|Tall cottongrass – Livid sedge|
|Eriophorum angustifolium – Carex livida|
|n = 3|
|III.A.3.j. Subarctic Lowland Sedge Bog Meadow|
|Ecosystem: Relict Lakebed, Depression, Kettle|
Working at the mouth of the Kenai River, Rosenberg (1986) describes this relatively common Kenai lowland type, and in Anchorage wetlands, Hogan and Tande (1983) delineate a similar livid sedge (Carex livida) – buckbean (Menyanthes trifoliata) type. Otherwise, livid sedge types are not described in the literature, and the plant is not listed at all in the Chugach forest (DeVelice, et. al., 1999) and Copper River (Boggs, 2000) classifications. Tall cottongrass (Eriophorum angustifolium) communities are primarily described as tundra types in the Alaska Vegetation Classification (Viereck, et.al., 1992).
Tall cottongrass - livid sedge is widespread and more common than the low number of plots sampled indicates. It occurs on relict glacial lakebeds where some degree of groundwater flow has created a strang-flark complex (low peat ridges, a meter or two high alternating with elongate pools (or flarks) oriented perpendicular to groundwater flow). Northwest of the Kenai airport lies a particularly well-developed strang-flark complex. Tall cottongrass - livid sedge frequently occupies the edges of flarks where it exhibits low overall cover.
Tall cottongrass and livid sedge are emergent (rooted under standing water) in about equal quantities, with lower amounts of English sundew (Drosera anglica) and sometimes moor rush (Juncus stygius). On low hummocks, or at the edge of the flark, tufted bulrush (Trichophorum caespitosum) and bog rosemary (Andromeda polifolia) are found, sometimes with sweetgale (Myrica gale).
Peat is usually over one meter thick, but often not over 160 cm. The water table is above the surface, or sometimes just below it. pH averages a moderately acid 5.6. All sites qualify as jurisdictional wetlands.
Table 1. Summary of plant frequency and average cover for plants occurring
in more than 50% of plots .
|Wetland Indicator Status|
|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 09:40