canterbury’s own lifestyle magazine / a great local read

Exotic forests have become so much a part of the New Zealand landscape that one could be forgiven for thinking they have always been here. Forestry has been generating economic growth for the country ever since the 1950s. Yet the science behind forestry and the discoveries that made New Zealand’s Forest Research Institute (now called Scion) world-renowned have remained largely under the radar.
Dr Geoff Sweet, retired forester, geneticist, and University of Canterbury forestry professor, has spent his entire professional life focused on the science of growing tree crops.

Geoff, who grew up as a friend of the very outdoor family of the late Louise Lady Hillary, became passionate about the outdoors. He and his wife Margaret say there are few valleys in New Zealand they have not visited.
Now, at 87, Geoff reflects on his career as well as the future of forestry and environmental issues, in the comfortable living room of his suburban home in the heart of leafy Fendalton.

Geoff grew up in Auckland. His father was a paediatrician and his mother was a nurse. He was educated at King’s College during World War II, when many members of the teaching staff were away on war service. He studied biology, botany and zoology at Auckland University, qualifying with a Bachelor of Science. ‘I spent a lot of time tramping. I also joined the New Zealand Alpine Club and started active climbing.’
He met Margaret, a historian, language and arts student, on the slopes of Mt Ruapehu in 1952. These were the days when you couldn’t mix science and the arts in one degree. ‘Margaret knew nothing about science and I knew nothing about the arts. We’ve been remedying that ever since.’

This was also where he first met Sir Edmund Hillary. 
‘I didn’t know him particularly well,’ Geoff recalls, ‘but 
we did build a hut together on Mt Ruapehu, and I went to 
his wedding.’

After getting his degree, the question arose, then as now: Where are the jobs? ‘When I graduated I wondered about training to become a guide at Mt Cook, but a big chunk of me knew that that wasn’t going to work out for a lifetime.’ His mother suggested forestry; a brilliant thought. ‘I needed an academic job, a mind job, but I wanted some outdoor activity as well and forestry produced that.’

By the 1950s, thousands of pine trees that had been planted during the Depression were just reaching maturity. ‘The crop was planned to keep New Zealand in timber once the native forest ran out,’ Geoff explains. ‘There was no thought back then in the ’30s that we cared so much about our native forest that we would ever want to preserve it.

‘The new crops grew very well. They would have been harvested normally at the beginning of World War II but there weren’t any men around to harvest them, so when the war was over, the Forest Service did a huge expansion and put a lot of work into deciding how it was going to use these trees.’

In general, the best parts were used for houses; other parts for pulp and paper. Canadian loggers, who had great forestry experience, were brought in. The first Director-General of the Forest Service after the war was an engineer who got the processing industry going.  A pulp and paper mill was built at Kawerau.  ‘All of this was new.’

Geoff joined the New Zealand Forest Service in 1955.  ‘The Forest Service was a very enlightened organisation that took on trainees when they left school. Then when they got science degrees it sent them overseas to do forestry training. I talked the Forest Service into hiring me even though I had not gone through their formal training scheme.’ 

Geoff did a degree in forestry at the Australian Forestry School in Canberra, graduating as top student and being awarded the Schlich Medal.  On his return to New Zealand he was appointed to the genetics group at the Forest Research Institute in Rotorua.

Geoff married Margaret in 1959. ‘Margaret and I had known each other for seven years before we got married. The delay was largely because till then we had never managed to live in the same town at the same time.’

One of the first areas Geoff worked on at FRI was ‘studying which non-native trees grew best in New Zealand.  The genetics group was evaluating trials of a number of potential species. It’s not just the species, but where in their natural range the seed comes from that is important. This has a huge impact on how well the trees will grow in New Zealand. A senior colleague had made major collections, world-wide, and we tested them in different parts of New Zealand.’

Pinus radiata, however, which has a very small natural distribution in North America on the coast south of San Francisco, was the clear winner, showing up as easily the favourite species.  Pinus radiata grew faster, dramatically, than any other species. It was as simple as that.  Its only problems are on very cold sites.’

Another important advantage was that Pinus radiata is a good timber, easy to saw and dry.

The Forest Service needed more researchers, so in 1964 the Forest Service paid Geoff his full salary to travel overseas to complete a PhD at ‘the best place in the world’ he could find for his research area. A scholarship from New Zealand Forest Products covered return fares by sea to Britain for Geoff, Margaret, and their two children, Robert, two, and Sarah, eight months. (A third child, Andrew, was born in Wales.)

Usually a PhD would take three years excluding travel time, but Geoff squeezed it into much less by working 80-hour weeks. He studied under Philip Wareing, who held the chair of botany at Aberystwyth at the University College of Wales, and was a world leader in tree physiology and genetics research.

Geoff’s thesis was on the genetics of growth rate and physiology.  ‘We looked at fast-growing trees.  Growth rate is a complex thing.  Can I find out some more specific parameters? Can we predict: if it’s got a high rate of photosynthesis, will it grow faster? No. Or do the fast-growing trees produce leaves at a faster rate? Yes. Are there other factors?  Absolutely.’

Sea travel took six and a half weeks each way. ‘People of my generation had never been overseas. It was a once-in-a-lifetime opportunity. I had never travelled (apart from Australia) and it seemed unnecessary to sit at a desk or be in a laboratory the whole time.’ 

On the few occasions that they could, the family travelled to France, Germany and elsewhere in Europe, and went walking in the Welsh hills every Sunday.

On his return to New Zealand, Geoff rejoined the Forest Research Institute in Rotorua. The institute became world-renowned, ‘largely because we could grow trees faster than anywhere else so we could get our research results out much faster. We were at the forefront of publishing,’ says Geoff.

Why do trees in New Zealand grow so much faster? ‘Totally climate and soils. Trees grow fast under reasonably warm temperatures and with lots of rainfall; and that’s New Zealand. We have got quite good soils over much of the country: what’s good agricultural soil is generally good forestry soil, and we’ve got the rainfall.’

In 20 years as a research scientist at FRI in Rotorua, Geoff was responsible for undertaking tree breeding research.  As a senior manager, he then became responsible for (at times) the work of up to 100 staff from across the institute. ‘That was quite fun but it was certainly challenging.’

Before he left the FRI at Rotorua, Geoff had conferred on him the degree of Doctor of Science by the University of Canterbury.  It is a degree that marks the quality and quantity of a scientist’s research contribution.  During his research life he published more than 80 papers and chapters of books, a number of them in partnership with overseas scientific researchers.

In 1985, Geoff and Margaret were ready to move on.  Geoff had two choices: deputy director of research for the Forest Service in Wellington, or professor of forestry at the University of Canterbury. ‘We were South Islanders at heart, so we said, right let’s go there because we’ll spend all our spare time out in the hills, and we’ll love that, and we did.’

Geoff retired in 1995 but is still fascinated by science and the environment. He is pleased that logging New Zealand’s native forests was phased out. ‘Trees from North America and Europe got wiped out in the Ice Age and they were replaced with tree species that were a lot more cold-resistant. New Zealand, sitting in the middle of the ocean didn’t get the same cold levels, and the pre-Ice Age flora is still growing in New Zealand, so we are biologically relatively unique. 

‘Regarding climate change, although CO2 levels are clearly rising, the degree to which humans are causing this and the level to which this will increase air temperatures remain controversial. This is because the beliefs about global warming are based largely on computer modelling and such models need to be verified. So far this has not happened. I am one scientist who doesn’t think that the science is settled.

‘There is no alternative to timber as used in the world today. I think we will need forests commercially for a long time to come.

‘We’re always going to need forest products for usage by humans. There’s no other high volume crop that we have learned to deal with, to solve our structural problems.’

However, Geoff warns that we are also responsible for maintaining the health of our forests. ‘It’s vital. If we just get one serious disease we could be in deep trouble. I think we should be constrained in our choice of species. We shouldn’t be putting large areas of land into single species of animals or forests, because sooner or later we know they will be subject to significant disease risk.’ 

Words David Killick