What is an alvar? Burnt Lands Alvar: rare ecosytem
What is an alvar?
The word alvar refers to an open area of limestone or marble pavement ‘barrens’ or ‘plains’ with little or no soil or may sometimes refer to the plant community found there (as on the Swedish ‘Great Alvar’ on the island of Oland, Sweden).
Alvars have unique ecological features that support distinctive flora and fauna. Alvar environments are rare and are recognized as globally imperiled ecosystems by The Nature Conservancy of Canada. Often flooded in the spring and affected by drought in midsummer, they are home to a very hardy group of flora and fauna that have adapted to the harsh conditions of the alvar.
From a conservation perspective, alvar communities command interest because of their rarity, distinctive character and their large number of rare species; some of these rare species may be relicts from ancient times which became isolated populations surviving where other species cannot.
“What alvars have in common is an ancient and unforgiving environment, a set of climatic and geographic parameters that seem designed to make it as challenging to life forms as any habitat on the temperate side of the Arctic circle.”
Dan Brunton: ” . . anything that can grow there is one tough cookie”
Summary: alvars are globally imperiled ecosystems; home to rare life forms; relicts of an earlier postglacial landscape
Burnt Lands Alvar: a rare ecosystem of exceptional quality
The Burnt Lands Alvar, designated as a provincially significant Area of Natural and Scientific Interest (ANSI), is an outstanding example of alvar habitat – combining various vegetation communities on alvar pavement, alvar grasslands, alvar shrub lands, treed alvar and wetlands. Besides its unique flora, the alvar also supports 82 breeding bird species, 48 butterfly species, 98 species of owlet moths, globally rare species of land snail, globally rare invertebrates, and a kind of carabid beetle found nowhere else in the world.
The alvar meadows and rock flats communities on the Burnt Lands Alvar are provincially significant. Although the alvar is not a prairie, its significant grassland meadows of dropseed are extensive and considered equivalent to grassland habitat of the Great Plains and a relict from the receding glaciers.
The Burnt Lands Alvar : ” . . . stands in a class by itself in terms of condition, extent, alvar development, and significant species and features. Due to the rarity of alvar environments, and the exceptional quality of the Burnt Lands, there has been, and will continue to be, significant research interest by MNR, university, conservation and scientific groups and others.” [reference/link to Burnt Lands Interim Management Statement, Ontario Parks, 2001].
Summary: Burnt Lands Alvar is home to western prairie-like grasslands, unique rare species, unusual fossils and is an important research and teaching site.
Blue link below: a recent presentation What is an Alvar? and What’s So Special about the Burnt Lands Alvar by Ken Allison to the Mississippi Valley Field Naturalists on January 15, 2015 (note: all photos in the pdf by Ken Allison except title page picture from Wikipedia). Ken Allison is an expert naturalist and former President of both the Ottawa Field Naturalist’s Club and the Mississippi Valley Field Naturalists.
Burnt Lands Alvar MVFN Walk in 2009 led by alvar expert/botanist Dr. Paul Catling; snail found on alvar during walk (photos Pauline Donaldson); Fringed Gentian (photo Cathy Keddy).