Axial (tip to base) conduit widening
Conduit diameter increases from top to bottom
Make the resistance less dependent from the tree height
Rate of change follows a power function (b=0.2)
Water potential is highest at the top —> lowest resistance on top —> smaller conduits on top
Radial conduit size
Increase in conduit size from pith to bark
Axial alliometry
Other anatomical features show similar power relationship with distance from tree top:
tracheid length
pit size
Axial trends in cell wall thickness and ray tissue and wood density
Cell wall thickness: Axial trend —> bigger cell wall thickness with distance from the tree top
Ray tissue: no axial trend
Negligible trends in wood density, counteracting trends compensate each other (wider but spatially less densely arranged vessels
Last changed10 months ago