Comparing forest assessment based on computer visualization versus videography

This study examined the representational validity of computer-visualized forests by comparing them with field-recorded walkthrough videos (field videos) from a timber stand management perspective. Computer-visualized replicas of field conditions at selected locations in loblolly pine (Pinus taeda, L.) stands were generated using measured data. Human subjects examined either field videos or computer visualizations and assessed characteristics of five distinct stands which consist of three well managed spacing stands (1.5 m, 2.4 m, and 3.0 m) and two minimally managed stands (immature and mature stands). Subjects viewing computer visualizations tended to estimate lower stem density and higher mean diameter of the well managed stands. Assessed stand structure of the well managed stands through the field videos and computer visualizations were in relatively high level of agreement. In minimally managed stands, significant differences were not found in density assessments including mean spacing, stem density, and mean diameter; however, horizontal crown cover in the immature stand was estimated lower using computer visualizations. Field video and computer visualization groups perceived different stand structure in the mature stand in which hardwoods were present in the mid-canopy.