A TRANSPORT-RESISTANCE MODEL OF FOREST GROWTH AND PARTITIONING

The transport-resistance approach to dry-matter partitioning is used to construct a model of forest growth The model is at the stand level for a monoculture of identical trees of the same age There are five major organ compartments in the model foliage, branches, stem, coarse roots, and fine roots and mycorrhizas The matter in each compartment is further subdivided into menstem, structure, carbon substrate, and nitrogen substrate The model is driven by daily radiation including day length, ambient CO2 concentration, and daily means of air and soil temperature The fine roots are provided with constant values of soil mineral nitrogen pools (ammonium and nitrate) from which uptake occurs Growth over about 100 years is simulated for various environmental conditions and soil mineral nitrogen levels, thinning is also simulated Natural tree death occurs within the model Particular attention is paid to dry matter partitioning patterns, and to the dry matter per stem when death occurs The model is robust and responsive, and provides a framework for further development and application to many ecological and environmental scenarios, as well as to some forest management problems © 1991 Annals of Botany Company.