From a geological point of view, Corsica is mainly made up of granite rocks with the exception of the northeast quarter of the island which is slaty and more wooded. It is in its large crystalline part with magmatic rocks, located west of a Losari-Ghisonaccia line, that we find the highest peaks. The relative biological poverty linked to insularity does not prevent endemic taxa such as the Laricio pine (Pinus nigra laricio) and the sweet alder (Alnus alnobetula suaveolens).