Elemental Composition Of Xanthoria Mandschurica In Northern Taihang Mountains

Lichens are a special symbiotic association between lichenized fungi and algae or cyanobacteria.These organisms have been regarded as one of the best biomonitors for atmospheric deposition.In recent years,air pollution has been continuously increased in China,especially in Beijing,Tianjin and Hebei,has received worldwide concerns.However,there are only a few studies on the assessment of atmospheric pollution degree at the large spatial-temporal scale using lichens as biomonitors in China.In this study,the lichen Xanthoria mandschurica were collected from 32 sites in the northern part of Taihang Mountains,and elements concentration in the lichen samples were analyzed.The concentrations of 35 elements(Al,Be,Bi,Cd,Ce,Cu,Dy,Er,Eu,Fe,Gd,Ho,K,La,Lu,Mn,Mo,Na,Nb,Nd,Ni,P,Pb,Pr,Rb,S,Sb,Si,Sm,Tb,Th,Ti,Tm,Y,and Zn)in the lichen samples were determined by ICP-MS.The sources for lichen elements were analyzed by multivariate analysis,ternary diagram analysis,calculation of EF and PLI,and comparision with the relevant studies.Combining with GIS technology,the pollution degree of these sites was analyzed and mapped.The results show that: 1)Xanthoria mandschurica can well reflect the spatial pattern of atmospheric element deposition in the study area,and is suitable for large-scale spatial monitoring.2)Air pollution is widespread in the study area.The spatial trend of pollution degree in the study area is decreasing from the basin/plain and Mongolian plateau to mountains.3)According to the degree of pollution,serious pollution can be identified in three regions: a)Yangquan-Shijiazhuang region: this region is characterized by relative enrichment of K,P and S,which are mainly affected by anthropogenic activities and atmospheric transportation.b)East of Wutai Mountain: this region is heavily polluted with enrichment of pollutants(Bi,Cd,Cu,Pb,Sb and Zn)derived from anthropogenic activities in the North China Plain,especially in Beijing and Baoding areas.c)West of Wutai Mountain and Xinding Basin region: this region is characterized by the enrichment of soil-derived elements(Al,Be,Fe,Mn,Mo,Na,Nb,Ni,Rb,Si,Th and Ti)and lanthanides,which are mainly from a largenumber of industrial and agricultural activities in Shuozhou and Datong and sand dust transported from the nearby Mongolian Plateau.