Until the late 1980’s, the ornamental shrub Amur Honeysuckle (Lonicera maackii) was promoted by the USDA Soil Conservation Service to control erosion and to provide food and habitat for wildlife. Amur Honeysuckle has fallen out of favor with conservation organizations since its negative effects on native forest plant species have been recognized. Coralberry (Symphoricarpos orbiculatus), a native species, could be used in place of Amur Honeysuckle for erosion control, wildlife conservation/restoration, and ornamental landscaping. The objectives of this study were to compare Coralberry and Amur Honeysuckle and determine if Coralberry has similar negative effects on forest communities. In spring of 2001, Coralberry was removed from three 100-m2 plots in Burgner Acres Nature Area, Loxa, IL. Control plots were established and twenty 1-m2 quadrats were surveyed in each plot. Four transects were established, three at Burgner Acres and one at Hidden Springs State Forest, Strasburg, IL. Thirty quadrats were sampled along each. All vascular plants species and percent cover of Coralberry and Amur Honeysuckle were recorded. ANOVA test results showed a small but highly significant (P=. 01) increase in mean herbaceous species richness (6.4 control, 7.3 removal) and mean woody species richness (1.3 control, 1.5 removal) in coralberry removal plots. Regression analysis of transect data showed a significant (P=0.016) negative association between percent cover of coralberry and herbaceous species richness (slope= -0.25). There was a highly significant (P=0.001) association between percent cover of Amur honeysuckle and herbaceous species richness (slope= -0.31). There was no significant association between percent cover of either shrub and woody species richness. Although both species show a negative effect on forest herbs, coralberry lacks sufficient size to achieve the high level of cover or form the dense thickets characteristic of Amur honeysuckle.

Key words: Caprifoliaceae, exotic species, invasive species, Lonicera maackii, species richness, Symphoricarpos orbiculatus