Illuminating the nexus between non-biodegradable microplastics and soil nitrogen dynamics: A modulation through...

The characteristics of vegetation cover significantly influence nitrogen (N) cycling in soils. However, there is currently a lack of comprehensive assessment regarding how altered vegetation cover types affect soil N cycling in the context of emerging contaminants, such as non-biodegradable microplastics (MPs). Initial observations indicated substantial priming effects across all experimental groups upon the introduction of polystyrene MPs (PSMPs). Shrub soil demonstrated greatest resistance and resilience to PSMPs disturbance, while tree soils exhibited lower tolerance. In contrast, grass soils displayed maximum sensitivity, as evidenced by early peaks in N₂O emissions in shrub group, primarily driven by denitrification and nitrification before and after emission peaks, respectively. From a microbial perspective, Rhizobiales and Xanthomonadales/Nitrososphaerales exhibited significant roles in enhancing the resistance and resilience of shrub soils by facilitating efficient N transformation (particularly oxidation reaction-mediated N₂O emissions) and retention (manifested by stable amino acids and reduced bio-available dissolved organic matter). These findings contribute crucial theoretical insights into the capacity of vegetation cover to mitigate N₂O emissions induced by MP inputs, underscoring the pivotal role of biodiversity in maintaining ecosystem stability.