Term of Award

Fall 2011

Degree Name

Master of Science in Biology (M.S.)

Document Type and Release Option

Thesis (open access)

Department

Department of Biology

Committee Chair

Lissa M. Leege

Committee Member 1

Ray Chandler

Committee Member 2

John C. Pascarella

Abstract

Baptisia arachnifera, hairy rattleweed, is a federally endangered, herbaceous, legume endemic to Wayne and Brantley Counties in Georgia. The species has declined by 89% in the past 20 years. Therefore I examined the early life stages of the species for weevil predation, fungus infection, and germination; information used to help prevent the species extinction. Seed pods of Baptisia arachnifera from six sites were examined for weevil predation and fungal infestation. Germination was examined under greenhouse conditions. One site had intense weevil predation, fungal infection, and reduced germination compared to other sites. Over 62% of seeds germinated within the greenhouse. To determine the effects of light and litter on Baptisia arachnifera, I planted 320 seedlings into a 2x2 factorial shade and litter experiment within the natural range of the species. Another 480 seedlings were planted across 12 sites within three habitat types: four replicates for each of two types of pine plantations and power-line cuts. Both experiments were compared for germination and seedling growth. Of seeds planted in the field <8% germinated in the shade and litter experiment; while <1% germinated within the forest and power-line cut habitats. Shade and litter increased seed germination within treatments. All germinated seeds died for both field experiments. Transplanted seedling survival dwindled down to 40%. Four percent of seedlings across forested habitats survived initial planting, and plant numbers dwindled down to <1% by the end of the study. Neither experiment showed an effect of shade or litter on seedling growth. This study showed seeds that escaped predispersal mortality collected from the natural range of Baptisia arachnifera can be used to obtain numerous seedlings within a greenhouse, and additional factors other than light and litter determine germination and seedling survival within the species natural range. Reintroduction of greenhouse grown seedlings showed potential use for restoration projects, field sown seeds did not. Future research should focus on increasing reintroduced seedling survival within the species range for use within restoration projects.

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