Dry mass production and leaf area development of field-grown ornamental conifers: measurements and simulation

A dynamic simulation model of dry mass (DM) production and leaf area index (LAI) development in ornamental conifers, CONGRO, was developed. The concept of a constant radiation use efficiency (RUE) was combined with a model for radiation interception by row crops. A field trial was used to calibrate RUE, DM partitioning and the specific leaf area (SLA). LAI increase was simulated through leaf dry mass increase and SLA. Ten independent trials (1991–1999) were used for validation. Predicted above ground DM agreed well with measured data (R² = 0.94) with a standard error of the regression of 149 g m⁻². Predicted LAI agreed less with experimental field data (R² = 0.90), standard error of the regression was 0.312 m² m⁻². Sensitivity analysis showed a large positive sometimes more than proportional effect of RUE, SLA and partitioning into the leaf dry mass on simulated total DM, LDM, LAI and intercepted radiation.