Distribution,properties and formation of some wood extractives

Summary In the future, wood will be used largely for the manufacture of fibre products and particle board. The quality of wood used to meet increasing world demand will vary considerably. One feature of quality that can affect utilisation is the amount and type of wood extractives present. The distribution and variation in composition of extractives in the tree, as well as their effect on pulp manufacture, durability and surface films, are summarized. Methods to reduce the effects of some extractives in existing trees are described. Extractives can be reduced in plantation material by minimizing heartwood formation and by using silvicultural methods which result in small amounts of extractives being formed in this tissue. Current knowledge on heartwood formation is summarized.Paper presented to the 3rd Plenary Meeting of the International Academy of Wood Science held at the N. C. State University, Raleigh, March 11, 1971.