PARENT SESSION
Oral Session #8: Restoration Ecology: Grasslands, wetlands, aquatic. Presiding: G. Noe.
Monday, August 6, 2001. 8:00 AM to 12:15 PM. Hall of Ideas H.
Developing a predictive framework for the restoration of Midwestern prairie-savanna plant communities.
Suding, Katharine1,2, Gross, Katherine1, 1 2
ABSTRACT- While restoration ecology has been criticized for taking an ad hoc, site-specific approach, there has been little success in generating principles to guide restoration efforts across a wide range of sites. This difficulty may be due, in part, to the dependency of many management techniques on site characteristics. To predict how site conditions influence management techniques, we established an experiment to examine the effects of seed addition, woodchip addition, and time of burning across seven degraded prairie-savanna sites in southwestern Michigan. These sites varied in their exotic species/floristic quality and productivity. In late April and mid-July we established experimental burn crossed with woodchip addition treatments to 25m2 plots in all seven sites. Seeds of 21 native species were added to subplots immediately following the treatments. After one growing season, burning in the summer, but not in the spring, enhanced the relative abundance of exotic species. The effect of native seed addition was greatest at more productive sites. While burning enhanced recruitment at sites dominated by exotic species, it had little or even negative effects on recruitment at sites with higher floristic quality. Addition of woodchips had weak positive effects on recruitment at all sites. These results suggest that there may be easily measurable site characteristics, such as proportion of exotic species or productivity, that can predict the site-specific success of particular restoration techniques in grasslands.
KEY WORDS: floristic qualitic index, burn timing, exotic species control, native species recruitment