This peculiar peat bog environment can be seen from the path to the Petit Maclu. The few trees and bushes able to grow in these difficult conditions (waterlogged soil, lack of oxygen, etc.) are birches, willows and alder buckthorn. In the spring, the white cotton grass bobbles - a plant typically found in these environments - can be seen above the grass.
The lake used to be bigger. Little by little, aquatic plants have grown, and the permanently humid conditions have not allowed dead vegetation to decompose. By building up, all of these plants have formed what is called peat. In this peat bog, the peat isn’t very thick, but in the peat bog between the Grand Maclu lake and the Ilay lake, it has reached over 1.5m.