Subalpine sloping fen (S1)
(formerly subalpine sliding fen)
Subalpine sloping fens are steeply-sloped (5-30 degree) peatlands that occur along the brow of alpine/subalpine cliffs. They are dominated by Pickering's bluejoint, mountain avens, and pioneer peat mosses. The species composition is otherwise similar to other alpine/subalpine peatlands. Soils consist of a shallow peat (1-35 cm) over bedrock. Wetlands are unusual in steep settings, but they are occasionally made possible by a rare combination of surface runoff, seepage, cloud-intercept, cold temperatures, and low evaporation. In New Hampshire’s only documented example, portions of the peat mat periodically supersaturate and slide over the edge.
Characteristic Vegetation: This community is floristically similar to alpine/subalpine bog but differs by having an abundance of Pickering's bluejoint (Calamagrostis pickeringii), mountain avens (Geum peckii), and Sphagnum compactum. Sphagnum compactum is a pioneer peat moss species that grows well on seepy, exposed bedrock or sand. Tussock bulrush (Trichophorum cespitosum), Sphagnum russowii, S. capillifolium, and S. girgensohnii are abundant, along with various shrubs including sheep laurel (Kalmia angustifolia), Labrador tea (Ledum groenlandicum), small cranberry (Vaccinium oxycoccos), black crowberry (Empetrum nigrum ssp. hermaphroditum), and bog laurel (Kalmia polifolia).
A good example of this community can be seen on the steeply-sloped brow of Cannon Cliff.
This community may occur as part of a larger alpine/subalpine bog system.
A subalpine sloping fen community occurs on the brow of Cannon Cliff
(left photo by Stephanie Neid; right photo by Ben Kimball)
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