Note (ZL): This paper reports the results of a survey conducted in August 2007, the first detailed study of lichens on Sable Island since 1899 when John Macoun recorded 27 taxa. During 1988-1991, Zoe Lucas had collected 192 lichen specimens, and photographed species and habitats on the island. However, the specimens remained unidentified until 2007 when they were examined by David Richardson (Saint Mary’s University). During the August 2007 survey on the island, Richardson and Lucas revisited some of the previous collection sites, and additional locations were investigated. The study revealed that 39 macrolichens and 42 crusts presently occur on Sable Island—on sand, bone, lignum (woody), and cement substrata (surfaces). This paper’s annotated checklist of current and former records includes 62 macrolichens and 46 crustose species, as well as 7 lichen parasymbionts. There have been significant changes in the island’s lichen flora since Macoun’s visit in 1899, and even since Lucas’s collections. For example, Bryoria fuscescens occurred on Sable in 1990 but could not be found in 2007. The authors suggest that the island’s lichen flora is likely to become less diverse during the next few decades. Local factors include loss of substrata. For example, the rich flora of Ramalina species and mosaic of crustose lichens on the old telephone poles is likely to be lost as the poles rot, are pushed over by horses, and occasionally struck by lightning.
