Effects of land use on annelid assemblages in Pampean wetlands

Context Land use significantly affects wetlands, altering various biotic components and threatening biodiversity. Aims This study assessed the ecological status of Pampas wetlands under different land uses by examining environmental characteristics and annelid assemblages. Methods Four water systems in the Argentine Pampas were surveyed, including riverine wetlands and upstream and downstream sections affected by urbanisation, intensive agriculture, or extensive livestock farming. Key results Multivariate analysis showed correlations among environmental factors and sites, whereas PERMANOVA analysis showed density variations among streams, sections, and land uses, although species richness and diversity remained consistent within each stream. In total, 42 annelid species and morphotypes were identified and linked with various environmental factors. Conclusions Enchytraeidae were correlated with nitrate and phosphorus concentrations, whereas Limnodrilus species and Tubifex tubifex were associated with nitrites, ammonium, vegetation coverage and fine sediments. Species such as Pristina spp., Aulophorus costatus, Dero spp. and Aulodrilus pigueti preferred sandy sediments enriched with organic matter and higher current velocities, indicating their potential as indicators of anthropogenic impact. Implications These findings highlighted the importance of annelid assemblages in wetland monitoring and underscore the need for integrated watershed management and sustainable planning to protect wetlands.