RELIABILITY OF MOSS (HYLOCOMIUM-SPLENDENS AND PLEUROZIUM-SCHREBERI) AS A BIOINDICATOR OF ATMOSPHERIC CHEMISTRY IN THE BARENTS REGION - INTERSPECIES AND FIELD DUPLICATE VARIABILITY

As part of a collaborative ecogeochemical mapping project in the Europ ean Arctic, the terrestrial mosses Hylocomium splendens (Hs) and Pleur ozium schreberi (PI) have been used to document atmospheric chemistry. The regional importance of the variability of interspecies and field duplicate samples on the element distribution in the central Barents r egion has been calculated. Of the 36 elements studied, 17 have signifi cantly different concentrations in the two species. Except for K, in w hich all PI samples are significantly enriched compared to Hs samples, all elements showed at least one pair that displayed the opposite beh aviour to the overall trend. For the regional data set of the central Barents region, the interspecies results for (B), Bi, Cd, Co, Fe, Mn, (Na), Ni, P, Pb, S, Si, Sr, Th, U, V and Zn are directly comparable wi thout calibration, due to lack of significant interspecies differences or a higher field duplicate uncertainty. The regional distribution of Ag, Ba, Hg, K and Sb must be interpreted cautiously in background are as, since these elements lack interspecies correlation and show signif icant differences between the species. Furthermore, calibration may be advisable for Al, As, Co, Cr, Cu, Fe, Mo, Tl and V for which the inte rspecies ratio (PI:Hs) varies from 0.56 to 0.91, and Ca, Cd, Mg, Pb an d Rb for which the ratio varies from 1.10 to 1.38. However, as a resul t of our study we recommend that the original data be used without und ertaking calibration, but interspecies ratios need to be quantified in all multispecies datasets. Calibrated maps of the latter elements gav e no striking changes in the patterns, and a new uncertainty is introd uced by calibrating the original data sets. Striking differences betwe en interspecies ratios from six comparable studies are found, especial ly for As, Ni, Pb and V, which underline the fact that interspecies va riations depend greatly on deposition levels and living conditions for the moss. (C) 1998 Elsevier Science B.V. All rights reserved.