Get access

The biogeography of naturalization in alien plants

Authors

  • Petr Pyšek,

    Corresponding author
    1. Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, Czech Republic and Department of Ecology, Charles University, Viničná 2, CZ-128 02 Praha 2, Czech Republic
      *Petr Pyšek, Institute of Botany, Academy of Sciences of the Czech Republic, CZ-25243 Průhonice, Czech Republic.
      E-mail: pysek@ibot.cas.cz
    Search for more papers by this author
  • David M. Richardson

    1. Department of Botany and Zoology, Centre for Invasion Biology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
    Search for more papers by this author

*Petr Pyšek, Institute of Botany, Academy of Sciences of the Czech Republic, CZ-25243 Průhonice, Czech Republic.
E-mail: pysek@ibot.cas.cz

Abstract

Aim  This paper reviews the main geographical determinants of naturalization in plants.

Location  Global.

Methods  Comparative studies of large data sets of alien floras are the main source of information on global patterns of naturalization.

Results  Temperate mainland regions are more invaded than tropical mainland regions but there seems to be no difference in invasibility of temperate and tropical islands. Islands are more invaded than the mainland. The number of naturalized species in temperate regions decreases with latitude and their geographical ranges increase with latitude. The number of naturalized species on islands increases with temperature. Naturalized species contribute to floristic homogenization, but the phenomenon is scale-dependent.

Main conclusions  Some robust patterns are evident from currently available data, but further research is needed on several aspects to advance our understanding of the biogeography of naturalization of alien plants. For example, measures of propagule pressure are needed to determine the invasibility of communities/ecosystems/regions. The patterns discussed in this paper are derived largely from numbers and proportions of naturalized species, and little is known about the proportion of introduced species that become naturalized. Further insights on naturalization rates, i.e. the proportion of aliens that successfully naturalize within regions, and on geographical and other determinants of its variation would provide us with better understanding of the invasion process. Comparative studies, and resulting generalizations, are almost exclusively based on numbers of species, but alien species differ in their impact on native biodiversity and ecosystem processes.

Get access to the full text of this article

Ancillary