UBC Theses and Dissertations
Radiotracer study of some aspects of the role of mosses in the biogeochemical cycle Otchere-Boateng, Jacob
Some aspects of the role of mosses in the biogeochemical cycle of a coastal forest ecosystem in British Columbia were studied using radioisotopes. The average concentration of ¹³⁷ Cs from atmospheric fallout in ground-dwelling mosses was 36.7 pCi/g or 6025 pCi/m². Concentrations increased with precipitation, with the highest concentrations being found in Plagiothecium undulatum (Hedw.) B.S.G. and Sphagnum squarrosum Crome. Experiments involving a dual labelling with ⁸⁵Sr and ¹³⁴Cs indicated that nutrients which are leached from stem tissues of host plants, and those in the crown washings of the overstorey trees are sources of nutrients for epiphytic mosses. Epiphytic mosses were efficient in filtering radioisotopes from solution, the activity of through-fall and stemflow being reduced after passage through epiphytic mosses by up to 70%. ⁸⁵Sr and ¹³⁴Cs concentrations in ground-dwelling mosses under western hemlock trees (Tsuga heterophylla (Rafn.) Sarg.) followed the distribution pattern of throughfall nutrients which decreased from close to the stem towards the crown edge.
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