This article is part of the folder : SESAME : Intégrer l'arbre dans les projets de renaturation urbaineSee the 9 news related to this folder
Biodiversity and terrestrial and marine natural environments serve numerous purposes: preservation of ecosystems and biodiversity, actions on climate and pollution, on run-off water, on the living environment and health, thus serving to promote the regions.
To help communities and regional stakeholders preserve and develop this heritage, Cerema disseminates tools and methods, organises exchange and feedback days and supports communities in the context of innovative projects, upon which it then capitalises.
Integrating nature and biodiversity into development projects
The amplification, at both the global and local levels, of phenomena such as heatwave episodes, pollution peaks, periods of drought, floods, or coastal erosion, have gradually led to awareness of the issues related to climate change.
Research work carried out at the national and European levels has shown that Nature-Based Solutions are an important lever for the adaptation of regions to these phenomena.
Knowledge in this field has progressed considerably over recent years thanks to experiments and approaches such as:
The national French Capitals of Biodiversity competition, which rewards the actions of communities in favour of the preservation and development of biodiversity. This year's theme was "Climate: nature as a source of solutions"
The call for projects "nature-based solutions for resilient coastal regions" of the Biodiversity Plan,
Local innovative projects such as the SESAME project, which made it possible to create, in partnership between Cerema, the City and the City of Metz, to develop a decision support tool to select the plant species to plant in the city in depending on the services expected.
The management of or contribution to research projects such as Nature4Cities or CoolParks, to supplement knowledge, particularly on a practical level, of nature-based solutions, their operation and their impact.
Nature in the city: many levers for action
Various levers are available to integrate nature into development projects. This concern, however, must be integrated upstream of project implementation, in the regional strategy, in order to optimise the revegetation of the urban space and soil unsealing.
Cerema has produced developed a series of educational tools for communities, to promote the development of nature and biodiversity in cities:
Urban agriculture projects are born in the city's nooks and crannies and in spaces that stakeholders (communities, economic stakeholders, associations, citizens, etc.) decide to conserve, protect or design specifically for this form of agriculture. Over the past 10 years, so-called urban agriculture (collective gardens, eco-pastures, urban farms, etc.), has become one of the components of the city's fabric.
It is also multifunctional, meeting both the needs of city dwellers (nature, local food, fresh produce, etc.) and the need to increase density in order to limit wastage of agricultural land.
We note that public and private initiatives are increasingly integrating food concerns. They are increasingly focused on relocating production and the food circuit, to meet the quantitative and nutritional needs of the inhabitants, while respecting social-environmental balances.
A method for creating urban agriculture spaces in Eco-Districts has been developed through working groups and the monitoring of operations carried out in Eco-Districts with various specificities. Indeed, there is no standard approach: it must be adapted to the context and to the needs.
Urban Agriculture and Eco-Districts (in French)
Developing nature in the city
Faced with the climate issue, cities must absolutely be reconsidered to reconcile sustainable development and habitat. The presence of nature, of green spaces, provides many services:
Improvement of the living environment and health
Reduction of heat islands
Run-off reduction and storm water management
Protection of biodiversity
Reduction of soil artificialisation and sealing
The concept of ecosystem allows these spaces to be considered by integrating their functions and the various ecosystem services provided.
These initiatives represent an opportunity to involve citizens in the creation, management and/or running of these spaces. A guide drawn up from feedback presents several nature projects in the city, in various contexts, in which citizens have played a role.
A series of "Nature in the City" sheets presents methods and procedures for integrating these natural spaces, in particular wetlands, into urban development projects.
Green and Blue Grid: ensuring ecological continuity
The concept of a green and blue grid consists in ensuring the ecological continuity of waterways and vegetation, to promote circulation and wildlife and the preservation of biodiversity. The regions define a regional ecological coherence scheme (RECS), which is then applied locally.
The green and blue grids can be viewed on a national map, created in partnership with the Centre de Ressources Trame Verte et Bleue and the Institut national de l'information géographique et forestière (IGN) under the leadership of the Patrinat Mixed Service Unit.
Urban lighting is now considered to be a pollution, and there is more and more talk of a black grid, consisting in avoiding light pollution along corridors used by nocturnal species.
Cerema has deciphered the order on the prevention, reduction and limitation of light pollution, which imposes new obligations in terms of public lighting management, with the dual objective of preserving biodiversity and saving energy.
In cities, the issue of brown grid is increasingly raised to ensure the continuity of unsealed soils and allow the development of ecosystems.
Cerema has developed a method to preserve and develop the green and blue grid within the framework of the RECSs.
Reducing soil artificialisation
Soil artificialisation is becoming a major concern in public policies. Tending towards a rate of zero net artificialisation involves anticipating land use planning and knowing the functions of the soil.
Innovative projects are being carried out to unseal soils. The Greater Narbonne Area, Cerema and State services are developing a methodology to integrate this issue into town planning documents.
In terms of taxation, an approach which aims to adapt the taxation of development to the urban development strategy is currently being tested with the new town of Mauges-sur-Loire. In this project, Cerema is developing a tool to help manage the development tax according to the project included in the local urban development plan.
To support decision-making, a soil artificialisation observatory has been put online by Cerema, IGN and Irstea (national research institute in science and technology for the environment and agriculture) at the request of the Government. Accessible to all, it will allow local soil artificialisation changes to be monitored.
Monitoring mitigation measures for damage to biodiversity
An observatory has been put online on the Géoportail site to allow agents and elected officials of communities and the general public to monitor mitigation measures for damage to biodiversity via web mapping.
It was developed by CGEDD in partnership with Cerema, which collects and processes data, and the French Agency for Biodiversity (AFB) and is accessible to all.
The map is combined with the GéoMCE tool that automates the reporting of geolocated data on mitigation measures and facilitates the management, geolocation and monitoring of ARC (Avoid, Reduce, Compensate) measures.
Observatory of mitigation measures
This observatory has several objectives:
To improve the traceability of mitigation measure location;
To avoid the superimposition of several mitigation measures at a given site;
To improve implementation
To improve monitoring and control.
In the folder : SESAME : Intégrer l'arbre dans les projets de renaturation urbaine