Human-mediated long-distance dispersal: an empirical evaluation of seed dispersal by vehicles

Authors

  • Kimberley Taylor,

    1. Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
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  • Tyler Brummer,

    1. Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
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  • Mark L. Taper,

    1. Department of Ecology, Montana State University, Bozeman, MT, USA
    2. Department of Biology, University of Florida, Gainesville, FL, USA
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  • Alexandre Wing,

    1. Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
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  • Lisa J. Rew

    Corresponding author
    1. Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
    • Correspondence: Lisa J. Rew, Weed and Invasive Plant Ecology and Management Group, 334 Leon Johnson Hall, Land Resources and Environmental Sciences Department, Montana State University, Bozeman, MT 59717, USA

      E-mail: lrew@montana.edu

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Abstract

Aim

To determine seed retention rates on vehicles as a function of distance driven, road surface, weather condition and seed location on the vehicle undercarriage.

Location

Montana, United States.

Methods

Metal plates were covered with a seed-soil slurry, dried and attached to different locations underneath a vehicle. The vehicle was then driven on paved and unpaved roads under both wet and dry conditions. Plates were removed from the vehicle at seven distances between 4 and 256 km. The number of seeds remaining was determined. Four general models were assessed to explain observed seed retention.

Results

Under dry conditions, seed retention rates were high on both unpaved and paved roads, with 86–99% of the seeds remaining at 256 km. Under wet conditions, lower rates of seed retention were observed for both road surfaces: 0.3–80% of seeds were retained at 256 km on paved wet roads and 50–96% of seeds were retained at 256 km on unpaved wet roads. Plate location had a significant effect on seed retention under certain road surfaces and conditions, with loss generally being highest from the wheel wells. Of the statistical models compared, a double exponential model explained the most variation in seed retention.

Main conclusions

Vehicles act as vectors of long-distance dispersal. Seed adhered to vehicles can be retained for hundreds of kilometres under dry conditions. When wet conditions occur, a greater proportion of seeds will be dispersed shorter distances. Consequently, vehicle seed dispersal has implications for plant invasions and species migration rates, and those concerned with prevention and control of non-native plant invasions should consider vehicle seed transport when developing management strategies and plans.

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