Influencia de la contaminación asociada al tráfico vehicular y la estacionalidad en la diversidad de tardígrados en ecosistemas urbanos

Urbanization negatively impacts biodiversity, particularly through habitat modification and pollution. While invertebrate diversity changes along urban gradients, the effects of vehicular pollutants remain understudied.This study investigated the influence of vehicular traffic and seasonality on tardigrade diversity in Salta, a rapidly expanding city in Argentina. We aimed to assess how different levels of traffic intensity and microhabitat conditions affected tardigrade species richness and composition across seasons. We conducted sampling in winter and summer at sites classified as having high, medium or low traffic levels.A total of 2254 tardigrades from 6 genera and 11 species were identified. No significant seasonal differences were found in species abundance, richness or composition. Notably, medium-traffic sites exhibited lower species richness, suggesting instability due to fluctuating pollution levels. Species composition differed significantly between traffic levels, with Macrobiotus olgae Rocha et al., 2024 (Parachela: Macrobiotidae) and Milnesium quiranae Rocha et al., 2022 (Apochela: Milnesiidae) identified as ecological indicators of pollution tolerance and contamination thresholds, respectively. Beta diversity analysis showed that species turnover was the main factor that caused seasonal changes in the assemblage, while nestedness explained the loss of diversity across traffic levels.Our findings underscore the detrimental effects of vehicular pollution on urban tardigrade assemblages and highlight the need for biodiversity conservation strategies in urban environments, particularly in developing countries. This research contributes to understanding urban biodiversity dynamics and informs management practices aimed at mitigating pollution impacts on meiofauna.