|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.
|STARICHKOF||5||1, 2B2, 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|
|tall Picea X lutzii||0.9||38.6||np|
|medium Picea X lutzii||0.7||5.5||np|
|Vaccinium ovalifolium||0.8||2.4||FAC||FACU*, FAC|
|regeneration Picea X lutzii||0.8||0.8||np|
|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|
|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|
|np- not present on the wetland indicator status list|
|Contact: Mike Gracz Kenai Watershed Forum PO Box 15301 Fritz Creek, AK 996033 907-235-2218||
Alaska Natural Heritage Program
and Natural Resource Institute
707 A Street, Suite 101
Anchorage, Alaska 99501
04 May 2007 09:51