Water supply and demand remain balanced during leaf acclimation of Nothofagus cunninghamii trees
Article first published online: 16 JUN 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 192, Issue 2, pages 437–448, October 2011
How to Cite
Brodribb, T. J. and Jordan, G. J. (2011), Water supply and demand remain balanced during leaf acclimation of Nothofagus cunninghamii trees. New Phytologist, 192: 437–448. doi: 10.1111/j.1469-8137.2011.03795.x
- Issue published online: 27 SEP 2011
- Article first published online: 16 JUN 2011
- Received: 4 April 2011, Accepted: 16 May 2011
- leaf hydraulics;
- vein density;
- •Higher leaf vein density (Dvein) enables higher rates of photosynthesis because enhanced water transport allows higher leaf conductances to CO2 and water. If the total cost of leaf venation rises in proportion to the density of minor veins, the most efficient investment in leaf xylem relative to photosynthetic gain should occur when the water transport capacity of the leaf (determined by Dvein) matches potential transpirational demand (determined by stomatal size and density).
- •We tested whether environmental plasticity in stomatal density (Dstomata) and Dvein were linked in the evergreen tree Nothofagus cunninghamii to achieve a balance between liquid and gas phase water conductances. Two sources of variation were examined; within-tree light acclimation, and differences in sun leaves among plants from ecologically diverse populations.
- •Strong, linear correlations between Dvein and Dstomata were found at all levels of comparison. The correlations between liquid- and vapour-phase conductances implied by these patterns of leaf anatomy were confirmed by direct measurement of leaf conductance in sun and shade foliage of an individual tree.
- •Our results provide strong evidence that the development of veins and stomata are coordinated so that photosynthetic yield is optimized relative to carbon investment in leaf venation.