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A.1402 | EcoArt 2002
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Name: A.1402
Reference: EcoArt 2002
Description: This alliance occurs around the eastern and central Great Lakes. The physiognomy is dominated by sedges and grasses with scattered shrubs, and sometimes trees, growing in thin soil over calcareous bedrock. Areas of exposed bedrock pavement are common. There are three mosaic patches that typically make up stands of this alliance. The dominant species in each are as follows: Mosaic Patch 1: ~Schizachyrium scoparium, Sporobolus heterolepis, Carex scirpoidea$, and ~Carex$ spp. Mosaic Patch 2: ~Eleocharis compressa, Andropogon gerardii, Muhlenbergia richardsonis$, and ~Spartina pectinata$. Windthrow is probably common in alvar because of the thin soils and proximity to major streams (which often funnel windstorms) and the Great Lakes. The thin soils are also droughty, giving the potential for tree-killing drought or ground fires. Thus, stands of this alliance are maintained as primarily herb-and-shrub-dominated communities. Flooding after spring snowmelt may also limit tree growth by creating anaerobic conditions for a few weeks. ^Alvar is found over calcareous bedrock (dolomite or limestone) of Middle and Late Ordovician and Early Silurian origin. Within these sites there are three mosaic patches: Mosaic Patch 1 in places where there is a soil layer of about 15 cm over bedrock and in areas where soil is present only in crevasses in bedrock; Mosaic Patch 2 in moist areas. The soils are mildly to moderately alkaline (pH 7.2-8.0) sandy loams or loamy sands less than 25 cm deep. Although saturated by water in the spring, they are very droughty in the summer. Lower areas can be more moist and therefore often develop loam. 
Accession Code: VB.CC.1176.A1402
Plot-observations of this Community Concept: 0
      Party Perspective according to: NatureServe (organization)
Perspective from: 26-Nov-1997 to: 17-Mar-2005
     
  • status: accepted
  • Community's Parent: V.A.5.N.c
  • This Community's Level: Alliance
  • This Community's Children: [none]
Names:   Scientific: SPOROBOLUS HETEROLEPIS - (DESCHAMPSIA CAESPITOSA, SCHIZACHYRIUM SCOPARIUM) HERBACEOUS ALLIANCE
  Code: A.1402
  Common: Prairie Dropseed - (Tufted Hairgrass, Little Bluestem) Herbaceous Alliance
(convergence) and Synonyms:
(undetermined) Sporobolus heterolepis - (Deschampsia caespitosa, Schizachyrium scoparium) Herbaceous Alliance