Tage der Biodiversität 2027

The study of fungal biodiversity has undergone a profound transformation during the 21st century. Traditionally, fungal species were identified and classified primarily on the basis of morphological characters, ecological preferences, and, in some groups, secondary metabolites. In many cases, species could be reliably recognized in the field, and these approaches formed the foundation of fungal taxonomy and species concepts for decades.

Today, however, molecular methods have become indispensable for understanding fungal diversity. DNA-based approaches, ranging from multilocus phylogenetics to phylogenomics, are now widely accepted as the basis for modern species concepts. In most cases, molecular data support and refine previously established taxonomic frameworks, while at the same time revealing an unexpectedly high level of hidden diversity that is often difficult to comprehend even for specialists. Molecular phylogenies help to resolve taxonomic relationships, discover new species, and correct nomenclatural inconsistencies. These developments will be illustrated using selected examples from the ectomycorrhizal genus Cortinarius.

The enormous diversity uncovered by molecular studies raises an important question: to what extent can fungal species still be recognized and differentiated using non-molecular approaches? Ecological adaptation and co-evolutionary relationships, particularly with ectomycorrhizal host plants, play a crucial role in fungal speciation and diversification. Furthermore, secondary metabolites represent valuable taxonomic markers in several fungal groups and may indicate distinct evolutionary lineages. However, chemotaxonomic traits remain insufficiently explored across many larger taxonomic groups. This is reflected in genera that contain both edible and poisonous species, where chemical diversity may provide important evolutionary and taxonomic insights.

By integrating examples from agaricoid fungi, the presentation highlights the complementary roles of morphology, ecology, chemistry and molecular phylogenetics in documenting and understanding fungal biodiversity. Ultimately, combining these approaches not only helps us to unravel the enormous diversity and evolutionary history of fungi, but also provides insights into their ecological roles and functions in ecosystems.