Stability of Viburnum lentago Shrub Community After 30 Years

Abstract
A nannyberry (Viburnum lentago L.) shrub community on a post-agricultural site has exhibited remarkable resistance to invasion by the surrounding hardwood forest species for at least 55 years. Since the initial survey in 1953 the density of Viburnum stems > 2.5 cm dbh has dramatically declined from 14 x 103 to 6.5 x 103 ha-1. Viburnum canopy has also decreased considerably. Seedling reproduction of white ash (Fraxinus americana L.) has increased and sugar maple (Acer saccharum Marsh.) is now present. However, tree seedlings present in 1954 have not penetrated the canopy. These results provide support for Connell and Slatyer's (1977) Inhibition Model, a proposed successional mechanism operative in community change. Such shrub stability is relevant to wildlife and right-of-way vegetation management and the maintenance of landscape diversity.