Modelling carbon allocation in forest ecosystems

Allocation of carbon to plant organs is considered as one of the most important plant adaptation mechanisms to environmental changes. Several empirical studies presented that carbon partitioning between individual plant organs depends on environmental conditions and stand structure. From the modelling perspective, carbon allocation is one of the crucial modules that affect the final outcome of forest simulators. A variety of different modelling approaches of carbon allocation from simple methods based on fixed ratios up to highly sophisticated thermodynamic approaches have been developed. They differ in the complexity and sensitivity to changes in site and stand conditions. In the presented study we examine which modelling approaches of carbon allocation are most frequently used in forest simulators and analyse how environmental factors affect the modelled partitioning of carbon. The study is based on the information gathered with a questionnaire distributed to forest model developers worldwide. The results identify the possibilities to improve carbon allocation modelling in forest simulators to enable them to appropriately reflect the ongoing changes in forest ecosystems in their output.