Lichens and atmospheric sulphur: what stable isotopes reveal

Isotopic compositions and total sulphur (S) levels were measured in Alectoria sarmentosa collected from over 80 sites on the island of Newfoundland, Canada. The spatial distribution of isotopic compositions of all samples is consistent with contributions of S from sea spray, local point sources and minor long-range transport. Thalli of A. sarmentosa were also transplanted from a relatively pristine area to an area of higher anthropogenic S input and monitored for 12 months. The transplanted lichens gradually approached the sulphur concentration and isotopic character of the new location. However, with single strands of A. sarmentosa collected near an oil refinery, isotopic signature of the youngest parts resembled the refinery emissions, while the oldest parts more closely matched the natural background signature.