Invasive alien species are one of the main direct drivers of change in nature. The biological invasion process comprises the following 
stages: transport, introduction, establishment and spread (or dispersal). Definitions of native, alien, established alien and invasive alien 
species are provided. Indirect and other direct drivers of change facilitate biological invasion.
THE THEMATIC ASSESSMENT REPORT ON INVASIVE ALIEN SPECIES AND THEIR CONTRO
The thematic assessment report on
INVASIVE ALIEN SPECIES
AND THEIR CONTROL
Figure SPM 1 Key concepts within the biological invasion process.7