Lutz spruce / Rusty menziesia / Field horsetail
Picea X lutzii / Menziesia ferruginea / Equisetum arvense  
n = 50
I.A.2.  Open Needleleaf Forest
Ecosystem: Discharge Slope


No rusty menziesia (Menziesia ferruginea) types are described in The Alaska Vegetation Classification (Viereck, et. al., 1992).  On Chugach National Forest, DeVelice, et. al. (1992) describe a  much drier Lutz spruce (Picea X lutzii) / rusty menziesia type with very different co-dominants.  They also describe a Lutz spruce / alder rusty menziesia type.  On the lowlands we can discriminate two Lutz spruce / horsetail (Equisetum arvense) types: an alder type, that is frequently found at toeslope positions, and that commonly grades to the rusty menziesia type described here.

Lutz spruce / rusty menziesia / field horsetail forms a widespread and common wet-to-mesic forest along foot and toeslopes on a variety of landforms on the Kenai lowlands.  It frequently occupies the upper edge of a groundwater discharge zone, or where dense till perches a water table grading to an upland Lutz spruce / rusty menziesia / oakfern (Gymnocarpium dryopteris) community.

Although the spruce bark beetle (Dendroctonus rufipennis) has recently caused extensive mortality in Kenai lowlands spruce stands, Lutz spruce / rusty menziesia / field horsetail seems to have escaped (or will be the last forest type to succumb to the beetle epidemic).  Most stands are still only lightly affected, or were visited before the outbreak reached them.   

Lutz spruce forms a moderately open canopy over thick rusty menziesia, which, in turn, tops a dense field horsetail herb layer.  A rich assemblage of other plants are scattered throughout the herbaceous layer under the menziesia.  Usually present are: twisted stalk (Streptopus amplexifolius shieldfern (Dryopteris expansa), woodland horsetail (Equisetum sylvaticum), Canadian burnet (Sanguisorba canadensis), and bluejoint (Calamagrostis canadensis).  On the ground, trailing raspberry (Rubus pedatus), and twinflower (Linnea borealis) frequently form carpets.  Oakfern can be abundant.  Oval-leaf blueberry (Vaccinium ovalifolium is often present and Sitka alder (Alnus viridis ssp. sinuata) and paper birch (Betula papyrifera) are present at about half the sites.  

The organic layer is usually thin, though at four sites it was greater than a meter thick.  The water table is usually encountered within 30 cm (one foot) of the surface, or redoximorphic features indicate that it is usually present within 30 cm for at least some of the season.  Not always a wetland, 32 of the 50 sites meet jurisdictional criteria.  The upslope portion of a site covered by this community might be upland, while downslope, it might be wet.  Greater field horsetail cover, and less oakfern cover usually indicates wetter conditions.

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 5 1, 2B2, 3
SLIKOK 1 2B3, 3
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


f  Average Cover   Alaska National
tall Picea X lutzii   0.9 38.6 np
medium Picea X lutzii 0.7 5.5 np
Menziesia ferruginea 1.0 24.0 FACU* FACU*,
Vaccinium ovalifolium 0.8 2.4 FAC FACU*, FAC
regeneration Picea X lutzii 0.8 0.8 np
Low Shrub
Ribes triste   0.6 0.4 FAC FAC, OBL
Equisetum arvense 1.0 49.0 FAC* FAC*, FACW-
Rubus pedatus 1.0 14.2 FAC* FACU*, FAC*
Linnaea borealis 0.9 3.0 FACU FACU-, FAC
Streptopus amplexifolius   0.9 1.2 FAC UPL, OBL
Dryopteris expansa   0.9 5.3 FACU FACU, FACW
Orthilia secunda   0.9 1.0 FACU* UPL, FAC+
Equisetum sylvaticum 0.8 8.2 FACU FACU, FACW
Calamagrostis canadensis   0.8 8.1 FAC FAC, OBL
Sanguisorba canadensis 0.8 6.0 FACW FACW,
Spiraea stevenii   0.7 1.7 FAC FAC
Cornus suecica 0.7 1.0 FAC FAC
Gymnocarpium dryopteris   0.7 30.6 FACU UPL, FAC
Lycopodium annotinum 0.7 2.4 FAC FACU*, FAC
Chamerion angustifolium   0.6 1.5 FACU FACU, FAC
Trientalis europaea 0.6 0.3 FAC FAC*, FAC
Moss 1.0 66.4
Lichen 0.8 0.4
np- not present on the wetland indicator status list


 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  996033
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 09:51