Production and description of plants as a living building material
Simple and rather small baubotanical buildings can be realized with common plant material (see also: project footbridge). But to implement more complex structures in the dimension of a full-grown tree, it is on the one hand important to use specific construction (e.g. plant addition) and plant connection methods. However, above all, particular requirements are needed concerning the living building material.
A determinant condition is particularly that the plants can be curved in very tight radii. Therefore they should be as thin and flexible as possible, but at the same time should offer a maximum possible total length. Therefrom, a morphological and biomechanical requirements profile derives: the plants should possess a maximal possible slimness (relation between length to diameter), a small modulus of elasticity and a high tensile strength.
In breeding attempts, it is being studied how these morphological and biomechanical attributes can be influenced by divergent growth conditions and what kind of connection between these qualities and their anatomic structure exists. By generating specific combinations of environmental stimuli, it is tried to increase the slimness parameter up to the limits of morphological plasticity. As a sign stimulus the luminance level and the spectral compostition of the radiation in particular was choosen to influence the morphology. Since the Platanus acerifolia (common plane-tree) proves to be appropriate for baubotanical projects altogether, the experiments are implemented with this type.
For the implementation of the experiments, a special breeding greenhouse was constructed. The lighting conditions can be regulated in nine separate chambers by attaching filter foils onto the translucent doors. Additionaly, in some chambers, exclusively the stalks of the growing plants were coated with opaque light filtering folies.
Current results show that plants can be bred with the desired characteristics particularly by coating the stalks. At this point it still has to be clarified in what way these results can be adapted to the practice of plant production.
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
- Experimental area: