Stems move air: Phragmites australis Dead stems of Phragmites
australis move air to shoot and root meristems by use of
differential air pressure. |Biomimetic Application Ideas|
|Passive way to move air through buildings, mines.| > Visit
strategy page From Fig. 4.8: "A. Differential air pressure
caused by wind blowing across dead culms sucks air into the
lower culms through the rhizomes and into the taller culms. B.
Pressurization of new culms due to a build up of vapour pressure
or higher temperatures causes mass flow of gasses [sic] down the
culms into the rhizome and up into more porous older culms. The
movement of oxygen from the rhizomes into the roots and out of
the roots into the soil is due to diffusion. (Redrawn from
Colmer 2003)" (van der Valk 2006: 64-65) "Internal transport of
gases is crucial for vascular plants inhabiting aquatic, wetland
or flood-prone environments. Diffusivity of gases in water is
approximately 10 000 times slower than in air; thus direct
exchange of gases between submerged tis