Spring Floral Community in a Kentucky Forest Influenced by Amur Honeysuckle (<i>Lonicera maackii</i>) Density and Removal

Amur honeysuckle (<i>Lonicera maackii</i>) is an invasive shrub introduced to the U.S. in the late 1800s for ornamental use. Since its introduction, it has spread throughout the eastern U.S., becoming especially problematic in urban and peri-urban forest fragments. Once introduced in an ecosystem, <i>L. maackii</i> establishes a dense thicket that restricts understory light and alters understory plant communities. This study monitored the flowering early spring floral community in forests with varying densities of <i>L. maackii</i> (high, low, and no-density) before and after <i>L. maackii</i> removal in Raven Run Nature Sanctuary, a natural area on the outskirts of Lexington, KY, U.S. In plots from which <i>L. maackii</i> was removed, we documented higher flowering spring flora abundance (102–125%), diversity (32%), and richness (47%) compared to plots from which <i>L. maackii</i> was not removed. While abundance did not vary with prior <i>L. maackii</i> density, diversity and richness were 40% and 53% higher, respectively, in plots with low prior <i>L. maackii</i> density than high prior <i>L. maackii</i> density. Finally, flowering plant assemblages were similar across prior <i>L. maackii</i> density (low vs. high) but differed with <i>L. maackii</i> removal treatment (removed vs. unremoved and no <i>L. maackii</i> vs. removed). Flowering spring plants quickly recover after <i>L. maackii</i> removal, but some residual effects of <i>L. maackii</i> continue to structure understory plant communities even after removal. Early removal of. <i>L. maackii</i> from invaded stands and continued management to prevent re-introduction are essential to support recovery of diverse understory plant communities in affected forests.