Regular Army units largely train on their home installation, while National Guard and Army Reserve components may often train at several locations in a year. Regular Army units may conduct joint exercises at other installations or on National Forest or Bureau of Land Management public lands as well. Only a few locations require vehicles to be cleaned before entering. We know intrinsically that movement of vehicles, persons and equipment has the potential to transport seeds and other plant parts among locations where they ahve been stored or operated. Just how great IS this risk, and what reasonable steps may be taken to completely or partially alleviate the risk?
Results/Conclusions
A series of research efforts over several years has allowed the risks of different activities to be quantified. One important aspect has been to determine how effective existing cleaning methodologies are in removing seeds and other propagules from the vehicles. The U.S. Forest Service and the California Division of Forestry also cooperated in this series of equipment tests. In one study, it was found that existing vehicle cleaning using field-portable equipment typically removes up to 80% of the soil on a vehicle. This clearly reduces risk of transport from place to place, but does not eliminate it. Another focus has been to quantify the potential for different vehicles to pick up weed seeds when they are operated either on or off road, and also how much of the seed load is lost along the driving route between the field site and the destination. These studies have shown that considerable seed loads may remain almost intact over hundreds of kilometers on paved roads in dry weather. Rain or water on the pavement however, will create a “cleaning” action, significantly reducing numbers of adhering seeds. The data and risk assessments are applicable to all types of vehicles and all public and private operators of the vehicles, including the Army, Forest Service, private ranchers, and the recreational public