The first finding of lichen Solorina saccata at an algific talus slope in Korea

Abstract

An algific talus slope is composed of broken rocks with vents connected to an ice cave, releasing cool air in summer and relatively warmer air in winter to maintain a more stable microclimate all year round. Such geological features create a very unusual and delicate ecosystem. Although there are around 25 algific talus slopes in Korea, lichen ecology of these areas had not been investigated to date. In this study, we report the first exploration of lichen ecology at an algific talus slope, Jangyeol-ri, in Korea. A total of 37 specimens were collected over 2017-2018. Morphological and sequencing analysis revealed 27 species belonging to 18 genera present in the area. Of particular interest among these species was Solorina saccata, as it has previously not been reported in Korea and most members of genus Solorina are known to inhabit alpine regions of the Northern Hemisphere. We provide here a taxonomic key for S. saccata alongside molecular phylogenetic analyses and prediction of potential habitats in South Korea. Sequences were generated from all S. saccata specimens collected in this study, together with three S. saccata specimens from China for comparison. Phylogenetic analysis based on nuclear small subunit (nuSSU) showed that all the S. saccata specimens are tightly grouped into one clade with high support values (P=0.99) and showed close relatedness to S. spongiosa than S. crocea. Additional analyses were carried out using concatenated sequences: 65 sequences of mitochondrial small subunit (mtSSU) combined with nuLSU and 66 sequences of RPB1 with nuLSU. In these analyses, genus Peltigera was found to be the closest genus to S. saccata. Furthermore, regions in South Korea potentially suitable for Solorina spp. were predicted based on climatic features of known habitats around the globe. Our results showed that the suitable areas are mostly at high altitudes in mountainous areas where the annual temperature range doesnt exceed 26.6{degrees}C. Further survey of other environmental conditions determining the suitability of Solorina spp. should lead to a more precise prediction of suitable habitats and trace the origin of Solorina spp. in Korea.