Digital photo monitoring for tree crown

Abstract

Assessing change in the amount of foliage within a tree’s crown is the goal of crown transparency estimation, a component in many forest health assessment programs. Many sources of variability limit analysis and interpretation of crown condition data. Increased precision is needed to detect more subtle changes that are important for detection of health problems. Digital photomonitoring can be used to increase the precision of these measures provided exact camera parameter replication is performed and movement of canopy structures is not severe. Two measures of transparency (compactness and DSO, or fractal dimension of silhouettes minus fractal dimension of outlines) show sensitivity to small branches or small canopy gaps, but may offer some unique descriptive information over area ratio measures. Point-wise and region-wise transparency distribution maps provide easy to interpret visual representations of localized transparency.

Parent Publication

• Proceedings, 15th central hardwood forest conference

Citation

Clark, Neil; Lee, Sang-Mook. 2007. Digital photo monitoring for tree crown. e-Gen. Tech. Rep. SRS–101. U.S. Department of Agriculture, Forest Service, Southern Research Station: 46-54 [CD-ROM].