Black spruce / Woodland horsetail - Labrador tea
Picea mariana / Equisetum sylvaticum - Ledum palustre ssp. decumbens
n = 53
I.A.2.f / 3.d. Woodland to Open Black Spruce Forest
Ecosystems: Discharge Slope, Relict Lakebed / Drainageway, Kettle, Depression

    

Although black spruce (Picea mariana) / woodland horsetail (Equisetum sylvaticum) - Labrador tea (Ledum palustre ssp. decumbens) is very common on the Kenai lowlands, it is not mentioned in the literature.  It is similar to the Black spruce / Labrador tea / feathermoss (Hylocomium splendens) type described for interior Alaska floodplains (Viereck, 1989; but on a different landscape on the Kenai), and the Black spruce / Labrador tea community described on this website, but with a dense woodland horsetail component, distinctive to the Kenai lowlands.

The black spruce / woodland horsetail- Labrador tea community occurs on foot and toeslopes where the organic horizon thins above a peatland, usually just above the black spruce / Labrador tea zone.  This zone frequently occupies the groundwater discharge slope edges of low relief kames.  

An open-to-woodland canopy tops an often dense Labrador tea shrub layer.  Woodland horsetail cover can be nearly continuous and is distinctive to this type.  Crowberry (Empetrum nigrum) is present, and frequently abundant, as is cloudberry (Rubus chamaemorus).  Dwarf birch (Betula nana) and bog blueberry (Vaccinium uliginosum) are usually present, but at lower abundances.  Rarely, field horsetail (Equisetum arvense) substitutes for woodland horsetail as a co-dominant.  

Organic horizons are thinner, often not qualifying as an organic soil (40 cm).  The water table was encountered within 30 cm (one foot) of the surface at about half the sites.  The pH was measured at only four sites, and varied from moderately to extremely acid.  Thirty-six of the 53 sites fit the soils criteria for a jurisdictional wetland.  

Another community occasionally occurring as a narrow band on mineral soil groundwater discharge slopes, that is not named separately in this classification, and will key to this type, is the Black spruce / Barclay's willow / Field horsetail type.  It frequently has lingonberry as an associate.  On the Kenai Lowlands, it is a northern equivalent of the more southern Lutz spruce / Barclay's willow / Field horsetail community.

Black spruce / Barclay's willow / Field horsetail

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

STARICHKOF 9 1, 2B2, 3
SLIKOK 6 2B3, 3
NIKOLAI  5 1
DOROSHIN 3 1
COAL CREEK 2 2B3
SPENARD 2 2B3
TRUULI1 1  
CASWELL 1  
CLAM GULCH 1 2B3
FORELAND 1 2B3
KALIFONSKY 1 2B3
TUXEDNI2 1
1Proposed series, definitely hydric
2Proposed series, hydric status unknown

 

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
Tree
Picea mariana  1.0 19.7 FACW FACW-, FACW
Shrubs
Empetrum nigrum 1.0 18.9 FAC FACU, FACW
Ledum palustre ssp. decumbens   1.0 13.5 FACW FACW
Betula nana 0.9 8.6 FAC FAC, OBL
Vaccinium vitis-idaea 0.9 7.4   FAC FAC
Vaccinium uliginosum 0.9 7.1 FAC FACU+, FACW
Dwarf shrub
Vaccinium oxycoccos 0.5 2.3 OBL OBL
Herbs/Graminoid
Equisetum sylvaticum 0.9 16.3 FACU FACU, FACW
Rubus chamaemorus 0.9 10.5 FACW FACW
Calamagrostis canadensis   0.5 2.3 FAC FAC, OBL
Moss 0.9 92.3
Lichen 0.9 2.6      

 


 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 09:53