Fate of Log Exports and ETS Implications

In:
2017 Forest Growers Conference
Report No:
AC2017-22
Report Date:
October 18, 2017
Author(s):
Bruce Manley: UoC

Material flows and end uses of harvested wood products produced from New Zealand log exports

Conference presenter: Professor Bruce Manley, University of Canterbury School of Forestry

A recent review of material flows and end uses of New Zealand’s log exports focused on three main export markets which combined take some 96% of all log exports – China (68% of 2015 log exports), South Korea (17%) and India (11%).

New Zealand’s main log exporters were surveyed to gather information about the destinations and end uses of their logs. In addition, researchers visited each country to gain more detailed information about what actually happens to NZ logs once they reach those countries.

This research aimed to gain insight into the wood products produced from New Zealand logs, and the lifespan of these products. Models were developed to quantify the harvested wood products (HWP) manufactured in each country, and the lifecycle of these HWP. This in turn enabled the calculation of decay curves for HWP in each country. Ultimately this will inform calculations on carbon liabilities at different times in the lifecycle of timber.

The fate of log exports by country

China: carbon stocks in HWP are halved in just under two years. Some 46% of the HWP is in lumber and plywood used for temporary construction, while 13% is lumber and plywood used for packaging, which is also short-lived.

 

South Korea: carbon stocks are halved in just under 12 years. Although the 42% of material used for temporary construction has a short life in this intermediate use, most is recycled into longer-lived particleboard. In addition, 30% of log volume (mainly sawmill slabwood and plymill residues) goes to produce medium density fibreboard (MDF), another relatively long-lived panel product.

India: carbon stocks in HWP are halved in less than one year. Some 26% of radiata pine log volume is used directly for fuel. This includes slabwood (14% of log volume) and most sawdust (12%). Construction lumber (27%) is used for fuel after use for concrete formwork. Packaging material (31%) is also short-lived, especially domestic packaging.

In combination, the aggregate decay curve for the three countries indicates carbon stocks are halved in just over two years. These findings have implications for New Zealand’s international carbon accounting and reporting. In addition, if the deferred liability for emissions from the HWP is devolved to forest growers participating in the NZ Emissions Trading Scheme, whatever decay rate is adopted will likely have a major impact on the carbon stock profile over the life of a tree crop. This will affect forest profitability and risk, and hence the financial viability of afforestation.

For full details of this project, see: Manley, B. and Evison, D. (2017) Quantifying the carbon in harvested wood products from logs exported from New Zealand. NZ Journal of Forestry (62) 3, p36-44.

(N.B. The numbers used in these calculations are indicative only, some are assumptions rather than estimates, and they apply at a particular point in time)

Presentation below.

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