The Natural Abundance of Heavy Nitrogen Isotope (15N) in Plants Increases near a Large Copper Smelter

Abstract

The ratio of stable isotopes of nitrogen (¹⁵N and ¹⁴N) has been assessed in leaves of the forest plants from different functional groups (with ectomycorrhiza, ericoid, and arbuscular mycorrhiza; in a nitrogen-fixing symbiosis) under the conditions of strong transformation of ecosystems by the Karabashsky Copper-Smelting Plant effluents in the Southern Urals. The abundance of ¹⁵N in the plants generally increases in polluted habitats. The abundance of the heavy isotope ¹⁵N increases significantly with pollution in ericaceous dwarf shrubs (by 3.3‰) and herbs with arbuscular mycorrhizae (by 2.8‰). This indicates a strong alteration in conditions or modes of plant mineral nutrition under the influence of heavy metal pollution of forest ecosystems.