Riparian forests provide a large number of important ecological functions and services, including the role of ecological corridor. These riparian corridors enable, for example, terrestrial animals to move from one favourable habitat patch to another, and many animal species spend at least part of their life cycle on the banks of streams and rivers.
At the same time, certain hydrochorous seeds (= dispersed by flowing water) or pieces of vegetation circulate at the bottom of the bank, allowing sexual or vegetative reproduction for certain species, while the wind and birds carry other seeds through the air.
European beaver on the riverbank border. © Sébastien de Danieli.
However, seed dispersal may also involve invasive alien species, also known as invasives, such as Japanese knotweed. Regularly flooded areas can then become a massive source of propagules (seeds or plant pieces that can propogate themselves) of invasive species for downstream areas or for nearby terrestrial ecosystems.
From a regulatory point of view, ecological continuities comprise two major components: the “green” belt (terrestrial habitats) and the “blue” belt (aquatic habitats). Riverbanks are at the interface of these two spaces: they thus become a connection between upstream and downstream. But they can also act as borders on both sides of their shores for other species.
A programme “Trame bleue : espaces et continuités” accompagnies the implementation of SRCE (“schéma régional de cohérence écologique”) from Rhône-Alpes about these questions.
To elaborate
Programme “Trame bleue : espaces et continuités” https://www.tramebleue.fr/
Decamps, H. (2003). Ripisylves : la biodiversité par l’instabilité = Biodiversity through instability. Journées dʹétudes sur les ripisylves méditerranéennes, Pont‐du‐Gard, FRANCE (10/04/2003).
Lévêque, C. (2016). Quelles rivières pour demain? Réflexions sur l’écologie et la restauration des cours d’eau, Editions Quae.
Naiman, R. J., H. Décamps et M. E. Mc Clain (2011). Riparia. Ecology, Conservation, and Management of Streamside Communities, Elsiever.
Naiman, R. J., H. Decamps et M. Pollock (1993). The Role of Riparian Corridors in Maintaining Regional Biodiversity. Ecological Applications 3(2): 209‐212.
