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New insights into carbon allocation by trees from the hypothesis that annual wood production is maximized
Author(s) -
McMurtrie Ross E.,
Dewar Roderick C.
Publication year - 2013
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12344
Subject(s) - canopy , primary production , basal area , biomass (ecology) , wood production , production (economics) , botany , picea abies , biology , root system , carbon fibers , agronomy , mathematics , ecology , ecosystem , forest management , macroeconomics , algorithm , composite number , economics
Summary 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.