Nitrogen nutrition and isotope differences among life forms at the northern treeline of Alaska (original) (raw)

We’re sorry, something doesn't seem to be working properly.

Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.

Abstract

Natural abundances of nitrogen isotopes, δ15N, indicate that, in the same habitat, Alaskan Picea glauca and P. mariana use a different soil nitrogen compartment from the evergreen shrub Vaccinium vitis-idaea or the deciduous grass Calamagrostis canadensis. The very low δ15N values (-7.7 ‰) suggest that (1) Picea mainly uses inorganic nitrogen (probably mainly ammonium) or organic N in fresh litter, (2) Vaccinium (-4.3 ‰) with its ericoid mycorrhizae uses more stable organic matter, and (3) Calamagrostis (+0.9 ‰) exploits deeper soil horizons with higher δ15N values of soil N. We conclude that species limited by the same nutrient may coexist by drawing on different pools of soil N in a nutrient-deficient environment. The differences among life-forms decrease with increasing N availability. The different levels of δ15N are associated with different nitrogen concentrations in leaves, Picea having a lower N concentration (0.62 mmol g−1) than Vaccinium (0.98 mmol g−1) or Calamagrostis (1.33 mmol g−1). An extended vector analysis by Timmer and Armstrong (1987) suggests that N is the most limiting element for Picea in this habitat, causing needle yellowing at N concentrations below 0.5 mmol g−1 or N contents below 2 mmol needle−1. Increasing N supply had an exponential effect on twig and needle growth. Phosphorus, potassium and magnesium are at marginal supply, but no interaction between ammonium supply and needle Mg concentration could be detected. Calcium is in adequate supply on both calcareous and acidic soils. The results are compared with European conditions of excessive N supply from anthropogenic N depositions.

Access this article

Log in via an institution

Subscribe and save

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

Download references

Author information

Authors and Affiliations

  1. Lehrstuhl Pflanzenökologie, Universität Bayreuth, D-95440, Bayreuth, Germany
    E.-D. Schulze & G. Gebauer
  2. Department of Integrative Biology, University of California, 94720, Berkeley, CA, USA
    F. S. Chapin III

Authors

  1. E.-D. Schulze
    You can also search for this author inPubMed Google Scholar
  2. F. S. Chapin III
    You can also search for this author inPubMed Google Scholar
  3. G. Gebauer
    You can also search for this author inPubMed Google Scholar

Additional information

Dedicated to Prof. Dr. Drs. h.c. H. Ziegler on the occasion of his 70th birthday

Rights and permissions

About this article

Cite this article

Schulze, ED., Chapin, F.S. & Gebauer, G. Nitrogen nutrition and isotope differences among life forms at the northern treeline of Alaska.Oecologia 100, 406–412 (1994). https://doi.org/10.1007/BF00317862

Download citation

Key words