Unintentional Human Dispersal of Weed Seed

Abstract

Seed dispersal is an important biological process as propagule pressure affects the success of plant invasions. The role and importance of humans in this process is increasingly recognised, particularly in relation to long distance seed dispersal. There is still comparatively limited research on unintentional human-mediated seed dispersal, including for seed dispersed from clothing, compared to other dispersal mechanisms such as wind or seed attached to fur. With more people travelling globally, including to remote locations, humans can unintentionally transport seeds over long distances. This can facilitate biological invasions in urban, rural and remote natural areas when it involves the dispersal of weed seed. Weeds, which are often defined as plants growing in sites where they are not wanted, are a major problem in both natural and agricultural systems. They can reduce biodiversity in natural ecosystems and productivity in agricultural regions, and once established, they are expensive to control or eradicate. Therefore, limiting weed seed dispersal, including over long distances, is important in controlling their spread globally. This thesis examines aspects of unintentional human-mediated weed seed dispersal, using data mining, experimental, modelling and social methods.