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Great Lakes native flora

2 | Brief floral history of the Great Lakes basin

Before the European settlers arrived more than 400 years ago, the Great Lakes basin was made up of tallgrass prairies, oak savannas, woodlands and wetlands, and these different ecosystems were home to many land animals, birds and amphibians. Since then the region has lost much of its original landscape to agriculture, urban development and industry, such as logging. For example, approximately 65 percent of Illinois was originally tallgrass prairie; today, less than 0.01 percent of the original prairie remains. The Great Lakes region has also lost more than two-thirds of its natural wetlands to agriculture, urban uses, shoreline development, and recreation.

Click for larger image. Logging
In the mid-1800s, commercial logging became an important industry in the region. The earliest loggers harvested the easy to cut and abundant white pine; the pine was much in demand for shipbuilding and construction. The trees were hundreds of years old and could not be replaced quickly; when the pines were gone, lumbermen had to utilize other species. Hardwoods, such as maple and oak, were then cut to make furniture, barrels and specialty products.

Unfortunately, the forests of the region were often not reforested during this time of intense logging. Taking a look at the maps of Minnesota, Wisconsin and Michigan, you can compare the vegetation changes from the mid-1800s to the present. The gray areas are non-forested lands, including prairies, farmlands and urban areas. And when the land was replanted, different types of trees were often used, altering the ecosystem of the area even more.
Presettlement forests of the Great Lakes states
Modern forests of the Great Lakes states

Non-native plants
Another influence on the flora in the region has been the introduction of non-native, or nonindigenous, plants. As the area became more populated, people began bringing plants and trees from other regions to plant in their yards and fields. Click for larger image. Many of these non-native plants have no natural enemies to control their growth, therefore, they can out-compete native plants and eventually dominate a landscape. Diverse plant communities that once populated an area and supported a large animal community are often choked out by non-native plants, changing the ecosystem drastically.

Purple loosestrife is one of the most common non-native plants in the Great Lakes region. Once used in landscaping because of its beauty, purple loosestrife quickly invaded native plant areas and took over riverbanks and wetlands. For example, wetlands infested with purple loosestrife can lose as much as 50 percent of their native plants, limiting food and protection for birds and causing some birds to leave the region altogether. Today, growing purple loosestrife as an ornamental plant is discouraged, and it is illegal to sell it in nurseries in many areas.

Follow these links for lists of other non-native plant species
Illinois | Minnesota | Ohio | Wisconsin

Non-native species are not only limited to plants. Read TEACH's Non-native invasive species segment for information on invasive animal species.

Graphics: logging operation, 1890 (credit: Minnesota Historical Society); purple loosestrife infestation (credit: Great Lakes Indian Fish & Wildlife Commission)

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