A bibliometric analysis of the invertebrates inhabiting the hyporheic zone: Too fragmented and biased knowledge?

This study explores the publishing patterns concerning invertebrates inhabiting the hyporheic zone (HZ), a topic indexed by Scopus. This review was then used to investigate the patterns and biases of scientific articles in multiple aspects such as the temporal progress of HZ-ecology studies from 2000 to 2024, geographical areas of research vacancy, sampled river, substrate type present, location (country and continent), methodological techniques and the main ecological themes addressed by authors. We detected that HZ field studies are fragmented across continents and absent in many geographical areas. Besides, we identified unjustified tendencies in the sampler selection and the lack of an international sampling protocol. In a similar way, we noticed that sampling depth and the net size to filter organisms are not normalized yet, making difficult (if not impossible) direct comparisons between different studies and regions. Finally, we suggest that the ecological knowledge of the HZ invertebrate community is still predominantly descriptive and basic in many cases. We encourage researchers to standardize a sampling protocol, to enlarge more HZ studies covering geographical areas of vacancy, to test ecological hypothesis and to use this community in applied ecology studies (ex. biomonitoring studies).