The project will integrate taxonomic, genetic, and functional approaches in a combination of observations and experiments to test the Enemy Susceptibility Hypothesis (ESH) for tropical tree diversity and rarity. This hypothesis predicts that rare tree species will have a greater percentage of hollow-trunk trees, harbor more pathogenic fungal species, and also share more of these pathogens with other tree species, than common tree species. At forest plots on Barro Colorado Island, Panama, researchers will survey all trees, sample and culture fungi, and determine which fungal species are present on which trees. Fungal pathogenicity and specificity will be tested, and the mechanistic basis for why some fungal species have broader host ranges than others will be explored through comparative genomic sequence analyses.
If the Enemy Susceptibility Hypothesis holds up to these tests, it may prove to be a general explanation for the high diversity and rarity of tree species in tropical forests worldwide. The project will also include participation of high school and college students, as well as high school science teachers from California, Georgia, and Panama. The participants will travel to Panama and take a two-week field-biology course that will expose them to the exciting new research questions in ecology and evolution being opened for study by the high-throughput DNA sequencing technologies now available. This course will be taught each year for the first three years of the project.
