The Second Tibetan Plateau Scientific Expedition and Research Program
Carbon sequestration of forest ecosystem has unique and significant contributions to the "carbon peak and neutrality" strategy in China. The greenhouse gas mitigation function of forestry includes not only pre-harvested stages, i.e., carbon sinks in forests, but also post-harvest stages. The post-harvest greenhouse gas mitigation, including life-cycle carbon stocks and substitution benefits of harvested wood products, plays a critical role in middle- and long-term carbon sink of forestry. Currently. the post-harvest greenhouse gas mitigation researches of China are far more cutting-edge compared to those of Europe and America. As a result, existing China's post-harvest greenhouse gas mitigation researches are insufficient for constructing a comprehensive national forestry carbon budget model and designing effective policies of forest management for increasing carbon sink. We systematically reviewed the post-harvest greenhouse gas mitigation researches in the recent 30 years to outline methodological revolution in post-harvest greenhouse gas mitigation in this period and to summarize the key parameters of the models used in previous studies. The major achievements in post-harvest greenhouse gas mitigation assessment methodology in the recent 30 years include: 1) the establishment of Production Approach and Simple Decay Approach, which is timber-harvesting country-based assessment frameworks, and Stock-Change Approach and Atmospheric Flow Approach, which is end-use country-based assessment frameworks; 2) the establishment of systematic carbon stock calculation method which had been applied in developed countries and major developing countries; 3) primary establishment of substitution model and scenario-based analytical framework which were mainly applied in substitution benefit assessment of harvested wood products in European and American countries. Our literature review reveals three major methodological shortcomings of existing studies. First, the expensive data collection cost of existing field survey restricted the wide application of high-tired method, resulting in large research gap in developing countries. Second, international trade flows are hard to track under existing methodological frameworks, restricting comprehensive assessment of the countries involved in harvested wood product supply-and-use chain. Lastly, the substitution benefit assessment ignored the real substitution under socio-economical rules, undermines the accuracy of the results. We suggest that future studies should: 1) summarize general rules and empirical models based on existing parameters to reduce the data collection cost in developing countries; 2) establish an analytical framework based on semi-finished harvested wood product manufacturing country and use multiregional input-output table to link the countries involved in the supply-and-use chain; 3) introduce the classical economic substitution elasticity and industrial linkage analysis as a potential approach to improve the substitution benefit assessment.