Alien and native plant seed dispersal by vehicles

Abstract

Vehicles play a significant role in spreading plants, both in terms of quantity and quality (species). This study was conducted in Southeast Queensland to determine the role of utility vehicles in spreading seeds. These vehicles were found to carry up to 397 seeds per vehicle and in all four seasons of the year, with the majority of these species being alien to Australia and/or Queensland. The largest seed loads were found in autumn in this summer rainfall environment. Seeds were shown to attach to all parts of the vehicle, often in mud picked up from the ground, affixed directly to the engine or radiator, or carried into the cabin by the driver. Therefore, much of the seed load is to be found on the underside, on the back and front mudguards while smaller collections were found in the cabin, on the radiator and engine, and on the tyres. Fewer viable seeds were found on the engine, presumably as desiccation and heat contributed more to their death on this part of the vehicle. One method used to reduce weed seed spread by vehicles in Queensland is washing and vacuuming of vehicles. From the present study, these procedures would need to be applied to all parts of the vehicle and in all seasons of the year.

Spread pathways of the invasive weed Parthenium hysterophorus L.: The potential for water dispersal

“…; Khan et al . ). Survival time of parthenium weed cypselae suggested by this study may raise the concern and provide information for improved hygiene of wash‐down facilities.…”

Road verges facilitate exotic species’ expansion into undisturbed natural montane grasslands

“…Since these construction vehicles originated from an area where P. hysterophorus is particularly abundant (Richards Bay, South Africa; approximately 400 km from the study area), it is a plausible assumption that a construction vehicle was the dispersal vector in this case. Since private vehicles are frequently cleaned, the actual number of attached propagules is usually quite low (Lonsdale & Lane, 1994;Khan et al, 2018). Moreover, remaining propagules are predominantly dispersed in close vicinity to home (Taylor et al, 2012).…”

“…This indicates that the exotic species pool is not merely expanding its range gradually, but that additional factors are aiding long‐distance dispersal (Higgins et al, 2003; Jordano, 2017). Typically, the introduction of exotic propagules to montane road verges is attributed to anthropogenic dispersal vectors such as adhesion to vehicles (Taylor et al, 2012; Ansong & Pickering, 2013; Khan et al, 2018) and, to a lesser extent, footwear (Liedtke et al, 2020). Indeed, for both the 2007 and 2017 survey, distance from potential points of introduction was an important explanatory variable for exotic species richness and composition (Table 1; Figure 3).…”

Study on Environmental Conditions of Seed Germination and Seedling Growth of Invasive Plant <i>Amaranthus palmeri</i> S. Watson

“…After 3 years of naturally existing in soils in Nebraska, vigor of Amaranthus palmeri seeds was found to be less than 10% [19,57]; after 5 months of waterflooding, their vigor was found to be 86% [18]. Therefore, Amaranthus palmeri seeds exhibit a certain tolerance to short-term high temperatures and high humid environments [58,59]. The effect of time and temperature on the viability of Amaranthus palmeri seeds is greater than that of humidity.…”