The Grand Bois loop at Rivière-Enverse

4 points of interest

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  Lake

  Negative impact of artificial dams on rivers

  Occasionally, hikers and families may build a temporary dam just for fun. By creating artificial dams, they slow down the natural flow of the river and cause harmful effects: - The movement of aquatic species is essential to enable them to feed and reproduce. - The temperature of the water rises, silt and algae thrive and it becomes more difficult for fish to breathe. - Stones are refuges and habitats for many of the micro-organisms that feed fish. Moving or turning stones upside down endangers the aquatic environment. To protect the river, we must let it flow freely.
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  Flora

  Riparian forest

  The riparian forest is a group of wooded areas (trees, shrubs and bushes) found along the banks of a watercourse. The riparian zone has many benefits for the ecology of the watercourse: - Combats erosion: rooted trees help maintain riverbanks. - Filters pollutants: fertilisers and pesticides can be absorbed by plants and soil-dwelling micro-organisms, limiting their presence in watercourses. - Shading: riparian vegetation provides shade, reducing warming, evaporation, eutrophication and additional oxygen. - Dissipates water flow: riparian vegetation slows the flow of water during floods, reducing the risk of flooding. - Shelter and food: the riparian forest is a source of food, a breeding ground, a refuge and a place to live for numerous animal and plant species, both terrestrial and aquatic.

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  Fauna

  The Otter

  Having disappeared from a large portion of France, the Eurasian otter is now in the process of recolonising certain territories, albeit quite slowly due to a low reproduction rate. Now classified as a "protected species", the otter is suffering the consequences of certain human activities that are hampering its population growth, such as river pollution, development of road networks and land fragmentation. This discreet and rare species can be distinguished from nutria or other semi-aquatic animals by : - Its swimming technique: the otter's back and head stay out of the water - Its tail is broad and thick - It is carnivorous, eating fish and small amphibians

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  Flora

  Invasive non-native plants

  Solidago, butterfly bush, Japanese knotweed, Himalayan balsam, all these garden escapees are causing problems today because they are displacing our wild plants. These are aggressive plants that compete with other species, upsetting the local ecological balance. The Conservatoire d'espaces naturels de Haute-Savoie, which manages the nature reserve, regularly calls on volunteers to uproot these invasive plants in order to preserve the local vegetation.