Ecosystem Service-Based Deconstruction of Ancient Tree Values: Implications for Biodiversity Conservation and Socio-Ecological Management

Ancient and large old trees hold significant ecological, cultural, and landscape importance. While numerous studies have investigated the ecosystem services these trees provide—such as carbon sequestration, air purification, and microclimate regulation—the findings remain dispersed and fragmented. To address this gap, the present study employs ecosystem service theory alongside a combination of bibliometric analysis and systematic review, examining 217 articles indexed in the Web of Science Core Collection. This approach offers a comprehensive synthesis of global research on ancient trees. The bibliometric results reveal a rapid expansion of research since 2015, with a particularly notable surge after 2019. Research focus has progressively shifted from traditional resource surveys and conservation management toward regulating services, emphasizing ecosystem functioning, carbon storage, microclimate regulation, and biodiversity conservation. Concurrently, methodological approaches have diversified, incorporating GIS-based spatial analysis, remote sensing techniques, and carbon storage modeling. Despite these methodological advancements, current research faces several challenges, including insufficient integration across spatial and temporal scales, limited long-term dynamic monitoring, and a weak linkage between ecological functions and sociocultural values. To enhance the protection and revitalization of ancient trees, future investigations should adopt multiscale and interdisciplinary frameworks that integrate ecological functions, landscape spatial dynamics, and sociocultural dimensions. Such approaches will facilitate the sustainable management of ancient trees globally and ensure the enduring provision of their ecosystem services.