Abstract. Images acquired with a commercially available digital
camera were used to make measurements on 20 red oak (Quercus spp.) stems.
The ranges of diameter at breast height (DBH) and height to a 10 cm
upper-stem diameter were 16–66 cm and 12–20 m, respectively. Camera
stations located 3, 6, 9, 12, and 15 m from the stem were studied to
determine the best distance to be used with the maximum wide angle setting
on the camera. Geometric mean diameter estimates from the 12 and 15 m
distances were within 94 cm at any height (95% x 2 ). Though unbiased,
measurement variation was found to increase with stem height. Using camera
derived heights and diameters, volumes were found to be within 8% of
volumes calculated using taped measurements of individual stems two times
out of three - an improvement over existing DBH-height volume equations.
This preliminary work demonstrates the ability of using a digital camera
to acquire stem diameters and heights. Some limitations of the current
technology are also noted. By combining equipment and procedural
modifications with improved data flow from imagery to information,
terrestrial digital imagery may revolutionize stem or even plot level data
collection.