Conservation Implications of the Reproductive Biology of the Endangered Vine Ipomoea microdactyla (Convolvulaceae)EPA Grant Number: U916090
Title: Conservation Implications of the Reproductive Biology of the Endangered Vine Ipomoea microdactyla (Convolvulaceae)
Investigators: Geiger, John H.
Institution: Florida International University
EPA Project Officer: Michaud, Jayne
Project Period: January 1, 2002 through January 1, 2005
Project Amount: $114,098
RFA: Minority Academic Institutions (MAI) Fellowships for Graduate Environmental Study (2002) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Fellowship - Environmental Science and Engineering , Academic Fellowships
The objective of this research project is to gauge the relationship between genetics and demography for the threatened species Ipomoea microdactyla (Convolvulaceae), a hermaphroditic perennial vine. In the United States, it occurs only in the pine rockland habitat of Miami-Dade county; it also occurs in Cuba and the Bahamas. In Florida, this species is listed as endangered, and it has populations at 12 conservation areas in the county, including Everglades National Park. Presently, less than 2 percent of the original pine rockland habitat remains, outside of the large habitat block protected in Everglades National Park. Empirical evidence showing that habitat fragmentation results in population genetic consequences for plants is accumulating rapidly. The effects have been variable, most often negative, but also positive. Habitat fragmentation followed by reductions in population size generally leads to decreases in genetic variation, both allelic richness and heterozygosity of individuals. The danger to the fragmented populations may be reductions in the fitness of individuals and the immediate viability of these populations.
I will conduct a population viability analysis (PVA) to determine which factors are important for the continued persistence of this species in Florida. The first part of my research will be a breeding-system experiment to gauge self-compatibility/self-incompatibility. This entails a protocol of hand pollinations at several levels: the individual, within population, and among populations. The second part of my project will be a multiyear demographic study at all 12 conservation areas. The final component will be a genetic study (using microsatellite genetic markers) to determine the spatial pattern of genetic variation and incorporate this into the PVA. Preliminary results from the breeding system experiment suggest this species is self incompatible and unable to set fruit without a pollen vector. This implies potentially severe Allee effects for these low-density populations.