By Mitch Lex
On Thursday March 22, Stewardship Coordinator Andrew Bacon set out with fellow MNA Regional Stewardship Organizers Katherine Hollins and Matt Schultz to conduct the first set of controlled burns of the season. One of them was at Big Valley Nature Sanctuary. With the assistance of five volunteers, the stewardship staff was able to successfully burn 10 acres of the Big Valley sanctuary—a process that is vital to the ecological health of the prairie fen and oak upland communities found there.
The essential burn invigorates the native flora and fauna at the sanctuary by damaging the encroaching woody overgrowth, and creates additional opportunity for sun to infiltrate the understory and create future habitat. Without prescribed burns, hardwood canopies can become too dense and crowd out the essential undergrowth altering the composition of the prairie and forest floors. Invasive species such as the autumn olive and dogwood are kept in check by prescribed burns.
Several rare insect species found at Big Valley Nature Sanctuary as well as numerous species of snake also depend on burning for the long term survival of the population. The endangered tamarack tree cricket and poweshiek skipperling both rely on the open canopy characteristics found in prairie fens at Big Valley. To protect reptiles, insects and other species that have difficulties escaping burns, MNA patrols the burn unit prior to the burn and moves individuals out of the area. Smaller units are burned in sanctuaries with fire-sensitive species to protect the overall population. Backing fire is used as much as possible in sites with more reptiles, giving them more time to take cover.
Although prescribed burning is essential to the protection of many of MNA’s sanctuaries, it does not come without risk. The MNA staff plans out burn units several months in advance and must track the burn history of each sanctuary to ensure the areas of most concern are being treated. Following a burn, MNA monitors the results.