Oecologia

, Volume 159, Issue 4, pp 705–715

Photosynthetic performance in Sphagnum transplanted along a latitudinal nitrogen deposition gradient

  • Gustaf Granath
  • Joachim Strengbom
  • Angela Breeuwer
  • Monique M. P. D. Heijmans
  • Frank Berendse
  • Håkan Rydin
Physiological Ecology - Original Paper

DOI: 10.1007/s00442-008-1261-1

Cite this article as:
Granath, G., Strengbom, J., Breeuwer, A. et al. Oecologia (2009) 159: 705. doi:10.1007/s00442-008-1261-1

Abstract

Increased N deposition in Europe has affected mire ecosystems. However, knowledge on the physiological responses is poor. We measured photosynthetic responses to increasing N deposition in two peatmoss species (Sphagnum balticum and Sphagnum fuscum) from a 3-year, north–south transplant experiment in northern Europe, covering a latitudinal N deposition gradient ranging from 0.28 g N m−2 year−1 in the north, to 1.49 g N m−2 year−1 in the south. The maximum photosynthetic rate (NPmax) increased southwards, and was mainly explained by tissue N concentration, secondly by allocation of N to the photosynthesis, and to a lesser degree by modified photosystem II activity (variable fluorescence/maximum fluorescence yield). Although climatic factors may have contributed, these results were most likely attributable to an increase in N deposition southwards. For S. fuscum, photosynthetic rate continued to increase up to a deposition level of 1.49 g N m−2 year−1, but for S. balticum it seemed to level out at 1.14 g N m−2 year−1. The results for S. balticum suggested that transplants from different origin (with low or intermediate N deposition) respond differently to high N deposition. This indicates that Sphagnum species may be able to adapt or physiologically adjust to high N deposition. Our results also suggest that S. balticum might be more sensitive to N deposition than S. fuscum. Surprisingly, NPmax was not (S. balticum), or only weakly (S. fuscum) correlated with biomass production, indicating that production is to a great extent is governed by factors other than the photosynthetic capacity.

Keywords

Chlorophyll fluorescenceChlorophyllCarbon dioxide exchangePhotosynthesisPeatlands

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Gustaf Granath
    • 1
  • Joachim Strengbom
    • 1
    • 2
  • Angela Breeuwer
    • 3
  • Monique M. P. D. Heijmans
    • 3
  • Frank Berendse
    • 3
  • Håkan Rydin
    • 1
  1. 1.Department of Plant Ecology, Evolutionary Biology CenterUppsala UniversityUppsalaSweden
  2. 2.Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
  3. 3.Nature Conservation and Plant Ecology GroupWageningen UniversityWageningenThe Netherlands