The ecological importance of soil-borne organisms are becoming increasing appreciated by scientists. For example, symbiotic soil fungi called arbuscular mycorrhizal fungi are required by most plants for nutrient uptake. Species composition of arbuscular mycorrhizal fungal communities is thought to have great influence on the plant community. Therefore, understanding how different mycorrhizal fungal species are distributed in the soil, and what factors lead to these distributions, will contribute to a full understanding of the process of forest regeneration. While most species of mycorrhizal fungi are dispersed short-distances through root growth, a subset of mycorrhizal fungal species can be dispersed long distances by rodents. These species produce their spores in relatively large clusters, which are consumed by rodents and passed as living spores in their feces. My dissertation research aims to address the ecological and evolutionary importance of rodent-mediated spore dispersal to both fungi and to tropical-tree seedlings. Specifically, can rodent movement patterns be linked to the distribution of rodent-dispersed arbuscular mycorrhizal fungi? Also, do plants respond differently to rodent-dispersed mycorrhizal fungi than to fungal species incapable of rodent-mediated dispersal? Furthermore, what are the consequences of forest fragmentation on the dispersal of mycorrhizal fungi by rodents? Besides providing needed information on the importance of soil fungi and their dispersers to the regeneration of tropical forests, this project will facilitate the biological training of several Latin American students. This project has already allowed me the opportunity to co-direct the undergraduate thesis of a student from Colombia and will allow at least two Panamanian undergraduates the opportunity to learn techniques for studying both above- and belowground organisms.
