Fences in the Urban Context – an Animal Aided Design Challenge?

Flaneuring in the Tegel neighborhood, one can easily identify the presence of fences everywhere: in front of the residential houses, surrounding public and private edifices, along the paths in the parks and natural areas. Putting forward a more than human mindset, one can ask what are the benefits for all species, and whether these support biodiversity in the urban context?

Fences are a human-made intervention over space, supplying a mode to mark territories and to enclose spaces. It is also a means for protecting trespassing of other humans and of specific wild animals. For some, it can give psychological confidence of security. Looking at the others, the non-human species, fences can create protected areas for specific species and guide movement in risk areas (e.g. protect from vehicle collisions on the roads). On the other hand fences can cause injuries and hair loss, help to develop stress, alter wildlife movement and enclose natural habitat and life cycles.

Looking at the urban context of Tegel, with its expansive green areas and lakes, we can ask whether fences support or restrain biodiversity? In the shade of the environmental contemporary challenges it is time to consider a paradigm shift about the use and practice of fences. Animal Aided Design§trademark (AAD) gives a possible alternative and supply design tools that are based on scientific research. It uses an interdisciplinary approach encompassing ecology, zoology, architecture, landscape architecture, and planning to show how specific initiatives to protect and develop urban biodiversity in the living environment can succeed in a way that is both ecologically meaningful and aesthetically pleasing. This approach was developed by landscape architect Thomas E. Hauck, University of Kassel, and ecologist Wolfgang W.Weisser, Technical University of Munich.

The core assumption of AAD is that plant life and animals live in coordination, supporting  each other in various life cycles, which include migration, food chains, procreation, birth and hibernation phenomena. The challenge at task is to find supportive ways that can facilitate these natural processes in an urban context, thus creating conditions for rich biodiversity. AAD suggests design tools for that, such as:

• planting native trees which can support dirts and insect lives, 
• plant hedges and shrubs that can support little birds, insects and small mammals like the hedgehogs, 
• leave space for wildflower meadows that supports insects and the pollination processes, 
• Introduction of large stones and boulders that support insects and create places for hibernation
• Creation of sand beds, where birds can do sand baths, and can support insects, invertebrates and reptiles 

And more complex, labor oriented solutions:

Insect hotels, bird houses, bee boxes and the use of flat roofs for plantations. 

Creation of wetlands with shallow bodies of water, which supports amphibians, reptiles, birds, mammals and insects. This situation can pave the way for a rich biodiversity.

A passive way of creating life conditions: dry leaves and twigs presence on the ground can support fungus, insects and small mammals. They also improve the health of the soil.

Creating an area that support biodiversity, by planting trees and implementing activities such as stones and creating wetlands, is not enough, since in urban context, in order to create an ecological shift, there is a need to expand to cover all urban area, and that’s where the AAD has a very interesting contribution, which brings back to mind our initial concern with fences.

AAD defines three types of connectivities between species:

• no connectivity, where separate islands of habitats – life forms exist with no possibility to connect
• Functional connectivity, where the presence of hedges and shrubs allow the possibility of species to go from area A of biodiversity to Area B (the squirrel challenge). But there are some animals which are very shy and hesitate to do such jumps, which can be risky as well. Thus it depends on the type of the species to achieve such mobility.
• Structural connectivity offers continuity between zones, with the use of stepping stones, habitat patches that altogether create green corridors composed of all possible components: trees, hedges and shrubs. Thus allowing free species movement between the different habitat patches.

Implementation

By the creation of habitat patches buffering and bridging actions, where planting trees, hedges and shrubs, help to create different habitat patches, with the use of stepping stones as a way to bridge in between areas. And finally creating corridors that serve as ways for connections, by again planting trees/shrubs/hedges.

By planting native plants and trees there is an optimal chance to achieve biodiversity, since they have the power to start life cycles.