A new field experiment is underway in Lake Llebreta, a high-mountain lake in the Aigüestortes i Estany de Sant Maurici National Park, to follow how microbial biofilm communities colonize and develop over time.
Every 15 days, submerged disks in the littoral zone of the lake are retrieved and sampled for two complementary lines of evidence: molecular eDNA analysis, to track shifts in community composition, and pigment analysis, to capture changes in the photosynthetic and functional makeup of the colonizing biofilm community.
The experiment runs for 4 months, with sampling concluding in mid-November. Together, the two datasets will offer a detailed view of biofilm community succession in an extreme, high-altitude aquatic environment — from early colonizers to a more established community — while also helping disentangle the complex species interaction dynamics that shape it.
The setup is complemented by environmental sensors deployed in the lake, logging variables such as CO2, O2, water level, conductivity, and temperature on an hourly basis. This continuous record will allow the biofilm succession patterns to be interpreted against fine-scale environmental variability throughout the experiment.
