A paper just published in Swainsona (the taxonomic journal of the State Herbarium of South Australia) by lichen taxonomist Gintaras Kantvilas from the Tasmanian Herbarium provides a comprehensive account of the lichens of Kangaroo Island.
The paper is a rare bird - very few Australian taxonomic papers deal with lichens, largely because Australia has very few lichenologists, despite having plenty of lichens.
The most recent edition of the Checklist of the Lichens of Australia and its Island Territories (maintained by the Australian Biological Resources Study) lists nearly 4000 species. That this is an underestimate is shown by the fact that this single paper, a comprehensive assessment of a single island, adds nineteen new species never before seen in Australia.
Lichens, of course, are ecologically incredibly important. They break rocks down into soil, fix nitrogen, reduce erosion and provide habitat and safe sites for many plants and animals to live and thrive. They may have been the first organisms to colonise land, paving the way for life as we know it.
Several of the Kangaroo Island species that are new records for Australia were previously only known from the Northern Hemisphere. Bipolar distributions - species that occur in the temperate or polar regions of both hemispheres, are quite common in lichens. In some cases the bipolar populations are clearly genetically very close, while in other cases careful study shows that they comprise closely related sister species, one in the north and one in the south.
In both cases, this indicates that lichens regularly travel around the world (the difference is simply in the timing and frequency of their dispersal).
It's good to know that some of these world-travelling lichens have made Australia, and Kangaroo Island, home. Now we just need more lichenologists.