Articles | Volume 13, issue 5
Biogeosciences, 13, 1621–1633, 2016
Biogeosciences, 13, 1621–1633, 2016

Research article 16 Mar 2016

Research article | 16 Mar 2016

Climatic controls on leaf litter decomposition across European forests and grasslands revealed by reciprocal litter transplantation experiments

Miguel Portillo-Estrada1,2, Mari Pihlatie3, Janne F. J. Korhonen3, Janne Levula3,4, Arnoud K. F. Frumau5, Andreas Ibrom6, Jonas J. Lembrechts1, Lourdes Morillas7, László Horváth8, Stephanie K. Jones9,10, and Ülo Niinemets2,11 Miguel Portillo-Estrada et al.
  • 1Centre of Excellence PLECO (Plant and Vegetation Ecology), Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
  • 2Department of Plant Physiology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51014, Estonia
  • 3Department of Physics, Division of Atmospheric Sciences, 00014 University of Helsinki, Helsinki, Finland
  • 4Hyytiälä forest station, Hyytiäläntie 124, 35500 Korkiakoski, Finland
  • 5ECN, Environmental Assessment group, P.O. Box 1, 1755 ZG, Petten, the Netherlands
  • 6Technical University Denmark, Department of Environmental Engineering, Centre for Ecosystem & Environmental Sustainability, Frederiksborgvej 399, Risø-Campus, 4000 Roskilde, Denmark
  • 7Department of Sciences for Nature and Environmental Resources, University of Sassari, Via Enrico de Nicola, no. 9, 07100, Sassari, Italy
  • 8Hungarian Meteorological Service, P.O. Box 39, 1675 Budapest, Hungary
  • 9Scotland Rural College, King's Buildings, West Mains Road, Edinburgh EH9 3JG, UK
  • 10Centre for Ecology and Hydrology (CEH), Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
  • 11Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia

Abstract. Carbon (C) and nitrogen (N) cycling under future climate change is associated with large uncertainties in litter decomposition and the turnover of soil C and N. In addition, future conditions (especially altered precipitation regimes and warming) are expected to result in changes in vegetation composition, and accordingly in litter species and chemical composition, but it is unclear how such changes could potentially alter litter decomposition. Litter transplantation experiments were carried out across six European sites (four forests and two grasslands) spanning a large geographical and climatic gradient (5.6–11.4 °C in annual temperature 511–878 mm in precipitation) to gain insight into the climatic controls on litter decomposition as well as the effect of litter origin and species.

The decomposition k rates were overall higher in warmer and wetter sites than in colder and drier sites, and positively correlated with the litter total specific leaf area. Also, litter N content increased as less litter mass remained and decay went further.

Surprisingly, this study demonstrates that climatic controls on litter decomposition are quantitatively more important than species or site of origin. Cumulative climatic variables, precipitation, soil water content and air temperature (ignoring days with air temperatures below zero degrees Celsius), were appropriate to predict the litter remaining mass during decomposition (Mr). Mr and cumulative air temperature were found to be the best predictors for litter carbon and nitrogen remaining during the decomposition. Using mean annual air temperature, precipitation, soil water content and litter total specific leaf area as parameters we were able to predict the annual decomposition rate (k) accurately.

Short summary
We studied tree and grass litter decomposition across several climates in Europe. Climatic (air temperature, precipitation and soil water content) controls on litter decomposition were quantitatively more important than species or site of origin. The data were used to generate prediction models of remaining litter mass, and carbon and nitrogen contents during the decomposition period. We also observed a significant drop in remaining litter mass after the first couple of days of decomposition.
Final-revised paper