Forestry has come a long way since the early days of European settlement. Chopping down ancient native trees was a huge business – but it was not sustainable. The landscape felt the brunt.
Fast-forward more than 100 years and the forest industry is again a big exporter, although the pioneer woodsmen would never recognise it. It is infinitely sustainable – some stands of radiata pine are into their fifth rotation. The trees are replanted immediately after harvest and grow to maturity in less than 30 years.
During their growth, the trees are extremely efficient at holding the soil together. They filter and clean the streams that flow through the forests. Pines are very good at reducing atmospheric carbon; a single hectare of mature trees will store 900 tonnes of carbon dioxide, whereas a regenerating podocarp forest will take 40 years to store 300 tonnes. And of course, wooden buildings will continue to store the carbon for potentially centuries.
The government’s billion tree planting aim heralds a long overdue expansion of New Zealand forestry, and not just with pines. Many of these trees are likely to grow on hill country that is marginal for farming.
The forest industry welcomes the challenge. Mechanised harvest, rather than chainsaws, has become a safer harvest norm. And science, in breeding “better” trees and sorting out the downsides of harvesting, in particular, is playing an increasing role. For more information, see nzwood.co.nz.