Assessing the leaning, bending, and sinuosity of sapling-size trees

Many factors result in trees with non-straight stems. An important prerequisite to investigating the causes of stem deformity is an ability to assess stem displacement. An ideal system would be easy to implement, be objective, and result in an index that incorporates the essential characteristics of the stem deformity into a dimensionless number. We tested a number of indices that could be measured and calculated from a photo taken from the side showing the tree’s greatest deformity. Image analysis software was used to measure the characteristics that define the stem displacement and calculate an index of deformity. This system was tested on trees completing their fifth growing season in a long-term study of the effects of container cavity size and copper root pruning on longleaf pine (Pinus palustris Mill.) planted on moderately well-drained, gently sloping soils in central Louisiana.