Assessment of atmospheric sulfur with the epilithic moss Haplocladium microphyllum: Evidences from tissue sulfur and δ34S analysis

The application of geochemical signals in mosses is more and more popular to investigate the deposition of atmospheric pollutants, but it is unclear whether records of atmospheric sulfur in mosses differ between their diverse habitats. This study aimed to investigate the influence of growing condition on tissue sulfur and δ34S of Haplocladium microphyllum. Epilithic and terricolous mosses in open fields, mosses under different canopy conditions were considered. We found that tissue sulfur and δ34S of mosses under different habitats were not consistent and could not be compared for atmospheric sulfur research with each other even collected at the same site, moss sulfur and δ34S records would be distorted by subsoil and upper canopies in different degrees, which possibly mislead the interpretation of atmospheric sulfur level and sources. Consequently, mosses on open rocks can be used reliably to assess atmospheric-derived sulfur in view of their identical sulfur and δ34S evidences.