Can classic biological invasion hypotheses be applied to reported cases of non-native terrestrial species in the Maritime Antarctic?

Understanding the success factors underlying each step in the process of biological invasion provides a robust foundation upon which to develop appropriate biosecurity measures. Insights into the processes occurring can be gained through clarifying the circumstances applying to non-native species that have arrived, established and, in some cases, successfully spread in terrestrial Antarctica. To date, examples include a small number of vascular plants and a greater diversity of invertebrates (including Diptera, Collembola, Acari and Oligochaeta), which share features of pre-adaptation to the environmental stresses experienced in Antarctica. In this synthesis, we examine multiple classic invasion science hypotheses that are widely considered to have relevance in invasion ecology and assess their utility in understanding the different invasion histories so far documented in the continent. All of these existing hypotheses appear relevant to some degree in explaining invasion processes in Antarctica. They are also relevant in understanding failed invasions and identifying barriers to invasion. However, the limited number of cases currently available constrains the possibility of establishing patterns and processes. To conclude, we discuss several new and emerging confirmatory methods as relevant tools to test and compare these hypotheses given the availability of appropriate sample sizes in the future.