Kirschbaum, M.U.F. (1999). CenW, a forest growth model with linked carbon, energy, nutrient and water cycles. Ecological Modelling 181: 17-59.
Abstract. A comprehensive forest growth model (CenW) is described here. The model links the flows of carbon, energy, nutrients and water in trees and soil organic matter. Modelled tree growth depends on physiological plant factors, the size of plant pools, such as foliage mass, environmental factors, such as temperature and rainfall, and the total amount and turn-over rates of soil organic matter, which drives mineralisation of soil organic nitrogen.
The model was validated against experimental data obtained for Pinus radiata from the Biology of Forest Growth (BFG) site near Canberra, Australia. The BFG experiment was conducted over five years, and included controls and treatments with irrigation and/ or fertiliser addition. Growth rates across treatments ranged about 2.5-fold. The model realistically simulated water use, foliage production and turn-over, foliar nitrogen dynamics, wood production and stand architecture across a wide range of responses under variable water and nitrogen supply due to experimental treatments and natural variations in rainfall.
The model can be used to simulate the effects of silvicultural treatments, such as stand thinning, or to assess the sustainability of long-term site productivity based on simulation of the nutrient budget of forest stands. A sensitivity analysis was carried out to identify the parameters and external drivers to which overall growth was most sensitive. Sensitivity differed depending on growth conditions, but growth was always highly sensitive to biomass allocation factors and photosynthetic parameters. Growth was also highly sensitive to parameters describing crown nutritional relationship when nutrients were limiting and to ambient CO2 concentration and stomatal parameters when water was limiting.