This research will examine the community composition, number of species, spatial structure and ecological importance of fungi infecting seeds of the tropical pioneer tree Cecropia insignis in two lowland forests in Panama and Costa Rica. This study will combine (i) measurements of seed mortality in the field with (ii) molecular analyses to determine the identities of fungi infecting C. insignis seeds, and (iii) re-inoculation of healthy seeds to determine which fungal cultures are pathogenic. Results of this study will provide the first assessment of the importance of fungal communities and focal fungal taxa in influencing demographics of a common tree species in tropical forests, and will provide the first detailed characterization of the identities and diversity of fungal communities associated with seeds of any tree, temperate or tropical. Comparisons of seed-fungal interactions of a single host species conducted at two of the best-studied tropical forests will add important new information regarding the diversity of fungi in soils at large spatial scales, and enhance our knowledge of fungal biodiversity overall. Isolates will be deposited in the Gilbertson Mycological Herbarium (University of Arizona), and maintained in a culture collection of tropical plant-associated microfungi. Novel genetic sequence data will be submitted to the on-line database Genbank.
