Since the 2010s, “nature-based solutions” have referred to projects and initiatives that seek to benefit both biodiversity and the well-being of human societies.
They call on nature in development projects, whether urban, peri-urban or rural, while ensuring the conservation or restoration of biodiversity.
Appropriate forest management will, for example, support food and energy security while preserving ecosystems.
Forest areas are crucial for adaptation to climate change and are also recreational spaces © Evan Wise / Unsplash
With the goal of an ecological transition to sustainability, uniting development and the environment is now a major challenge for local communities.
Preserve, improve, recreate
According to the International Union for Conservation of Nature (IUCN) – organizer of the World Conservation Congress, to be held in Marseille in September 2021, which defined this concept – these “solutions” can correspond to three types of actions.
Preservation of functional ecosystems in good ecological condition; improving the management of ecosystems to meet the objectives of sustainable development; restoration of degraded ecosystems or creation of ecosystems.
Nature-based solutions incorporate various existing concepts, such as plant techniques that use plant, seed and pruning techniques to decontaminate soil and restore biodiversity in degraded areas.
Calanque de Sugiton is located in the Calanques Massif, in the southern part of the Marseille metropolitan area © Adam Dore / Unsplash
We should also mention “green infrastructure” – afforestation along streams or roads – or even “nature in the city”, which mobilizes the planting of trees or the creation of cool vegetation islands.
A very wide range of applications
“Nature-based solutions” must be based on the functioning of ecosystems and applied on consistent spatial and temporal scales by involving all actors.
They seek to reconcile local issues – such as protecting a house against a natural hazard – and global – conservation of water resources in a catchment area, for example.
The scope of these initiatives is enormous: reduction of natural risks, conservation of human health, water supply, food security (with agroecology for example), socio-economic development (with the circular economy) or still struggle and adaptation in relation to climate change.
Development of plant techniques using plants of different species and with strong soil stabilization ability thanks to their root development. This structure thus makes it possible to restore biodiversity and at the same time stabilize the width during floods (construction of SYMBHI on the upstream Isère) © Inrae (via The Conversation)
The example of water management
“Nature-based solutions” find many applications in water management (natural, waste, rain or drinking water).
Here they make it possible to improve the quality of water bodies by combining applications – such as fishing, hydropower production or even leisure – to ensure the quality of treatment and discharges to the natural environment, promote seepage and recycling of rainwater, or save and optimize water resources.
This involves, for example, reducing natural hazards associated with water, floods, floods or even drought.
Nature-based solutions make it possible to unite the management of aquatic environments – known as GEMA (middle column) – and flood prevention – known as PI (right column) © Inrae (via The Conversation)
In 2020, the Syndicat mixte des basinshydraulics de l’Isère thus completed the creation of controlled floodplains by exploiting the existing natural areas, the reconnection of dead weapons or the restoration of alluvial forests, all on a large part of the river.
At the mining sites in New Caledonia
Terrestrial environments can also benefit from such initiatives, for example by conserving a natural area through the protection of ecological habitats and by using plant species that are beneficial to the life of an animal species.
This facilitates the development of fauna and flora, while at the same time constituting carbon sinks that are crucial for mitigating climate change.
This can cover the sustainable management of a forest, which contributes to the biodiversity of a place and at the same time ensures a recreational and relaxing role for the peoples; or again, the ecological restoration of an environment that will provide many regulatory services – maintenance of air and soil quality, maintenance of supply thanks to regulation of the amount of fish the size of a lake, for example.
Video illustrates the use of “nature-based flood protection” solutions (source: INRAE / IUCN)
As part of the INNER-MINE project, to take a concrete example, it involves the development and promotion of ecological engineering techniques that emphasize their application in the mining context and tropical climate of New Caledonia.
Demonstration sites for several of these techniques using plant techniques (planting, sowing and cuttings) and animal techniques (reintroduction of ants or other ecosystem engineering species) have been created.
Plants and animals thus reintroduced must make it possible to reconstruct living and functional environments. The aim is to restore the affected New Caledonian ecosystems while controlling erosion and sedimentation of steeply sloping land.
Ecological restoration of a nickel mine in New Caledonia involving ecological engineering work, with particular attention to the cleft context and associated severe constraints, the sustainability of the techniques used, their cost-benefit ratios and their character that can be copied in other territories. Plantations help combat soil erosion while restoring plant diversity on bare soil © Inrae (via The Conversation)
The challenge of training actors
The emergence of nature-based solutions is now everyone’s business, as illustrated by the ARTISAN project, whose main goal is to demonstrate and improve the potential for “nature-based solutions” by using a demonstration program that occupies ten pilot sites. It is a matter of raising awareness and training the various actors to develop the projects on national territory, in particular abroad.
Economic and social development can no longer take place in ignorance of the natural component of the environment. Conversely, the protection of natural environments can not hinder development. Nature offers a diversity of riches that one can rely on to consider uniting these different imperatives as suggested by these “nature-based solutions”.
This analysis is written by Freddy Rey, Director of Research in Engineering Ecology at the National Research Institute for Agriculture, Food and the Environment (Inrae).
The original article was published on the site of The conversation.