Indiana Wildflowers: A Survey of Species Diversity in the Presence of Invasive Plant Species

Indianapolis, IN

Most state parks and forests have programs designed to contain and destroy invasive species in order to preserve the natural composition of native species in an area. In order to determine if the active removal of invasive species from a wooded area increases the species diversity of native wildflowers compared to unmanaged areas, vegetation surveys were performed in 8 different wooded areas located in central Indiana that differ in management/usage regimens from May 12 to June 6, 2014. Five sites actively managed the spread of invasive species while three sites had no invasive species management regime. At each site, ten random plots were sampled using a 1m2 grid made from PVC pipe. Within each plot, all species larger than 6 cm long were identified and counted. To assess species diversity, a Simpson's Index number was calculated for each of the eighty total plots assessed. A rank abundance curve was created for each site to represent species evenness at each site. Finally, species richness was determined by calculating the average number of species found at each of the eight sites. Although there was no significant difference among sites for species richness, an analysis of variance (ANOVA) indicated that management of invasive species and site location have a significant effect on the species diversity of wildflowers and herbaceous species in central Indiana.