An Integrative Ecohydrological Framework Linking Variables and Water Ecosystem Services Derived from Bibliometric Analysis

Despite the growing recognition that ecohydrological processes underpin water-related ecosystem services, conceptual integration between ecology, hydrology, and landscape ecology remains fragmented. The study analyzed 1,855 articles published between 1974 and 2020 in Scopus, using co-occurrence networks, thematic evolution mapping, and multiple correspondence analysis to uncover knowledge gaps and disciplinary boundaries in ecohydrology. Results revealed that while publications grew at 12.16% annually—with marked increases following UNESCO's formalization of ecohydrology (1995) and the adoption of the SDGs (2015)—conceptual distance persists between "ecosystem services" and specific hydrological variables. Surface runoff was consistently linked to land-use changes, while evapotranspiration, a major component of the hydrological cycle, was underrepresented.

To address these gaps, a multiscale ecohydrological conceptual model is proposed, positioning evapotranspiration as a central integrating variable connecting ecosystem structure with water service provision. The model identifies four structural control variables—leaf area index, root depth, canopy structure, and soil properties—as modifiable attributes influencing the biophysical limits within which ecohydrological processes operate. The model also acknowledges scale dependence: microscale processes are influenced by species-soil-water interactions, mesoscale dynamics are determined by hydrological connectivity, and macroscale responses involve atmospheric moisture recycling. This framework complements integrated water resource management by incorporating ecohydrological variables as ecosystem service indicators, highlighting nonlinear thresholds of change, and emphasizing feedbacks between anthropogenic landscape modifications and hydrological cycle alterations.