Les lichens des cimetières du canton de Genève.

The importance of cemeteries for the diversity of lichens is questioned. All 60 cemeteries in the canton of Geneva were visited and all lichens present recorded. 272 different species were identified, i.e. more than half (57.9%) of the 469 species found in the canton from 2000 to 2011. From 8 to 108 species were recorded depending on the cemetery, with an average of 59.8 species per cemetery! This unexpected abundance of species is all the more important given that the cemeteries occupy only 0.11% of the total area of the canton. Even more surprisingly, 53 species were found only in cemeteries! The partial renewal of the inventory of the Lancy cemetery, in 2019, showed the dynamism of species, with 11 species not located and 6 new species discovered, including Xanthoparmelia mougeotii (D. Dietr.) Hale. It also appears that the species diversity is concentrated on a very small number of gravestones and that the majority are without lichen, either because they are too recent or because they have been polished and remain without any lichen for a long time. Cemeteries are therefore hot spots for local lichen biodiversity, particularly for saxicolous species and in relation to the canton of Geneva, which does not have an abundance of natural rocky outcrops. Cemeteries could become true sanctuaries for these and other organisms in the future. Advice is offered to municipalities and individuals to encourage this development. [ABSTRACT FROM AUTHOR]