Michigan’s natural features are the result of glaciation, where the topography created by ice, combine with water and climate, determine the natural plant communities that will be present. River Bend Gardens lies in a geographical region known as the Ann Arbor Moraines. Moraines are hills formed in parallel rows like a washboard that result from a glacier’s melting retreat that drops sand and stone along the ice edge. Occasionally along the ice edge a large chunk of dirty ice fractures off the glacier. As this ice melts, the sand and stone are deposited in an isolated mound away from the moraines, and this feature is known as a kame. River Bend Gardens has several kames. The property’s elevation at the river is 890 feet above sea level, while the highest point on the largest kame is 964 feet above sea level. This change in elevation makes for a very interesting topography in the gardens, where our kames hold the gardens’ Dry Mesic Southern Forest with its stately Oaks and Hickories. As the elevation drops heading west towards the river the forest gives way to savanna where the gardens’ Oak Opening transitions to the hay fields that are being restored to Dry Mesic Prairie.
The hydrology of the property is equally as interesting with the river frontage that harbors a Floodplain Forest along the western boundary. Running along the southern parameter of the property is a creek sourced from groundwater east of the property where it runs through the pond and continues west ultimately draining to the river. The eastern side of the property has a stream sourced from one of four springs on the property that runs south connecting to the pond creek and forming the Wet Mesic Prairie that is in need of love and attention to restore.
To document the natural features of River Bend Gardens, and confirm the plant communities that would have historically been present, we have engaged Michael A. Kost to set the course of our restoration. Mike was previously on staff at Michigan Natural Features Inventory, and is one of the authors of A Field Guide to the Natural Communities of Michigan, which is the definitive work on the subject. Mike is currently the Assistant Curator of the Matthaei Botanical Garden and Nichols Arboretum.
Mike’s survey of River Bend Gardens will eventually be published on the site.