Ecophysiological adjustment of two Sphagnum species in response to anthropogenic nitrogen deposition
2009 (English)In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 181, no 1, 208-217 p.Article in journal (Refereed) Published
Here, it was investigated whether Sphagnum species have adjusted their nitrogen (N) uptake in response to the anthropogenic N deposition that has drastically altered N-limited ecosystems, including peatlands, worldwide.A lawn species, Sphagnum balticum, and a hummock species, Sphagnum fuscum, were collected from three peatlands along a gradient of N deposition (2, 8 and 12 kg N ha(-1) yr(-1)) The mosses were subjected to solutions containing a mixture of four N forms. In each solution one of these N forms was labeled with N-15 (namely (NH4+)-N-15 (NO3-)-N-15 and the amino acids [N-15] alanine (Ala) and [N-15] glutamic acid (Glu)).It was found that for both species most of the N taken up was from, followed by Ala, Glu, and very small amounts from. At the highest N deposition site N uptake was reduced, but this did not prevent N accumulation as free amino acids in the Sphagnum tissues.The reduced N uptake may have been genetically selected for under the relatively short period with elevated N exposure from anthropogenic sources, or may have been the result of plasticity in the Sphagnum physiological response. The negligible Sphagnum NO3- uptake may make any NO3- deposited readily available to co- occurring vascular plants.
Place, publisher, year, edition, pages
2009. Vol. 181, no 1, 208-217 p.
amino acids, nitrogen (N) deposition gradient, N uptake, NH4+, NO3-, Sphagnum
IdentifiersURN: urn:nbn:se:uu:diva-106991DOI: 10.1111/j.1469-8137.2008.02628.xISI: 000261397400020PubMedID: 18811618OAI: oai:DiVA.org:uu-106991DiVA: diva2:227540