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System: Palustrine
Subsystem: Shrubland
PA Ecological Group(s): Basin Wetland

Global Rank: G4, G3G5 rank interpretation
State Rank: S5

This community type usually occurs in small upland depressions or in basins surrounding small streams and drainages. The substrate is typically very poorly drained but lacks a thick organic layer. These wetlands are seasonally to permanently flooded, often influenced by beaver or other impoundments. The pH of these wetlands is less acidic to circumneutral.

Highbush blueberry (Vaccinium corymbosum) and meadow-sweet (either Spiraea latifolia or Spiraea alba) are usually both present. Additional woody species include shadbush (Amelanchier spp.), speckled alder (Alnus incana ssp. rugosa), arrow-wood (Viburnum recognitum), steeplebush (Spiraea tomentosa), swamp dewberry (Rubus hispidus), winterberry (Ilex verticillata), elderberry (Sambucus canadensis), and seedling and sapling size red maple (Acer rubrum). The herbaceous layer is generally dominated by graminoids such as tussock sedge (Carex stricta), rushes (Juncus spp.), and spike-rushes (Eleocharis spp.), and by ferns, especially cinnamon fern (Osmunda cinnamomea), royal fern (O. regalis), sensitive fern (Onoclea sensibilis), and marsh fern (Thelypteris palustris). Forbs like marsh St. John's-wort (Triadenum virginicum), skunk-cabbage (Symplocarpus foetidus), and jewelweed (Impatiens spp.) may also occur. Sphagnum either forms a continuous layer or occurs on hummocks.

Common, widespread, and abundant in the jurisdiction.

*Vascular plant nomenclature follows Rhoads and Block (2007). Bryophyte nomenclature follows Crum and Anderson (1981).

Plant species of conservation concern found in this community may include screwstem (Bartonia paniculata). This community also serves as a buffer for sediment and pollution runoff from adjacent developed lands by slowing the flow of surficial water causing sediment to settle within this wetland.

Highbush Blueberry – Meadow-sweet Wetlands are threatened by habitat alteration (e.g., conversion to agricultural land, logging in adjacent uplands), deposition (e.g., sedimentation, nutrient loading), and alterations to the hydrological regime (e.g., removal of beaver dams or other impoundments, lowering of the water table). Invasive species such as reed canary-grass (Phalaris arundinacea) may alter the species composition of this community type.

A natural buffer around the wetland should be maintained in order to minimize nutrient runoff, pollution, and sedimentation. The potential for soil erosion based on soil texture, condition of the adjacent vegetation (mature forests vs. clearcuts), and the topography of the surrounding area (e.g., degree of slope) should be considered when establishing buffers. The buffer size should be increased if soils are erodible, adjacent vegetation has been logged, and the topography is steep as such factors could contribute to increased sedimentation and nutrient pollution. Direct impacts and habitat alteration should be avoided (e.g., roads, trails, filling of wetlands) and low impact alternatives (e.g., elevated footpaths, boardwalks, bridges) should be utilized in situations where accessing the wetland cannot be avoided. Care should also be taken to control and prevent the spread of invasive species within the wetland. Alterations to groundwater sources should be minimized.