Unintentional human‐vectored dispersal contributes to the spread of high risk weed species

Abstract

AbstractNaturalisation risk and the vulnerability of many countries to future plant invasions is predicted to increase with human movement and climate change. Unfortunately, the geographical limitation on studies assessing unintentional human‐vectored dispersal (HVD) has hampered progress in understanding its importance, particularly its probability of introducing species that will become naturalised or invasive. The current paper used an explorative approach to determine if human clothing and vehicles disperse species with higher potential to become invasive globally. The study specifically relies on available database of unintentional human‐vectored seed dispersal and recent studies that considered the outcomes of plant species' interaction with humans around the world. The results indicate that human vehicles and clothing contribute to the spread of many extreme risk and most naturalised species of the world. For example, 55% of the 200 most naturalised species have been reported to be dispersed on vehicle while almost one ‐third (32%) have been reported to be dispersed on clothing. Also, of the 235 extreme risk species 41% have been reported to be dispersed on vehicles and 31% on clothing. The results indicate that graminoids, herbs and species with long‐term seed bank are more dispersed via HVD. Conservation managers and practitioners should consider the role of human‐vectored seed dispersal in the spread of invasive weeds, especially in popular and frequently visited areas. Individuals embracing responsible travel practices and adopting proactive measures and protocols to prevent the accidental transport of seeds can significantly enhance our conservation endeavours in our interconnected global ecosystem.