To develop straight, plants require a motor system that controls their stance by creating powers to counterbalance gravity. Researchers have long imagined that this motor compel was controlled just by the interior powers incited in wood.
A new study by the CNRS and Cirad suggests that bark is also involved in the generation of mechanical stresses in several tree species. To understand the role of bark, scientists grew tropical species at a tilted angle.
The powers that created in the stems of the young staked trees delivered a stem ebb and flow when the stakes were expelled. In specific species, when the bark of the stem was expelled, this bend was lost, which shows that the powers in charge of stem up-rightening are situated in the bark.
The system producing these powers is connected to the particular structure of the bark, where the filaments are sorted out as a trellis. At the point when the stem develops, the advancement of the layers of wood expands the circumference of the bark. The trellis structure of the filaments in the bark is with the end goal that this pressure produces powers along the stem.
If the stem is titled, the growth is more rapid on the upper side of the stem, leading to the generation of asymmetric forces. It is this asymmetry that allows the stem to curve upwards. In five of the nine tree species studied, the generation of forces enabling the tree to offset gravity is thus not simply due to the maturing of the walls of the wood cells, but also to the wood growth in this smartly organized trellis of fibers in the bark.
Nature has solved an infinite number of engineering problems. The need for trees to grow vertically by optimizing the organization of their tissues is today a potential source of remarkable inspiration for materials science.
The study is published in the journal New Phytologist.