Utilization of spatial interpolation technique to compare metal accumulation pattern by lichens in plain and mountainous regions of North Central India

Abstract

Based on the physicochemical characteristics, metals emitted from the source (both natural and anthropogenic) contributes towards spatial continuity at regional scale. Apart from intrinsic properties of metals, meteorological conditions and topography of the region is also known to contribute towards the spatial continuity. In the present study comparative spatial assessment of twelve metals in lichen Phaeophyscia hispidula collected from mountains and plains of north western India was carried out with the help of indicator kriging method. In plains and mountains the total metal concentration varies between 25.38–429.24 µgg− 1 and 22.77- 506.95 µgg− 1 dry weight respectively. Geospatial mapping provided insight into the spatial behavior of different metals in plain and mountain regions. In plains, Cr, Cd, Cu and Pb had higher concentration having higher coverage area, while metals like Cd and Hg had highest localized distribution indicating point sources. Observations indicated that apart from local sources, meteorological conditions specially wind direction also plays important role in spatial behavior of the metals, which has been verified by the bioaccumulation pattern of metals in lichen samples from mountainous region. Among which three mountainous states of North Western India, Uttarakhand has higher concentration of metals which may be attributed to the wind direction together with local anthropogenic sources.