Forests as climate change and economic stabilisers

Forests will help to catalyse New Zealand’s much-needed transition towards a new, more sustainable bio-economy that is not subject to the global instability of finite fossil fuels and their associated greenhouse gas emissions.

The forest sector exports earnt $6.7 billion in 2021, and forestry and wood processing form New Zealand’s forth largest primary industry, employing 40,000 people.

“Forests are Aotearoa New Zealand’s largest renewable resource and are vital in our move toward a more circular, zero-emissions economy. The materials, energy, and wood products that the sector produces are at the heart of the emerging bio-economy,” Industry Transformation Plan 2022.

New Zealand plantation forests have a standing volume of 530 million m³ an average tree age of 18 years, and a harvest of 34 million m³ per annum. 90% of the forest is Pinus Radiata with an average harvest age of 28.7 years, 6% is Douglas Fir (mostly in Otago and Southland with a harvest age of 40.4 years) and modest amounts of other softwoods, cypress and eucalyptus.

Forests also provide a large number of other environmental advantages in preventing surface erosion, providing fresh air, improving freshwater quality, providing wildlife habitats and supporting ecosystem health.

The materials, energy, and wood products that the sector produces are at the heart of the emerging bio-economy.

Different forest management procedures are used to produce useful wood products. The illustration shows production from a representative pinus radiata tree from a typical thinned and pruned forest harvested at 35m height. Most value (50%) is from the clear timber used for its consistency, high quality and excellent appearance. 

Trees planted for structural applications have 60% sawn logs by volume with a much larger 80% value proportion and 20% industrial logs. These forests are thinned after around 10 years but are not pruned. Timber Unlimited is largely focused on increasing the efficient use of sawn timber in high-quality applications to replace high-emission materials.

There are many initiatives underway to efficiently use the final 4% of the tree for renewable energy, such as wood pellets and biofuels. Research has shown the potential for a large range of biochemicals, bioplastics, pharmaceuticals and other products that will replace those that use fossil fuels.