Reconnecting nature: biodiversity, a challenge for infrastructure

Biodiversity and fragmented habitats

Housing projects, expanding cities, new business developments and transport networks are changing the face of the natural environment. A building, a road, a railway line and a fence are just some of the physical barriers that prevent animals and insects from coming and going as they please. Depending on their size, some wildlife species can still make their way past these obstacles, but it can prove to be a perilous journey: 194 million birds and 29 million mammals are killed every year in Europe¹.

Some species that are used to roaming freely across wide-open areas, whether for finding food or reproducing, are now limited in their movements after human activities have encroached on their natural habitat.
 

“To ensure the long-term success of biodiversity conservation, protected and conserved areas must be integrated into wider landscapes and seascapes, while promoting sustainable use that is fully consistent with conservation outcomes. This requires a commitment to integrated spatial planning, strong governance and collaborative management, ensuring both biodiversity protection and the enhancement of local livelihoods”², stresses the 2024 Protected Planet Report, which is supported by the UN Environment Programme.  

Awareness of the issue is clearly growing. Several States have enshrined biodiversity conservation in their spatial planning laws. In France, the law aimed at improving access to housing and renovating urban planning practices (the Alur Act), which was revised in March 2014, steps up the obligations for ensuring that spatial planning policies give greater focus to the environment, biodiversity and ecological continuity³. Businesses and associations also have a role to play. The VINCI Group has actually turned these issues into one of its three environmental objectives, i.e. act for the climate, optimise resources through the circular economy, and preserve natural environments.  The Group is focused on its ambition of achieving "no net loss" of biodiversity by 2030" . 

Balancing human needs with nature:

The challenge lies in scaling up the deployment of innovative solutions to stop biodiversity loss in its tracks.

Ecological engineering, colours and biodiversity

Let’s start with a few definitions that are essential for clearly understanding biodiversity issues and conservation.

• Ecological continuity:  this concept refers to the free movement of animal and plant species on land or in aquatic environments. We often talk about ecological continuity in waterways, which concerns aquatic organisms and natural sediment transport⁴.
• Green corridors: this refers to the networks of natural terrestrial environments that allow animals and insects to move and colonise new areas.
• Blue corridors:  this refers to the networks of water bodies (rivers, streams, canals, ponds, wetlands, etc.) that allow fish, amphibians and other water-dependent species to move and interact.
• Brown corridors:  this refers to connecting networks in underground environments or the soil. Sometimes, soil sealing needs to be reversed so that micro-organism and microfauna life can survive.⁵
• Black corridors: this refers to preserving dark skies at night, which are vitally important for nocturnal animals, including bats, certain insects and migratory birds.

Meanwhile, ecological engineering harnesses scientific knowledge, techniques and practices based on the living environment (wildlife, plant-life and biodiversity) to sustainably design, restore, manage or develop natural or urbanised environments⁶. Equo Vivo⁷ is VINCI Construction’s dedicated brand for carrying out ecological development projects, including green and blue corridors, or renaturing and restoring wetlands and waterways.

Existing schemes: wildlife crossings, urban greening…  

Wildlife crossings can be created along roads, railway lines and even dams blocking waterways. Eco-bridges, ecoducts, bat gantries, amphibian tunnels and fish passes are being deployed across France and abroad.

In Brazil, Entrevias (VINCI Highways / VINCI Concessions) has already built 44 wildlife crossings across its 570 km motorway network, and 30 more were under construction by the end of 2024, primarily along the SP-333 between entre Marília and Florínea. These crossings are designed to protect a wide variety of species, such as jaguars, deer, capybaras, reptiles and birds. For an even more effective response, fencing is being installed along the motorways to direct animals towards the crossings so that they can safely reach the other side.

In France, VINCI Autoroutes is also implementing these solutions. By the end of 2022, there were  178 crossings on 21 motorways within the VINCI Autoroutes network⁸.  Despite these tremendous efforts, the whole of the French network has yet to be covered, but work is continuing with this goal in mind, and the wealth of data collected by dedicated structures (chamber of agriculture, French National Forestry Office, associations, etc.) are encouraging. For example, 21 wild species have been detected using the 15 eco-bridges recently created throughout the VINCI Autoroutes network⁹.

In urban areas, along with efforts to conserve natural and wooded areas, biodiversity reservoirs are being created, namely greenways or green corridors. In some cases, soil-sealed areas need to be redeveloped, where the ground surface is first made permeable and then replanted. During the summer of 2022, EJL’s Vitry-sur-Seine agency (a VINCI Construction subsidiary) redeveloped two primary school playgrounds in Vincennes and created an open-air water circulation system with channels, rock streams, and swales fed by rainwater harvesting tanks. As for spatial planning, some architectural solutions, such as using green roofs and walls, integrating shared gardens and parks into cities, and planting flowers for pollinators, are also aimed at protecting nature and biodiversity.

Light pollution in cities plays havoc with the migration and reproduction cycles for some nocturnal species. Black corridors help maintain darkness at night, which is essential for animals and insects. With a helping hand from ecology experts, VINCI Energies subsidiary Citeos inventoried the different species inhabiting the city of Blois in France, determined the nesting periods and offered to provide the authorities with solutions designed to have a low impact on nocturnal biodiversity. With warmer orange lights and projectors that are no longer pointed at the sky or water, and which switch off at 10:30 pm, the city has seen an increase in its energy performance, while helping tackle light pollution. Citizens and local authorities must be consulted to gain their acceptance for these types of solutions.

Companies and local authorities are especially effective at taking action, particularly if biodiversity issues are taken into consideration during the earliest stages when designing urban and infrastructure projects.

Sources :

¹ Libération : “Watch out for elk” – https://www.liberation.fr/forums/la-prudence-du-wapiti-20250330_ENJIK6NLAVDSHISDOYH3PO37U4/  

University of Reding : "Roadkill risk and population vulnerability in European birds and mammals” – https://centaur.reading.ac.uk/89172/16/Grilo%20et%20al_2020_Frontiers.pdf  

² Protected Planet Report 2024 : “Executive summary” – https://pp-digital-report-document.s3.eu-west-2.amazonaws.com/Protected+Planet+Report+2024_Executive+Summary.pdf 

³ Alur Act, Ministry for Housing and Territorial Equality: “Biodiversity in local planning regulations and territorial coherence plans”  – https://www.ecologie.gouv.fr/sites/default/files/documents/alur_fiche_la_biodiversite_dans_les_plu_et_scot.pdf  

⁴ Ministries for the Ecological Transition, Spatial Planning, Transport, Cities and Housing: “Green and blue corridors” –https://www.ecologie.gouv.fr/politiques-publiques/trame-verte-bleue  

⁵ Sol&Co : “Brown corridors: Why? How? Which limitations?” –https://www.trameverteetbleue.fr/sites/default/files/3_jet_nouvellestrames_2023_vincent.pdf  

⁶ Ministries for the Ecological Transition, Spatial Planning, Transport, Cities and Housing: “Ecological engineering roadmap for 2030” – https://www.ecologie.gouv.fr/politiques-publiques/feuille-route-ingenierie-genie-ecologiques-horizon-2030?utm#quand-faire-appel-a-lingenierie-et-au-genie-ecologiques-1  

⁷ https://equo-vivo.com/  

⁸ VINCI Autoroutes : “Ecological continuity. Feedback 2” –https://www.trameverteetbleue.fr/sites/default/files/3-ppt_jet_paf_chavaren_vf.pdf  

⁹ Ibid.  

¹⁰ Biodiversité.gouv : “The five pressures responsible for biodiversity loss” – https://biodiversite.gouv.fr/en/living-harmony-nature  

¹¹ CNRS : “Agricultural intensification is driving a decline in bird populations across Europe” – https://www.cnrs.fr/en/press/agricultural-intensification-driving-decline-bird-populations-across-europe  

¹² Biodiversité.gouv : “Biodiversity: what purpose does it serve?” – https://biodiversite.gouv.fr/en/living-harmony-nature  

¹³ VINCI : conférence “The joint environmental benefits for the economy, health and well-being, at l’archipel”