Long-term Fungal Community Dynamics in a Hyper-Arid Ecosystem Post Petroleum- Hydrocarbon Contamination: Insights from 7 and 47 Years of Natural Bioremediation

This study investigates the impact of crude oil contamination on the fungal community dynamics in the Evrona Nature Reserve, situated in Israel's hyper-arid Arava Valley. The reserve experienced petroleum-hydrocarbon-spill pollution at two neighboring sites in 1975 and 2014. The initial contamination was left untreated, providing a unique opportunity to compare its effects to those of the second contamination event. In 2022, soil samples were collected from both contaminated areas and nearby clean (control) sites, 47 and 7 years after the spills. The taxonomic diversity of fungal community and functional guilds, as well as various properties of the soil, were analyzed. We focused on three functional groups within fungal communities: Saprotrophs, Symbiotrophs, and Pathotrophs. The results revealed a significant decrease in number of fungal species in the contaminated samples over time, accompanied by replacement of fungal species capable of utilizing and degrading crude oil . Consequently, prolonged effect of crude oil-contaminated soils can facilitate the development of a distinct fungal community, which has adapted to the conditions of oil contamination.