Initial response of pondberry released from heavy shade.
Pondberry [Lindera melissifolia (Walt.) Blume] is a federally endangered woody shrub in the Lauraceae family. The U.S. Fish and Wildlife Service developed a recovery plan in 1993 that emphasized the need to study pondberry biology and ecology and to develop management practices that would promote recovery and conservation of this species. We initiated a large-scale study in 2005 to determine the effects of soil flooding and light availability on pondberry survival and growth. The study was conducted in Sharkey County, MS in a network of research impoundments known as the Flooding Research Facility. Following the conclusion of our initial research, we implemented a release study to utilize plants which were established in 12 shade houses that provided a light availability near 5 percent of full sunlight. We randomly assigned new shade cloth densities to these 12 houses so that four provided 70 percent of full sunlight, four provided 37 percent of full sunlight, and four provided 5 percent of full sunlight. Our research objective was to quantify survival, stem length, stem diameter, and ramet production of pondberry shrubs released from a heavily shaded environment. Three growing seasons after release, shrub survival averaged 71 percent, and stem length averaged 113 cm regardless of assigned light level. Pondberry released into 70 or 37 percent light developed 58 percent larger stem diameters than those maintained under 5 percent light. Plants released into 70 or 37 percent light also produced 274 percent more ramets than those grown under 5 percent light. These results indicate pondberry growth should respond positively to silvicultural practices such as midstory or overstory canopy treatments that increase light availability in the understory of floodplain forests. However, we speculate that control of competing understory vegetation invigorated by canopy treatment may be necessary to ensure pondberry release.