Polycyclic aromatic hydrocarbons in plants of natural frost mound bogs

We determined the qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) from dominating plants of tundra frost mound bogs using the method of high-performance liquid chromatography. It was stated that in natural conditions plants might contain large amounts of polyarenes. When accumulating in the plants they can further participate in the formation of PAH composition of tundra frost mound bogs. We revealed the significant correlations of the PAH composition between Sphagnum riparium, sedges, and cotton grasses, as well as between tree and shrub species. It indicates the similarity in PAH accumulation patterns inside the mentioned plant groups. The moss Polytrichum strictum and the branches of the trees Picea abies and Betula pubescens and shrubs Salix lapponum and Betula nana have a maximum accumulation of PAHs among swamp species. We identified the features of PAHs accumulation in various plant organs of the studied species. Thus, in grasses PAHs mainly accumulates in the underground parts. It was shown that in high water level conditions in frost mound bogs the PAHs accumulation decreased in grass roots in comparison with dry places. In mosses PAHs prevails in the dead parts. In shrubs and woody species polyarenes concentrate in branches and roots. The study of shoots Picea abies of different ages allowed us to reveal that 1-year-old shoots were more enriched in PAHs than 2-7-year-old shoots. This fact is largely associated with active growth processes in 1-year-old needles contributed to the formation of great amount of naphthalene. 2-7-year-old shoots are similar in PAH mass content. The obtained data on the background PAH content in swamp plants are useful for monitoring the polyarenes pollution. In the future, when conducting the additional study of PAH content in frost mound bogs on the basis of the obtained results it will be possible to assess the contribution of swamp plants to the formation of PAH composition in peats at different formation stages.