The Japanese Agricultural Standard (JAS) cubic metre is a global industry standard measurement of log volume. JAS is a measure of useable log volume rather than weight.  It is an attempt to measure the volume of the log available to the saw miller, involving special methodologies of assessing log diameter and length.
Export log grades are typically measured and sold in JAS m3. Payments to most contractors are made based on weight, which is appropriate for handling heavy material. This means the return to the forest owner is affected strongly by the conversion of weight to volume in the logs.
Conversion has seasonal trends and varies between log grades, length and log quality. Accounting for conversion is necessary to report comparable values from different sales options. Our convention is to report all prices converted to the ‘per tonne basis’, which would appear different if compared with a per cubic metre (JAS) series. Hence why our harvest reports show monthly JAS-to-tonne conversion per forest.