SPLS Seminar: Compositional dynamics of soil fungal communities along environmental and disturbance gradients in temperate and tropical forests

Abstract: Soil microbial communities represent the greatest reservoir of biological diversity, with thousands of microbial species found a single gram of soil. Soil and plant-associated fungi (e.g., root symbionts, decomposers, mutualistic endophytes, and pathogens) have key roles in nutrient cycling and water and nutrient acquisition by plants, and they shape plant resistance and resilience to biotic and abiotic stresses. It is crucial to understand how climatic and edaphic factors influence the structure and functioning of forest fungal communities, because forests are major reservoirs of biodiversity, provide crucial ecosystem services, and play important roles in biogeochemical cycling and climate regulation. In this talk, I will give an overview of several projects on the compositional dynamics of soil fungal communities along environmental and disturbance gradients as well as secondary forest succession in temperate and tropical forests. Our studies show that, similar to plants, temperature, soil pH, and soil moisture are the main drivers shaping the diversity and distribution of soil fungi at regional and landscape scales. Overall, compositional turnover in fungal communities is driven by niche-based environmental filtering due to contrasting habitat preferences among fungal species in all functional and taxonomic groups. For functional groups dependent on symbioses with plants (especially ectomycorrhizal fungi), the distribution of host plants drives richness and community composition, resulting in important differences along topographic gradients and among biogeographic regions. The compositional and functional turnover along temperature and moisture gradients implies that many soil fungi are sensitive to environmental changes, including climate change and disturbance, and are well-suited for monitoring purposes as indicators of environmental conditions.

Bio: Dr. József Geml is a Hungarian microbial ecologist professor, who studies spatial and temporal dynamics of fungal communities and their relations to environmental factors, disturbance, vegetation, and plant physiology. He earned two Ph.D.s, one in Plant Pathology at the Pennsylvania State University and another in Mycology at the Corvinus University of Budapest, Hungary. He worked for five years at the University of Alaska Fairbanks as a Presidential Postdoctoral Fellow, and as a faculty member at Leiden University and the Naturalis Biodiversity Center in the Netherlands for ten years, before returning to Hungary to form his Environmental Microbiome Research Group at the Hungarian Academy of Sciences. He has twenty years of experience in soil and plant microbiome research in several biomes and continents, e.g., in the arctic tundra and in boreal, temperate, and tropical forest ecosystems, resulting in over 100 publications. He is currently a Visiting Fulbright Scholar at the University of Arizona, hosted by Prof. A. Elizabeth Arnold, with whom he studies the compositional and functional dynamics of symbiotic fungi associated with oaks along gradients of climate stressors in Arizona.