Ecological Niche Modeling of Invasive Macrophyte (Urochloa subquadripara) and Co-Occurrence with South American Natives

Abstract

Invasive macrophytes are considered problematic in natural environments and hydroelectric reservoirs. Climate changes, the occurrences of watercourses, and biotic interactions influence biological invasions of macrophytes. The abundance of native species can be positively or negatively correlated with the occurrences of invasives. Urochloa subquadripara is an invasive in natural or disturbed habitats co-occurring with the natives Eichhornia crassipes and Salvinia minima in South America. Aquatic plant communities can be altered by climate change, so species distribution models (SDMs) are important tools for predicting invaded areas. This study aimed to apply an SDM to study correlations of U. subquadripara with the potential distributions of native species E. crassipes and S. minima. Occurrence data for U. subquadripara, E. crassipes, and S. minima were collected from databases and in consultation with the published literature. Parameters encompassing biological information of the species were entered into the CLIMEX software and used to generate the Ecoclimatic Index (EI). The species co-occurrence was performed based on multicriteria decision-making (MCDM), and weights were assigned using the analytical hierarchy process (AHP). It was observed that U. subquadripara, E. crassipes, and S. minima had a higher occurrence in tropical and subtropical regions. However, it is predicted that these species may move to high latitudes from climatic changes. Considering climate changes, such as the increase in temperature and CO2, the risk of invasion by U. subquadripara in the northern hemisphere is mainly in lakes, whereas the areas conducive to invasions are rivers and reservoirs in the southern hemisphere. In general, emerging and floating macrophyte species such as U. subquadripara, E. crassipes, and S. minima will be favored, causing suppression of submerged species. Therefore, identifying the potential distribution of these species allows the creation of pre-invasion intervention strategies.