoccos 0.8 0.4 OBL OBL
Herb/Graminoids
Trichophorum caespitosum   1.0 41.8 OBL OBL
Eriophorum angustifolium   1.0 14.4 OBL OBL
Drosera rotundifolia 0.6 0.7 OBL OBL
Moss 0.9 73.0
Open water 0.8 16.3
1,2 Plant with known morphological and physiological 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
907-235-2218
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 10:04