Online first articles

The Sierra Nevada lakes (Iberian Peninsula) lie at elevations and distances that make them highly exposed to Saharan dust intrusions, which are frequent across the Mediterranean Basin. Over the past three decades, we have systematically studied the nature and ecological consequences of this atmospheric deposition in these remote lakes. Rather than isolated events, Saharan dust pulses constitute recurrent inputs with well-defined seasonal and interannual patterns that have reshaped nutrient limitation (nitrogen vs. phosphorus) in these systems. Dust deposition delivers substantial amounts of phosphorus, calcium, iron, and terrestrially derived organic matter, altering the activity and taxonomic composition of microbial communities and leaving a clear isotopic imprint in zooplankton, particularly in Daphnia pulicaria. Saharan dust also carries viable microorganisms, with deposition fluxes of bacteria and viruses ranging from millions to billions of cells and particles per square meter per day. These atmospheric inputs likely act as both nutrient subsidies and biological inocula, but their long-term integration into lake food webs and microbial metacommunities remains unresolved. Understanding whether and how these airborne microbes establish permanent populations is a key question for assessing the role of Saharan dust in shaping biodiversity and biogeochemical functioning of Mediterranean high-mountain lakes.