Illustration (RestaurE)

Interaction between aquatic and riparian zones

The “interaction between aquatic and riparian zones” (RESTAURE) project studies the capacity of the Selune ecosystems to regain its ecological functioning (resilience) by considering the interactions between the morphology of the river, the recolonization of the river and its banks by vegetation and by aquatic and terrestrial invertebrate species.

The project in short…

Theme Biocenosis, functioning and evolution
Full title Ecosystem restauration following dam removal: a functional approach of the interaction between aquatic and riparian zones (RESTAURE)
Objectives 1. To characterize and understand the interaction between the morphological changes of the river and the recolonization of its banks by vegetation following dam removal. 2. To identify new habitats for aquatic and terrestrial organisms and their interaction with vegetation.
Study subject(s) Morphology of the watercourse; Aquatic and riverine vegetation; Aquatic and terrestrial invertebrates
Methods used Aerial imagery; topographic surveys; morphological monitoring of the watercourse; cover/characterization of dominant species; functional and biological traits analyses; invertebrate communities surveys; stable isotopes.
Length of the project 2019-2021
Coordinator(s) Christophe Piscart and Simon Dufour
Laboratories involved UMR Ecosystèmes, Biodiversité, Evolution (ECOBIO), Rennes UMR Littoral Environnement Télédétection Géomatique (LETG), Rennes et Caen UMR Ecologie et Santé des Ecosystèmes (ESE) INRAE/Agrocampus Ouest, Rennes
Funding source AESN

Scientific context

The movements of nutrients, matter and energy from the terrestrial part of a river’s watershed to its aquatic part are important factors for the maintenance of ecosystems. Historically, the interaction between aquatic and terrestrial ecosystems has been studied by looking in the direction of natural flow. 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. The Selune valley is currently undergoing major changes in the morphology of its watercourse and its banks. Studying the interaction between the aquatic and riparian zones in this context of restoration represents a unique scientific opportunity to understand the ecological mechanisms that underlie not only resilience, but also the overall functioning of ecosystems.

Study subject(s)

The project focuses on the interaction between riparian and aquatic ecosystems and in particular between the river morphology, riparian vegetation and aquatic and terrestrial invertebrates.

Objectives and methodology

The objective of this research project is to initiate the analysis of new habitats resulting from the restoration of the Selune valley by focusing on terrestrial/aquatic interactions at the level of riparian interfaces. It will thus make it possible to understand the specific role of these interactions in the resilience of ecosystems undergoing restoration. The restoration of connectivity in the Selune River will be analysed through a double angle:

  1. To characterize the bio-geo-morphological functioning of the river and its banks.
  2. To study the functioning of food webs (aquatic and terrestrial).

To do this, two types of interactions are analysed:

  • The interaction between riparian vegetation and channel morphology.
  • Trophic interactions between riparian and aquatic ecosystems, by monitoring invertebrate species.
Orthophoto (PlateformeD2T-2020)
Figure 1 : Orthophoto created from a series of drone images of the Selune River, upstream of the old Vezins dam, in September 2020 by D2T Platform. Aerial drone imagery helps following the evolution of new habitats and the recolonization of riverbanks by vegetation.

The sampling strategy proposed for this project is based on the need to analyse sites with contrasting environmental conditions. In fine, we will determine their relative importance in the restoration process (occupation of the surrounding land with or without trees, more or less steep-sided topographic context, etc.) and compare these sites with others located outside the reservoir area.

Results and conclusions

This project is ongoing. Results and conclusions will be elaborated later.

Publications and reports

This research project is ongoing. Here you will find the list of reports and publications.

The project “Interaction between aquatic and riparian zones” (RESTAURE) is part of the second phase of the Selune scientific program. Find all the research projects here.