© 2000 Heron Publishing—Victoria, Canada
Tapered conduits can buffer hydraulic conductance from path-length effects
Peter Becker (1, 4), Ronald J. Gribben (2) and C. M. Lim (3)
1. Department of Biology, Universiti Brunei Darussalam, Gadong BE1410, Brunei, SE Asia / 2. Department of Mathematics, Universiti Brunei Darussalam, Gadong BE1410, Brunei, SE Asia / 3. Department of Physics, Universiti Brunei Darussalam, Gadong BE1410, Brunei, SE Asia / 4. P.O. Box 367, Bunker, MO 63629, USA / Received October 15, 1999
Summary
The model of West, Brown and Enquist showed that total hydraulic resistance in trees can be independent of path length, provided
that vascular conduits taper sufficiently. This model assumes that the tree branch network is volume-filling, so that segment
lengths increase exponentially from tree top to base. We show that partial buffering of hydraulic resistance from path-length
effects can occur even for moderate tapering, and that this effect is stronger when segment lengths are fixed. Still needed
are measurements of tracheary size and hydraulic resistance designed to test this model, which shows how hydraulic limitation
of tree height growth may be mitigated.
Keywords:
conduit diameter, hydraulic limitation, hydraulic resistance, tree height.
