The essential is invisible to the eyes: the crucial role of aquatic fungi in intermittent rivers and ephemeral streams

Abstract

Aquatic fungi play a crucial role in global biogeochemical cycles. Despite their significance, knowledge about how desiccation affects their composition and functioning in intermittent rivers and ephemeral streams is limited, even though these are the most common river ecosystems worldwide. Available studies indicate that fungal diversity (both taxonomic and functional) in these environments is lower than in permanent rivers. These organisms employ resistance mechanisms against desiccation through various life strategies and functional adaptations. This adjustment involves trade-offs between growth, reproduction, and dispersal, ultimately impacting ecosystem function. Therefore, an increase in desiccation could jeopardize the ability of aquatic fungi to ensure ecosystem functioning, even though they have the capacity to cope with desiccation. This brief note advocates for studying their responses to desiccation to safeguard the resilience of these ecosystems.