Black spruce / Field horsetail - Dwarf birch
Picea mariana / Equisetum arvense Betula nana
n = 5
I.A.3. Needleleaf Woodland
Ecosystem:  Discharge Slope, Relict Drainageway


Black spruce (Picea mariana) / field horsetail (Equisetum arvense) dwarf birch (Betula nana) is a new type.  Coastal black spruce communities are poorly documented in the literature.  The most similar community DeVelice, et. al. (1999) describe is a black spruce / lingonberry (Vaccinium vitis-idaea) (PICMAR / VACVIT) type on nearby Chugach National Forest.  Yarie (1983) describes a remotely similar black spruce / dwarf birch / cottongrass / sphagnum moss type for the Porcupine River drainage in interior Alaska.

Black spruce / Field horsetail - Dwarf birch is an uncommon plant community occupying a few groundwater discharge slopes at relict glacial lakebed fen edges near the coast.  Four of the sites visited cluster on the southern peninsula near Nikolaevesk, while the fifth (with much lower horsetail abundance) is located on the large isostatically rebounded marine terrace between the Kenai and Kasilof Rivers.  

Black spruce / Field horsetail Dwarf birch forms an open to woodland canopy of medium-height black spruce with a moderately closed understory shrubland and abundant field horsetail.  Crowberry (Empetrum nigrum) is common, and cloudberry (Rubus chamaemorus) can be abundant.  The low shrubs, Labrador tea (Ledum palustre ssp. decumbens), and bog blueberry (Vaccinium uliginosum) are present in low abundance, as is bluejoint grass (Calamagrostis canadensis)The shrubs, leatherleaf (Chamaedaphne calyculata) and lingonberry are also typically present.  

The organic mat is often thicker than one meter, and the water table is always within 20 cm of the surface.  pH was only slightly acid (6.3) at the one site where it was measured.  All five of the sites visited qualify as 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 1 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
Picea mariana   1.0 16.8 FACW FACW-, FACW
Betula nana 1.0 26.3 FAC FAC, OBL
Empetrum nigrum 1.0 11.3 FAC FACU, FACW
Ledum palustre ssp. decumbens   1.0 8.8 FACW FACW
Vaccinium uliginosum 1.0 4.0 FAC FACU+, FACW
Chamaedaphne calyculata   0.8 4.3 FAC FAC
Low shrub
Vaccinium vitis-idaea 0.8 0.7 FAC FAC
Dwarf shrub
Vaccinium oxycoccos 1.0 0.3 OBL OBL
Equisetum arvense 1.0 48.0 FAC* FAC*, FACW-
Rubus chamaemorus 1.0 29.3 FACW FACW
Calamagrostis canadensis   1.0 1.3 FAC FAC, OBL
Moss 1.0 87.5
Lichen 1.0 0.1      


 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 09:53