Creation of Relatively Stable Shrublands with Herbicides: Arresting "Succession" on Rights‐of‐Way and Pastureland

Two decades of selective—use herbicide management on a demonstration right—of—way within the Connecticut Arboretum has resulted in a mosaic of relatively stable shrub communities and less stable herblands within the central hardwoods forest region. Areas of continuous dense shrub cover have resisted tree invasion for at least 15 yr. On abandoned pastureland shrub clones of Gaylussacia baccata, Smilax rotundifolia, and Vaccinium vacillans, from which associated tree growth was selectively removed, were analyzed for subsequent tree invasion. They have remained essentially stable for 5 yr, with virtually no tree invasion in the closed clones, as compared to pronounced invasion of the graminoid periphery of the clones. This stability can be explained in terms of Egler's "initial floristic composition" hypothesis for vegetation change, as explained in this paper. The ability of shrub communities to resist tree invasion has always belied the so—called classical concepts of succession and climax, as have the findings of other investigators. The substitution of the term "vegetation development" for "succession" and "relative stability" for "climax" would stimulate a more creative interpretation of vegetation dynamics. Creating relatively—stable shrub communities by the selective use of herbicides has practical applications in right—of—way and wildlife habitat management, naturalistic landscaping, and the maintenance of habitat diversity.