Project: PRJNA325556
Rhizospheric bacteria play critical roles in soil nutrient cycling and plant species functioning in cover soils used in land reclamation. However, the impact of capping materials used below the cover soil on rhizospheric bacterial community structure, function, and co-occurrence pattern in the cover soil has not been studied. Here, we examined the influence of two capping materials: overburden (OB) and tailings sand (TS), in comparison to the no capping layer (NC) control, on the structure, function, and co-occurrence pattern of the rhizospheric bacterial communities in the peat-mineral mix (PMM) used as the cover soil in a column study that simulates soil reconstruction in land reclamation. The abundance of operational taxonomic units (OTUs) in the rhizosphere became more depleted in the NC and OB treatments than in the TS treatment. The rhizospheric bacterial communities in the cover soil were different between the NC, OB, and TS treatments.The bacterial communities between the rhizosphere and bulk soil were differentiated by the first axis of ordination for the OB treatment but by the second axis for the TS treatment, but were not different for the NC treatment . The TS treatments increased functional genes for nutrient metabolism in rhizosphere but the NC and OB treatments increased the functional genes for environmental adaption. Moreover, the degree values were the greatest for OTUs only presented in the rhizosphere in the OB treatment. We conclude that the type of capping material used affect the structure, function and co-occurrence pattern of rhizospheric bacterial communities in cover soils used in land reclamation and thus has implications for ecosystem re-establishment after surface disturbance.
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