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, ho w accurate and truthful the information conveyed by the visualisation is, h as not been investigated. This study analysed the precision and accuracy of stand characteristic assessment by computer visualisation. A total of 20 f orestry specialists assessed quantitative stand characteristics from the ou tput of two software packages, Monsu and SmartForest, representing 40 stand s of varying stand age, density and species composition. The selected softw are packages are available for practical use in Finland. They represent dif ferent techniques of producing forest visualisation, one using line graphic s and the other scanned photographs of trees. The stand basal area and numb er of trees per hectare were not assessed accurately from computer visualis ations. The mean tree height and diameter were estimated reasonably well. T he visualisations produced an averaging effect, characteristics being often overestimated for young and small-sized strata and underestimated for stra ta of old and large trees. (C) 2001 Elsevier Science B.V. All rights reserv ed.