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A hitch-hiker’s guide to climate change – don’t panic

Howard Moore, New Zealand Tree Grower May 2017.

It was nearly 40 years ago, but some of you might remember in the Hitchhiker’s Guide to the Galaxy that Zaphod Beeblebrox owned a pair of dark glasses that turned completely black when danger threatened. The idea was the owner could carry on blithely without getting stressed about imminent death, until torn to pieces by the nearest ravenous beast. I have not seen those glasses on the market myself but I am sure they are available and being tested by some newly elected head of state.

For the rest of us, to survive we have to see the ravenous beast and hopefully poke it in the eye with a sharp stick while still at arm’s length. In a way, that sums up climate change. We desperately need to know where there is a sharp stick and if we can poke it in the eye. Reports are written and careers are made answering such questions. These reports keep coming in and it is always tempting to wait for the next one before trying to summarise them. However, when editors ask you to choose between deadlines and death, I start writing.

Farm forestry is the future

The reports are comprehensive, widely discussed and broadly accepted. Although their language is edged with urgency, they focus on responses, not consequences. They describe the stick in detail, tell us how to sharpen it and where to poke it. Assuming we are brave enough to do that, from an NZFFA perspective these reports can be summed up in two words − don’t panic. Things will get tough but New Zealand’s future looks more and more like farm forestry.

One thing these reports have in common is a call to plant more forests to soak up carbon dioxide. The loose aim is new planting at the rate of 30,000 hectares a year over the next 30 to 50 years. If radiata is sequestering 30 tonnes a hectare each year, they suggest we plant around a million hectares. If it is a mixture of radiata and slower growing native species they suggest one and a half million hectares. We can manage the planting rate and there is enough marginal land to meet the target, so on the face of it there is no problem.

However, there is a big ‘but’. First, no-one is going to clear a million hectares of scrub in order to plant pines so the new forests will have to be planted on grassland.

Second, the commercial forestry sector does not own grassland – it is owned by farmers and the government. As the government is unlikely to give up conservation or defence land, the focus is all on the farmers.

Third, farmers encouraged or pressured into planting parts of their farms are likely to give up the worst areas first. The result will be fragmented, remote, sensitive, mainly inaccessible pockets of forests which will absorb carbon, but will do little for wood supply.

Unpleasant future

This is a farm forestry future but not a very pleasant one. How can we improve it?

Species selection

When it comes to choosing useful species for difficult sites the NZFFA has the biggest pool of skills and knowledge in New Zealand. Whether it is Turkey oak, totara or teak, a member somewhere knows how and where to grow it and what it is likely to produce in terms of growth rate, forage and timber.

Of course, for many species the nurseries have limited stocks and there is little market for the wood, but that is an education problem. The trees will grow and produce value in the future, irrespective of today’s market. Markets change, and a high quality species on a remote site has more potential than a low quality species.

Genome selection

Tree breeding for radiata pine has been practised since the late 1950s. Unimproved planting stock has become rated as GF and now GF Plus. Genetic gain in terms of recoverable volume per hectares has risen by around 30 per cent in 50 years. Scion is currently researching how well different genetic variants or genomes grow on different sites. They are being selected for growth rate, form, disease resistance and wood quality.

Rather than simply plant a whole forest with a range of genomes, foresters should be able to plant specific variants on specific sites, getting the best from each. A clonal woodlot which produced uniform logs of known quality could command high log prices, justifying a more accessible, higher value site.

Site selection

New aerial scanning technology is providing higher resolution information about forest sites in terms of vegetation, the presence of fungal diseases, topography, microclimate and fertility. This information is being used to delineate sites with the right potential for genetically improved tree stocks.

Acknowledged public benefits

Forests are associated with a range of public benefits which in the past have helped motivate government afforestation. However, government stopped direct investment in forestry in the mid-1980s, and in 1991 passed responsibility for the public benefits such as erosion control, watershed protection and landscape enhancement to local authorities.

Their risk management strategy was to pass it on to forest owners, with substantial increases in the costs of compliance and forest management. A more even-handed approach to regulation – for example, giving forest owners nitrate discharge allowances equal to farmers on similar land classes, and allowing trading in such allowances − would encourage afforestation.

Higher carbon prices – carbon forests

At present New Zealand Units are selling for around $18 each and this price is unlikely to rise while the government’s offer of $25 sits in the market like the threat of a Vogon poetry recital. Against that, the whole point of the Emissions Trading Scheme was to give a market signal that encouraged behaviour change. To achieve that, all of the reports imply carbon prices will have to rise into three figures by 2050.

High carbon prices will encourage farmers to retire pasture and plant forests as the income from carbon credits will substitute for lost pastoral earnings. Carbon forests could be planted on steep, remote land not suitable for harvest, in species that will continue to produce carbon credits into the future. Rising carbon prices will inflate the value of that land, encouraging capital gains.

Averaging for production forests

In the 2015/16 Emissions Trading Scheme Review officials suggested ‘averaging’ as an incentive for landowners to plant new forests. The idea is that if a qualifying area of bare land were converted into a production forest, it should earn carbon credits equal to the average carbon it sequestered, allowing for regular harvesting and replanting.

Providing that carbon credits were issued up to the average and no more, the landowner could sell them and never have to repay them for as long as the forest endured. In effect, the mechanism would offer the landowner a ‘conversion grant’ for changing his land use. The carbon credits would be a one-off. After that, in order to earn a return, the landowner would have to manage the forest for timber. By implication, it would have to be planted on accessible land reasonably close to markets.

Harvested wood products for production forests

Also in the Emissions Trading Scheme Review officials suggested accounting for the carbon stored in harvested wood products. The idea is that when a tree is felled, some carbon ends up in durable products such as timber buildings and furniture which last for decades. Under harvested wood products, the carbon liability for a grower harvesting his trees could be reduced − deferred to the future − by allowing for the carbon carried forward in the product mix.

Because the grower’s next rotation would store more than enough carbon to offset the deferred liability, this approach should encourage them to harvest and replant. In effect, it would be similar to averaging, but it would offer the growers a little more control over earning and selling carbon credits.

Using the sharp sticks

Most of these factors are here now. Many of them will work together on the same site. Our climate change future looks like an extended mosaic landscape where pastoral farming, cropping and forestry co-exist, in a community we are familiar with. Like farm foresters, pastoral farmers are optimists and innovators, as evidenced by their many experiments into agricultural diversification

The NZFFA members give proof that a widening variety of land uses can be versatile, profitable and look good. As well as running farms, we know how to grow the best trees from which to take sharp sticks, and these reports help us point those sticks at the right target.

Howard Moore is a member of the Wellington Branch of the NZFFA.


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