Simulation of the daily growth of an aspen population from the measured CO2-exchange rates of the components

Abstract

The daily total CO2-exchange of an aspen population (32 trees) was measured using a growth chamber gas analysis system which had been shown to measure accurately the actual carbon gain of the population. The CO2-exchange rates of the components (e.g. roots, stems, leaves) were measured in the light and dark and these rates were used to calculate the total CO2-exchange of the population using a computer model. The carbon gain during the photoperiod was underestimated by 25% in the simulation while the carbon loss during the nyctoperiod was overestimated 100% by the simulation.