Counties: Brown

Photos:

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Red Banks Glades. Cedar glade with rich understory. Photograph by NHI staff.

Site Description

Red Banks Glades is a privately owned site located in northeastern Brown County. It contains an unusual and unique array of natural communities that owe their origins to glacial and Great Lakes processes. Red Banks supports Wisconsin's best example of an alvar community and unusual variants of the prairie-savanna and cedar forest communities. The glades comprise a linear area 2 1/2 miles long by 1/4 to 3/4 of a mile wide that is perched on top and at the edge of the Niagara Escarpment, a bedrock feature composed of Silurian Age dolomite, extending from southeastern Wisconsin north and east to New York state. The site is characterized by areas of exposed bedrock and very thin soils. Moisture conditions vary widely throughout the year, ranging from inundated to extremely droughty.

Fire suppression and disrupted hydrology have allowed much of the vegetation to form an almost closed canopy dry forest of bur oak, shagbark hickory, red cedar, and aspen, with small scattered openings supporting plants characteristic of savanna or prairie communities such as big and little bluestem, Indiangrass, goldenrods, asters, and sedges. The exotics Kentucky bluegrass and smooth brome are common and sometimes dominant in the openings. The generally dense shrub layer includes the native New Jersey tea, common juniper, gray dogwood, ninebark, snowberry, and perfumed cherry, and the exotics common buckthorn and Tartarian honeysuckle. An interesting form of this community occupies abandoned pastures and consists of an open savanna of scattered red cedars, a scattering of native prairie species, and some herbaceous exotics such as Kentucky bluegrass.

A unique white cedar woodland community also occurs at this site, bordering Gilson Creek on the dolomite cobbles of the relict beach ridges left by Glacial Lake Oshkosh following its retreat. This community is dominated by white cedar, native sedges and the shrub, common juniper. The rare Great Lakes endemic, dwarf lake iris, is a local dominant in the groundlayer.

The western edge of the site is defined by the rocky bluffs of the Niagara Escarpment. Highly specialized, very rare land snails occupy cliffs, fissures, talus, and spring seepages associated with the bedrock. Trees growing on the forested portions of this geologic feature include some of the oldest red and white cedars known from Wisconsin.

Major disturbance factors affecting this site include hydrologic disruption, quarrying, heavy grazing, invasive plants, encroachment by residential development, and fragmentation by roads and power line corridors. A long history of fire suppression, in concert with these other factors, has altered the composition and structure of the alvar community by increasing the dominance of woody species. That being said, portions of this large site are relatively intact or restorable. In addition, many rare plant and animal species occur here, including several endemic to this area or with highly specialized habitat needs. In particular, invertebrate diversity is high in both the insect and land snail groups, with many rare taxa represented.

Additional Comments

This site contains unique geologic features, natural communities and rare species. Threats remain very high, and Red Banks Glades is a priority for immediate conservation attention.