Diversity and Functional Traits of Lichens in Ultramafic Areas: A Literature Based Worldwide Analysis Integrated by Field Data at the Regional Scale

While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a survey of diversity and functional traits in saxicolous communities on ultramafic and non-ultramafic substrates was conducted in Valle d’Aosta (North-West Italy) to verify whether a relationship can be detected between substrate and functional traits that cannot be explained by other environmental factors related to altitude. Analyses (unweighted pair group mean average clustering, canonical correspondence analysis, similarity-difference-replacement simplex approach) of global lichen diversity on ultramafic substrates (2314 reports of 881 taxa from 43 areas) displayed a zonal species distribution in different climate zones rather than an azonal distribution driven by the shared substrate. Accordingly, variations in the frequency of functional attributes reflected reported adaptations to the climate conditions of the different geographic areas. At the regional scale, higher similarity and lower species replacement were detected at each altitude, independent from the substrate, suggesting that altitude-related climate factors prevail over putative substrate–factors in driving community assemblages. In conclusion, data do not reveal peculiarities in lichen diversity or the frequency of functional traits in ultramafic areas

Ecological Specialization of Two Photobiont- Specific Maritime Cyanolichen Species of the Genus Lichina

22 páginas, 4 tablas, 4 figurasAll fungi in the class Lichinomycetes are lichen-forming and exclusively associate with cyanobacteria. Two closely related maritime species of the genus Lichina (L. confinis and L. pygmaea) show similar distribution ranges in the Northeast Atlantic, commonly co-occurring at the same rocky shores but occupying different littoral zones. By means of 16S rRNA and phycocyanin operon markers we studied a) the phylogenetic relationships of cyanobionts associated with these species, b) the match of divergence times between both symbionts, and c) whether Lichina species differ in photobiont association and in how geography and ecology affect selectivity. The cyanobionts studied are closely related to both marine and freshwater strains of the genus Rivularia.We found evidence of a high specificity to particular cyanobiont lineages in both species: Lichina pygmaea and L. confinis incorporate specific lineages of Rivularia that do not overlap at the haplotype nor the OTU levels. Dating divergences of the fungal and cyanobacterial partners revealed an asynchronous origin of both lineages. Within each fungal species, selectivity varied across the studied area, influenced by environmental conditions (both atmospheric and marine), although patterns were highly correlated between both lichen taxa. Ecological speciation due to the differential association of photobionts to each littoral zone is suspected to have occurred in marine Lichina.Both ROA (BES-2013-066105) and SPO (CTM2012-38222-C02-02) were supported in the form of salary by grants from the Spanish Ministry of Economy and Competitiveness.Peer reviewe