The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), founded by the United Nations in 2012, sounded the alarm in its Global Assessment Report on Biodiversity and Ecosystem Services. According to the report, species extinction is greatly increasing. Of eight million plant and animal species in the world, one million are threatened with extinction, according to the 2019 report, which IPBES says is the most comprehensive international study of species conservation to date. Efficient countermeasures are therefore more urgent than ever. And this can begin on your own doorstep – for example, in your private garden by creating habitats and food sources for bees, butterflies, birds, and the like through native plants and other elements such as flower meadows, dry stone walls, and deadwood piles or trees and hedges.
Urban Gardening is on trend
In addition to working in your own garden, community gardening on small, often neglected areas in the middle of the city has also been popular for several years. “Urban gardening” began in New York, among other places. In the 1970s, residents of neglected neighborhoods protested against urban decay and deteriorating living conditions with their politically motivated “Guerilla Gardens” and “Community Gardens”, transforming vacant lots in their neighborhoods into green oases. Today, a prime example from New York in particular is the former elevated train track in western Manhattan, which was transformed into High Line Park between 2006 and 2019 according to plans by Dutch landscape gardener Piet Oudolf. The roughly 2.5-kilometer-long line is home to more than 500 species of plants and trees. The park is maintained by Friends of the High Line in cooperation with the NYC Department of Parks & Recreation.
Another special feature is the largest urban rooftop farm in Europe, which the company Nature Urbaine inaugurated in Paris in July 2020 on the roof of Pavilion 6 in the Exhibition Center at Porte de Versailles. The site occupies an area of 14,000 square meters, where more than 20 gardeners produce 20 different varieties of fruits and vegetables in season. The goal of Nature Urbaine is to make this urban farm a global model for responsible production, organizing a form of ecological resilience for the cities of tomorrow.
Redesigning urban development with a focus on nature and people
The contribution that even the smallest green spaces can make to biodiversity in cities is illustrated by a study conducted in Melbourne and published in 2021. In the capital of the state of Victoria in Australia, a team led by Luis Mata from the University of Melbourne and the research institute Cesar Australia studied a green space measuring just under 200 square meters over a period of four years before and after planting twelve native plant species. The area borders a main road, is surrounded by large buildings, and embedded in dense urban development. After just one year, there were five times as many different insect species in the area as before, and after three years even seven times as many – associated with a wide variety of interactions between insects and plant species.
“The adverse effects of human-induced climate change manifest themselves acutely in urban environments,” says Luis Mata. While urban green spaces are known to mitigate these impacts, there is still limited evidence of the ecological outcomes of urban greening, he adds. Studies conducted over a longer period of time therefore take on all the more importance. “We’ve been able to show how investments in greening measures help reintroduce native species to green spaces where they have become rare or locally extinct.”
„BiodiverCities by 2030“
“BiodiverCities by 2030” also emphasizes the urgency of such measures. This is a joint initiative of the World Economic Forum and the Bogotá-based Alexander von Humboldt Biological Resources Research Institute, funded by the Colombian government. Its stated goal is to help city governments, businesses, and citizens redesign urban development with a focus on nature and people. The goal is to create nature-friendly and climate-resilient cities by 2030, where every urban activity enriches the earth rather than further depleting it. Ultimately, this is precisely the concern of the EU Biodiversity Strategy 2030, which calls for “Urban Greening Plans”, which contribute to the well-being of the population, the protection of biodiversity, and climate adaptation and mitigation for all European cities with more than 20,000 inhabitants.