Advancing ecosystem service monitoring by mapping the current use of essential ecosystem service variables

Essential variables are a well-established tool to support the calculation of ecological indicators. The recently conceptualized Essential Ecosystem Service Variables (EESVs) are regrouped into six classes – Ecological Supply, Demand, Use, Relational Value, Instrumental Value, and Anthropogenic Contribution – designed to capture changes in the multiple dimensions of ecosystem services. Prior to the proposal to monitor ecosystem services using EESVs, many variables relevant to these classes were already used in ecosystem services studies. Here, we perform a systematic retrospective analysis across disciplines to determine the potential of EESV classes for monitoring ecosystem services effectively. We conducted a comprehensive keyword search across 439 studies, based on a review paper on ecosystem services. Network analyses revealed that Anthropogenic Contribution had the highest overall presence based on odds ratios, while Relational Value was the least represented, often showing interdependencies with other classes and low network connectivity and centrality. Network centrality metrics identified Ecological Supply as the most interconnected class, reflecting its foundational role across studies. Journal analysis across seven major journal types showed a good overall distribution of EESV classes across fields, while still emphasizing disciplinary priorities. Urban journals focused more on Anthropogenic Contribution and Relational Value while biological journals prioritized Ecological Supply. Agricultural journals often highlighted Use and Demand as well as Instrumental Value and management and policy journals emphasized Instrumental Value. Addressing gaps in EESV class coverage stresses that underrepresented classes like Relational Value are empirically grounded and measurable, yet these classes are essential for monitoring both the ecological and socio-cultural dimensions of ecosystem services.