New insights into carbon allocation by trees from the hypothesis that annual wood production is maximized
Article first published online: 5 JUN 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 199, Issue 4, pages 981–990, September 2013
How to Cite
McMurtrie, R. E. and Dewar, R. C. (2013), New insights into carbon allocation by trees from the hypothesis that annual wood production is maximized. New Phytologist, 199: 981–990. doi: 10.1111/nph.12344
- Issue published online: 2 AUG 2013
- Article first published online: 5 JUN 2013
- Manuscript Accepted: 26 APR 2013
- Manuscript Received: 10 FEB 2013
- canopy photosynthesis;
- gross primary production;
- leaf area index;
- maximum wood production;
- optimization model;
- root nitrogen uptake;
- rooting depth;
- tree carbon allocation
- Allocation of carbon (C) between tree components (leaves, fine roots and woody structures) is an important determinant of terrestrial C sequestration. Yet, because the mechanisms underlying C allocation are poorly understood, it is a weak link in current earth-system models. We obtain new theoretical insights into C allocation from the hypothesis (MaxW) that annual wood production is maximized.
- MaxW is implemented using a model of tree C and nitrogen (N) balance with a vertically resolved canopy and root system for stands of Norway spruce (Picea abies).
- MaxW predicts optimal vertical profiles of leaf N and root biomass, optimal canopy leaf area index and rooting depth, and the associated optimal pattern of C allocation.
- Key insights include a predicted optimal C–N functional balance between leaves at the base of the canopy and the deepest roots, according to which the net C export from basal leaves is just sufficient to grow the basal roots required to meet their N requirement. MaxW links the traits of basal leaves and roots to whole-tree C and N uptake, and unifies two previous optimization hypotheses (maximum gross primary production, maximum N uptake) that have been applied independently to canopies and root systems.