Did you know that there are more than 20,000 animal and plant species in Berlin? Of the 234 breeding bird species in Germany that are endangered or threatened with extinction, two-thirds can be found in Berlin. A big city like this has more diversity to offer than you might think. Here, we’ll take a look at the importance of biodiversity in urban and agricultural areas and explore measures to promote biodiversity in the city.

Traditionally, the term “biodiversity” refers to variation in the number of species. According to current understanding, however, it encompasses not only species diversity but also the diversity of ecosystems and genetic diversity within different species.

For a long time, agriculture was a source of species and habitat diversity, but that has changed; it is now one of the main drivers of the biodiversity crisis. Today’s agricultural landscapes are, in many respects, no longer as conducive to biodiversity as they once were. The heavy use of fertilizers, mechanized farming, and pesticides for pest control, as well as extensive monocultures, harm biodiversity in farmland.

To promote species diversity in agricultural areas, there are a number of measures aimed at creating structurally rich habitats without jeopardizing agricultural production.

Skylark windows are one example: these small, uncultivated patches in grain fields provide nesting sites for ground-nesting birds such as the skylark. Hedges also play an important role as structural elements and habitats for various animal and plant species. They also promote the connectivity of biotopes. Perennial fallow fields and wild fallow areas provide refuges, shelter, and breeding grounds for wildlife and birds. Their abundance of flowers attracts many insects and encourages the settlement of species such as bats. Flower strips in fields connect biotopes and provide a diverse food supply as well as refuges for many animal species.

What does the Weltacker in Berlin look like? Naturally, neither pesticides nor chemical fertilizers are used on our small plot of land. As a result, there are many creatures to be found there:

Contrary to expectations, cities exhibit high species diversity and density, often even more so than intensively used agricultural landscapes. The diversity of urban sites—which often feature extreme and unique ecological conditions within a small area—gives rise to a distinctive habitat structure. Many species find important alternative habitats there, and a significant portion of urban biodiversity consists of introduced species, known as neophytes. These, along with many ubiquitous species that have few environmental requirements, shape the range of species found in cities.

Pollinating insects, in particular, are the foundation of a species-rich urban environment, which in turn provides numerous benefits. Ecologically, for example, it helps cities adapt to climate change by providing shade, retaining rainwater, and serving as a flood retention area during heavy rainfall. Plants also play an important filtering role by reducing dust and noise pollution and helping to cool the environment through the process of evapotranspiration. As a result, they significantly improve the microclimate in urban areas.

Green infrastructure is key to supporting urban biodiversity. It can take various forms, including parks and green spaces, as well as green roofs and green facades, community gardens, and flower strips.

“More Bees for Berlin – Berlin Blooms” Initiative

Since 2018, this pilot project has been enhancing public green spaces and open areas for wild bees and other insect species.  To this end, flowering meadows with various plant species, perennial gardens, and nesting habitats have been created in all twelve districts. A total of 157 wild bee species have already been identified in these areas, representing 65 percent of the species currently found in Berlin.

The "Stadtgrün" Project by the Museum für Naturkunde Berlin and Humboldt University of Berlin

The “Stadtgrün” project, a collaboration between the Museum für Naturkunde and Humboldt University of Berlin, has been underway since 2017. Originally, the project was designed to test 25 native plant species for their suitability for greening median strips. The researchers sought to observe hardy flowering plants such as sea thrift, ox tongue, and St. John’s wort, as well as their effects on insects, at the Frankfurter Allee, Adlergestell, and Heerstraße sites. Through the project, entomologist Dr. Frank Koch was able to identify around 400 different insect species from six different orders, including some on the list of endangered species—among them, in 2019, the grasshopper wasp, which had been believed to be extinct. This high species diversity can be explained by the isolation effect on the median strip. Another key factor is that the areas are not mowed constantly.

Since September 2023, the median strip on Friedenstraße in Friedrichshain has been undergoing renaturation and redesign. The soil, which had previously been compacted mainly due to unauthorized parking, has been improved to facilitate water retention and planting. Subsequently, a site-appropriate seed mixture of wild perennials was planted, and nesting aids for wild bees were installed. Information signs and a path make the median strip appealing to visitors as well. The redesign aims to create an important ecological corridor connecting Volkspark Friedrichshain and the cemeteries along Landsberger Allee.

Even in private settings, it’s possible to find areas that can be ecologically enhanced. For example, a balcony or a spot in the backyard can be planted with native plants whenever possible. It’s also worth looking into neighborhood initiatives that work together to green tree pits and similar areas.

Promoting biodiversity is of crucial importance in both agriculture and urban areas. Through targeted measures, structurally rich habitats can be created and preserved. Whether in the fields or in the city, initiatives and projects make a valuable contribution to the conservation of biodiversity.

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