Biological Invasions

, Volume 13, Issue 7, pp 1599–1614

Secondary invasion of Acer negundo: the role of phenotypic responses versus local adaptation

  • Alexandra Erfmeier
  • Martin Böhnke
  • Helge Bruelheide
Original Paper

DOI: 10.1007/s10530-010-9917-2

Cite this article as:
Erfmeier, A., Böhnke, M. & Bruelheide, H. Biol Invasions (2011) 13: 1599. doi:10.1007/s10530-010-9917-2

Abstract

During plant species invasions, the role of adaptive processes is particularly of interest in later stages of range expansion when populations start invading habitats that initially have not been disposed to invasions. The dioecious tree Acer negundo, primarily invasive in Europe in wet habitats along riversides and in floodplains, has increased its abundance in dry habitats of industrial wasteland and ruderal sites during the last decades in Eastern Germany. We chose 21 invasive populations from wet and from dry habitats in the region of Halle, Saxony-Anhalt, Germany, to test whether Acer negundo exhibits a shift in life-history strategy during expansion into more stressful habitats. We analyzed variables of habitat quality (pH, soil moisture, exchangeable cations, total C and N content) and determined density, sex ratio and regeneration of the populations. In addition, we conducted germination experiments and greenhouse studies with seedlings in four different soil moisture environments. Local adaptation was studied in a reciprocal transplant experiment. We found habitat type differentiation with lower nutrient and water supply at the dry sites than at the moist sites and significant differences in the number of seedlings in the field. In accordance, seeds from moist habitats responded significantly faster to germination treatments. In the transplant experiment, leaf life span was significantly larger for populations originating from dry habitat types than from moist habitats. This observed shift in life history strategy during secondary invasion of A. negundo from traits of establishment and rapid growth towards traits connected with persistence might be counteracted by high gene flow among populations of the different habitat types. However, prolonged leaf life span at dry sites contributed remarkably to the invasion of less favourable habitats, and, thus, is a first indication of ongoing adaptation.

Keywords

Germination velocityLeaf life spanEcotypesReciprocal transplant experimentRGRSecondary phase of invasion

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Alexandra Erfmeier
    • 1
  • Martin Böhnke
    • 1
  • Helge Bruelheide
    • 1
  1. 1.Institute of Biology/Geobotany and Botanical GardenMartin Luther University Halle-WittenbergHalleGermany