Potential distribution of aquatic invasive alien plants, Eichhornia crassipes and Salvinia molesta under climate change in Sri Lanka

Abstract

Eichhornia crassipes and Salvinia molesta are two of the world’s worst aquatic invasive alien plant Species (AIAPS) that have a major impact on the environment, agricultural production and food security. The aim of this study was to understand the current and potential distribution of E. crassipes and S. molesta under climate change in the tropical island of Sri Lanka. The MaxEnt species distribution modelling technique was used to generate predictive models using global distribution data and environmental variables. For future projections, the mean of two best performing climate models was used under two emissions scenarios, Representative Concentration Pathways (RCP) 4.5 and 8.5 for time periods 2050 and 2070. The study revealed that at present, the majority of the aquatic habitats of the country, particularly lowland areas, are vulnerable to the invasion of these two species; however, a striking difference was observed under future RCP scenarios. Aquatic habitats suitable for E. crassipes is predicted to decrease substantially by 2050 and increase again until 2070. The suitable habitats of S. molesta are likely to decrease sharply until 2070. This study provides insights for decision-makers that climate change influences should be considered for long-term management of AIAPS.