DISTRIBUTION OF THE NON-NATIVE SHRUB LONICERA MAACKII IN KRAMER WOODS, OHIO

Abstract

This study examined the distribution of Lonicera maackii (Amur honey-suckle) in a 5.2-ha old-regrowth deciduous forest in southwestern Ohio, and focused on its associations with: (1) forest-edge and internal-forest conditions; and (2) composition and structure of the native flora. Fine-scale vegetation patterns were measured in 60 nested plots and mapped with a geographic information system. L. maackii accounted for 24% of the relative importance of understory trees and shrubs based on its density (3361/ha), frequency (95%), and basal area (1.89m²/ha). Within-patch densities correlated significantly with edge attributes, but stem-basal areas were best explained by a covariate model that coupled edge conditions with internal topographic settings. Detrended correspondence analysis identified spatial patterns of community diversity in the understory native flora, and honeysuckle abundances were highest in small discontinuous community patches. Species richness and densities of native shrubs (Lindera benzoin and Viburnum prunifolium) and Acer saccharum saplings were lower when honeysuckle abundances were >3000/ha and/or basal areas were >4 m²/ha. These findings identified the importance of forest-edge and internal-forest conditions on spatial patterns of invasion by L. maackii and support management plans that target locations within a forest patch and forest-patch locations of highest potential impact. [Key words: conservation, eastern deciduous forest, exotic plants, forest ecology, landscape ecology.]