Interaction between aquatic and riparian zones

Ecosystem restauration following dam removal: a functional approach of the interaction between aquatic and riparian zones (RESTAUR)

Coordinator(s)

Christophe Piscart (UMR ECOBIO) and Simon Dufour (UMR LETG)

Scientific context

Historically, the relationship between aquatic and terrestrial ecosystems has been studied by looking in the direction of natural flow, from upstream to downstream: by considering nutrient, matter and energy movements from the terrestrial part of the watershed towards the aquatic compartment. Nowadays, the aquatic environment is no longer considered as a simple receptacle, but as an environment interacting with the terrestrial environment. However, these interactions represent a blind spot in research for river restoration ecology.

Objectives

The objective of this project is to initiate the analysis of new habitats resulting from the restoration of the Sélune river by focusing on terrestrial / aquatic interactions at the level of riparian interfaces and the specific role of these interactions in the restoration process. The analysis of interactions between aquatic and riparian zones in the context of restoration represents a unique scientific opportunity to understand the ecological mechanisms that underlie not only restoration processes, but also the overall functioning of aquatic environments.

Methodology

The restoration of connectivity in the Sélune river will be analysed from a double angle: the bio geomorphological functioning of the fluvial corridor and the functioning of food webs (aquatic and terrestrial). Two interactions will be analysed: firstly, the interaction between riparian vegetation and channel morphology, and secondly, trophic interactions between riparian and aquatic ecosystems. First, it involves analysing the two-way relationships between terrestrial and aquatic compartments. Secondly, the sampling logic that we propose is based on two points : (1) to analyse sites that present contrasting environmental conditions in order to determine their relative importance in the restoration process (surrounding land use with or without trees, context more or less deep topographic, etc.) and (2) to compare these sites with comparable sites outside the reservoir area.

Laboratories involved

UMR CNRS 6553 ECOBIO

UMR CNRS 6554 LETG (Rennes et Caen)

UMR INRAE ESE