Elemental Characterization of Medicinal Plants and Soils from Hazarganji Chiltan National Park and Nearby Unprotected Areas of Balochistan, Pakistan.

Abstract

The aim of this work was to evaluate the variability in elemental composition of seven medicinal plants and their respective soils belonging to protected and nearby unprotected sites of the Hazarganji Chiltan National Park. The medical plants under study were Achillea wilhelmsii C. Koch, Peganum harmala Linn, Sophora mollis (Royle) Baker, Perovskia atriplicifolia Benth, Seriphidium quettense (Podlech.) Ling, Hertia intermedia (Bioss) O. Ktze, and Nepeta praetervisa Rech. F. Macro (C, H, N, S, K, Ca), micro (Cl, Cu, Fe, Mn, and Zn), beneficial (Al, Co, Na), others (As, Br, Cr, Cs, Hf, Pb, Rb, Sb, Sr, Sn, V and Th) and rare earth elements (Ce, Eu, La, Lu, Nd Sc, Sm, Tb and Yb) were characterized by means of standard organic elemental and instrumental neutron activation methodologies and by flame atomic absorption spectroscopy. Results showed that, among macro nutrients, carbon concentration was the highest element in both plant and soil samples followed by H and K. Elements such as Cl, Na and Fe were detected in considerably good amounts; all the other elements were found in trace quantities. Principal component analysis (PCA) was applied to identify spatial variation in elemental composition of medicinal plants, in which 80-90% of the total variance in whole set of data was found. In particular, the findings highlighted the presence of essential and beneficial elements such as C, H, N, K, Ca, Fe, Mn and Na, in samples from protected sites, while potentially dangerous elements such as Al, As, Br and Cr were detected in samples from unprotected sites. These results emphasized on the need for rational exploitation of valuable medicinal plants and supporting protected areas as an excellent source of biodiversity conservation.