Air, fresh water and soil on which we depend are available thanks to biodiversity. Climate regulation, the reduction of natural risks and the diversity of living species are made possible by biodiversity. As the new 2019 report of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) reminds us, “nature is declining globally at a rate unprecedented in human history – and the rate of species extinction is accelerating, already causing serious effects”.
What is biodiversity?
According to the Convention on Biological Diversity signed in Montreal in 2020, “Biodiversity is the result of billions of years of evolution, through natural processes and are increasingly subject to human influence. It is the web of life of which we are an integral part and on which we are totally dependent. Biodiversity encompasses a variety of ecosystems such as those found in deserts, forests, wetlands, mountains, lakes, rivers and agricultural landscapes. In each ecosystem, living beings, including humans, form a community, interacting not only with each other, but also with the air, water and land around them”. From ecosystem to biodiversity, the difference lies in the eminent presence of the environment: it is the association between the biocenosis (the living) and the biotope (the habitat of the living).
What functions does Biodiversity have in urban areas?
• An ENVIRONMENTAL function: it provides a habitat for fauna and flora and allows water to infiltrate the soil. This environmental function is also ecological as it preserves living species and restores their natural living space.
• ECONOMIC and HEALTH reasons: biodiversity is a food resource and allows for the development of short food supply chains.
• A LANDSCAPE dimension: biodiversity has long been an integral part of the landscape until the emergence of dense urban spaces. It is therefore a source of renaturation of urban spaces.
• A SOCIAL link: biodiversity in the city will bring people together around a common element. Shared gardens, for example, are an opportunity to meet one’s neighbors, to learn about natural ecosystems collectively and intergenerationally. Sharing green space has no age limits!
How to restore biodiversity in the city?
The first solution is to counteract the fragmentation of natural spaces in the city. Surfrider Europe is committed to opposing infrastructure projects in natural urban areas, which are a source of biodiversity degradation in coastal areas. Its Coastal Defenders programme aims to reinforce active local struggles against polluting and unreasonable projects that are harmful to the coastal environment. The Surf Park planned in the municipality of Saint-Jean-de-Luz in France, for example, would contribute to the artificialisation of soils and the massive loss of biodiversity. And yet, in 2015, according to the report of the regional biodiversity conference in Nouvelle Aquitaine, 9.5% of the region’s land has already been artificialised and 61% of the soil is sealed. This planned development of 7 ha is in contradiction with the Biodiversity Plan, which defines the “zero net artificialisation” (ZAN) objective and with the recommendations of the Citizens’ Convention for the Climate.
The second solution is to limit, mitigate and compensate soil sealing. Soil sealing is “the permanent covering of a parcel of land and its soil with an impermeable artificial material such as asphalt or concrete” (European Commission, 2012). The water that infiltrates helps renew ground water tables and reduce urban runoff. The latter is a risk factor for flooding and is largely responsible for plastic pollution of the ocean. The idea is therefore to limit impermeable spaces as far as possible, such as car parks with concrete surfaces.
The third solution is to revegetate cities. This involves restoring biodiversity in order to preserve and reproduce the habitat conditions of fauna and flora, species that contribute to the stability of urban environments. Ocasionally planting trees? No. Restoring biodiversity corridors? Yes. They allow living species to move, evolve, feed, capture light and communicate with each other. The Green and Blue Trames policy set up in 2007 in France is part of this perspective of creating ecological continuity in an urban environment. Revegetation also means creating ecosystem services, favouring short food supply chains and turning cities into natural ecosystems.
Ocean Friendly Gardens, a programme for biodiversity
Led by Surfrider Europe, this programme focuses on preserving water quality in coastal catchment areas through sustainable rainwater management. Urban landscapes are considered as solutions to fight against pollution of aquatic environments because 80% of ocean pollution comes from the continent. Soil, flora and fauna represent the first natural filter in an urban environment. They are therefore at the heart of the programme, to be preserved and developed. Three components are integrated in this programme: education, training and the implementation of participative work sites.
Ocean Friendly Gardens proposes to structure, support and amplify collective and citizen actions on the scale of coastal watersheds with a view to adapting to the effects of climate change. From the restoration of wetlands from a watershed scale to private gardens and rainwater harvesting, all actions, both individual and collective, count!
Reintegrating biodiversity in cities is therefore a contemporary concern, a climatic, environmental and social issue. Biodiversity is an integral part of a more sustainable development for our planet.
