The Lake of Longemer's delta is bordered by floating rafts. Made of sphagnum moss, they are gradually filling the lake that could evolve into a peat bog over the upcoming millennia. Forming the moss are Clovers of water and Comarets of the swamps. They are pioneer plants that thrive on trembling vegetables. Alders, another plant, can colonize permanently flooded and therefore asphyxiated soils. To survive there, they develop nitrogen-fixing microorganisms at their roots that enrich the environment.