Name:
Alnus incana - Cornus sericea / Clematis virginiana Shrubland
Reference:
Eastern Ecology Working Group of...
Description:
These shrublands occur along large streams and rivers in New England and northern New York. They are found on river-margin alluvial deposits of moderate-energy reaches, where the flooding regime prevents forests from developing. The setting can range from flats to moderately steep banks; soils are usually sandy or silty and have little organic matter. Most are temporarily flooded, and the soils may not remain saturated through the entire growing season. Tall shrubs (1.5-3 m in height) dominate the vegetation, usually forming at least 50% cover and often creating a dense thicket. The amount of lower shrub and herb vegetation varies inversely with the tall-shrub canopy. Bryophytes are usually sparse, but may be locally abundant in some settings. Alnus incana is a constant and usually dominant shrub. In some cases, Alnus serrulata (in more temperate settings) or Alnus viridis (in more boreal settings) may occur with or in place of Alnus incana. The ability of alders to bend under strong currents, and their nitrogen-fixing root nodules, may give alders a competitive advantage over other shrubs in this setting. Cornus sericea and Salix spp. are frequent associates and may dominate in some areas. Viburnum nudum var. cassinoides is occasional but not abundant. Acer rubrum, Prunus serotina, Ulmus americana, and/or Acer saccharinum may be present, as sparse individuals; in more southerly examples of this type, Acer negundo and Salix nigra may occur. Spiraea alba is usually present, and may be abundant, as a lower shrub. Clematis virginiana is a typical vine, often clambering in tangles on the shrubs. Common herbs include Doellingeria umbellata (= Aster umbellatus), Calamagrostis canadensis, Elymus riparius, Elymus virginicus, Eupatorium maculatum, Iris versicolor, Lycopus uniflorus, Lysimachia ciliata, Lysimachia terrestris, Osmunda claytoniana, Matteuccia struthiopteris, Onoclea sensibilis, and Thalictrum pubescens. This type is distinguished from other northeastern Alnus-dominated associations by its alluvial setting. Although common, this association is little studied and comprehensive surveys have yet to be undertaken.
Accession Code:
VB.CC.26522.ALNUSINCANACORN
Plot-observations of this Community Concept:
0
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