Colourful ribbons for our cities in times of climate change: near-natural urban flowering areas along transport axes to promote ecological functionality

The steady growth of many European cities and the in­creasing seal­ing of rural areas are dramatically chang­ing the land­scape and habitats of many animal and plant species: In many places in Europe, declines in habitats and wild­life popu­lations are being observed, and the decline of many insect species (es­pecially wild bees) is currently the focus of public atten­tion.

As the degree of urbanisation increases (proportion of sealed area, density of buildings, traffic density, etc.), the diversity and abun­dance of polli­nators de­creases, caused mainly by habitat frag­men­tation in urban areas. The genetic ex­change of isolated insect popu­lations is often limited, especially in urban areas.

A sub-area of the "Colorful Ribbons in Cities" project is there­fore concerned with the net­working of individual polli­nator populations and is intended to give the corres­ponding species better oppor­tunities to migrate along an inner-­city perimeter gradient. To this end, flower­ing areas will be created along major traffic axes (inner city periphery) in Munich. Varying dis­tances between areas should show which maximum distances insects are able to overcome.

In addition to their attractiveness for insects, a large-scale use of flower­ing areas for urban areas is to be tested. The seed mixtures of the planted areas will vary in their composition with the inclusion of rare species, and their usa­bility will be investi­gated in practice tests.

In addition to biodiversity effects and its aesthetic and spatial roles, urban greenery also fulfils the function of climate regu­lation. In addition to impro­ving the living condi­tions of polli­nators, the design of flowering strips should also be investi­gated with regard to micro­climatic site characteristics in compari­son to con­ventional planting.

The following scientific and practical goals are aimed for in the "Bunte Bänder" project:

  1. development and testing of a flowering area network along several main urban traffic axes to pro­mote polli­nators and urban climate adap­tation
  2. evaluation of climate resilience and attractiveness of different species mixtures for pollinators and other beneficial insects in compari­son with existing flower­ing areas and green spaces
  3. climatic optimisation of the size and distances of the flower­ing areas as corridors for polli­nators and other beneficial organisms along an urban-­rural gradi­ent on the basis of their move­ment behaviour
  4. improving the quality of life of urban dwellers through the micro­climatic and aesthetic effects of flower­ing areas
  5. recommendations for practicable compromises between the require­ments of nature conservation and urban green manage­ment in order to increase urban climate resili­ence and the bio­diversity of polli­nators


Regina Bauer-Foundation and Bavarian State Ministry for the Environment and Consumer Protection (StMUV)