Forest harvest index: Accounting for global gross forest cover loss of wood production and an application of trade analysis

Forest cover loss is a major cause of both the decline in global biodiversity and the increase in carbon emissions into the atmosphere. Focusing on the effects of logging, this study introduces an index of wood production, the forest harvest index (FHI), which calculates the expected gross forest cover loss (GFCL) reflecting the demand for timber and wood products at the global scale. We examined the accuracy and precision of the index by investigating the relationship between the FHI and actual GFCL measured through remote sensing. The index incorporates wood- and climate-specific biomass expansion factors and country-specific growing stock densities to convert wood production volume to expected GFCL. We quantitatively examined the effect of data uncertainty in the growing stock density values obtain from FRA 2010 on the predicted relationship between the FHI and actual GFCL. We quantified the FHI for both industrial roundwood and wood fuel during a 5-year period (FY2000–FY2004) in each of the 139 nations considered. Results demonstrated that the FHI of industrial roundwood (18.6 million ha  yr−1−1) corresponds well to actual GFCL (19.3 million ha  yr−1−1) during the same period. The data uncertainty analysis suggested that increasing the frequency of forest monitoring at the national level can improve the precision and accuracy of the FHI, but discrepancies between the FHI and actual GFCL were also identified. Furthermore, to demonstrate the utility of our index as a metric of virtual GFCL of wood products, we disaggregated the FHI into export, import and domestic based on global wood trade data and compared the strength of the relationship with actual GFCL. Export FHI had a strong positive relationship with GFCL, which effect far exceeded the compensating effect of import FHI, indicating that wood trade overall increased GFCL at the global scale.