How the giant sequoia tree protects itself

The outer bark of the sequoia tree contains many fibers, which are organized in fiber bundles. These cross over each other and are also layered on top of each other, creating a three-dimensional netted structure. In between the fiber bundles are air-filled cavities. When a rock strikes the bark, these cavities are compressed. Compressing the hollow spaces and stretching the fiber network has the effect of distributing the energy evenly over the bark and protecting the inside of the tree with the sensitive cambium that forms wood and bark. The bark later returns almost completely to its original state. The cavities also insulate the tree so that it is resistant to the heat generated during wild fires.

Due to this structure, the bark of the sequoia tree behaves like an open-pored foam similar to the foam used in the construction of cars and houses, for example. On the basis of their findings, the researchers are, among others, to develop with colleagues from the University of Stuttgart a new type of light weight concrete with bundles of hollow fibers, which could be used to insulate and to better protect buildings against earthquakes, for example.