Humans impact terrestrial, marine and freshwater ecosystems, yet many broad-scale studies have found no systematic, negative biodiversity changes (for example, decreasing abundance or taxon richness). Here we show that mixed biodiversity responses may arise because community metrics show variable responses to anthropogenic impacts across broad spatial scales. We first quantified temporal trends in anthropogenic impacts for 1,365 riverine invertebrate communities from 23 European countries, based on similarity to least-impacted reference communities. Reference comparisons provide necessary, but often missing, baselines for evaluating whether communities are negatively impacted or have improved (less or more similar, respectively). We then determined whether changing impacts were consistently reflected in metrics of community abundance, taxon richness, evenness and composition. Invertebrate communities improved, that is, became more similar to reference conditions, from 1992 until the 2010s, after which improvements plateaued. Improvements were generally reflected by higher taxon richness, providing evidence that certain community metrics can broadly indicate anthropogenic impacts. However, richness responses were highly variable among sites, and we found no consistent responses in community abundance, evenness or composition. These findings suggest that, without sufficient data and careful metric selection, many common community metrics cannot reliably reflect anthropogenic impacts, helping explain the prevalence of mixed biodiversity trends.

The datasets here were used to examine relationships between various community metrics (e.g., abundance, richness), biomonitoring indices, and ecological quality across European riverine invertebrate communities during 1992-2019. Here, we provide two datasets used in the publication by Sinclair et al. titled "Multi-decadal improvements in the ecological quality of European rivers are not consistently reflected in biodiversity metrics". Each dataset is provided as a separate Excel document. The first dataset ("Community metrics, biomonitoring indices, and EQRs") provides the data for each site and year used in the majority of the analyses. The second dataset ("EQCs") provides the additional data used to model temporal changes in Ecological Quality Classes depicted in Fig. 2 and Fig. 4. A summary and explanation of each variable in each dataset is provided in the "Info" tab. Further information on how values were calculated (and transformed if necessary) is provided in either the Info tab or the methods and supporting information of the associated article.

Peer reviewed