Thinning guidelines from crown area relationships for young hardwood plantationsThis article is part of a larger document. View the larger document here.
Crown closure in hardwood plantations signals the first opportunity to apply density control treatments such as thinning or release. The proper timing of these treatments is a function of stocking levels and is generally scheduled within several years after initial crown closure. Predicting crown closure for a plantation provides practitioners with the ability to plan intermediate treatments and is based upon crown development in a stand. Stem diameter and crown surface area relationships coupled with plantation spacing and age can be used to estimate crown closure. This study provides crown area relationships for 7- to 10-year-old free-to-grow Quercus rubra, Q. alba, Liriodendron tulipifera, and Fraxinus Americana trees that were located in five plantations established over a wide range of site conditions from abandoned farm land to reclaimed surface mine sites in Kentucky. Stem ground line diameter ranged 0.5 to 6 inches and regressions of crown and stem diameters of free-to-grow trees indicated acceptable fit statistics with the majority of the species/site R2 values > 0.80.