Strategy for implementing silvicultural practices in Japanese plantation forests to meet a carbon sequestration goal

Abstract

The strategy for implementing silvicultural practices in Japanese plantation forests was examined to achieve a carbon uptake of 13.0 Mt-C year⁻¹, which was capped by the Marrakesh Accords, during the first commitment period, 2008–2012. The plantation forests that implemented silvicultural practices in the period 1990–2012 (FM plantation forests) were identified in compliance with the hypothesized identification rules, and carbon uptake in the forests was estimated using a simple model composed of simulation and optimization components on the assumption that whole plantation forest is classified into only two groups. Furthermore, parametric analysis was conducted to investigate the relationships among three factors: (1) the average annual harvesting volume (including thinning) in plantation forests during the first commitment period, (2) the total area of FM plantation forests in 2012, and (3) the average annual amount of carbon to be sequestered in FM plantation forests during the first commitment period. The results imply that young stands have to be prioritized in implementing silvicultural practices under any harvesting plan and carbon sequestration goal, and that FM plantation forests sequestered 8.0–10.5 (Mt-C year⁻¹) carbon in inverse proportion to the harvesting volume of 21.0–14.0 million m³ year⁻¹ (log volume), assuming that most of the plantation forests were incorporated into them.