Timber Volume Estimation Based on Airborne Laser Scanning -- Comparing the Use of National Forest Inventory and Forest Management Inventory Data

Abstract: Large-scale forest resource maps based on national forest inventory (NFI) data and airborne laser scanning may facilitate synergies between NFIs and forest management inventories (FMIs). A comparison of models used in such a NFI-based map and a FMI indicate that NFI-based maps can directly be used in FMIs to estimate timber volume of mature spruce forests. Traditionally, FMIs and NFIs have been separate activities. The increasing availability of detailed NFI-based forest resource maps provides the possibility to eliminate or reduce the need of field sample plot measurements in FMIs if their accuracy is similar. We aim to 1) compare a timber volume model used in a NFI-based map and models used in a FMI, and 2) evaluate utilizing additional local sample plots in the model of the NFI-based map. Accuracies of timber volume estimates using models from an existing NFI-based map and a FMI were compared at plot and stand level. Estimates from the NFI-based map were similar to or more accurate than the FMI. The addition of local plots to the modeling data did not clearly improve the model of the NFI-based map.The comparison indicates that NFI-based maps can directly be used in FMIs for timber volume estimation in mature spruce stands, leading to potentially large cost savings.