asked the Minister for Fisheries and Forestry if observations made by his Department reveal the average annual growth of or yield from conifers in forests; if so, the annual increment in (a) bulk and (b) weight from year one to year ten; and if he will relate the average annual growth figures to the fastest growing conifers in forests.
Written Answers. - Conifer Yields.
The information sought is not readily available in the precise format requested but I trust the following information will meet the Deputy's requirements.
The average yield class of conifers in State forests is around 14; exceptionally, in suitable soil and local climatic conditions, yield class may reach 30. In this context yield class represents cumulative production in cubic metres divided by age at the age of maximum production for a crop.
In conventional forestry since volume up to ten years is insignificant and not a reliable indicator of future production, it is not the practice in my Department to measure trees up to that age.
Lest the Deputy's primary concern may be with short rotation forestry for biomass purposes I may say that current experimental work is not sufficiently long in progress to permit firm conclusions to be drawn from it.