Gastony's cliffbrake and smooth cliffbrake in an alvar habitat in the Interlake area of Manitoba.

Gastony's cliffbrake and smooth cliffbrake in an alvar habitat in the Interlake area of Manitoba.

Alvar in Manitoba

April 22, 2013


NCC contributes to an understanding of globally rare alvar habitat in Manitoba

The Nature Conservancy of Canada (NCC) announces the discovery of a globally uncommon habitat in the Interlake region of Manitoba. The existence of this habitat only recently confirmed  as ”Alvar” is a plant community found only in a few countries in Europe and only a few provinces and states in North America. Alvar only occurs in areas with 10 cm or less of soil over unbroken limestone bedrock ‘pavement’ – an extreme environment which over the course of a single growing season can be prone to both temporary flooding and to extreme dryness.

The Alvar habitat in Manitoba was identified through a joint partnership between the Nature Conservancy of Canada, Manitoba Conservation & Water Stewardship, and the Manitoba Association of Plant Biologists. Approximately 9,700 acres (3925 ha) of Alvar habitat has been identified through the partnership known as the Manitoba Alvar Initiative.

Alvar is an important habitat for a variety of birds, reptiles, mammals and insects including; Red-sided Garter Snakes, Black Bears and Sharp-tailed Grouse. This habitat also provides important gene pools and sources of information about plant adaptation in extreme environments which could be applied in agricultural and horticultural research.

The Nature Conservancy of Canada is Canada’s leading national land conservation organization. Through partnerships NCC has secured over 23,000 hectares (55,00 acres) of important habitat in Manitoba. NCC Manitoba’s work is focussed on eight priority Natural Areas which include the Riding Mountain area, St. Lazare Plains, mixed-grass prairie and wetlands in southwestern Manitoba, the Whitemouth River Watershed, the Tallgrass Prairie and the Interlake region.

“A hearty ‘thank-you’ to the Interlake landowners, land managers and First Nations who have protected these sites for generations – it is because of their land stewardship that these rare habitats have persisted,” said Cary Hamel, the Nature Conservancy of Canada’s Conservation Science Manager for the Manitoba region.

"Manitoba is pleased to partner with conservation organizations and landowners to identify, manage, and protect alvars and the unique species that call them home,” said Manitoba Conservation and Water Stewardship Minister Gord Mackintosh. “This project helps us move ahead to meet our commitments in TomorrowNow – Manitoba’s Green Plan to protect special species and places across the province."
“The province has committed to provide $7 million in support for the Nature Conservancy of Canada Natural Areas Conservation Program to acquire and preserve ecologically significant lands in eight areas in southern Manitoba over nine years.”


  • Researchers recently determined that there may be fewer than 4,000 hectares (
  • Alvars are sometimes found in association with other interesting landforms such as inland cliffs and sinkholes which may support snake denning sites.
  • Manitoba’s Interlake region is characterized by ridges and lowlands that were created by the advancement and retreat of the glaciers. On some of these ridges, the soil was scraped or washed away from the limestone bedrock, leaving it flat and exposed.  It is on these exposed ridges that alvar is found.
  • The Interlake is the site of a number of new mosses and liverworts that were just recently discovered in Manitoba for the first time including rare Grimmia Dry Rock Moss.
  • Alvars and associated limestone cliffs and boulders support two rare cliffbrake fern species.
  • The combination of species in alvars is unique, some have an unusual mixture of boreal and prairie plants. Most alvars have an abundance of mosses and lichens that can grow on little or no soil and survive the harsh conditions. 
  • Private landowners are key to alvar conservation - one third of alvar sites are privately-owned.
  • 75% of alvar sites in Manitoba are grazed by livestock. Light grazing may be beneficial in some alvars by preventing the encroachment of trees and shrubs.


Alvar Report: Click on this link to read the 2012 Alvar Initiative Final Report

Alvar Fact Sheet:   Click on this link to read the Alvar Fact sheet

Alvar Story & Photos: Click on this link to read about Alvars and see photos

Rare Fern Discovery: Click on this link to read about the Shell Conservation Intern Discovery of a rare fern


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