Vegetatio

, Volume 113, Issue 1, pp 13–23

The role of disturbance in the establishment of indigenous and alien plants at Inaccessible and Nightingale Islands in the South Atlantic Ocean

  • W. R. J. Dean
  • S. J. Milton
  • P. G. Ryan
  • C. L. Moloney
Article

DOI: 10.1007/BF00045460

Cite this article as:
Dean, W.R.J., Milton, S.J., Ryan, P.G. et al. Vegetatio (1994) 113: 13. doi:10.1007/BF00045460

Abstract

Disturbances play an important role in the establishment of vegetation at Inaccessible and Nightingale Islands in the South Atlantic Ocean. Type, altitude and age of disturbance all influenced the species richness, life-form and abundance of seedlings. A few indigenous species appear to be dependent on small disturbances, such as the clearings around albatross nests, for their perpetuation, e.g. Acaena sarmentosa and Gnaphalium thouarsii. Alien forbs and grasses, e.g. Conyza albida, Holcus lanatus, Pseudognaphalium luteo-album and Rumex obtusifolius, tended to dominate large recent disturbances such as soil-slips and depressions, and to colonize man-modified sites. Alien plants were less common on the plateau at Inaccessible Island than on the lowlands. Their success appears to be enhanced by large-scale disturbances. The highest density and diversity of seedlings occurred on large soil-slips where mineral soil was exposed and vegetation cover was minimal.

Key words

AlbatrossAlien-plantsDisturbancesSeedlingSoil-slipSouth Atlantic Islands

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • W. R. J. Dean
    • 1
  • S. J. Milton
    • 1
  • P. G. Ryan
    • 1
  • C. L. Moloney
    • 1
  1. 1.Percy FitzPatrick Institute of African OrnithologyUniversity of Cape TownRondeboschSouth Africa