Thin-walled Tubular Stems Resist Buckling

worms eye view of a canopy of bamboo leaves

Biological Strategy

Bamboo

AskNature Team

Image: kazuend / Unsplash / Free non-commercial use

Prevent Buckling

When a living system undergoes compression to the extent that it causes structural damage, it results in buckling. For example, if a person pushes down on the top or the side of a paper cup, the cup’s wall will eventually give way, or buckle. Although a living system could add material to strengthen a structure, this requires expending precious energy. Instead, it must use energy and materials conservatively to avoid buckling, strengthening structures through careful placement of materials to resist, absorb, or deflect compressive forces. For example, instead of one long, tubular stem, some plants like bamboo have stronger nodes scattered along their stems. When compressed, these nodes keep the round stems from taking on an oval shape that weakens the structure and could result in buckling.

Search this Function

Flowering Plants

Clade Angiosperms (“receptacle seed”): Dandelions, oaks, grasses, cacti, apples

With 416 families containing some 300,000 known species, angiosperms are the most diverse group of plants, and they can be found around the globe in a wide variety of habitats. They are characterized by seeds that grow enclosed in ovaries, which are enclosed in flowers. The floral organs then develop into fruits of myriad kinds and dimensions, from simple seed casings on maples to elaborate fleshy growths like papayas. The oldest flower known from fossils, Montsechia vidalii, appeared during the Jurassic Period 130 million years ago. They are the primary food source for herbivorous animals, which in turn makes them the indirect food source for carnivores as well.

Search this Living System

The stems of many plants may resist buckling by including transverse bulkheads that prevent ovalization.

Fiber Arrangement Is Highly Efficient

Fish-pole bamboo

Fibers in stems of bamboo use materials efficiently because of their arrangement

Image: Dinesh Valke /

Image: Andrea Leggitt / The Biomimicry Institute /

Quick illustration to explain concept and to connect to real world examples.

Image: Aroid /

“The condition of having one fixed end is of particular biological interest–it’s the situation of long, slender plant stems such as those of dandelions, grass, bamboo, and others…As emphasized by Schulgasser and Witztum (1992), their anisotropy greatly increases the risk of buckling for plants that use thin-walled tubular construction. Mainly, the tubes, normally circular in cross section, go somewhat oval just prior to buckling, and that reduces the critical force. Preventing that ovalization may be one of the roles of the periodic transverse bulkheads so conspicuous in, for instance, bamboo.” (Vogel 2003)

Last Updated September 14, 2016

References

Book

Comparative Biomechanics: Life's Physical World, Second Edition

17/06/2013 | Steven Vogel

embedly preview

Reference

Journal article

On the strength, stiffness and stability of tubular plant stems and leaves

Journal of Theoretical Biology | 21/07/2006 | K. Schulgasser, A. Witztum

embedly preview

AskNature