Concepts of modelling carbon allocation among plant organs

Abstract

The simulation of carbon allocation among plant organs is one of the weakest features of crop growth models. This paper briefly discusses five concepts of modelling carbon partitioning: 1. Descriptive allometry, proposing a predetermined ratio between the (relative) growth rates of plant organs; 2. Functional equilibrium, proposing an equilibrium between root and shoot activity; 3. Canonical modelling, a mathematical approach based on only a qualitative understanding of the allocation process; 4. Sink regulation, proposing allocation to be determined by sink strengths of the different organs; and 5. Transport resistance, calculating carbon transport from source to sink through a resistance and its utilization in the sink organs. These five concepts are ordered in increasing complexity. Pros and cons of the different concepts are discussed. The most appropriate concept will depend on the species studied and the aim of the research.