Species richness effect over the establishment success of an exotic invasive aquatic plant species

Abstract

Biological invasions pose threats to the biodiversity of ecosystems, especially in aquatic environments. The objective of this work was to evaluate the role of species richness and biomass of aquatic macrophytes native to the Amazon on the invasive potential of the exotic species Urochloa arrecta. Our hypothesis is that species richness and native biomass negatively affect the invasive establishment, since greater competition between native and invasive species is expected on small scales. For this, we carried out an experimental study using three native species, they were planted and after their establishment the invasive species was introduced. After 90 days, the native biomass and shoot height, aerial and root biomass of the weed were measured. The results showed a negative effect of species richness and native biomass on the attributes of the invasive species, demonstrating that species richness can reduce the successful establishment of exotic species. However, an important result also obtained in this study is that there was no total exclusion, showing the importance of further studies, such as monitoring and verification of in situ response, also evaluating temporal aspects of biological invasion of this species, given the ripple effect that can be generated by your establishment in aquatic environments.