Have you ever wondered why the lakes in southern Minnesota are generally shallower and “greener” than the lakes in northern Minnesota? This difference is mainly based on a lake’s ecoregion. An ecoregion, is a geographical area where the land use (agriculture, forest, prairie, etc.), underlying geology, potential native plant community, and soils are relatively similar.

Many of these differences in soil fertility and underlying geology are from where the glaciers advanced and where they scraped and deposited till. Northern Minnesota was scraped fairly clean down to the bedrock, with boulders, sand and clay left behind, while southern Minnesota was left with a rich, fine prairie (now agricultural) soil. [Read more…]