LAUSR

ABSTRACT  In response to widespread losses of savanna ecosystems worldwide, many restoration efforts are underway. For savannas degraded by fire suppression and hardwood invasion, a first step towards restoration typically involves removal of unwanted trees and shrubs, but after invasive nonnative woody plants are top-killed, savanna restoration is often impeded by their resprouts. To evaluate patterns of vegetative recovery following clear-cuts and to explore their implications for ecosystem restoration, we determined the origins of the vegetation that develops after a clear-cut in hardwood-invaded sites being restored to pine savanna in Florida. We excavated stumps and other sprout sources, characterized the soil seed bank, and estimated seed production by early-to-mature species during the first growing season after treatment. In twenty 100-m2 plots, there was approximately one source of woody plant sprouts per square meter. Root sprouts were more abundant than sprouted stumps, and most of the stumps that did sprout were small (<10 cm diameter). Plants that emerged from seeds were only abundant in a previously disturbed area where Vitis rotundifolia Michx. seedlings were common. The soil seed bank was dominated by herbaceous ruderal species. During the first year after the hardwood clear-cut, seed production was dominated by the ruderal Phytolacca americana L. and the short-lived shrub Callicarpa americana L. Hardwood removal is a reasonable first step towards savanna restoration, but managers should be aware that the removal of invasive nonnative woody species will not shift the restoration sites toward savanna if needle-shedding pines and ground layer species that carry fire are not abundant.