Red Maple – Mixed shrub Palustrine Woodland
PA Ecological Group(s): Basin Wetland
State Rank: S5
This community type usually occurs on mineral soil with a thin layer of muck. The pH is somewhat acidic to circumneutral. Trees are sparse (10-60% cover) and generally less than 30 feet tall. Red maple (Acer rubrum) dominates the canopy, sometimes with a mixture of other trees such as blackgum (Nyssa sylvatica), Eastern hemlock (Tsuga canadensis), eastern white pine (Pinus strobus), black willow (Salix nigra), swamp white oak (Quercus bicolor), pin oak (Q. palustris), and black ash (Fraxinus nigra). The shrub layer is typically dense and includes silky dogwood (Cornus amomum), winterberry (Ilex verticillata), spicebush (Lindera benzoin), smooth alder (Alnus serrulata), silky willow (Salix sericea), swamp rose (Rosa palustris), and buttonbush (Cephalanthus occidentalis). Ferns usually dominate the herbaceous layer. Characteristic species include marsh fern (Thelypteris palustris), cinnamon fern (Osmunda cinnamomea), sensitive fern (Onoclea sensibilis), crested wood fern (Dryopteris cristata), and royal fern (Osmunda regalis). Other herbs include skunk-cabbage (Symplocarpus foetidus),
beggar-ticks (Bidens spp.), jewelweed (Impatiens capensis), and in wetter areas, arrow-arum (Peltandra virginica), wapato (Sagittaria latifolia), and marsh-marigold (Caltha palustris).
Common, widespread, and abundant in the nation or state.
- Tree cover between 10 and 60%, dominated by red maple (Acer rubrum) and usually less than 30 feet tall
- Shrub layer is extremely dense with shrubs growing on hummocks, including silky dogwood (Cornus amomum), winterberry (Ilex verticillata), spicebush (Lindera benzoin), smooth alder (Alnus serrulata), silky willow (Salix sericea), swamp rose (Rosa palustris), and buttonbush (Cephalanthus occidentalis).
- Have standing water between the hummocks for most of the year with wapato (Sagittaria latifolia), bur-reed (Sparganium americanum), and other emergent aquatic plants
*Vascular plant nomenclature follows Rhoads and Block (2007). Bryophyte nomenclature follows Crum and Anderson (1981).
International Vegetation Classification Associations:
NatureServe Ecological Systems:
Northern Appalachian-Acadian Conifer-Hardwood Acidic Swamp (CES201.574)
North-Central Appalachian Acidic Swamp (CES202.604)
Central Appalachian Stream and Riparian (CES202.609)
Origin of Concept
Pennsylvania Community Code*
*(DCNR 1999, Stone 2006)
Similar Ecological Communities
Red Maple – Mixed shrub Palustrine Woodland differs from the Red Maple – Highbush Blueberry Palustrine Woodland and Red Maple – Sedge Palustrine Woodland in that the dominant shrub species is a combination of silky dogwood (Cornus amomum), winterberry (Ilex verticillata), spicebush (Lindera benzoin), smooth alder (Alnus serrulata), silky willow (Salix sericea), swamp rose (Rosa palustris), and/or buttonbush (Cephalanthus occidentalis). Red Maple – Sedge Palustrine Woodland lacks a definitve shrub layer and is dominated by sedge species in the herb layer. Red Maple – Highbush Blueberry Palustrine Woodland has a shrub layer dominated by highbush blueberry (Vaccinium corymbosum).
Red Maple – Mixed shrub Palustrine Woodland
This community serves as nesting habitat for birds such as swamp sparrow (Melospiza georgiana), yellow-rumped warbler (Dendroica coronata), and American goldfinch (Carduelis tristis) as well as foraging habitat for wood ducks (Aix sponsa), black ducks (Anas rubripes), and bat species. This community may serve as habitat for many species of dragonflies and damselflies. 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.
Red Maple – Mixed shrub Palustrine Woodlands are threatened by habitat alteration in the watersheds they occupy and nutrient input from surrounding uplands. Clearing and development of adjacent land can lead to an accumulation of run-off, pollution, and sedimentation. Clearing adjacent lands can also lead to wind damage since the trees have shallow root systems. Alterations to the hydrologic regime (beaver dams, road crossings that impede water movement, lowering or raising of water tables) may actually encourage this wetland type. Invasive exotic plant species are a threat when there is nutrient input from surrounding uplands. Species such as common reed (Phragmites australis ssp. australis), purple loosestrife (Lythrum salicaria), and other exotic invasive species can become abundant with increases in nutrients, sediments, and other disturbances.
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 (i.e., 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 in the wetland should be avoided (e.g., roads, trails, filling of wetlands). Where disturbances are unavoidable, the wetland should be monitored for changes in vegetation, especially invasive species.
Variations may occur at ecoregional levels. There is a need to collect plot data to characterize variations and guide further classification of this community.
This community tends to benefit from disturbance and may be expanding due to beaver population expansion as well as hydrological alterations resulting from housing development and road construction.
Connecticut, Delaware, Maine, Massachusetts, New Hampshire, New Jersey, Pennsylvania, Rhode Island, and Vermont
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Davis T. 2011. Pennsylvania Natural Heritage Program. Red Maple – Mixed shrub Palustrine Woodland Factsheet. Available from: https://naturalheritage.state.pa.us/Community.aspx?=16048 Date Accessed: July 02, 2022