Bluejoint - Field horsetail
Calamagrostis canadensis - Equisetum arvense  
n = 36
III.A.2.b. Bluejoint -Herb
Ecosystem: Discharge Slope, Riparian

   

Bluejoint (Calamagrostis canadensis) – field horsetail (Equisetum arvense) is not well documented in the Alaskan literature.  A new category, (III.A.3.x) “Subarctic Lowland Grass Wet Meadow (or Fen)” is warranted.  Its closest fit, the “III.A.2. Mesic Gaminoid Herbaceous” in the Alaska Vegetation Classification (Viereck et. al. 1992) is not appropriate, as Bluejoint filed horsetail is typically wetter than mesic on the Kenai lowlands.  Saturated bluejoint stands are common on the lowlands and warrant a new Alaska Vegetation class.  

Boggs (2000) describes a similar Bluejoint / Marsh fivefinger (Comarum palustre) type, on the Copper River, but only half of those plots contain field horsetailOn Chugach National Forest, the type described here probably falls between two types they document: the pure field horsetail (with low, inconsistent bluejoint cover) and the pure bluejoint (with about 1/3 of those plots with field horsetail) (DeVelice, et. al., 1999).

Bluejoint - field horsetail communities are common on foot and toeslopes near the coast all over the lowlands, but especially at the base of the Homer bluffs.  A few sites are located in appropriate landscape positions in the Caribou Hills.  This type can be an indicator of human-generated disturbance. 

Bluejoint cover is dense, and tall field horsetail is typically abundant just under the bluejoint (mostly the more robust Calamagrostis canadensis ssp. langsdorfii).  Fireweed (Chamerion angustifolium, typically the robust ssp. circumvagum) is a common associate.  Sites with thick organic mats (up to 160 cm) tend to have less field horsetail; sites with high water tables have more.

The presence of this type does not necessarily indicate a wetland.  Organic horizon thickness and depth to water table vary tremendously (3-160 cm and 15-145 cm where measured, respectively);  25 of the 36 locales visited would probably qualify as jurisdictional wetlands.   

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

BELUGA 6 2B3
NIKOLAI 5 1
STARICHKOF 5 1, 2B2, 3
CHUNILNA 1 2B3
MOOSE RIVER 1 2B3
KALIFONSKY 1 2B3
KENAI 1
REDOUBT 1
TLIKAKILA1 1  
 1Proposed series, definitely hydric.

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
Herbs/Graminoids
Calamagrostis canadensis   1.0 84.4 FAC FAC, OBL
Equisetum arvense 1.0 41.8 FAC* FAC*, FACW-
Chamerion angustifolium   0.7 15.7 FACU FACU, FAC
Polemonium acutiflorum   0.5 1.6 FAC FAC
Moss 0.8 1.9      

 


 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 09:37