An expert observer gives insight into Cedar Campus ecology.
No, alvar is not the name of some old Scandinavian man, but there are alvars in Scandinavia! An alvar is an exceedingly rare (globally rare) type of natural community that is characterized by shallow, calcareous soils over limestone/dolomite bedrock.
Harsh environmental conditions are typical of alvars with cold winters and hot, dry summers. Depending on precipitation patterns, drought and flooding are characteristic, creating an environment that is not conducive to supporting trees. Alvars support a distinctive suite of plants with rare species of sedges, grasses and other flowering forbs typical.
In the northern Great Lakes, alvars occur as sort of a geographic ring along the north shores of lakes Michigan, Huron, Erie and Ontario. While over 120 locations of alvars have been found in this region, these communities are usually small in size and very sensitive to human disturbance. Since most alvars are found near the Great Lakes shoreline, they are suffering tremendous pressure from residential development and mining of the limestone/dolomite.
Some of the best examples of these unusual communities are found from east of the Straits of Mackinac to Drummond Island and then south to the Bruce Peninsula of Ontario. Among the rare plants found on these alvars are dwarf lake iris, lance-leaved coreopsis, prairie smoke, red anemone, wild chives and alpine bluegrass. Alvars are also characterized by an unusual insect fauna, with many species being more common on grassland on the western Great Plains.
Maxton Plains alvar on Drummond Island
The two alvars near Cedar Campus are west of the largest and most distinctive alvars on Drummond and Manitoulin islands and don't have the characteristic rare species found on the latter sites. However, both the Narnia and Sandy Cove alvars are relatively undisturbed and very representative of this natural community. It is also possible that either or both of these sites have specific alvar rarities that have yet to be discovered.
Typical alvar species found at Cedar Campus are: wild calamint (Calamintha Arkansana), columbine (Aquilegia Canadensis), bellflower (Campanula rotundifolia), smooth agalinis (Agalinis purpurea), Indian paintbrush (Castilleja coccinea), brook lobelia (Lobelia kalmi). shrubby cinquefoil (Potentilla fruticosa), and dune lily or death camas (Zigadenus glaucus). While none of these are rare species, their clear assemblage identifies these areas as alvars.
This compact alvar is part of the "Narnia" (historically Bush Bay) shoreline.
Posted on: Apr 4, 2006 Last modified on: Jan 9, 2007
