Variation of Elemental Composition of Leaves in Nitraria schoberi L. and N. sibirica Pall. Depending on Edaphic Growth Conditions

Abstract

A study was conducted about the variation of levels of macro- and microelements in the soil and leaves of two species of the genus Nitraria L. in various habitats in Siberia. New data were obtained on the concentration variations of K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Ni, Li, Sr, and Cd in leaves of N. schoberi L. and N. sibirica Pall. It was found that the salinity of habitats of N. sibirica (up to 3.23%) can exceed salinity of soils under N. schoberi (up to 0.5%) by more than sixfold. Soils of N. schoberi habitats are characterized by lower contents of carbonates (1.0–3.8%) and of physical clay (2–19%) as compared to soils of N. sibirica habitats: 1.2–18.2 and 9–40%, respectively. An increase in the physical-clay content of soil positively correlated with the accumulation of Mg, Cu (p ≤ 0.01), and Mn (p ≤ 0.001) in the plant leaves. The degree of soil salinity was positively associated with the accumulation of Ca, Zn, Sr (p ≤ 0.01), Mg (p ≤ 0.05), and Cd (p ≤ 0.001) in the leaves. An increase in concentration of mobile Na in soil positively correlated with concentrations of Ca, Cu (p ≤ 0.01), and Zn (p ≤ 0.001) in the leaves. In N. sibirica leaves, the concentration of K, Ca, Mg, Fe, Sr, Mn, Zn, and Cu was 1.5–3 times higher than that in N. schoberi leaves. Both species are capable of accumulating very high concentrations of Na (N. schoberi: up to 83.8 g/kg and N. sibirica: up to 77.2 g/kg). In the leaves of N. schoberi plants of immature age, K and Na levels were seven times higher than those in leaves of adult generative plants, whereas Mg and Ca levels were 3–5 times higher. This study should expand the understanding of mechanisms of Nitraria species’ adaptation to high-salinity conditions.