Short Communication: Co-occurring Lobaria pulmonaria and Ricasolia quercizans share green algal photobionts: Consequences for conservation

Photobiont sharing among lichens within communities is a well-documented phenomenon, especially among closely related fungal species that form photobiont-mediated guilds (Dal Grande et al. 2014; Rikkinen et al. 2002). Species of Lobaria and other closely related genera that associate with Symbiochloris reticulata are one example of a photobiont-mediated guild that have been the subject of extensive research (Dal Grande et al. 2014). In their study, Dal Grande et al. (2014) compared algal multi-locus genotypes (MLGs) at one site in Taiwan and one site in Madeira among four species of Dendriscosticta, 16 species of Lobaria, and one species of Ricasolia, and, using pairwise FST values, found the species did not associate with significantly different green algal partners when they co-occurred. Green algal symbiont sharing has also been documented between the predominantly sexually reproducing Umbilicaria spodochroa and predominantly vegetatively reproducing Lasallia pustulata (Hestmark et al 2016). Werth (2012) recovered a more complex pattern of compartmentalization in Ramalina menziesii and adjacent lichen species. Photobiont sharing may also occur with co-occurring non-lichen organisms, such as liverworts (Cornejo & Scheidegger 2016).