Mapping Biodiversity Research on Urban Forests and Green Spaces: Conceptual and Intellectual Structures and Country-Level Collaboration

Research at the interface of biodiversity conservation, urban forestry, and urban green space spans ecology, forestry, landscape planning, environmental management, and public health, making its intellectual structure difficult to apprehend through narrative review alone. This study maps a corpus of 3747 documents published from 2006 to 17 August 2026, retrieved from the OpenAlex API on 13 October 2026 after integrity checking and deduplication. Performance analysis, country-level collaboration networks, lexical co-occurrence on titles and abstracts (abstract coverage 82.6% after supplementation), strategic mapping, thematic evolution, co-citation, and bibliographic coupling were computed with scripts released with the article; stochastic community partitions were evaluated over 200 seeded runs. Across the complete years 2006–2025, retrieved annual output increased at a compound annual rate of 15.89%. The corpus spans 1316 journals and affiliations in 124 countries. China leads publication output, whereas Germany and the USA occupy the strongest brokerage positions in the collaboration network. Author-derived text resolves six lexical clusters (modularity = 0.442), in which health and planning vocabulary joins climate and green-infrastructure terms and carbon vocabulary joins tree and plant species, and co-citation of the 200 most cited references identifies six communities (modularity = 0.507). More than half of the corpus (54.9%) enters only through green-space terms, and removing these documents changes the lexical partition substantially; a replica of a prior green-space mapping shows that urban-forestry terms distinguish the corpus. The mapped literature is increasingly connected to climate, health, and planning agendas.