Plant Ecology

, Volume 216, Issue 11, pp 1481–1498

Temporal changes in the impacts on plant communities of an invasive alien tree, Acacia longifolia

  • Hélia Marchante
  • Elizabete Marchante
  • Helena Freitas
  • John H. Hoffmann
Article

DOI: 10.1007/s11258-015-0530-4

Cite this article as:
Marchante, H., Marchante, E., Freitas, H. et al. Plant Ecol (2015) 216: 1481. doi:10.1007/s11258-015-0530-4

Abstract

Studies on the impacts of invasive plants are common but most are short term and fail to consider the temporal context of invasion. The present work investigated particular invasions on two different time scales and asked: (1) Do the impacts of an invasive tree on plant communities change after decades of invasion? (2) Are patterns of impacts dynamic over a period of five years? (3) Can multiple parameters reveal impacts that are unnoticed when single-value parameters are measured alone? Contrasting plant communities (long invaded, recently invaded and non-invaded) of a Portuguese coastal dune were compared during a 5-year period to assess the impacts of the invasive Acacia longifolia. Plant diversity, richness, cover, plant traits, indicator species analysis, similarity between areas and species turnover were analysed to reveal spatial and temporal patterns of change. Native species richness declined in both invaded areas. As invasion time increased, species shared with natural habitats decreased along with native plant cover, diversity and species turnover. Many species typical of dunes were replaced by generalists and exotics species, and richness of species with some level of nitrophily increased, particularly in recently invaded areas. Life form spectrum was radically transformed in invaded areas with several small-sized life forms being replaced by one single microphanerophyte. Germination of A. longifolia was greatest in long invaded areas. Findings show that modification of plant communities intensifies with invasion time and that invasion promotes a diversity of structural and functional changes which are dynamic over a few years (medium-term scale) but which tend to stabilize after several decades (long-term scale). An analysis of parameters in combination revealed changes that were not apparent when the same parameters were considered separately.

Keywords

Acacia longifolia Coastal ecosystems Indicator species analysis Long-term impacts Medium-term impacts Plant traits Invasion chronology Species turn over 

Copyright information

© Springer Science+Business Media Dordrecht 2015

Authors and Affiliations

  • Hélia Marchante
    • 1
    • 2
  • Elizabete Marchante
    • 2
  • Helena Freitas
    • 2
  • John H. Hoffmann
    • 3
  1. 1.Instituto Politécnico de CoimbraEscola Superior Agrária de CoimbraCoimbraPortugal
  2. 2.Centre for Functional Ecology, Department of Life SciencesUniversity of CoimbraCoimbraPortugal
  3. 3.Department of Biological SciencesUniversity of Cape TownRondeboschSouth Africa

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