Eighteen years of herbaceous layer recovery of a recreation area in a mesic forest

We sampled permanent plots to observe the effects of removing recreational impacts on the botanical composition of the herbaceous layer vegetation in Feme Clyffe State Park, Illinois. Prior to 1979 this site was a recreationa l facility used primarily as a picnic and camping area. Seventeen 1 m(2) pl ots were sampled in 1979. 1981. 1988 and most recently in 1997. Exotic spec ies including Pou annua and Festuca pratensis dominated the flora early on, but these were replaced by mesic forest species including Carex jamesii, M uhlenbergia sylvatica and Ostrya virginiana. Species richness increased sig nificantly across the four sampling periods, and most markedly from 1988-19 97. Detrended Correspondence Analysis (DCA) was used to examine trends in o verall species composition. The ordination illustrates the change in specie s composition of the herbaceous layer that occurred over 18 years. Our stud y shows that with little active management or restoration, species diversit y increased as exotic species abundance declined and mesic forest species i ncreased. This suggests that given enough time after discontinuation of hig h impact recreational use, the vegetation will succeed to a community compa rable with the surrounding flora.