Louca, StilianosHabibi Soufi, Hengameh2025-02-242025-02-24https://hdl.handle.net/1794/30475To understand the factors shaping microbial assembly and community composition in intertidal sediments along the Oregon coast, we collected sediment samples from 10 cores at depths of 160–190 cm, spanning over 300 km. Using metagenomic and 16S rRNA data, we constructed functional and taxonomic profiles, revealing redundancy in functional groups but variability in taxonomic composition. Regression models using chemical data measured in lab, geographical distances, and environmental variables from public datasets failed to significantly predict taxonomic composition. However, permutation null model tests suggested that biological interactions play a significant role in driving taxonomic variation in subsurface sediments, namely through taxa excluding each other via different mechanisms.en-USAll Rights Reserved.BiogeochemistryEnvironmental microbiologyMetagenomicsMicrobial EcologyOcean SedimentsTaxonomic CompositionElectronic Thesis or Dissertation