Propagule resistance of an invasive Poaceae as a trait of its invasiveness

Biological invasions and consequent mass development of aquatic macrophytes constitute a significant threat to aquatic environments. As a consequence, species invasiveness is becoming of great interest. Urochloa arrecta is a mass development invasive Poaceae that has caused many impacts in freshwaters in Brazil. Studies have described its remarkable tolerance to stressful conditions, but propagules resistance to desiccation while in dispersion is unknown. Here, we analyzed through a microcosm experiment U. arrecta's small propagules regeneration after desiccation and without any sediment-thus simulating a transportation scenario. As expected, the longer the time of stress, the lower the propagule regeneration performance. Even so, the macrophyte propagules can survive up to six days off of water and any sediment. Even when the propagules seemed unviable, there was some degree of regeneration. As a consequence of the results, we state that removal and transportation of U. arrecta should be controlled considering the propagule viability.

Automated summary

Biological invasions and mass development of aquatic macrophytes pose a significant threat to aquatic environments. Urochloa arrecta, an invasive Poaceae, has caused significant impacts in freshwaters in Brazil. A microcosm experiment revealed that the propagules of U. arrecta can survive up to six days without water and sediment, highlighting the need to consider their viability when controlling removal and transportation.