Preliminary evaluation of an individual tree growth model for Norway spruce stands | Ein Ansatz zur Evaluierung eines Einzelbaumwachstums-simulators für Fichtenreinbestände
2001
Sterba, Hubert | Korol, Nikolaj | Rössler, Günter
The applicability of the distance independent individual tree growth simulator PrognAus is tested in three Norway spruce experiments in a long term observation plot with target diameter thinning, a thinning experiment in Bavaria with 6 plots, and an Austrian experiment within the European Norway Spruce Thinning Experiment. Individual tree breast height diameters and heights after 20 years are generally sufficiently well-forecasted. The simulated basal area increments deviate from the observed values less than is to be expected from the statistics found in the parameterization procedure. The considerable underestimation of the height increment in the European Norway Spruce Thinning Experiment results from its extremely high site class (m.a.i. at age 100>22 m³ha⁻¹a⁻¹), which most probably was not represented in the parameterization data set. A small effect of underestimation of small basal area increments and overestimation of large increments is in line with other findings, indicating that the effects of dbh and competition are smaller in pure Norway spruce stands and larger in mixed species stands. The treatment effects are depicted in the correct order by the model, but nevertheless the simulated thinning effects are generally slightly overestimated.
显示更多 [+] 显示较少 [-]