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This review was prepared while gathering data for a Master of Applied Science thesis concerning the Energy Requirements of ExoticProduction Forestry. In addition to providing background information for this thesis, a further objective of the report was to serve as an introduction for students of the Joint Centre for Enviromnental Sciences, Lincoln College, to forestry and production forest management in New Zealand. A brief outline of the impact of man on the natural forest environment, his gradual development of a forest policy and evolvement of an exotic forest estate, is followed by a review of production forest management practices, The report concludes with a discussion on the management for timber production of New Zealand is merchantable indigenous forests. The review is based on a literature survey which encorporated FRI symposiums, FRI branch reports, articles from the N.Z. Journal of Forestry, LIRA reports and numerous. relevant publications available in the libraries of the University of Canterbury, In addition, a considerable quantity of information was forwarded by well informed individuals actively engaged in forest management.

The process analysis technique was adopted for determining the energy requirements for the management of radiata pine in New Zealand forestry. It is estimated that for a 25 to 30 year rotation, between 120 MJ and 160 MJ are expended in the production of one m³ of roundwood on the truck deck, excluding labour. Of this, 63% is attributed to the direct consumption of liquid fuels, 16% to the manufacture, repair and maintenance of machinery, and 21% to the requirements for goods and services. The heavy dependence on diesel oil, which accounts for three quarters of the liquid fuel usage, is noted. By operation it is apparent that roading and site preparation account for 17% to 21% of the total energy requirement, establishment and tending 8% to 12%, and harvesting 54% to 59%. Spread throughout the rotation is an administrative input of 11% to 14%. Labour inputs range between 360 and 570 hours per hectare for a 25 to 30 year rotation. Adopting an energy:dollar ratio of 23.1 MJ/$ (June 1980), this equates to an average of 88 MJ per m³ recovered. It is stressed that there are several approaches in energy analysis to assessing labour and these vary greatly with regard to the value placed upon this input. The ratio used in this study is high and converts labour into a major contributor to the energy requirements of production forestry. Energy inputs per m³ have been assessed on the truck deck, but the transportation of logs 60 kilometres or more doubles the total requirement, excluding labour. The downstream energy requirements from production forestry, that is the various forms of processing, are exceptionally large when compared to the requirements for producing the raw material. Assuming a requirement of 140 MJ per m³ to produce the wood and a similar amount for transportation, the production in 1977/78 of just over nine million m³ would have an energy value of 2.5 PJ. The estimated energy expended in the process of this volume was calculated to be 31.8 PJ. Consideration of downstream energy requirements is therefore particularly important if the predicted expansion in roundwood production over the next 35 years eventuates. Energy analysis is not seen as a new discipline developed to supersede economic analysis. The two are essentially complementary with the value of energy analysis arising from the identification and quantification of the energy resources utilized in production. Dollar costs of goods and services do not accurately reflect the value of energy expended to produce them, and energy values do not describe the supply and demand of the particular resource inputs. Hopefully the two disciplines together will provide a stronger analytical framework from within which planning decisions can be made.