Dispersal of the brachiaria invasive species in a tropical estuary

Abstract

Excess nutrients in estuaries favor the growth of aquatic plants. Invasive plants, such as brachiaria (Urochloa arrecta), increase competition, compromising native species survival and causing ecological imbalance. This study examined the spread of brachiaria in the Guaraguaçu River estuary in Paraná, Brazil, in two scenarios (rainy and dry), considering flow and salinity variations. The brachiaria spread was evaluated using a Lagrangian transport model to simulate inert particle trajectories. Results indicate that in the rainy scenario (lower salinity), particles tend to move more easily out of the modeled domain. In the dry scenario (higher salinity), they tend to remain for over 30 days. These findings show the dynamics of species fixation and adaptation