|Sphagnum moss - Ericaceous shrub|
|Sphagnum spp. - Ericaceae
|n = 26|
|II.C.2.e. Ericaceous Shrub Bog|
|Ecosystem: Relict Lakebed / Drainageway, Kettle, Depression|
Ericaceous bogs (fens) are well documented in Alaska, but the particular combination of co-dominants found on Kenai Lowlands fens are not. Usually ericaceous communities are described as alpine (DeVelice et. al., 1999), or with less dwarf birch (Betula nana) and more Labrador tea (Ledum palustre ssp. decumbens) (Bos, 1967; Cooper, 1942, Rigg, 1914 and Viereck, 1970, in Viereck, et. al., 1992) and/or bog blueberry (Vaccinium uliginosum(Boggs, 2000; Stiegers, et. al., 1983, in Viereck, et. al. 1992; Shephard, 1995) than is found on Kenai peatlands. Although these two ericads occur here, crowberry typically dominates with dwarf birch.
This common, widespread type is found on small relict glacial lakebed fens, or at the edges of larger lakebed fens where the peat is thicker and the water table a little deeper.
Sphagnum (Sphagnum spp.) - ericaceous shrub communities are characterized by a continuous sphagnum mat (sometimes other mosses dominate) with low to dwarf crowberry (Empetrum nigrum) cover dominating the shrub layer, and with dwarf birch and Labrador tea both usually present at woodland densities. Cloudberry (Rubus chamaemorus) and bog blueberry are usually present, and sometimes common. Bog cranberry (Vaccinium oxycoccos) is usually present, but at low abundance.
Peat is usually greater than a meter thick, though a few sites visited
lacked even a histic epipedon (20 cm, or 8” of organic horizon).
The water table is almost always less than 30 cm (one foot) below the
surface, though at three sites it was deeper.
At the three sites measured, pH was extremely acid (4.2).
Of the 26 sites examined, all but one qualify as a jurisdictional wetland.
Table 1. Frequency of soil series occurrence and hydric status at NRCS holes. Bold type indicates soils on the NRCS Alaska hydric soils list.
|STARICHKOF||7||1, 2B2, 3|
Table 2. Summary of plant frequency and average cover for plants occurring
in more than 50% of plots.
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||0.6||2.9||np|
|Empetrum nigrum||1.0||23.4||FAC||FACU, FACW
|Betula nana||1.0||14.3||FAC||FAC, OBL
|Ledum palustre ssp. decumbens||1.0||9.8||FACW||FACW|
|Vaccinium uliginosum||0.9||10.2||FAC||FACU+, FACW
|Equisetum arvense||0.6||4.0||FAC*||FAC*, FACW-|
|np- not present on the wetland indicator status list|
|1 Plant with known morphological 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 10:03