Urban Banyan Landscape Typologies - Creating New Urban Green Space by Implementing Living Root Structures

Bachelor thesis by Larissa Böhrkircher

[Excerpt]

Abstract

In the wake of global urbanisation and the densification that often accompanies it, green spaces in major cities are dwindling. At the same time, problems such as air pollution, species extinction, the urban heat island effect and, increasingly, social isolation are becoming more acute; green infrastructure, when properly implemented, can counteract these issues – yet there is hardly enough open space available.

The discovery of living bridges in India could now mark a turning point. The structures built by the Khasi people form a hybrid of architecture and living organism, in which bridges and other structures are formed from the roots of banyan trees using specially developed techniques. They are characterised by a high degree of flexibility and the strong resilience of the banyan trees.

This work attempts to analyse the structures of living bridges and apply them to highly densely populated city centres, using the megacity of Guangzhou as an example. In doing so, the growth habit of the trees is first analysed for its suitability for use in urban spaces. In particular, the epiphytic growth habit of banyan trees is well-suited for urban applications, as the trees are not spatially bound to the ground due to the formation of long aerial roots, thereby enabling the greening of vertical open spaces and roofs without the need for technical support systems.

By utilising living bridge techniques, four potential applications are developed as examples to illustrate the potential impact of these hybrid structures. Thanks to their versatility, urban banyan green space typologies can be applied in a wide variety of urban settings and create a high density of vegetation without affecting the city’s building density.

When implemented on a large scale, they improve the urban climate, reduce air pollution, create new habitats for animal and plant species, provide residents with sufficient green space and lead to cost savings in the energy supply of buildings. In this way, the Banyan typologies can make an essential contribution to a sustainable form of future urban development.