The stated goal of the Baubotanik is to construct living buildings in the ultimate dimension of a full-grown tree. A potential attempt to reach this goal is the plant addition. With this method young plants which root in special vessels are arranged in a room in a certain way and connected in such a way – comparable to the method with the horticultural plug – that they intergrow to a vegetable framework structure. In the beginning the single plants are provided continuously and local with water and nutrients and keep their shape due to a temporary supporting scaffold. In course of further developments a self-supporting strong structure should emerge by secondary growth in thickness. Therewith supporting structures become obsolete. First of all it is important to enable the transport of water, nutrients and assimilating substances over the primary individual borders – from the lowest root up to the top leave. Furthermore the lowest plants that sit in the ground have to develop a very powerful root system. Therewith the roots arranged in the scaffold become superfluous and can be removed together with the at first necessary watering and fertilising technique.
Principle of the Plant Addition
The growth pattern of the tropical strangler fig (e.g. Ficus benghalensis) is the natural counterpart of this development process. Individuals of this kind cover their need for water and nutrients “in the air”, which means they grow first epiphytal but adapt in the course of their growth a terrestrial living. At first they sprout in the crown of a host tree and send air roots to the ground to exploit the water and nutrient recources thence. Thereby, the host tree serves as a temporary scaffold which they strangle with their air roots in the course of time. While the host is dying off and rotting, the air roots form a self-supporting framework-like structure – similar to a baubotanical structure.
The principal feasibility of the method was proved so far by a linear plug experiment implying seven plants. Furthermore, it was used on an experimental structure, the baubotanical Tower. To achive the successful application of the method in practice it will be determant to create a method which causes the described reversing of the nutrient substances and a way to support the growth of the lower root areas in particular. Therfore an exact knowledge is required: First about the physiological efficiency of the actual root areas as well as about the conductivity of water in the plant axes and in the place spot of intergrowth.
These questions shall be worked on in an interdisciplinary research project of the research group Baubotanik collaborating with the Plant Biomechanics Group Freiburg, the AG Eco-physiology of the University of Hohenheim and the Institut für Landschaftsplanung und Ökologie of the University of Stuttgart (ILPÖ).
Part of the PhD intentions of Ferdinand Ludwig, supervised by Prof. Dr. Gerd de Bruyn (IGMA) and Prof. Dr. Thomas Speck (PBG Freiburg)
Scholarship of the DBU
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