Biochar Application for Soil Carbon Sequestration and Greenhouse Gas Mitigation in Forest Ecosystems: A Bibliometric Analysis Using CiteSpace

Research on biochar application in forest soil carbon sequestration and greenhouse gas (GHG) mitigation has evolved into a rapidly expanding and increasingly sophisticated field. To address the lack of systematic evaluation, this study employed a bibliometric approach using the Web of Science database to analyze literature published between 1996 and 2025. The visualization and analysis were conducted using CiteSpace, a bibliometric tool that identifies emerging trends and research frontiers through co-citation networks, keyword mapping, and burst detection. Our analysis reveals a sustained rise in publication output, with China, the United States, and the European Union identified as leading contributors, whose influence continues to grow. Thematic mapping indicates a clear progression from early studies focused on “black carbon” and “soil organic matter” toward mechanism-driven investigations, with the “microbial community” now recognized as a key mediator of biochar’s ecological effects. Keyword clustering and burst analysis further reveal that biochar’s influence on soil fertility and microbial functioning has become central to its role in enhancing soil carbon sequestration and mitigating GHG emissions. While biochar’s capacity to enhance SOC stocks is widely affirmed, its variable impact on GHG fluxes highlights the need for integrated assessments of net Global Warming Potential (GWP). Despite promising advances, critical barriers persist, including the paucity of long-term, landscape-scale field trials and the absence of standardized production protocols, both contributing to inconsistent outcomes across studies. Future research should prioritize mechanistic studies across diverse forest ecosystems and adopt comprehensive life cycle assessments that account for both soil and vegetation-mediated carbon sinks.