Beaked sedge Water horsetail
Carex utriculata Equisetum fluviatile  
n = 6
III.A.3.f. Subarctic Lowland Sedge Wet Meadow
Ecosystem: Relict Lakebed / Depression


Beaked sedge (Carex utriculata) - water horsetail (Equisetum fluviatile) and similar types have been well described for Alaska. Craighead et. al. (1988) describe it for Northwest Alaska in their Equisetum Sedge Marsh Subcomplex.  Nearer to the Kenai lowlands, both DeVelice (1999) and Boggs (2000) describe both a beaked sedge and a water horsetail type.  On the Kenai lowlands these two monotypes mix together in a narrow zone at the edge of open water pools, combining to form the beaked sedge water horsetail type.

Standing water dominates this site, and the only other plant commonly present is buckbean (Menyanthes trifoliata).  Beaked sedge - water horsetail is more common than the sample number indicates.  It occupies the edges of pools, in the strang-flark-pool complex commonly found on relict glacial lakebed peatland complexes, and in shallow kettles.

Emergent (rooted underwater) beaked sedge cover is open; water horsetail is generally uniform and less abundant.  It occurs just below the zone where livid sedge (C. livida) dominates.  

Average water depth is about 7 centimeters (although at an unusual site north of Nikiski the water table was encountered at 120 cm), and the submerged organic layer is greater than a meter thick.  The pH can be near neutral, but is typically moderately acid (5.5).  This type is always a jurisdictional wetland.

Table 1.  Summary of plant frequency and average cover for plants occurring in more than 50% of plots.

        Wetland Indicator Status
  f  Average Cover   Alaska National
Carex utriculata   1.0 26.4 OBL OBL
Equisetum fluviatile 1.0 7.3 OBL OBL
Open water 1.0 77.4      


 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