Further reflections on Bob Fenton and his development of the short-rotation sawlog schedule for radiata pine

Authors: Donald J Mead
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2025, Issue N.Z.J.For. 70(3) 2025, pp Pages 46 - 50, Nov 2025
Publisher: New Zealand Institute of Forestry

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Abstract: According to three letters by Dr Bob Fenton the following are the main drivers behind the direct short-rotation sawlog schedule (SRSL): (1) Grade studies showed that logs from extraction thinning and from late-pruned stands, as used before 1970, were of low value; (2) Extraction thinning was uneconomic and should be abandoned; (3) There were limited overseas markets for framing timber; (4) Most new planting was to provide overseas exchange and should be profitable; (5) Treasury’s demand for 7% and later 10% return on investment favoured short rotations; and (6) Grade studies of large crop trees (~ 60 cm diameter at breast height) showed that pruning to about 5–6 m should provide butt logs with substantial clearwood. The second log could provide clear-cutting grades. Also, the Beekhuis radiata pine growth model was not reliable for very early thinning to waste, but three stands were found where this had been done and these partially filled the gap. While Bob Fenton reviewed the work of other forest researchers on silvicultural management, including I.J. Craib from South Africa and W.E. Hiley from Oxford University, he considered they were not important in his thinking. However, he also stressed that C.H. Brown did influence him. Bob Fenton said he was solely responsible for the ideas behind the short rotation sawlog schedule first published in 1967 (Fenton, 1967). This paper is also partly putting forward a clarification about points made in a paper by Rowland Burdon and Bruce Manley in the New Zealand Journal of Forestry (70(1): 2025) titled ‘The Silvicultural Legacy of R.T. Fenton – Its Genesis, Its Heyday’.

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