Bedrocklamellierien

Bedrocklamellierien is a term coined to describe a distinct group of biofilm-forming microorganisms that colonise exposed bedrock surfaces in alpine and polar environments. The name derives from the German verb *lamellieren* (to form lamellae) and *Bedrock*, reflecting its characteristic laminated growth on primary geological substrates.

Morphologically, bedrocklamellierien are composed of filamentous bacteria and eukaryotic algae that secrete extracellular polymeric substances. These secretions bind mineral grains into layered sheets, giving the biofilm a translucent, mica-like appearance. Microscopic examination reveals that the layers are often less than 10 micrometres thick and vary in colour from pale green to deep charcoal, depending on the dominant phototroph present.

Distribution of bedrocklamellierien is largely restricted to cold, nutrient-poor regions such as the walls of glacial caves, high-altitude scree slopes, and fjord cliffs. They are most frequently encountered within the first decade after bedrock exposure, where they contribute to the initial weathering and biogeochemical alteration of silicate and carbonate rocks. Recent studies suggest that their metabolic activity may accelerate mineral dissolution, thereby influencing landscape evolution and carbon cycling in these ecosystems.

The ecological role of bedrocklamellierien extends beyond rock alteration; they provide microhabitats for other microorganisms and invertebrates and can influence the colonisation of vascular plants by modifying surface chemistry. Due to their specialized niche and sensitivity to environmental change, these organisms are considered indicator species for monitoring the impacts of climate change on alpine and polar geomorphic processes.