Soil Microbiomes Across Depth and Ecosystems in Dubai, UAE : Potential Environmental Signatures for Forensic Geolocation

ABSTRACT

Soil microbial communities exhibit strong sensitivity to environmental gradients, yet their distribution across depth and land‐use types in hyper‐arid environments remains poorly characterised. Using whole‐genome shotgun metagenomics via Oxford Nanopore Technologies long‐read sequencing, we profiled soil microbial communities across six contrasting land‐use sites in Dubai, UAE: urban, industrial (two locations), marine, desert and agricultural, where each sampled at three depth intervals (0–25 cm, 25–50 cm and 50–100 cm). Marine soils exhibited extreme salinity (EC 23.7–30.7 dS m ⁻¹ ) and the highest organic matter content (1.19%–1.76%), while desert soils were nutrient‐poor with minimal salinity. Actinomycetota and Pseudomonadota co‐dominated across all sites, collectively accounting for 77%–96% of classified sequences. Actinomycetota prevailed in undisturbed desert horizons (up to 53.4%), while Pseudomonadota dominated nutrient‐enriched environments, reaching 69.4% at industrial sites. A notable compositional reversal was observed in the desert deep horizon (50–100 cm), where Pseudomonadota increased to 56.8%, departing from the expected oligotrophic depth gradient. PERMANOVA confirmed land use as the primary driver of community composition ( p  = 0.001), with depth exerting a secondary but significant effect ( p  ≤ 0.01). NMDS ordination revealed strong site‐specific clustering, with each environment harbouring a distinctive microbial fingerprint with promising forensic geolocation potential.