page_title: Alvar
section_title: Some North American alvar locations
hierarchical_section_title: Alvar / Some North American alvar locations
caption_attribution_description: English: Alvar near Singing Sands Beach, Bruce County, Ontario
context_page_description: An alvar is a biological environment based on a limestone plain with thin or no soil and, as a result, sparse grassland vegetation. Often flooded in the spring, and affected by drought in midsummer, alvar support a distinctive group of prairie-like plants. Most alvars occur either in northern Europe or around the Great Lakes in North America. This stressed habitat supports a community of rare plants and animals, including species more commonly found on prairie grasslands. Lichen and mosses are common species. Trees and bushes are absent or severely stunted.
  The primary cause of alvars is the shallow exposed bedrock. Flooding and drought, as noted, add to the stress of the site and prevent many species from growing. Disturbance may also play a role. In Europe, grazing is frequent, while in North America, there is some evidence that fire may also prevent encroachment by forest. The habitat also has strong competition gradients, with better competitors occupying the deeper soil and excluding other species to less productive locations.
context_section_description: The rare Charitable Research Reserve – Cambridge, Ontario
  Lake Erie
  Kelley's Island, Ohio – North Shore Alvar State Nature Preserve
  Marblehead, Ohio – mostly destroyed by limestone quarrying
  Pelee Island, Ontario – Stone Road Alvar Nature Reserve
  Lake Huron
  Maxton Plains Proposed Natural Area, Drummond Island, Michigan
  Belanger Bay Alvar, Manitoulin Island, Ontario
  Quarry Bay Nature Reserve, Manitoulin Island, Ontario
  Bruce Alvar Nature Reserve, Bruce Peninsula, Ontario
  Baptise Harbour Nature Reserve, Bruce Peninsula, Ontario
  Misery Bay Provincial Park, Manitoulin Island, Ontario
  Lake Michigan
  Red Banks Alvar, Red Banks, Brown County, Wisconsin
  Lake Ontario
  Carden Plain Alvar, City of Kawartha Lakes, Ontario, including Carden Alvar Provincial Park
  Chaumont Barrens Preserve, New York
  Three Mile Creek Barrens, New York
  Burnt Lands Alvar, Almonte, Ontario
  Balsam Lake Indian Point Provincial Park, Ontario
  Quebec
  Quyon
  Alvar d'Aylmer
  Manitoba
  Interlake
caption: Alvar near the Singing Sands beach of Bruce Peninsula National Park, Canada
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