|Sphagnum moss - Leatherleaf|
|Sphagnum spp. - Chamaedaphne calyculata|
|n = 5|
|II.C.2.e. Ericaceous Shrub Bog|
|Ecosystem: Relict Drainageway, Depression, Floating Island|
Working in the bottomland bogs of the Fairbanks area, Mary Calmes (1976, in Viereck, et. al., 1992) describes a nominally similar leatherleaf (Chamaedaphne spp.) – willow (Salix spp.) - sedge (Carex spp.) type, that is the closest published description to what is found on the Kenai Lowlands.
Sphagnum moss (Sphagnum spp.) - leatherleaf (Chamaedaphne calycuta) communities are found on floating islands or mats, usually near the edges of lakes, although one site was in a functionally similar locale along a relict glacial drainageway merging with a relict lakebed near the edge of a floating mat. Another site was in a hydrologically altered position near a road. All sites are located on the northern peninsula, and leatherleaf is uncommon south of Soldotna.
This is one of the only communities (along with the Sphagnum - round sedge and Sphagnum - Red cottongrass communities) on the Kenai lowlands that can indicate ombrotrophic bog development. An ombrotrophic bog is a peatland that has built a sufficiently thick sphagnum layer to perch a precipitation-derived groundwater lens above the local groundwater table. These perched lenses are theoretically very poor in nutrients, since the groundwater in them is entirely derived from precipitation, unlike the local groundwater table, which is flowing with some contact with the mineral soil below.
Sphagnum moss - leatherleaf communities are characterized by a thick peat mat with sparse vegetation cover. A woodland density of leatherleaf overtops trace amounts of sundew (Drosera rotundifolia), bog rosemary Andromeda polifolia) and bog cranberry (Vaccinium oxycoccos).
Histosols are present, with organic mats almost always over one meter thick (40”). The water table is always less than a foot (30 cm) from the surface. The lowest pH recorded in the project area, 3.8, was found at one site, and the average of the four sites measured was very strongly acid (4.7), although at one site measured, near a drainageway, was moderately acid (5.7). All sites visited are jurisdictional wetlands.
Table 1. Summary of plant frequency and average cover for plants occurring
in more than 50% of plots .
|Wetland Indicator Status|
|Betula nana||0.8||0.9||FAC||FAC, OBL
|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