[in Chinese with English abstract: ]
Lichen element compositions are a reliable and effective tool for biomonitoring atmospheric element deposition. The lichen age effect is one of the important factors influencing lichen element concentrations. However, this effect is not fully understood for terricolous fruticose lichens. Herein, samples of a fruticose lichen Stereocaulon alpinum from a remote site of Huzhong Natural Reserve, Greater Khingan Mountains
of Heilongjiang Province were collected. Fifty-five elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Gd, Ge, Hg, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Tb, Th, Ti, Tl, Tm, U, V, Y, Yb, and Zn) were measured and their differences
among 3 parts (apical, middle, and base parts) of the pseudopodetia were compared in order to examine the effect of different parts of lichen and elements on lichen element accumulations in the uncontaminated ecological environment. The results showed that concentrations of all elements were in the range of the reported background/baseline values, suggesting a low degree of atmospheric element deposition in the study site.
Concentrations of most elements with limited metabolic significance were generally the highest at base part,
suggesting a continuous bioaccumulation and a low degree of translocation in the lichen thalli. Concentrations of some nutrients showed little differences among the different parts, or were higher in the apical part than in the middle part. These results suggest a nutrient translocation from the older parts to the younger parts of pseudopodetia. Therefore, in lichen biomonitoring studies, specific parts of lichen should be taken
into account based on the interested elements, and to ensure the comparability of data among different surveys, the same parts of the thallus should be selected. Key words: Stereocaulon; element concentration; biomonitoring; atmospheric deposition; fruticose lichens.