Nature-friendly green spaces for an attractive urban area

Many local authorities could do much more to ensure that natural and diverse green spaces are also created in urban areas. However, simple overall planning and convincing examples are likely to have more impact here than warning signs of a lack of implementation.

At first glance, urban areas appear to be inhospitable places for plants and animals. It is therefore astonishing that the Swiss Biodiversity Monitoring Programme found that settlements are on average richer in plant, moss and snail species than low-lying agricultural areas - although completely sealed areas are not included in this analysis. This means that gardens, borders, lawns, verges, embankments and car parks already have a certain biodiversity. If at least some of these areas were consistently designed and managed in a near-natural way, the contribution of the settlement area to the ‘ecological infrastructure’ would be even greater. Enhancing the ecological value of settlement areas is therefore one of the goals that the federal government and various cantons wish to pursue in the coming years. The promotion of nature and biodiversity should not be the sole responsibility of agriculture and forestry. Urban Switzerland, with its extensive infrastructure, should also bear part of this responsibility. The Federal Council's Biodiversity Action Plan and several cantonal biodiversity strategies or specialised plans for ecological infrastructure point in this direction. However, the prerequisites for creating and maintaining ecologically valuable areas are very different in urban areas than in open land or forests. There is often a lack of technical foundations such as a nature inventory that identifies valuable habitats and species occurrences. The location and quality of green spaces and open spaces are particularly unstable due to the high level of construction activity. Consequently, it is much more difficult to ensure the long-term protection of natural values in the construction area. The usual protection zones and areas hardly work or cannot be enforced. Building and development are expressly provided for, carry great weight when weighing up interests and are linked to economic benefits.

Analysis of the best options

Under these conditions, a special approach is required for the development of ecological infrastructure (EI) in settlement areas. If the municipalities are really to act as actors in favour of nature, complex concepts such as ecological planning must be translated into concrete options for action that also work in settlement areas. The aim is to use simplified planning for the settlement area of a municipality to show where the best starting point exists for creating and promoting natural values. It also clarifies the objectives according to which the green and open spaces should be developed. On the basis of this layout, the municipality can then realise opportunities for high-quality green spaces both on a situational basis as part of building projects and on a long-term basis on its own initiative and with the support of third parties - always guided by a vision for a municipality with attractive living and working spaces. Together with the company Quadra Mollis GmbH, we have developed a proposal on behalf of the cantons of Aargau, Bern and Zurich on how the cantons can transfer their specialised planning of EI to the settlement area. The municipalities can now take up this thread and deepen and implement the planning according to their ideas and possibilities.

Green spaces consistently upgraded

Aesch in the canton of Baselland is an agglomeration municipality in which the settlement area plays an important role in nature conservation. Although it does not yet have its own specialised ÖI planning, but is equipped with a communal structure plan and a detailed nature inventory, many opportunities have been taken in recent years to improve natural values in the settlement area. In some cases, we have been able to participate. For example, we have combined compensation measures for two different construction projects and the municipality's own enhancement project in such a way that a contiguous biotope complex of around 4.5 hectares could be enhanced, which also functions as a networking axis. Remaining undeveloped areas and existing green zones within the residential and commercial area were used for this purpose: two small afforestations, a sheep pasture and an overgrown embankment. New dry sites, flower meadows, diverse forest edges and small areas of light forest were created. The first parts of these were created in 2013 and have since been consistently maintained by the forestry service on behalf of the municipality and supervised by a specialist from our side. Thanks to this continuous maintenance and the use of seeds from high-quality donor meadows from the surrounding area, the biodiversity of some of the meadows is remarkable. Passers-by appreciate the beautiful surroundings and make active use of the neighbouring footpaths and seating areas.

Promoting species without a protected

Settlements can also provide habitats for endangered species. Drought-adapted plants such as the bee orchid, building dwellers such as the grey long-eared bat or typical species of small-scale cultivated landscapes such as the common redstart typically find a suitable habitat in settlements. In the canton of Basel-Stadt, the common redstart, which is otherwise scarce on the Central Plateau, even reaches record-breaking densities. Most territories are located in leisure gardens or small orchards. Since 2011, we have been able to implement the action plan we developed on behalf of the Stadtgärtnerei Basel. With a population increase of 20 % so far, this has been successful. Over 300 decentralised measures have been implemented to date. They aim to provide species-specific breeding cavities, trees as perches, insect food and access to prey thanks to partial cutting of the meadows. The measures in the leisure gardens are particularly exciting, where hobby gardeners are sensitised and actively participate in the support measures. In addition, individual plots are specifically prepared as habitats for the common redstart and provide important refuges in the mosaic of gardens. The action plan requires constant commitment. Nest boxes and small structures need to be renewed and maintained, new contacts need to be made and persuasion work needs to be done. However, the measures are already established, are widely anchored in decentralised locations and therefore also function independently of long-term protected zones.

Support for municipalities

The innovation project ‘Implementation strategies for ecological infrastructure’ shows how the development of a network of near-natural, ecologically valuable areas in settlement areas can be anchored in the planning of municipalities. The guide written as part of this project is strongly application-orientated and is aimed at municipal authorities in small and medium-sized municipalities.

Available from July 2025 at www.öim.ch.