Crown Radius and Diameter at Breast Height Relationships for Six Bottomland Hardwood Species

The relationship between a tree's crown radius and diameter at breast height (DBH) has a variety of uses including forest competition studies, tree crown densities, spacing and stoclung relationships, wildlife habitat suitability models, and tree volume estimations. Estimating DBH from mean crown radius (MCR) is of interest to natural resource managers because MCR can be estimated from high resolution digital imagery using remote sensing techniques. DBH is a common tree dimensional characteristic that is used to quantify tree and stand structure. This research presents MCR/DBH and DBH/MCR relationships for boxelder (Acer negundo L.), sweet pecan (Carya illinoensis (Wang) K. Koch), sugarberry (Celtis laevigata Willd.), green ash (Frasinus pennsylvanica Marsh.), Nuttall oak (Quercus nuttallii Palmer), and American elm (Ulmus americana L.). The linear model, y=a + b * x, provided the best model fit with adjusted r2 values of 0.567 to 0.855 for the 6 species. Crown radius can be determined from digital imagery and then used to predict DBH.