Nitrogen stable isotope composition of leaves and roots of plants growing in a forest and a meadow

• Published in: Isotopes in environmental and health studies Vol. 39; no. 1; pp. 29 - 39
• Main Authors: Dijkstra, P., Williamson, C., Menyailo, O., Doucett, R., Koch, G., Hungate, B. A.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 01.03.2003
• Subjects: Ammonium; Ecosystem; Environmental Monitoring; Fabaceae - chemistry; Forbs; Grasses; Legumes; Natural Abundance; Nitrate; Nitrogen; Nitrogen - analysis; Nitrogen - metabolism; Nitrogen Isotopes - analysis; Plant Leaves - chemistry; Plant Roots - chemistry; Poaceae - chemistry; Trees
• ISSN: 1025-6016; 1477-2639
• DOI: 10.1080/1025601031000102189

In controlled N-nutrition experiments, differences in δ 15 N composition of leaves and roots are regularly found. In this paper we report results from a survey of nitrogen stable isotope signatures of leaves and roots of 16 plant species growing under natural conditions in a meadow and a forest understorey, which differed in nitrate and ammonium availability. Significant differences between leaf and root were observed. The range of Δ 15 N [leaf-root] values was m 0.97 to +0.86, small compared to published values from controlled N-nutrition experiments, but almost as large as the range of leaf δ 15 N values (m 1.04 to +1.08). Forbs showed the largest differences between leaves and roots and showed a significant difference with respect to habitat. Grasses and legumes did not show significant differences in Δ 15 N [leaf-root] between the two habitats. Care must be taken when using leaf δ 15 N values as representative for whole-plant 15 N composition in these two habitats.