Content of biogenic and toxic elements in the leaves of Deschampsia antarctica É. Desv. (Poaceae): a preliminary study

Abstract

The Antarctic hairgrass (Deschampsia antarctica É. Desv.) is one of two flowering plants native to the Antarctic and therefore it was intensively studied for decades. However, there is still limited information available about the content of biogenic and toxic elements in the leaves of this plant. While being an important component of the Antarctic terrestrial ecosystems, the content of nutrients like K, P, and S in the plants of D. antarctica may significantly affect soil properties, especially in such hot spots like rhizosphere and detritosphere. Moreover, the content of toxic elements and trace metals in particular in the plant is an important criterion to evaluate its indicative role, whether or not D. antarctica may be used as a bio-indicator to monitor the Antarctica environmental state. In this study, we report the preliminary results about the content of K, P, Ca, S, Mg, Na, Si, Fe, Zn, Al, Sr, Mn, Cu, B, Cr, Ba, V, Pb, Cd, and Co in the leaves of D. antarctica from the natural habitats of the maritime Antarctіс. Dry leaves were digested in nitric acid (closed-vessel microwave digestion). Elemental concentration was measured by ICP-OES technique. It was found that differences between the samples taken from one location were far less notable than between samples from different locations. Among the biogenic elements, the content of potassium was the most variable – from 12.2 mg·g-1 on Galindez Island to 28.7 mg·g-1 on the Cape Tuxen (Antarctic Peninsula). The content of trace metals also varied greatly between the samples from different locations. The results of this preliminary study suggest that due to the high content of nutrients, leaves of D. antarctica should be considered as an important precursor of soil organic matter, as well as a possible bioindicator. However, future studies are needed to confirm these preliminary results and hypotheses.