The value of the terricolous lichen Cetrariella delisei in the biomonitoring of heavy−metal levels in Svalbard

The aim of this study was to identify a suitable lichen species for the long−term monitoring of heavy−metal atmospheric pollution in Svalbard. Cladonia and Cetraria s.l. species that have been widely used until now for assessing heavy−metal deposition in the Arctic are in decline over extensive areas of Svalbard, mainly due to climate change and over−grazing by reindeer. Cetrariella delisei, rarely used for biomonitoring, is still common and widespread in this area. Levels of Cr, Ni, Fe, Cu, Pb, Zn, Cd and Mn were measured in three lichen species: Cetrariella delisei, Cladonia uncialis, Flavocetraria nivalis and in a moss Racomitrium lanuginosum from Sorkapp Land, South Spitsbergen. The results imply that Cetrariella delisei can be safely compared to Cladonia uncialis for identifying the lev− els of heavy metals, but direct comparison between Cetrariella delisei and other species studied is more difficult owing to differences in levels of heavy metals even in samples from the same site.