preserving biodiversity

Réseau Ferré de France is particularly concerned by the challenges in preserving biodiversity. Railway lines may alter the ecological consistency of ecosystems and reduce exchanges between species. However, railway tracks may also play the role of ecological corridors, refuge corridors or passageways for some species.

The aim of biodiversity conservation is therefore being progressively integrated in our activities. Our actions concern new lines and the existing network, concrete projects on particular points in the network and long-term research and development activities.

 

Biodiversity and new lines
Throughout the development of a project for a new line, biodiversity is taken into account in four major stages:
 
Assessing the initial state of the natural environment: Réseau Ferré de France establishes a complete inventory of the natural environment in the area of the proposed line, through inventories that may be an opportunity to discover protected species.
 
Assessing and reducing the impacts: at all stages of the project, measures are taken to reduce the impacts on biodiversity: selection of the proposed line, engineering structures, moving the population to areas close by that are not impacted or specifically created, protection of sensitive areas during works.
 
Compensating the residual impacts: the areas impacted by the proposed line are compensated by the restoration or the creation of areas that are ecologically equivalent close to the line.
 
Additional measures: The positive effects of the project must be improved, while providing an environmental added value: creation of additional ponds, re-creation of areas of floristic interest through the ecological planning and management of mounds and other green dependencies for instance.

 

Discovery of a protected species: the yellow-bellied toad (Rhine-Rhone high speed line)       Digging of an additional pond and improvement to surrounding areas

 

Biodiversity and the existing network
An ecological management of the existing network enables the protection of a significant amount of biodiversity and also to support the 'corridor' effect created by the rail infrastructure.

Several studies, led for instance in the context of reopening the lines of Flamboin-Montereau (77), Nantes-Chateaubriant (44) or the La Narbonnaise (11) project have enabled new modes of management of acquired land, in particular the management of vegetation.
Physical anti-vegetation devices (track mats, textile membranes, grids) enable a reduction in the use of phytosanitary products and require less frequent maintenance.

Other actions are to be applied, such as installing hives in lands acquired and the good treatment of species having naturally colonised acquired lands.

 

Floristic inventory for the 'Petite Ceinture' (Paris) before maintenance works

 

Significant Research and Development challenges
In addition to a more ecological management of acquired lands, the main challenge for Réseau Ferré de France consists of getting the rail network to be in tune with the sustainable planning project for France, embodied in particular by the 'trame verte' and 'trame bleue' resulting from the "Environment Round Table".

The 'Trame verte et bleue' (TVB) aims to maintain, restore or even re-create ecological continuity, in order to connect protected areas to each other. It will more generally enable a meshing of ecosystems throughout France.
Réseau Ferré de France must therefore better understand the role of the rail infrastructure in this 'trame verte et bleue'. Our role is to assess on one hand, how the infrastructure fragments ecological areas and continuity, and on the other hand if it plays a beneficial role of refuge, dispersion and facilitation of movements for some species.

Several research projects have recently been launched in order to investigate these two questions, with the medium-term aim to have some indicators that enable us to assess our impacts on biodiversity as accurately as possible.