If I ask you to picture a pond, what do you see? Personally, I picture a tiny body of water with reeds, ducks, dragonflies and perhaps a few rocks at the edge or in the pond itself. But reality doesn’t necessarily match this stereotype! This is what we find with the seven ponds at the Domaine des Courmettes.
Monitoring the health of the pond ecosystem
Une mare a un cycle de vie spécifique : une cuvette dans le sol, à fond peu perméable, se remplit d’eau, puis de petites plantes viennent s’installer, suivies par les joncs et les roseaux, puis des pousses d’arbres. La mare est généralement destinée à se refermer un jour, pour devenir une forêt.
A pond has a specific life cycle: a depression in the ground, with a relatively impermeable base, fills with water; then small plants begin to grow there, followed by rushes and reeds, and then tree saplings. The pond is generally destined to close over one day, eventually becoming a forest.
At the Courmettes estate, monitoring the various ponds allows us to observe how they evolve over time, enabling us to assess the rate at which they are closing over. The data collected relates to the pond’s water level, its surface area, vegetation cover, and the animal species that inhabit it. This data is correlated with rainfall and temperature data.
A better understanding of the ponds enables us to manage them more effectively. For the time being, our teams are focusing on observation and avoiding any intervention. However, in order to slow down the process of the pond closing over, we may need to cut back vegetation such as reeds or dredge the bottom if there is too much sediment.
Mieux comprendre les mares permet de mieux les gérer. Pour l’instant, nos équipes privilégient l’observation et évitent toute intervention. Mais il peut arriver, pour ralentir le processus de fermeture de la mare, de couper des végétaux comme les roseaux ou d’exonder le fond s’il y a trop de sédiments.
Every mare has her own personality
Each of the ponds on the Courmettes estate functions in its own specific way.
It is important to note that there are both permanent and temporary ponds. The latter, which challenge our preconceptions of ponds teeming with ducks, remain dry throughout the summer. Monitoring the drying-out period of this type of pond provides valuable information: for example, if the pond dries out too early, this will have an impact on amphibian reproduction.
Conversely, if our scientific team observes that dragonflies and amphibians are breeding, this indicates that the pond’s ecosystem is in good health.
Currently, three water-filled depressions are being monitored on the estate. When water accumulates in a depression in the ground and there is a change in vegetation, ponds are created naturally, which could happen in these three water-filled depressions.
Essentials for biodiversity
Like all wetlands, ponds are essential for biodiversity. They are home to a large proportion of protected species: dragonflies, amphibians and some reptiles. They also provide a valuable habitat for other species, such as birds and mammals, which can come to drink or enjoy the cool water. In the event of a fire, ponds can act as a buffer zone. Another significant benefit is that the soil in the pond acts as a carbon sink.
If you’d like to create a pond in your private garden, you can therefore enjoy these benefits. A well-balanced pond does not produce excessive numbers of mosquitoes, as many predators – such as dragonfly larvae – feed on them. Mosquitoes may breed in the first year whilst the pond establishes its ecological balance. After that, you can sit back and enjoy the pleasure of a pond, with its coolness and biodiversity.