https://phys.org/news/2018-05-fungi-respire-millennium-old-carbon-antarctic.html

Soil from under Antarctic Hairgrass was taken from Léonie Island, near Rothera Research Station on the Antarctic Peninsula, and brought back to BAS headquarters in Cambridge. The sterilised soils were inoculated with fungi from the natural Antarctic environment, put into sealed jars and incubated at 4 °C in the lab.

The carbon dioxide emitted by the fungi from the soils was collected and analysed by the NERC Radiocarbon Facility. To their surprise, the scientists found that some of the carbon was about 1,200 years old.