Native seed is often collected en masse from remnant ecosystems to supply landscape-scale restoration. Successful large-scale restoration depends on sustained seed yields but also on donor population persistence. Native plants that reproduce solely by seed are especially sensitive to harvesting practices. We addressed the challenge of procuring sufficient seed from remnant sources to restore landscapes while also maintaining remnant populations of native plants. We evaluated: 1) the sustainability of seed harvest at varying intensities in Rudbeckia hirta, a seedreliant plant; and 2) the contribution of fire in promoting sustainability of seed donor populations. We planted seedlings of R. hirta in a field experiment that manipulated management type (burned or unburned) and harvest intensity (0, 50%, or 100% seed removed), and measured changes in seedling recruitment and seed production among treatments. Moderate intensity harvest and burning did not significantly reduce seedling recruitment, but high intensity harvest with burning reduced recruitment by 95% compared to controls. Seed production nearly doubled in burned treatments. In unburned prairie, recruitment is negligible, and harvest intensity does not have an effect on recruitment. For harvest-sensitive prairie species, a strategy incorporating moderate intensity seed harvest with burning is most likely to provide seed for large-scale restoration sustainably.
Bibliographical noteFunding Information:
We thank Neal Feeken, Travis Issendorf, and Brian Winter who assisted with important logistical support, as well as Rhett Johnson and Matt Mecklenburg who provided equipment and expertise for field operations. Sabin Adams and Jenny Heck were exceptional field and greenhouse assistants. Roger Meissner, Pam Warnke, and Julia Bohnen assisted with greenhouse seedling production. We also thank Tony D’Amato, Joe Fargione, and Bob Haight for valuable comments on research design. Aaron Rendahl gave helpful advice in experimental design and statistical analysis. The Nature Conservancy provided partial support for this work through the Nebraska Chapter’s J.E. Weaver Competitive Grants Program. Further support for this study was provided by The Dayton Fund of the Bell Museum of Natural History, a National Science Foundation Integrative Graduate Education and Research Traineeship in Risk Analysis for Introduced Species and Genotypes, and the Lessard-Sams Outdoor Heritage Fund.
© 2017 Université Laval.
- Great Plains
- fire management
- seed harvest
- seed supply