![]() Pour cela, des modèles prédictifs de distribution de diamètres à partir de la surface terrière ont été développés pour sept espèces d’arbres de Catalogne. Lors de la mise en œuvre de caractéristiques de peuplement, la distribution des diamètres des arbres était prédite à partir des variables de peuplement. Les données d’inventaire testées étaient soient des données concernant les arbres, soit des caractéristiques générales des peuplements. When stand basal area, number of trees per hectare and basal-area-weighted median diameter were used to calibrate the diameter distributions the results were rather close to those based on tree level inventory data.Ĭe travail analyse comment le type de données d’inventaire affecte les calculs de planification et de gestion forestières. Calibration of the predicted diameter distribution improved the accuracy of forest planning calculations. The results showed that tree- and stand-level inventory data give very similar results. The methods were compared in terms of calculated inventory results, growth predictions and treatment prescriptions (harvest removals per compartment) for the province of Lleida in Catalonia. Individual tree data were used as a reference method to which the stand level data and the alternative ways to derive the diameter distributions were compared. The predicted diameter distribution was either scaled to yield the measured total stand basal area, or calibrated with the help of more than one stand characteristics. An optimisation approach was used to find the coefficients of the parameters models. For this, prediction models for the parameters of the diameter distribution of stand basal area were developed for seven main tree species in Catalonia. When stand characteristics were used the diameter distribution of trees was predicted from the stand variables. The inventory data alternatives were tree level data vs. This study examined how the type of compartment inventory data affects the outcome of forest planning calculations.
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