CAREER: Coffee fungi below and aboveground: agroecological experiments for teaching and learning about fungal diversity and ecosystem function

Humans depend on biodiversity, the diversity of life on Earth, for our sustenance and survival, yet our current management of Earth’s natural resources has generated rapid losses of biodiversity across many different types of living organisms. Because agriculture is the largest contributor to this loss, a clear understanding of the relative importance of different agricultural practices to biodiversity loss is urgently needed.

Fungi play essential roles as decomposers that speed the return of nutrients to forms that crops can use, as pathogens that cause plant disease, as beneficial endophytes that live within plants and protect them from pests and pathogens, and as mycoparasites, fungi that feed on other fungi and reduce their potential to harm crops. Currently little is known about the effects of agricultural practices on biodiversity in these different fungal groups and about how changes in fungal biodiversity may alter critical functions of fungi.

This study will determine the relative importance of shade, nitrogen fertilizers, and fungicides for fungal biodiversity loss in coffee, a crop of critical importance to the global economy and to coffee producers, processors, purveyors, and consumers in the United States. It will examine the importance of fungal biodiversity for key functions of fungi in an agroecosystem, particularly the role of fungal diversity in reducing crop diseases and in improving crop nutrient cycling.

This project will provide high impact, cross-cultural research opportunities for training both U.S. undergraduate and graduate students to work effectively as scientists in international settings, as well as disseminating two educational modules to improve specific learning outcomes in undergraduate biology courses.

Over the last 30-years, biodiversity ecosystem function (BEF) research has clearly demonstrated the importance of diversity for ecosystem function, yet critical gaps remain for fungi. Fungal communities are highly diverse, their abiotic and biotic interactions are often cryptic and complex, and the importance of fungal diversity for key ecosystem processes, such as decomposition and disease regulation, remains to be determined.

Coffee represents an ideal ecosystem to study contributors to fungal biodiversity loss and their effects on ecosystem function, since resources vary with levels of shade and fertilization, and fungicides act to suppress fungal diversity. This project will 1) combine two manipulative field experiments with fungal metabarcoding to a) determine the relative importance of shade, inorganic nitrogen, fungicides and leaf litter diversity in structuring fungal communities and their functional diversity, and b) measure the effects of differences in functional diversity in fungal communities on ecosystem function; and 2) use culture-based techniques to identify currently undescribed fungi, link morphology to DNA barcode, and screen isolates for functional groups.

This CAREER award will advance understanding of the role of fungal diversity in ecosystem function, particularly the effects of diversity on decomposition rates and plant disease incidence and severity.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.