The standard and level of timber utilization define the species, dimensions and quality of trees that must be cut and removed from the site during harvesting operations. For stands younger than 140 years, all trees must be utilized to a minimum of 12.5 centimetres in diameter at breast height and to a minimum top diameter of 10 centimetres. For stands older than 140 years, trees must be utilized to a minimum of 17.5 centimetres in diameter at breast height and to a minimum top diameter of 15 centimetres. Stump height must not exceed 30 centimetres in either category. These standards reflect current practice and have been accounted for in the analysis.