Revegetation promotes soil microbial network stability in a novel riparian ecosystem.
Abstract
Soil microorganisms play a crucial role in ecosystem processes and functions, but how their co-occurrence networks respond to restoration of degraded ecosystems remains poorly understood. Here, we examined the effects of revegetation on the structure and function of the soil microbiome, including soil microbial network complexity and stability, in a novel riparian ecosystem with winter submergence opposite to the natural hydrological regime. We found that extreme flooding intensity (30 m submergence up to 286 days per year) reduced microbial α-diversity and network stability (robustness) but increased network complexity including network connectivity, connectance and average clustering coefficient over a 3-year period, and those effects were mitigated by active revegetation in comparison with natural regeneration. Revegetation increased microbial network stability directly by decreasing network complexity, while extreme flooding regulated network stability indirectly by changing the soil total carbon content. Nevertheless, those dynamics of microbial network were coupling with soil microbial functions such as greenhouse gas (e.g. CH4, CO2 and N2O) fluxes and nutrient cycling. Synthesis and applications: This study provides evidence to support the critical role of revegetation in preserving soil microbial network stability and functions under changing hydrological regime.