Diminished Plant Richness and Abundance Below Lonicera maackii, an Invasive Shrub

The Asian shrub Lonicera maackii (Amur honeysuckle) is now common in many secondary forests in southwestern Ohio and adjacent states. We found lower species richness and abundance in plots (0.5 m2) placed below crowns of L. maackii than in plots placed away: all species (53% lower richness and 63% lower cover), tree seedlings with canopy potential (−41% richness and −68% density) and seed bud bank (−34% richness and −33% density). Moreover, most individual taxa had lower abundance below L. maackii: 86% of herbs, 100% of trees and 56% of seed bud bank taxa. In addition, richness of all species and richness and density of tree seedlings decreased in forests with longer residence time of L. maackii.