Environmental gradient changes shape multi-scale food web structures: Impact on antibiotics trophic transfer in a...

Environmental change can alter the multi-scale foodweb structure, thereby impacting the pollutants trophic transfer in aquatic ecosystems. However, a quantitative understanding of how environmental gradient changes affect pollutant trophic transfer in natural lake ecosystems remains limited. This study investigated temporal variations in environment change index (ECi), multi-scale foodweb structure, and trophic transfer of quinolones antibiotics (QNs) in Baiyangdian Lake, Northern China, from 2018 to 2023. Our results demonstrated that the interaction strength (IS) in detritus (DIS) and macrophyte (MIS) in 2023 were significantly lower than those in 2018, and diversity indices exhibited significant temporal differences between 2018 and 2023. ECi was significantly correlated with DIS/MIS between species at the population scale and with diversity indices (D_H and H') at the ecosystem scale. The trophic magnification factors (TMFs) of QNs have higher values in 2023 compared to 2018, showing significant temporal differences. Through structural equation model, the results showed ECi directly impacted DIS, which in turn affected SEAc and H', while indirectly influencing TMFs. The TMFs of QNs was mainly regulated by environmental factors. These findings highlighted the influencing mechanism through multi-scale foodweb structures regulate pollutant trophic transfer under environmental change in natural lake.