The Effects of Fire versus Mowing on Prairie Plant Communities

Project summary:

Minnesota's Prairie and wetland ecosystems have been greatly diminished due to human encroachment, compounded by the invasion of exotic species. Restoration projects have been initiated at every civic level, including federally mandated prairie passages, networks of prairie preserves connected by corridors of prairie along roadsides and other rights-of-way. Such ecosystems are not maintenance free, however. Historically, fire has played a crucial role in maintaining prairies by preventing the invasion of shrubby species, removing litter cycling nutrients, and promoting the re-establishment of native grasses and wildflowers. Prescribed burning programs mimic the effects of naturally caused fires, yet may be difficult to implement in heavily trafficked roadside areas due to smoke effects and the threat of uncontrollable expansion of the burn. Specialized mowing has been proposed as an alternative to burning, as mowing can accomplish many of the same objectives as burning. Moreover, haying of roadside prairies by local farmers may be a cost-effective means of maintenance. However, mowing and burning may differentially affect soil composition, nutrients, temperature, and belowground communities, leading to divergent vegetation communities. Our primary goal for this project is to determine whether mowing can be a viable alternative to burning for managing roadside prairies in Minnesota. To this end, we will experimentally compare plant communities and soil parameters in burned versus mowed prairie plots in a MnDOT roadside prairie right of way. BY characterizing soil conditions under these management regimes, we may be able to determine mechanistic causes for differing vegetational outcomes, and make specific recommendations which could improve the vigor of roadside prairie communities.