Nitrogen Isotopes in Soils and Plants of Tundra Ecosystems in the Khibiny Mountains


Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

The isotopic composition of nitrogen in soils and plants may be an indicator of transformation of its compounds and sources of N nutrition of plants. Natural 15N abundance (δ15N) was determined in soils (the total, ammonium, and nitrate nitrogen) and in plant leaves and roots of four tundra ecosystems in the Khibiny Mountains. The studied soils (Folic Leptic Entic Podzol and Leptosols) significantly differ in N availability, and plants are represented by the species, forming ectomycorrhiza, ericoid mycorrhiza, and arbuscular mycorrhiza, as well as by the species, which usually do not form a mycorrhiza. The range of δ15N in soil inorganic compounds is from –16.2 ‰ in nitrates to +6.4‰ in ammonium, which reflects the correlation between the activities of N-mineralization and nitrification and δ15N-\({\text{NH}}_{4}^{ + }\), as well as a potentially strong effect on the isotopic composition of nitrogen in plants. The value of δ15N in plant leaves and roots changes in a narrower range (from –7.3 to +2.4‰), which may be related to N uptake from different sources and to fractionation of N isotopes during N assimilation. Roots are 15N-enriched in comparison with leaves in most of the studied plant species, which corresponds to the concept of mycorrhiza participation in N nutrition of plants. Regardless of the type of mycorrhizal symbiosis, the difference in δ15N between roots and leaves of most plant species decreases contrary to N availability in soils.

About the authors

M. I. Makarov

Lomonosov Moscow State University

Author for correspondence.
Email: mmakarov@soil.msu.ru
Russian Federation, Moscow, 119991

I. S. Buzin

Lomonosov Moscow State University

Email: mmakarov@soil.msu.ru
Russian Federation, Moscow, 119991

A. V. Tiunov

Severtsov Institute of Ecology and Evolution

Email: mmakarov@soil.msu.ru
Russian Federation, Moscow, 119071

T. I. Malysheva

Lomonosov Moscow State University

Email: mmakarov@soil.msu.ru
Russian Federation, Moscow, 119991

M. S. Kadulin

Lomonosov Moscow State University

Email: mmakarov@soil.msu.ru
Russian Federation, Moscow, 119991

N. E. Koroleva

Avrorin Polar-Alpine Botanical Garden-Institute

Email: mmakarov@soil.msu.ru
Russian Federation, Apatity, 184209


Copyright (c) 2019 Pleiades Publishing, Ltd.

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies