Quantifying the carbon in harvested wood products from logs exported from New Zealand

Authors: Bruce Manley, David Evison
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2017, Issue N.Z.J.For. 62(3) 2017, pp 36-44, Nov 2017
Publisher: New Zealand Institute of Forestry

Abstract: In 2015, New Zealand exported 15.4 million m3 of logs, some 53% of the national harvest, with 96% going to China, South Korea and India. Models have been developed to quantify the harvested wood products (HWP) manufactured in each country from these logs and the lifecycle of the HWP produced. The model allows the decay curve of the HWP carbon stock to be estimated. Carbon stocks in the products manufactured in China from New Zealand logs are halved in just under two years. Some 46% of the HWP is lumber and plywood used for temporary construction, while 13% is lumber and plywood used for packaging, which is also short-lived. In South Korea, the carbon stocks are halved in just over 12 years. Although the 42% of material used for temporary construction has a short-life in that intermediate use, most is recycled into longer-lived particleboard. In addition, 30% of log volume (mainly sawmill slabwood and plymill residues) is used for the production of medium-density fibreboard (MDF), another long-lived panel product.