Common (Translated Scientific) Name: Red Maple - Red Spruce - Eastern Hemlock Swamp Group

Colloquial Name: Laurentian-Acadian Acidic Swamp

Hierarchy Level:  Group

Type Concept: This group includes north-temperate acidic, nutrient-poor swamps of the northeastern U.S. and adjacent Canada, from southeastern Canada and New England to New York through the Central Appalachians south to Virginia and west to Ohio. They occur on mineral soils that are nutrient-poor; there may be an organic epipedon, and the substrate may be shallow to deep peat. Most are basin wetlands that remain saturated for all or nearly all of the growing season, and may have standing water seasonally. Some occur on gently sloping seepage lowlands, and even basin settings may have some seepage influence, especially near the periphery. Acer rubrum is a nearly constant and often dominant to codominant tree species. It may form a mostly deciduous canopy with Fraxinus spp., Betula alleghaniensis, or Nyssa sylvatica, or it may be mixed with conifers. Tsuga canadensis is the most widespread conifer in associations of this group. From central New England and New York north, Picea rubens is a characteristic associate (less commonly Picea mariana). Larix laricina, Pinus strobus, and Abies balsamea are occasional and in some places may be locally important. The herbaceous and shrub layers tend to be fairly species-poor. Ilex mucronata, Viburnum nudum var. cassinoides, Ilex verticillata, and Vaccinium corymbosum are typical shrubs through much of the range of this group, and Rhododendron maximum is often important in the central and southern portions of this group''s range. Typical herbs include Osmunda spp., Onoclea sensibilis, Dryopteris cristata, Carex folliculata, Carex intumescens, Carex stricta, and Carex scabrata, among others. Sphagnum is an important component of the bryoid layer. In many swamps, species richness tends to be higher near the periphery where seepage waters influence the hydrology.

Diagnostic Characteristics: Tree growth form with any combination of Picea rubens, Tsuga canadensis, Acer rubrum (>20% Relative Importance Value), and other tree species are any combination of Betula alleghaniensis, Abies balsamea, Ulmus americana, Pinus strobus (>30% RIV); Liquidambar styraciflua absent or of minimal importance; wetland shrubs and herbs characterize the understory layers.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Analyses of FIA plot data from the eastern U.S. combined this group and ~Laurentian-Acadian Alkaline Swamp Group (G046)$$ into a Northern White-cedar - Hemlock - Red Spruce Conifer Swamp Group (Faber-Langendoen and Menard 2006). In review, this FIA group was split based on broad patterns of substrate pH, with this group housing the more acidic swamps and G046 housing the more alkaline swamps. Distribution of north-central midwestern acidic swamps (specifically ~Larix laricina / Aronia melanocarpa / Sphagnum spp. Swamp Forest (CEGL002472)$$), share characteristics of both alkaline and acidic swamps, and contain boreal elements. Perhaps CEGL002472 could be placed in ~Laurentian-Acadian Alkaline Swamp Group (G046)$$.

Similar NVC Types: No Data Available

note: No Data Available