More and more of the world’s population lives in cities. When cities densify, natural areas and animal habitats often disappear. We know that when the distance to the nearest natural area increases, the health and quality of life for people living in the cities is reduced. As fauna corridors are cut off and natural habitats are reduced, the living conditions for fauna in cities deteriorate. At the same time, reducing these green areas also weakens a city's ability to regulate and absorb climatic changes, such as cloudbursts and rising temperatures.
What is great about improving biodiversity is that it has significant positive impacts on animals (humans included) and local flora and fauna. Sadly, urban dwellers are getting further and further removed from natural environments and no longer get the same natural benefits of our fore-fathers, the majority of whom grew up in rural settings. Biodiversity helps clean our water and air, improves our soil quality and thus the nutrient value and the taste of our food, and it adds texture and aromatic sensations to our urban environment. For flora and fauna, biodiversity is key. It assures the pollination of plants and crops, promotes pollution breakdown and absorption of airborne toxins, and helps diverse ecosystems to better withstand and recover from natural disasters.
In order to avoid reducing the quality of the city's nature, we need to consider new ways of designing cities. Green facades, roofs and natural areas with high biodiversity help increase the wellbeing and health of citizens in cities by stimulating their senses, absorbing and delaying rainwater, reducing harsh winds, and reducing airborne pollution and the carbon impact of a city. Nature in cities also means inviting birds, insects, and small mammals to be part of the urban natural lifecycle. Flora in cities can be much more diverse and more attractive to insects than the more monocultural agricultural lands.
To ensure the conditions for biodiversity in cities, architects, landscape architects, and urban planners need to demand more in terms of biodiversity. Why should a park be a mere expanse of grass, when it can be a mixture of grasses, shrubs, flowers, and trees? Often by multiplying the number of species of flora and fauna in a landscape environment, we can create self-reliant entities that need little to no maintenance – a winner for all.
In all projects, we aim to have a maximum of green natural areas and maximized diversity relating to the local context. An example is our project ‘BIOTOPE’ in Lille, France, where we have made a local nature biotope, an entire ecosystem, on top of and around an office building. From the beginning, we focused on creating the best possible conditions for birds and insects. On the roof, we’ve planted a 3.300 m2 natural landscape with local plant species, wetlands, scrub trees, soil, rock, and gravel. More than 650 bushes and trees have been planted, with more than 35 different local species represented. In addition, herbs and perennials are planted throughout the building. Before construction, the site consisted of a self-grown meadow. We collected deadwood, soil, and seeds from that meadow, and placed them on the BIOTOPE’s rooftop landscape so that insects and birds can keep their old habitat. The city ecologist is going to follow the development of biodiversity on the BIOTOPE building. We already see quite a lot of birds and insects finding their way to the roof forest, and self-sown seeds, and mushrooms have begun to spread and grow.
In the BIOTOPE, our landscape department worked in close collaboration with the city’s ecologist to create a diverse and rich landscape that covers the building’s four planted terraces, two bridges, balconies, and atrium. Other than planting a palette of local species, the bridges, and technical equipment are topped with brown roofs, where blow and dropped seeds can thrive. This project will, of course, benefit the BIOTOPE’s users: The soil rooftops provide extra thermal insulation for the building and planted interior spaces offer relaxing areas for occupants to take breaks during the day. The soil and plant life will help will absorb neighboring noise pollution, form home for local birds, and add extra ingredients to the canteen’s salad bar. Also, it’s scientifically proven that regular access to green space boosts our sense of happiness and focus.