A plantation management question ... Is it possible to estimate the distance from the ground to the first live branch of a planted pine tree? The Bast Texas Pine Plantation Research Project (ETPPRP) in a recent investigation addressed this question, and the answer was yes. An analysis of the ETPPRP data set produced equations to estimate crown height (the distance from the ground to the first live branch).
Lee, Young-Jin and Lenhart, J. David, "Project Report No. 40, Influence of Plantation Variables on Crown Height" (1996). Informal Project Reports. 31.