Dorsaf Kerfahi;Kevin K. Newsham;Ke Dong;Huacan Song;Mark Tibbett;Jonathan M. Adam

School of Natural Sciences, Department of Biological Sciences, Keimyung University, Daegu 42601 (Republic of Korea

abandoned mining site;ectomycorrhizal fungi;intact tundra;mine tailings;mineral extraction;polar ecosystem recovery;HEAVY-METALS;NY-ALESUND;VEGETATION;SVALBARD;METALLOTHIONEINS;MYCORRHIZAS;TOLERANCE;DIVERSITY;PATTERNS;FORES

Mineral extraction is known to affect soil fungi in polar environments, but it is unknown how long these effects persist. Here, by amplifying the internal transcribed spacer regions of rRNA genes in soil fungi, we compared soil fungal community in intact natural tundra with that in a nearby former coal mining area, abandoned 52 years previously, on Svalbard in the High Arctic. Compared with those in intact tundra, soils in the former mining area were more acidic and had lower plant coverage. Despite of similar diversity in the two areas, the fungal community was dominated by Basidiomycota in the intact tundra, but by Ascomycota in the former mining area. Ectomycorrhizal genera formed a major part of the tundra community, but were notably less abundant in the mining area. The principal variation among samples was soil pH. Surprisingly, network connectivity analysis indicated that the fungal community in the former mining area had greater network connectivity than that in the tundra area. Overall, the ecosystem in the former mining area has made only limited recovery towards the natural tundra state even after more than five decades. It is unclear whether the recovery of the fungal community is limited more by the low primary productivity, slow migration of fungi and plants, or slow changes in soil parameters. Our findings emphasize the susceptibility of polar ecosystems to disturbance, given their particularly slow recovery back towards the natural state.