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Abstract
Determination of reference conditions for small herb-dominated wetland depressions within the fire-maintained longleaf pine-wiregrass ecosystem is challenging. Most sites have been altered by legacies of fire suppression, which results in the development of an alternative hardwood-dominated community. To reestablish species-rich, herbaceous-dominated communities, we began with restoration of the open community structure and reintroduction of the historic disturbance regime. Specifically, we addressed the following questions: 1. What is the rate and pattern of hardwood succession? 2. Does hardwood canopy removal promote the reestablishment of a species-rich herbaceous wetland plant community? 3. Do depression wetland species form a persistent soil seedbank that provides a source for reestablishment of groundcover species following hardwood removal? In 2000, we selected ten wetland depressions and randomly assigned five a canopy harvest treatment. We identified a hardwood encroachment pattern that begins as a central nucleus and expands outward. The hardwood species tolerate a range of hydrologic conditions and expand across the moisture gradient, creating homogeneous vegetation across wetlands-upland ecotones. Five years post canopy removal, percent total vegetative cover, species-area curves, and non-metric multi-dimensional scaling analyses of the treatment communities indicated significant increases in species-richness and a shift in the community composition toward herbaceous domination. This rapid recovery of the vegetation and, therefore, of the fine fuels necessary for the reintroduction of frequent fire, was possible largely through initial recruitment from the persistent soil seedbank. We conclude that in certain cases, restoration goals may be guided by vegetation dynamics and defined by priorities to conserve biodiversity and promote the maintenance of rare communities. Key words: reference sites, depression wetlands, longleaf pine ecosystem, fire