Temporal dynamics of soil bacterial communities and multifunctionality are more sensitive to introduced plants than to microbial additions in a multicontaminated soil.
Soil microbial communities are crucial for regulating the stability and degradation of contaminated land. However, the temporal response strategies of particular microbial groups to biotic introductions and their contributions to ecosystem functions and services (i.e., 'multifunctionality') in contaminated soils have yet to be investigated. Here, we present results from a 90-day microcosm experiment aiming to evaluate the temporal changes in bacterial communities and functions in response to microbial and plant additions in a contaminated agricultural soil. In addition, we quantified the contributions of specific bacterial taxa with different response strategies over time to alterations in ecosystem multifunctionality in pollutant degradation (polyphenol oxidase) and the cycling of carbon (dehydrogenase), nitrogen (urease and available nitrogen), phosphorus (available phosphorus), and potassium (available potassium). Results showed that native bacterial communities exhibited strong resilience to the introduced microbial consortium and were altered by plant growth. Plant-enriched bacterial taxa were located in the core and central positions of the co-occurrence networks and had considerable influence on the other nodes. Plant growth substantially influenced soil multifunctionality, in a process driven by specific bacterial taxa with different response strategies. The more tolerant taxa contributed most to multienzyme activities, whereas the more affected taxa largely determined multinutrient levels in the soil. These results provide a new perspective in disentangling the roles of plant-associated bacteria in the assembly of community interactions and ecosystem multifunctionality of contaminated agricultural soils.