Volcanic rocks harbor an interesting biota well-adapted to the stressful conditions
imposed by the environment. Lichens species, with their remarkable resilience, are
the most conspicuous organisms colonizing these ecosystems reflecting higher percentages
of volcanic rocks coverage. This study provides a comprehensive analysis of lichen
diversity across mainland Spain, focusing on the different locations of the volcanic
zones and volcanism type, aiming to investigate differences in species richness, frequency,
and functionality in four volcanic zones: central, northeastern, southeastern coastal,
and southeastern inland. Fieldwork and literature review were used to compile a dataset
of 360 lichen species from 85 localities. The results indicate that regional differences
in species composition are driven by location of the volcanic zones. Functional traits
such as growth forms, photobiont types, and secondary metabolites exhibit similarities
across volcanic zones. At a local scale, differences in lichen composition appear
influenced by the chemical composition of volcanic rocks. The findings underscore
that despite high species turnover between volcanic zones, functionality remains consistent,
with a clear dominance of species developing crustose thalli with green algal photobionts
and secondary metabolites offering photoprotection in these harsh environments. This
research helps fill the knowledge gap on lichen diversity in the Iberian Peninsula's
volcanic regions.
