Format: ORAL

Patricia Moya1, Tamara Pazos1, Salvador Chiva1,2, Isaac Garrido-Benavent3, Pavel Skaloud4 and Eva Barreno1.

1Institut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBIBE)-Departament de Botànica, Universitat de València, Burjassot, València, Spain 2University of Trieste, Trieste, Italy 3Universitat de Valéncia Burjassot, València, Spain 4Faculty of Science, Czech Republic

Lichens are one of the most emblematic examples of the mutualistic associations between one fungi and populations of photosynthetic green microalgae and/or cyanobacteria. Aside from these major lichen symbionts, an indeterminate number of other microorganisms, co-occur, intermingled in these associations. Given all of these new players, the traditional lichen paradigm is evolving into a broader concept of lichen holobiomes. Advances in genomics and bioinformatics have provided a deeper understanding of this diversity. Therefore, lichen thalli are considered microecosystems in which numerous different symbiotic partners can interact. The fine functioning balance established in the thalli is one of the reasons for their recognition as bioindicators. Lichens are sensitive to a variety of anthropogenic disturbances, and are widely used as rapid bioindicators of both small-scale and global change. In the 1990s, a sampling network for the biomonitoring of forests using epiphytic lichen diversity was established in eastern Spain. In 1997, an assessment of the state of lichen communities was carried out and the results were published. In 2022, this previously established biomonitoring network was revaluated. To compare the results obtained in 1997 and 2022, the same methodology was used, and data from air quality stations were included. The results displayed a significant general decrease in the diversity and a generalised increase in damage symptoms in target lichen species, which seem to be the consequence of a multifactorial response (climatic and pollution). Taking advantage of this new sampling, genomic data were obtained from 188 thalli to explore lichen community structure. Our results showed differences in photobiont choice between sexually and asexually reproducing lichens in the epiphytic community. Using metagenomic approaches we explored the differences between the composition of microorganisms amongst healthy and damaged thalli. Our results provide a renewed perspective for biomonitoring. PROMETEO/2021/005 (GVA to EB), EU-MS21-058 (to SC), PID2021-127087NB-I00 (MICINN to IGB)