bark, and air 4 feet wide by 4 feet high and 8 feet long Stère – invented in France, equivalent to a cubic meter of cut wood with space for air Board foot – specialized unit of measure for lumber in North America, equivalent to the volume of a one foot length of a board one foot wide and one inch thick Stand growth assessment Increment borer – specialized tool used to extract a section of wood tissue from a living tree with relatively minor injury to the tree, used often for tree growth analysis Mean annual increment (MAI) – refers to the average growth per year a tree or stand of trees has exhibited at a specific age Periodic annual increment (PAI) – describes the average annual change in tree diameter between the beginning and ending of a growth period, used more often than MAI for percental growth Ecological yield -the amount of wood volume in any given year whose harvesting would be considered sustainable Growth and yield modelling – entails the creation of models of prospective tree growth and harvest yield for management purposes Economics Stumpage – the price charged by a land owner to loggers for the right to harvest standing timber on that land Optimal rotation age – the age at which the harvesting of stumpage will generate the maximum revenue or economic yield Harvesting Logging – cutting, skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. The term is sometimes used in a narrow sense to mean moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard. However, in common usage, the term may be used to indicate a range of forestry or silviculture activities... Harvesting methods Felling – process of cutting down a tree Bucking – splitting of a felled and delimbed trees into logs Scaling – measurement of felled trees to determine the volume of merchantable wood Skidding – transportation of logs from the site of felling to the landing along the ground Forwarding – transportation of logs from the site of felling to the landing above the ground, usually to minimize soil disturbance but limits the size or amount of logs that can be moved at once Hauling – long-distance transportation of logs from the landing to their final destination, usually with a semi-truck but occasionally with a train Woodchipping