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ŠUMARSKI LIST 11-12/2021 str. 73     <-- 73 -->        PDF

significantly on model performance. All models showed a similar trend (Figure 3), i.e. volume in stands with lover volume values were overestimated, while in stands with higher volume values were underestimated. However, overestimations (&8776; 8,5%) using SB models were considerably greater than underestimations (&8776; -4%) using PB models. Differences in SB and PB models performance are probably due to differences in stand and site characteristics between two forest areas (Spačva basin and Pokupsko basin). The obtained results suggest that the model with independent variables (Equation 1) originally developed for Spačva basin area can be used for Pokupsko basin and other areas with similar forest characteristics, but local model parameters have to be estimated in order to increase estimation accuracy. It has to be emphasized that the photogrammetric method tested in this paper can not replace the conventional field methods in regular forest inventory. However, its application is based on existing and easily available data (aerial images from regular topographic surveys, official DTM, forest management plan) and does not require additional field measurements and therefore present effective and low-cost solution when in a very short period large areas have to be inventoried. Further research should be focused on other important forest variables (e.g. mean stand height, mean stand diameter, basal area, stand density, biomass, etc.) and different forest types.
Key words: aerial images, digital photogrammetry, canopy height model (CHM), stand volume, forest inventory