Mahon Woods and Creek

Mahon Woods is a remnant of the diverse forests that once covered nearly all of Brown County. The upland portions are dominated by mature oaks (Quercus alba, Quercus rubra), in some places with an understory of sugar maple (Acer saccharum), a shade-tolerant tree that eventually may become a dominant species in this forest. A few large white pines (Pinus strobus) are conspicuous above the canopy of deciduous trees.

Other portions of the forest are younger and have a mixed tree species composition. Altogether about 59 species of trees and shrubs are known from Mahon Woods, along with a much greater number of herbaceous species in the ground layer. The spring wildflower displays here are spectacular during May. Large populations of trillium (Trillium grandiflorum), trout lily (Erythronium americanum, E. albidum), violets (Viola sororia, V. pubescens), toothwort (Dentaria laciniata, D. diphylla), and other species take advantage of the favorable light conditions that occur before leaf-out of the canopy trees.

Unlike intensively managed forests, Mahon Woods retains old and decaying trees or "snags," which provide important cavities for many types of animals, including southern flying squirrel (Glaucomys volans), raccoon (Procyon lotor), and eastern gray tree frog (Hyla versicolor). Fallen logs on the ground provide important shelter for species like short-tailed weasel (Mustela erminea) and red-backed salamander (Plethodon cinereus). If you listen carefully along the trails you will almost certainly hear cavity-nesting birds like red-bellied woodpecker (Melanerpes carolinus), black-capped chickadee (Poecile atricapillus), and white-breasted nuthatch (Sitta carolinensis), which thrive in the oldest portions of Mahon Woods. The name Mahon comes from the family homestead that was located near the mouth of Mahon Creek. Although the forest has been logged, the regenerating trees largely resemble the vegetation described by the Federal Land Survey in 1834. The woods have become an important sanctuary for birds and other animals in the increasingly urbanized landscape of eastern Green Bay. Except for places like Mahon Woods, species like the red squirrel have disappeared from much of their former range in central and southern Wisconsin.

A permanent forest study plot has been established in Mahon Woods. Teams of students are measuring trees in the plot to contribute data to an international forest ecology program run by the Smithsonian Institution. The woods are also routinely used by faculty and students for a variety of research projects including studies on snakes, arthropods, fungi, understory plants, and fish. Mahon Creek runs through much of the Mahon Woods and empties into the Bay of Green Bay. A water monitoring station records daily flow, precip, TSS loads; phosphorus loads; statistics; concentrations; and real-time data and is used for research activities by UW-Green Bay students and faculty.