|Tufted bulrush – Dwarf birch|
|Trichophorum caespitosum – Betula nana|
|n = 12|
|III.A.3.k. Subarctic Lowland Sedge-Moss Bog Meadow|
|Ecosystems: Kettle, Relict Lakebed / Drainageway, Depression|
Although Tufted bulrush (Trichophorum caespitosum) - dwarf birch (Betula nana) is relatively common on the Kenai Lowlands, it is only briefly mentioned for Alaska. Dachnowski-Stokes (1941) mentions dwarf birch in association with tufted bulrush in the “Anchorage District”, at Merrill field and in Spenard. For southeast Alaska, he mentions associates: “Empetrum nigrum, Kalmia polifolia and several species of Vaccinium.”
Tufted bulrush communities have been described for several areas (Shephard, 1995; Fox, 1983 and Jaques, 1973, in Viereck, et. al., 1992) and with other sedges (Dachnowski-Stokes, 1941; Streveler, et. al. 1973), and other ericaceous shrub co-dominants, but dwarf birch is absent from all of these descriptions.
On the Kenai Lowlands, this type is common on relict glacial lakebeds and drainageways, though restricted to the southern peninsula, primarily around Stariski Creek, Caribou Lake and the large peatland complex east of Anchor Point.
Tufted bulrush - dwarf birch communities are characterized by a moderately closed stand of tufted bulrush interspersed with a woodland density of low dwarf birch. The birch is usually about the same stature as the bulrush. Sometimes the birch is located on micro-topographic-highs. Bog rosemary (Andromeda polifolia) is present, and open water; bog cranberry (Vaccinium oxycoccosand tall cottongrass (Eriophorum angustifolium) are frequent associates. Tufted bulrush can tolerate high levels of disturbance (Lindsay, 1995), and this community may proliferate under moderate all terrain vehicle (ATV) use.
organic horizon is greater than one meter (40”) thick, and the water table is
at or very near the surface. pH at
the four sites measured varied from slightly to extremely acid.
All sites visited qualify as 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.
Table 2. Summary of plant frequency and average cover for plants occurring in more than 50% of plots.
|Wetland Indicator Status|
|Betula nana||1.0||12.3||FAC||FAC, OBL|
|Vaccinium uliginosum||0.7||5.0||FAC||FACU+, FACW|
|Empetrum nigrum||0.6||19.2||FAC||FACU, FACW
|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 10:04