Natural Communities of NH -- Photo Guide

Liverwort - horned bladderwort fen  (S3)


[note: community formerly named liverwort - horned bladderwort mud-bottom]

Liverwort - horned bladderwort fens consist of low, turfy mats of leafy liverworts that turn black and look like mud from a distance. Since this community tends to occur as patches within a larger peatland system, it is often isolated from the minerotrophic influence of upland runoff and the water is very acidic (pH averages 3.9). 

In this community, peat is typically poorly decomposed near the surface and has a relatively flat profile (hummocks are generally <0.20 m; average hummock height is 0.10 m). The average height of dwarf heath shrubs is 0.15 m. Mud-bottoms generally occur in association with floating or grounded peat mats of pond-border or lake-fill kettle holes. It occurs statewide, but is concentrated in southern and central areas where kettle holes are more abundant.

Characteristic vegetation:
The substrate is generally a saturated bed of peat moss (Sphagnum spp.). Sphagnum cuspidatum, Cladopodiella fluitans, horned bladderwort (Utricularia cornuta), white beak-rush (Rhynchospora alba), and spatulate-leaved sundew (Drosera intermedia) are all diagnostic and usually abundant. Dwarf shrubs are stunted (usually <0.2 m) and often contribute less than 10% cover. The most frequent shrubs that may be present are small cranberry (Vaccinium oxycoccos), bog rosemary (Andromeda glaucophylla), and leatherleaf (Chamaedaphne calyculata). Other species found in this community, but that also occur in other oligotrophic dwarf shrub peatland communities include Sphagnum rubellum, S. magellanicum, pitcher-plant (Sarracenia purpurea), and round-leaved sundew (Drosera rotundifolia). Trees and tall shrubs are always absent in this community.

North of the
White Mountains, meager sedge (Carex exilis) may be abundant in this community. Such fens with meager sedge can be the dominant community in the wet “flarks” of some patterned fens.


Good examples of this natural community occur at South Bay Bog (Clarksville), Lost Ponds (Ossipee), Cedar Swamp Pond (Kingston), Philbrick-Cricenti Bog (New London), and Little Church Pond (Livermore/Albany), and in the kettle hole bogs at White Lake State Park (Tamworth).

Liverwort - horned bladderwort fens
 usually occur as part of larger kettle hole bog systems, and less commonly as part of patterned fen systems.


Band of liverwort - horned bladderwort fen in the peat mat at Philbrick-Cricenti Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)
Band of liverwort - horned bladderwort fen in the peat mat
at Philbrick-Cricenti Bog in New London (photo by Ben Kimball)

Band of liverwort - horned bladderwort fen at Philbrick-Cricenti Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)
Band of liverwort - horned bladderwort fen in the peat mat
at Philbrick-Cricenti Bog in New London (photo by Ben Kimball)

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