This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Saprotrophic fungi are the primary agents of leaf litter decomposition in forest ecosystems. Fungal communities develop on millions of senescent leaves each year, providing an ideal opportunity to study how these biotic communities assemble and function. This project will examine the relationship between fungal community assembly and the distribution and biochemical makeup of dominant tree species. Two complementary approaches will be used: a spatially-explicit survey of fungal communities on leaves sampling at scales from individual leaves to the regional forest landscape, and an experimental manipulation of fungal colonization of leaves. These approaches will help elucidate the relative importance of leaf biochemistry, a species trait, and processes such as dispersal and priority effects, which are strongly influenced by local environmental factors. Decomposition of leaves by fungi is regulated by the presence and expression of specific functional genes encoding extracellular enzymes. Because of the enormous diversity, redundancy, and genomic plasticity present in fungi, it is unclear to what extent variation in microbial taxonomic composition affects leaf decomposition. The hypothesis that fungal traits associated with leaf decomposition can be regulated independent of the particular fungal taxa present on a leaf will also be tested. This project will train undergraduates, graduate students, and laboratory technicians in the fields of forest and fungal ecology, contributing to the development of future scientific workforce. It will provide undergraduates with research opportunities that are individualized, but which are also fundamentally integrated into larger research goals. The undergraduate program will involve mentoring and supporting coursework designed specifically to complement the research being performed. This will provide students with a research experience that will prepare them for graduate school and careers in science.
