Meadowsweet alluvial thicket (S3S4)
The meadowsweet alluvial thicket community occurs on riverbanks and open floodplains of large streams and small rivers throughout the state. The substrate is flooded when stream water levels are high in the spring. Shrub cover is moderate to high and dominated by meadowsweet (Spiraea alba). Other shrubs may be present in low (to low-moderate) cover. A shallow organic horizon often lies above a wet to mesic silt and fine sandy soil.
Characteristic Vegetation: Meadowsweet dominates this community. Several other woody species may be present, including witherod (Viburnum nudum), rhodora (Rhododendron canadense), brambles (Rubus spp.), red chokeberry (Aronia arbutifolia), male berry (Lyonia ligustrina), leatherleaf (Chamaedaphne calyculata), and seedling- and sapling-sized red maple (Acer rubrum), black cherry (Prunus serotina), balsam fir (Abies balsamea), and choke cherry (Prunus virginiana). Common herbs include bluejoint (Calamagrostis canadensis), fringed brome-grass (Bromus ciliatus), sallow sedge (Carex lurida), tussock sedge (C. stricta), Rudge’s sedge (C. debilis), inflated sedge (C. intumescens), bulrushes (Scirpus spp.), swamp candles (Lysimachia terrestris), water horehounds (Lycopus spp.), goldenrods (Solidago spp.), and northern blue flag (Iris versicolor). An expression of this community along the Swift River supports the uncommon Pickering’s bluejoint (Calamagrostis pickeringii).
A good example of this community occurs at the Annis Field recreation area along the Swift River (Albany). Other examples occur along the Ammonoosuc, Suncook, Soucook, Big, Swift, and Blackwater rivers.
Meadowsweet alluvial thickets often occur as a component community of emergent marsh - shrub swamp systems, low-gradient silty-sandy riverbank systems, and temperate minor river floodplain systems.
Meadowsweet alluvial thicket along the Soucook River in Loudon (photo by Dan Sperduto)