Estimation of tree stand characteristics through computer visualisation

Computer visualisation is increasingly used to demonstrate the consequences of forest management alternatives to laymen and forest owners. However, how accurate and truthful the information conveyed by the visualisation is, has not been investigated. This study analysed the precision and accuracy of stand characteristic assessment by computer visualisation. A total of 20 forestry specialists assessed quantitative stand characteristics from the output of two software packages, Monsu and SmartForest, representing 40 stands of varying stand age, density and species composition. The selected software packages are available for practical use in Finland. They represent different techniques of producing forest visualisation, one using line graphics and the other scanned photographs of trees. The stand basal area and number of trees per hectare were not assessed accurately from computer visualisations. The mean tree height and diameter were estimated reasonably well. The visualisations produced an averaging effect, characteristics being often overestimated for young and small-sized strata and underestimated for strata of old and large trees.