Great Lakes Mesoscale convective complexs or MCCs can cause damage to wide swaths of forest and shatter glass in city buildings. These storms mainly occur during the night, and the systems sometimes have small embedded tornadoes, but more often straight-line winds accompanied by intense lightning. Historically, the Great Lakes, in addition to their lake ecology, were surrounded by various forest ecoregions (except in a relatively small area of southeast Lake Michigan where savanna or prairie occasionally intruded). Logging, urbanization, and agriculture uses have changed that relationship. In the early 21st century, Lake Superior's shores are 91% forested, Lake Huron 68%, Lake Ontario
Eastern Great Lakes and Hudson Lowlands (ecoregion) addition the World Wildlife Fund developed its own classification system, in which much of this region is called the Eastern Great Lakes lowland forests. Eastern Great Lakes and Hudson Lowlands (ecoregion) The Eastern Great Lakes and Hudson Lowlands region extends along the south shores of Lake Erie and Lake Ontario and the St. Lawrence River to Lake Champlain, and south down the Hudson River. It is primarily within the state of New York. In the north it meets the Mixedwood Plains Ecozone of Canada. It is mostly temperate deciduous forest and agricultural land. It is one of the 104 Level