Afforestation Mitigating Soil N Loss by Modulating Microbial Community Structure: Bibliometric Review

Nitrogen (N) loss poses a significant threat to global climate stability and ecosystem sustainability. Afforestation, as a key ecological restoration strategy, regulates soil N cycling processes by modulating soil microbial community structure. However, a systematic synthesis of how afforestation influences microbial-mediated N loss remains limited. To address this gap, this study conducted a bibliometric analysis using CiteSpace software, based on 104 relevant publications indexed in the Web of Science Core Collection from 1997 to 2025, to comprehensively map the knowledge structure, research hotspots, and evolutionary trajectories in the field of afforestation-driven microbial regulation of soil N loss. The results reveal three developmental phases: initiation (1997–2005), growth (2006–2020), and stabilization (2021–2025). China contributed the highest number of publications (40), while the United States exhibited the greatest academic influence; the Chinese Academy of Sciences and the Russian Academy of Sciences clusters have emerged as core research institutions. Notably, keyword and citation analyses revealed that research hotspots have shifted from process-oriented measurements, including N mineralization and N2O emissions, toward a deeper exploration of microbial community structure, biodiversity, and functional mechanisms. This study presents the bibliometric synthesis of microbial N loss mechanisms under afforestation, revealing a paradigm shift from environmental driers to microbial diversity. These insights inform microbial forest management strategies that balance N retention with carbon sequestration.