Although the underlying phylogeny determines the qualitative wood structure, climate has a significant influence on the functional wood anatomy of Acacia. Warwick et al. use microscopy to investigate the structural diversity of the secondary xylem of 54 species of Acacia from five climate regions in New South Wales, Australia.
With increasing aridity, fibres are thicker-walled and more gelatinous, and prismatic crystals in chambered fibres and axial parenchyma cells become more abundant. With the shift from subtropical to arid environments, there is a two-fold increase in vessel frequency and a three-fold decrease in vulnerability index indicating ability to withstand drought-induced cavitation.