Abstract

The Protected Connected land indicator (ProtConn) and the Species Protection Index (SPI) are adopted under Target 3 of the Kunming–Montreal Global Biodiversity Framework to represent structural connectivity and species-level conservation outcomes, respectively. However, empirical evidence linking ProtConn to observed biodiversity outcomes remains limited. This study synthesizes ecological theory, international policy frameworks, and existing literature to clarify the conceptual relationship between ProtConn and SPI and to assess the feasibility of future empirical linkage analyses. The results indicate that ProtConn primarily functions as a structural condition indicator describing protected area network configuration, whereas SPI captures biological conservation outcomes, highlighting a clear distinction between structural conditions and ecological responses. Furthermore, this study demonstrates that nationally standardized biodiversity datasets in the Republic of Korea are spatially and taxonomically compatible with ProtConn-based analyses. These findings identify critical empirical gaps and provide a methodological foundation for future quantitative research examining the relationship between protected area connectivity and biodiversity conservation outcomes.