New Zealand pioneered some methods of tree and forest growth simulation and modelling.

In the early 1960's the then Director of Forestry in the New Zealand Forest Service saw that the time was ripe for significant advancement and that Hans Beekhuis, a perfectionist scientist of Dutch origin, had the answer in his head. Hans had an unrivalled knowledge of the Permanent Sample Plot system in New Zealand's planted forests of exotic (imported species) conifers, especially Pinus radiata from California. He pushed Hans further than Hans wanted - Hans would have waited until the data were perfect - but when are they ever perfect? - and the result was the published NZFS Technical paper

"Prediction of Yield and Increment in Pinus radiata stands in New Zealand. J Beekhuis. 1966, Technical Paper No. 49. Forest Research Institute, New Zealand Forest Service. (Originally published internally in July 1963).

an epoch-making work on which much subsequent work, and the following Growth Models, were based. These programs were initially run on Radio Shack TRS80's, then (translated) on ICL mainframe machines located in Trentham. You will need the DOS program msQuickBasic to run them.

At about the same time there was another personality in New Zealand forestry emerging; R. T. (Bob) Fenton (later Ph.D.). Bob is an original thinker, and quite critical as occasion demands. He had been (un)impressed while at Dusky Forest in South Otago where, in slow-growing, un-thinned stands of Corsican pine, pruning of the dead branches at considerable expense was the conventional order of the day. Clear wood would surely be produced eventually, but Bob showed that it would be too little, too late, and mostly end up in slab-wood. No-one had thought through the economic consequences of the work.

While an undergraduate at Oxford University (Commonwealth Forestry Institute and Forestry School), he had come in contact with the pioneering work of W. E. Hiley of Devon (whose work is mostly in the form of books, not published separate papers), and J. R. Craib of South Africa. These two individuals had done more between them than anybody else to that time in calculating and quantifying the effects of silvicultural thinning (mainly of planted, uniform stands) on the growth rate of individual stems and the whole stand, and the economic consequences thereof. Bob's published criticism of the economics of the pruning at Dusky forest offended the upper echelons of the Forest Service hierarchy, and he was temporarily banished to Conical Hill and Waipa State sawmills where he proceeded to do pioneering work with timber seasoning (which also offended the conventional sensibilities) but eventually he emerged to work at the Forest Research Institute in Rotorua where he produced an epoch-making string of papers about forest economics. (Other international workers in the field then who should be mentioned include S. H. Spurr, D. A. N. Cromer.)

With an increasing area of planted forest needing rational decison-making methodologies, and goaded by the economic analyses of Bob Fenton, there was plenty of pressure to develop growth models.

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