Climatic seasonality of the Cerrado and aquatic insect communities: a systematic review with meta-analysis

We conducted a systematic review to investigate the relationship between aquatic insects and climatic seasonality in the Cerrado biome in Brazil. The review encompassed the number of studies, the spatial distribution of studies across microbasins, the duration of the studies, collection methods, taxonomic resolutions, the most significant environmental predictors for the communities, and the impact of land-use changes on the seasonal variation of aquatic insect communities. We also tested the relationship between climatic seasonality and aquatic insect diversity using a meta-analysis and discussed the potential effects of climate change on these communities. To achieve this, we used a set of keywords related to aquatic insects and climatic seasonality in the Cerrado biome to search Scopus and Web of Science databases. Our main findings indicate that the collection methods are robust and well-established, and taxonomic resolutions are generally good. However, the number of streams and the duration of sampling are often inadequate for addressing ecological questions in most studies. Additionally, the spatial distribution of studies is concentrated around areas close to universities. Finally, it was evident that the richness and abundance of aquatic insects are higher during the dry season. These results indicate ways to improve studies with temporal questions using aquatic insect communities in the Cerrado and raise awareness about the potential issues caused by climate change. Changes in precipitation patterns and temperature are expected to transform some of the currently perennial streams into intermittent ones, thereby homogenizing aquatic insect communities and negatively impacting their potential to provide ecosystem services.