Seedling recruitment in artificial gaps

We examined the role of both intermediate-sized gaps and a dense shrub layer on subsequent tree seedling recruitment in a southern Appalachian deciduous forest. We monitored the density of tree seedlings in twelve artificial gaps and adjacent canopy controls under two contrasting understory conditions. Half of the experimental gaps were dominated by the dense, shade-producing shrub, Rhododendron maximum, while the remaining gaps were relatively open. Canopy gaps 20 m in diameter were created by girdling canopy trees, leaving standing dead trees with minimal disturbance to the understory. Density of first-year and first-year seedlings was monitored in transects extending from adjacent undisturbed forest through the experimental gaps.