The introduction of non-indigenous species (NIS) in new environments represents a major threat for coastal ecosystems. A solid understanding of the mechanisms and magnitude of the impact of NIS colonization on native ecosystems is becoming increasingly crucial to develop mitigation measures and prevent new invasions. Non-indigenous species interact with all components of the recipient ecosystem, either physical or biological, resulting in the eventual success or failure of NIS establishment. In particular, marine sessile fouling communities are distributed worldwide and are among the most diverse and productive assemblages of macro-organisms, which make them a suitable model system to test ecological theory. Research focused on these assemblages has evaluated classic paradigms in ecology, such as the Biotic Resistance hypothesis. Predicting community invasibility, species invasiveness or identifying factors that make places more or less prone to invasion is one of the most important issues in the study of biological invasions. In recent years, several research projects have been conducted in Madeira Island (NE Atlantic) to evaluate how different biotic factors and types of communities are affecting the settlement success of NIS. We used a standard PVC settling plate methodology to collect marine benthic communities and later manipulate biotic features and propagule pressure of NIS in the field and under mesocosm conditions.
Results/Conclusions
Results showed that NIS colonization success was modulated by predation and facilitation interactions and how final colonization patterns differed between types of biotic substrates, i.e. benthic community assembly. These series of assays contribute to a better understanding of the ecological processes driving colonization success at the local scale of an island system, in this case Madeira Island. Specifically, they add new evidences about the implications of the multiple interactive biotic factors and how relevant can be the nature of the resident communities facing invasions risks.