|Bog blueberry – Dwarf birch – Tufted hairgrass|
|Vaccinium uliginosum – Betula nana – Deschampsia caespitosa|
|n = 5|
|II.C.2.e. Ericaceous Shrub Bog|
|Ecosystem: Relict Lakebed|
This type has not been previously documented in Alaska. A similar crowberry (Empetrum nigrum) community with bog blueberry (Vaccinium uliginosum) is frequently described (Hultén, 1960, in Viereck, et. al., 1992; Boggs, 2000. DeVelice, et. al., (1999) and Shephard (1995) describe a bog blueberry - crowberry type which includes a significant tufted hairgrass (Deschampsia caespitosa) component. However, unlike on the Kenai, none of these types has any dwarf birch (Betula nana) present. Many workers have described closely related and variable types lumped under the shrub birch (Betula glandulosa, which has been tentatively lumped with B. nana) - bog blueberry – sedge / sphagnum type (Brock and Burke, 1980, Hanson, 1953; Viereck, 1970; Racine, 1978a&b; Hogan and Tande, 1983) in The Alaska Vegetation Classification (Viereck, et. al., 1992).
Bog blueberry – dwarf birch – tufted hairgrass is a diverse plant community generally found on relict glacial lake beds on the southern peninsula. A few areas at the margin of the large fen complex east of Anchor Point are occupied by this type.
Bog blueberry cover is about 50%, with about half as much dwarf birch. Crowberry is present at woodland densities, as is tufted hairgrass (at one site replaced by Bering’s tufted hairgrass, (Deschampsia beringensis)). Manyflower sedge (Carex pluriflora), field horsetail (Equisetum arvense), bog cranberry (Vaccinium oxycoccos), and bog rosemary (Andromeda polifolia) are often present.
The organic mat is greater than 1.5 m (60”) thick, and the water table is not far below the surface (0-15 cm). One unusual site is located on the large lakebed fen east of Anchor Point, with a thinner peat layer (58 cm, 23”), and deeper water table (51 cm, 20”). The pH at the one site measured was neutral, at 6.5. All five sites are jurisdictional wetlands.
Table 1. Frequency of soil series occurrence and hydric status at NRCS holes. Bold type indicates soils on the NRCS Alaska hydric soils list.
2. Summary of plant frequency and average cover for plants occurring
in more than 50% of plots.
|Wetland Indicator Status|
|Vaccinium uliginosum||1.0||46.0||FAC||FACU+, FACW|
|Betula nana||1.0||22.0||FAC||FAC, OBL
|Empetrum nigrum||1.0||9.5||FAC||FACU, FACW
|Deschampsia caespitosa2||0.8||7.8||FAC||FAC, FACW+|
|Swertia perennis||0.6||4.8||FACW||FAC+, FACW+|
|Calamagrostis canadensis||0.6||0.5||FAC||FAC, OBL|
|2Plant with known 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 10:05