Biological Invasions

, Volume 11, Issue 8, pp 1973–1986

Effects of exotic invasive trees on nitrogen cycling: a case study in Central Spain

  • P. Castro-Díez
  • N. González-Muñoz
  • A. Alonso
  • A. Gallardo
  • L. Poorter
Original Paper

DOI: 10.1007/s10530-008-9374-3

Cite this article as:
Castro-Díez, P., González-Muñoz, N., Alonso, A. et al. Biol Invasions (2009) 11: 1973. doi:10.1007/s10530-008-9374-3

Abstract

We assess the hypothesis that rates of nitrogen transformations in the soil are altered upon replacement of native by exotic trees, differing in litter properties. Ailanthus altissima and Robinia pseudoacacia, two common exotic trees naturalized in the Iberian Peninsula, were compared with the native trees Ulmus minor and Fraxinus angustifolia, respectively. Naturally senesced leaves of each species were collected and C:N ratio, N and lignin content assessed. We prepared 64 litter bags per species and left them to decompose, below the canopy of the same species and below the canopy of the paired species. Dry mass, N concentration and N pool of the remaining litter were assessed after 5 and 7 months. Soil samples were collected three times during the experiment to assess soil moisture, organic matter, pH, potential mineralization rates and mineral N pools. Mineral N availability was assessed three times in the field by using ion-exchange resin-impregnated membranes. Ailanthus litter decomposed faster than Ulmus litter, probably due to the higher toughness of the latter. In spite of its high N content, Robinia litter decomposed slower than Fraxinus one, probably due to its high lignin content. In both cases, litter decomposition was faster below the exotic than the native canopies. The release of N per unit of initial litter mass was higher under both invaded situations (Ailanthus below Ailanthus and Robinia below Robinia) than under the native ones. However, soils collected below native and exotic trees neither differed in potential N mineralization rate nor in mineral N. This may be attributed to a quick plant uptake of released N and/or to a high organic matter accumulation in the soil previous to invasion that can exert a tighter control on soil N transformations than the current exotic litter.

Keywords

Exotic trees Litter decomposition Mineralization rate Nitrogen availability Nitrogen cycle 

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • P. Castro-Díez
    • 1
    • 2
  • N. González-Muñoz
    • 1
  • A. Alonso
    • 3
  • A. Gallardo
    • 4
  • L. Poorter
    • 2
    • 5
  1. 1.Departamento de Ecología, Facultad de CienciasUniversidad de AlcaláMadridSpain
  2. 2.Forest Ecology and Forest Management Group, Centre for Ecosystem StudiesWageningen UniversityWageningenThe Netherlands
  3. 3.Aquatic Ecology and Water Quality ManagementWageningen UniversityWageningenThe Netherlands
  4. 4.Departamento de Sistemas Físicos, Químicos y NaturalesUniversidad Pablo de OlavideSevillaSpain
  5. 5.Resource Ecology Group, Centre for Ecosystem StudiesWageningen UniversityWageningenThe Netherlands

Personalised recommendations