Lichen elemental composition distinguishes anthropogenic emissions from dust storm inputs and differs among species: Evidence from Xilinhot, Inner Mongolia, China

Abstract

To test the applicability of lichens in the biomonitoring of atmospheric elemental deposition in a typical steppe zone of Inner Mongolia, China, six foliose lichens (Physcia aipolia, PA; P. tribacia, PT; Xanthoria elegans, XE; X. mandschurica, XM; Xanthoparmelia camtschadalis, XPC; and Xp. tinctina, XPT) were sampled from the Xilin River Basin, Xilinhot, Inner Mongolia, China. Twenty-five elements (Al, Ba, Cd, Ce, Cr, Cs, Cu, Fe, K, La, Mn, Mo, Na, Ni, P, Pb, Sb, Sc, Sm, Tb, Th, Ti, Tl, V and Zn) in the lichens were analysed using inductively coupled plasma mass spectrometry (ICP-MS). The results show that Cd, Pb and Zn were mainly atmospheric in origin, whereas the other elements were predominantly of crustal origin. Compared with other studies, our data were higher in crustal element concentrations and lower in atmospheric element concentrations, matching with the frequent, severe dust storms and road traffic in the area. The elemental concentrations in lichens are both species- and element-specific, highlighting the importance of species selection for biomonitoring air pollution using lichens. We recommend PT, XE, XM and XPT for monitoring atmospheric deposition of crustal elements; XPC and XPT for Cd and Pb; PA for Cd and Zn; and PT for Cd.

Spatial-Temporal Patterns of Element Concentrations in Xanthoparmelia camtschadalis Transplanted along Roads

“…Our results suggest severe air pollution at the exposure sites. A comparison with the relevant studies shows that the median values for the POST-cs of most elements in XPc were higher than the documented values from "clean sites" [9,12,20,[24][25][26] and "polluted sites" [15,[27][28]. This conclusion is consistent with the results of instrumental air quality monitoring (Fig.…”

“…The dominant vegetation is typical of the steppes of the Inner Mongolia Plateau interspersed with sand dune complexes. The landforms include hills, lava tablelands and sandy lands, with an average elevation of 1,350 m. A previous study in the area revealed accumulation of metals in XPc due to sand-dust deposition [15].…”

“…Xanthoparmelia camtschadalis (XPc) is a promising candidate for transplantation because this lichen can be easily collected intact, and the contamination of the thallus by soil is lower than in other lichen species [15]. XPc is a foliose lichen that is widely distribute in the grassland of northern China.…”

“…This organism partly attaches to the soil surface when it is young and can be readily dispersed by wind when mature. In the Inner Mongolian grasslands, relevant studies have reported that XPc was less contaminated by soil than other epigeal lichens and can accumulate atmospheric element depositions originating from anthropogenic emissions, especially Pb, Zn and Cd [15].…”

Vertical Distribution Patterns of Element Concentrations in Podetia of <i>Cladonia rangiferina</i> from Huzhong Natural Reserve, Heilongjiang, China

“…This conclusion is also supported by a comparison of our data with those from the other lichen biomonitoring studies conducted in remote sites, such as Usnea subfloridana from Canada [32], severally lichens from the France [33] and Arctic regions [34], Usnea sp. from the forest-grassland regions of Chile [35], Cladonia rangiferina and C. stellaris from the remote sites of Russia [24,27], epiphytic lichens from Italy [10,[36][37][38][39] and France [40], and several lichens from Inner Mongolia, China [41,42].…”