|Sweetgale – Dwarf birch / Water horsetail|
|Myrica gale – Betula nana / Equisetum fluviatile|
|n = 6|
|II.C.2.d. Open Low Shrub Birch-Ericaceous Shrub Bog.|
|Ecosystem: Relict Lakebed / Drainageway|
This is a newly documented type for Alaska. Two sweetgale (Myrica gale) – dwarf birch (Betula nana) types have been documented, but both have other associates, and lack water horsetail (Equisetum fluviatile). One, described by Seguin (1977, in Viereck, 1992) for Portage flats, has willow (Salix spp.) and bluej (Calamagrostis canadensis) as associates; the other, described by Rosenberg (1986) near the Kenai River, has shrubby cinquefoil (Dasiphora floribunda) and Labrador tea (Ledum palustre ssp. decumbens) as associates. That community is nearly identical to the sweetgale – shrubby cinquefoil type described elsewhere in this document.
Sweetgale – dwarf birch / water horsetail is common on Kenai lowland wetlands, and can form extensive stands where it occurs. The shrubs form a thicket, and are relatively tall, averaging between 70 cm and 1.2 m. Frequently, standing water occupies microtopographic-low spots. This community occurs on relict glacial lakebeds in broad zones of shallow groundwater discharge- near the base of terraces or along the margins of poorly defined drainageways.
It typically occupies a zone between Barclay willow / bluejoint – field horsetail (Salix barclayi / Calamagrostis canadensis - Equisetum arvense) discharge slopes above, and the strang-flark complex where sweetgale occurs with shrubby cinquefoil and a variety of sedges, below.
Associated plants, typically found where micro-topography is more developed, are: bog blueberry (Vaccinium uliginosum), shrubby cinquefoil, field horsetail (Equisetum arvense) and crowberry (Empetrum nigrum). In the typical stand, however, few associates are present besides the named dominants.
The water table is shallow, averaging 14 cm; it is often at or above the surface. Peat averages 101 cm thick. All six sites visited are 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.
|STARICHKOF||3||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|
|stunted Picea X lutzii||0.7||3.3||np|
|Betula nana||1.0||15.8||FAC||FAC, OBL|
|Vaccinium uliginosum||1.0||1.7||FAC||FACU+, FACW
|Dasiphora floribunda||0.8||10.8||FAC||FAC-, FACW|
|Empetrum nigrum||0.8||8.6||FAC||FACU, FACW|
|Equisetum arvense||0.8||10.7||FAC*||FAC*, FACW-
|np- not present on the wetland indicator status list|
|1,2 Plant with known morphological and physiological adaptation for occurrence in wetlands (USACE, 1987)|
|Contact: Mike Gracz Kenai Watershed Forum PO Box 15301 Fritz Creek, AK 99603 907-235-2218||
Alaska Natural Heritage Program
and Natural Resource Institute
707 A Street, Suite 101
Anchorage, Alaska 99501
04 May 2007 09:50