Alvar

Alvar

To some, it may look like an abandoned parking lot with weeds growing in the pavement cracks, but the life that flourishes in alvar areas is abundant and special. Alvar occurs in areas where all of the soils have been scraped away by wind, water and ice, leaving the 400 million year old limestone bedrock exposed. These areas are typically treeless, the vegetation dominated by grasses, sedges and herbs that grow in cracks within the bedrock, or in a very thin soil layer over the bedrock.

Alvar species must be able to tolerate extremes: when the sun beats down on the exposed rock of the alvar, temperatures climb, while in the winter, there is little to provide shelter or other relief from the cold. Three unusual early blooming flowers found in Michigan's alvar are Prairie Smoke (Geum triflorum), which is a species threatened with extinction in Michigan, the early buttercup (Ranunculus fasicularis), and also the early saxifrage (Saxafraga virginiensis). Other alvar species include osprey (state threatened), deer, bear, and a myriad of butterflies and moths, as well as shoreline and grassland bird species.

Areas of alvar are unique in a global sense, being found only in portions of Canada, the United States and Sweden. The alvars on Drummond Island, at the extreme east end of the Upper Peninsula, are the largest remaining high quality alvars in North America. Maxton Plains Proposed Natural Area on Drummond Island provides habitat for 10 Michigan state rare plants, and the unusual mix of arctic with prairie species is unique in itself.