Bacterial and Eukaryotic Communities Associated with Zostera marina Litter under Marine Heat Stress
This work investigates how sustained ocean warming and marine heatwave-level thermal stress influence sediment-associated microbial communities during Zostera marina litter decomposition. Intact seagrass-sediment cores collected from a temperate Z. marina meadow on the southern coast of Korea were maintained for 60 days under four simulated thermal scenarios representing ambient conditions, sustained warming, present-day marine heatwave-level stress, and intensified future marine heatwave-level stress. Above-ground leaf litter and below-ground rhizome+root litter were incubated in surface and rhizosphere sediments, respectively. Sediments associated with decomposing litter were collected at the end of the experiment for 16S and ITS amplicon sequencing to characterize bacterial and fungal community composition. The dataset was generated to determine how microbial communities respond to marine thermal stress across contrasting sediment environments and to evaluate their potential links with litter decomposition, organic matter transformation, and sediment organic carbon dynamics in seagrass ecosystems.