• Castle, Mark
  University of Maine Graduate School
  

Northern hardwood and mixed-wood forest types occupy a considerable percentage of the forest landscape across the Northeastern United States and portions of eastern Canada. While capable of producing valuable saw timber and veneer products, hardwood species demonstrate a wide range of stem quality resulting from the large variety of stem forms and defects that these species can manifest. The effect of different stem forms and damage has largely not been accounted for in predictions of volume, growth, and mortality. In addition to potential bias in growth and yield applications, the lack of quantification of these features has left the efficacy of silvicultural tools such as tree classification guides untested. Using a tree classification system developed by the Northern Hardwood Research Institute (NHRI), form and risk classifications were assigned to several commercial hardwood species across sites in Maine, New Hampshire, and New Brunswick. Regression analyses were used to accomplish the following objectives; 1) quantify sawlog recovery as a function of a trees size, form, and risk; 2) determine the occurrence of stem form and risk among species; 3) and evaluate the influence of stem form and risk on individual tree diameter growth and survival.