Nature in the city: how does Métropole de Lyon work?


Permeable city, urban forests, flowering meadows… Focus on the measures implemented by Metropolis Lyon as part of its nature plan

Each action included in the nature plan corresponds to the triple aim of combating global warming, preserving biodiversity and improving the daily lives of residents. For it to work, we must plant more and better, and choose the right species and forms of vegetation so that they are adapted to the city and favorable to life.

The city’s reforestation for freshness

Did you know that in addition to cooling, trees have another power? They absorb and store carbon dioxide, also called CO2, a greenhouse gas that amplifies climate change. This is why the metropolis multiplies urban afforestation. The first was planted in 2021 in Saint-Priest: 2,000 trees and 600 bushes over 2 hectares. The trees are still small, but within 3 or 4 years their branches will touch to form a protective shade. With those from Sathonay-Camp, Caluire, Feyzin, Corbas and Vénissieux, 6 forest areas have already been created. Two others are planned in Saint-Fons and Villeurbanne.

Meadows for pollinators

For 30 years, urbanization and intensive agriculture have chased bees, bumblebees, ladybirds and other pollinating insects from our cities. However, they are essential: 8 out of 10 local wild plants depend on pollinators to reproduce. So to facilitate their return, Metropolis sows flower meadows. 13 have already arisen on former industrial wastelands or abandoned areas.

  • Pollinating insects are essential for biodiversity

    © Metropolis Lyon

Public spaces are going green

Nature close to home also involves the more diffuse vegetation of streets, pavements and squares. 4,300 trees were planted this winter: if we put them together, they would cover almost 9 football pitches. Thus, more than 45 trees have been planted on part of the Cours Charlemagne and around the Confluence basin, one of the worst heat islands in Lyon. Results? Residents, passers-by and walkers are slowly reclaiming this corner of the metropolis thanks to the sunny days. Another example, Place Ambroise Courtois in the 8th, about thirty maple trees were planted this winter and spring.

Planting the streets is also an opportunity to facilitate the water’s path through the ground. The first “rain trees” thus took root in rue Vauban in the 6th arrondissement of Lyon. Behind this poetic name is the idea of ​​enlarging the space at the foot of the trees and adding plantations. The result is both attractive and efficient: these rooms collect up to 9 m³ of water during heavy rain.

Revegetation of university courses is also a priority: a total of 112 trees have been planted or replanted there. Finally, in terms of urban projects, more than 7,000 trees have come to reinforce nature in the heart of the new districts emerging from the ground in Saint-Genis-Laval, Marcy-l’Étoile, Vaulx-en-Velin, Villeurbanne , Caluire – et-Cuire, Lyon or even Chassieu.

  • Nature in the city: how the metropolis behaves

    More than 100,000 trees along the roads, along streets and sidewalks, around squares, are managed by Métropole, as here at Confluence.

    © Anaïs Mercey – Metropolis of Lyon

Private homes come into play

Only acting in the public space will not be enough. In fact, 70% of the planting potential is on private property, especially collective housing. So Metropolis encourages co-owners and social landlords to start financing part of their plantation projects. This support can cover up to 65% of the costs. 35 projects already aim to restore space for nature in homes.

Greening will continue to intensify. Goals? Plant 300,000 trees by 2026, all areas combined. And thus redraw the ecological corridors that are necessary for the survival of the species.

  • Nature in the city: how the metropolis behaves

    View of the metropolis and the Rhône from the allotments of Caluire

    © Laurence Danière // Metropolis of Lyon

Towards a permeable city

Unlike the impermeable city, covered with bitumen, which pushes rainwater towards the sewers, the permeable city allows rainwater to seep into the ground to feed plants and groundwater.

Rain trees: the spaces at the base of the trees are enlarged with plantations in the ground.

  • Valley: along roads or cycle paths, valleys, a kind of shallow and wide ditches, collect rainwater that runs off the road.
  • Afforestation in urban areas: trees collect and store with their leaves and roots water, which they then release. This is evapotranspiration, which has the effect of cooling the atmosphere.
  • Rain garden (either small at the foot of your gutter at home or in a public space): slightly hollow or sloped, they help retain water.
  • Porous floors (often in parking lots or bike parks): In new developments, materials that allow water to infiltrate are used for the floor or cobblestones with small spaces between them.

With the permeable city, the rainwater no longer goes into the sewers together with the waste water. On the contrary, it is a resource that we treasure.

Varied vegetation can in turn provide food and habitat for pollinating insects. If we do nothing, they could disappear by the end of the century. Without them nature will gradually become sterile.

Peter Athanasius
Deputy chairman with responsibility for the environment

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