From mycorrhizal fungal traits to ecosystem properties – and back again

Mycorrhizal fungi are known for their functional importance in plant growth and nutrition, and because these symbiotic fungi represent a fundamental linkage between plants and soils, they likely underpin a number of biogeochemical processes in ecosystems. However, our ability to isolate and quantify their role in ecosystems has remained a challenge. This special feature presents seven new studies that advance our understanding of how mycorrhizal fungi contribute to ecosystem function. We specifically highlight two complementary approaches by which ecologists are gaining insight: focusing on mycorrhizal fungal traits to target the biological mechanisms that scale up to the ecosystem, and capturing patterns and processes across ecosystems to understand the net effect of complex plant–fungal–soil interactions. The studies in our special feature provide evidence that traits both within and across species of mycorrhizal fungi can contribute to ecosystem processes, and that disturbance from global change and management may result in altered mycorrhizal traits and lead to compromised ecosystem function. From a broader perspective, studies also demonstrate that key ecosystem properties vary over gradients of mycorrhizal dominance and time, suggesting that mycorrhizal effects emerge from complex interactions within ecosystems Synthesis . Employing complementary approaches to the study of mycorrhizal ecology may allow us to isolate the mycorrhizal traits that matter most for ecosystem properties, as well as the suite of ecosystem properties that result from mycorrhizal fungi, thus converging on biogeochemical mechanisms that underpin terrestrial ecosystem function.