The roleof urbanbiodiversity

Biodiversity is one of the central issues of our time and also an important topic in the work of von lala.ruhr in an urban context. The contribution of urban nature to a livable environment not only promotes the quality of life of the human inhabitants of our cities. A high level of biodiversity enables our cities as green infrastructures to meet the demands of today’s world. For this reason, Stephanie Stiehm, an intern at lala.ruhr and a master’s student in geography with a specialization in urban and landscape ecology, has broken down the role biodiversity plays in our cities for our blog in this post.

The global population is growing – with more and more people living in urban areas, increasing the level of urbanization. By 2050, over 68% of people are expected to live in cities. Species extinction and the associated loss of biodiversity is also one of the great crises of our time. In the last 50 years, about 50% of all species have become extinct. What role do cities play in this? Our cities are also part of an interconnected ecosystem and thus also provide a good living environment for people. 

The term biodiversity is generally divided into three levels: Genetic diversity, species diversity and habitat diversity. They are subject to constant temporal and spatial dynamics: “urban biodiversity” does not only encompass natural processes, but also includes deliberate anthropogenic (human) actions. Consequently, biodiversity in urban areas is not found, but also co-created by citizens [1]. Furthermore, regional biodiversity impact refers to the influence of human life in the city on the surrounding countryside. On the global scale, regional influences are then transferred to distant countries and their ecosystems.

But where exactly does biodiversity exist in the city? Urban wilderness includes pavement crevice vegetation, areas of free succession, or completely pristine areas [2]. Biodiversity is actually higher in cities compared to rural areas due to their many different habitats. These include urban forests, urban parks, open green spaces, watercourses and many other micro-biotopes.

The high occurrence of species in urban areas is explained by many areas in the city that can be left to natural succession as well as different stages of succession coexisting. Examples include railroad tracks, rooftops, houses, industrial sites, roadsides, and brownfields. The number of therophytes (annual plants) increases with the degree of urbanization. This is due to the structural richness of the urban habitat explained above, as well as the availability of a variety of food and habitat. In addition, animals may live under reducing competition with other conspecifics. A common feature of cities is the increased occurrence of neobiota. The term neobiota refers to all species that live in an area (in this case, the urban area) by being non-native [1].

First, the difference between rarity and endangerment must be noted. The term rarity includes the actual occurrence of species without human intervention. If organisms occur infrequently, they are classified as rare. The endangerment is to be described with a negative population development. The cause of this is often man, which is why we also speak of anthropogenic rarity. The “Red List” serves as a directory or overview table of the endangerment status of animals and plants and is used as a data source. 

In North Rhine-Westphalia, 43,000 fungi, plants and animals exist [3]. Many of these creatures are endangered and are designated as species relevant to planning. Special attention must be paid to these species during construction projects and if their habitats are destroyed, replacement and compensation areas must be created.

Biodiversity is measured by means of biotope mapping (especially for plants) and counts of species groups or single individuals. In the process, values for population density are determined. In the end, species guidelines are often developed for the cities, whereby biodiversity can be increased in a targeted manner.

Activities in the Ruhr area 

The Urban Biodiversity Network has existed in the Metropole Ruhr since 2012. It consists of numerous researchers and institutions of the Ruhr area, which deal with the topic of biodiversity and develop a strategy for the Metropole Ruhr. The aim is to develop measures that preserve and promote regional biodiversity. Since mid-2020, the “Regional Biodiversity Strategy Ruhr Area” has been funded by the state government. It is a sub-project of the “Green Infrastructure Offensive 2030”, which is being carried out by the Ruhr Regional Association (RVR). 

In March of this year, position papers were produced that focused on nine key topics: Species and Biotope Protection, Industrial Nature, Urban Agriculture, Urban Forest Use, Open Space and Biotope Connectivity, Climate Change and Climate Adaptation, Urban Green and Social Cohesion, Urban Green and Health Care, and Environmental Education. They provide a guideline and serve as a basis for discussion for the future regional biodiversity strategy.

It is widely recognized that animals, plants and microorganisms are important to our natural and water balance. They provide numerous ecosystem services, such as cooling the ambient temperature, serve as natural retention areas, and can filter or break down pollutants and produce oxygen and store carbon, for example. In addition to these provisioning and regulating services, there are also cultural services. Biodiversity also brings a lot of aesthetics, spirituality, education and recreation [1]. The health and well-being of residents inside increases due to a biodiverse urban nature.

Now it is also up to you to rediscover biodiversity in cities and perhaps also contribute a small part on your doorstep to make our cities green and livable.

Author: Stephanie Stiehm

References:

[1] Breuste, J. (2019) Die Grüne Stadt. Stadtnatur als Ideal, Leistungsträger und Konzept für Stadtgestaltung. Berlin. 375 S. 

[2] Keil, P.; Hering, D.; Schmitt, T. & Zepp, H. (Hrsg.) (2021) Positionen zu einer Regionalen Biodiversitätsstrategie Ruhrgebiet – Studie im Rahmen der Offensive Grüne Infrastruktur 2030. Oberhausen, Essen und Bochum. 228 S.

[3] NABU (o.J.) Tiere und Pflanzen Nordrhein-Westfalens. Artenvielfalt erhalten und schützen https://nrw.nabu.de/tiere-und-pflanzen/index.html