Thursday, August 9, 2007
Exhibit Halls 1 and 2, San Jose McEnery Convention Center
Lupinus perennis, an indicator species for savanna and barrens habitat, is the sole larval food source for the federally endangered Karner blue butterfly and an important food source for several other butterfly species. Although butterfly recovery programs include restoration of existing lupine populations and establishment of new ones, the determination of the optimum conditions and method of lupine restoration has received little attention. This study compared the survival, growth and reproduction of L. perennis 13 months after planting as seed and greenhouse transplants from four population sources across naturally occurring gradients of light, soil moisture, pH, phosphorous, and soil surface materials along field transects in a savanna restoration. Estimates of labor required in the production, planting and aftercare of both greenhouse plants and seeds were also compared. Both population source and substrate type significantly influenced seedling emergence, while survival decreased with high light levels, herbivory, and disturbance. As expected, transplants had significantly greater survival than seedlings, but were also affected by initial size, population source, herbivory and disturbance. Seedling size was influenced by population source, light, and soil pH, while transplant size varied only with population and light. Only 1% of seedlings flowered, compared to 25% of transplants, but only population source had a significant effect on seed production. Although approximately 9.5 times more labor was required for transplants, their greater success in survival, growth, and reproduction may warrant their use for butterfly restoration programs.
