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.