Tuesday, August 7, 2007

PS 30-93: Initial response of forest communities to removal of the invasive Amur honeysuckle (Lonicera maackii)

Richard L. Boyce, Northern Kentucky University

Four forest stands with different coverage levels of the invasive exotic shrub Amur honeysuckle (Lonicera maackii (Rupr.) Herder) at Woodland Mound Park in Hamilton County, Ohio, were surveyed in summer 2005, using 1000-m2 modified Whittaker plots. Honeysuckle was cleared in fall 2005, and the stands were resurveyed in summer 2006. Species number increased at 2 out of the 3 most heavily honeysuckle-infested sites, and this was also reflected in species accumulation curves with higher intercepts and slopes at those two sites. There are indications that both species loss and entry rates were higher in the more heavily infested sites. The total number of invasive exotic species increased at the 3 most heavily infested stands after honeysuckle removal, and the number that flowered increased at 2 of these stands. Total herb coverage did not show a response to honeysuckle removal, however. Shannon diversity and evenness also showed little change at any site. Stands with lower initial honeysuckle infestations in 2005 had quite similar community compositions after removal, whereas those with higher infestations showed greater changes. Thus, initial forest community response to honeysuckle removal is manifested mainly as an increase in the number of species present.