How Engineers and Roadside Vegetation Managers Maintain Roadside Vegetation in Iowa, USA

Recently the value of roadside vegetation as habitat for pollinators has gained increased attention, particularly in areas dominated by agriculture where there is little native vegetation available. However, many factors, including safety, cost, public perception, erosion control, and weedy plants must be considered when managing roadside vegetation. Although their decisions influence thousands of hectares of public rights-of-way, how engineers and roadside managers maintain roadside vegetation has been the subject of little research. In this study, we surveyed county engineers and roadside managers who manage vegetation along secondary roads in Iowa, USA to assess how they maintain roadside vegetation. Some counties employ roadside managers, who often have an environmental sciences background, to implement the on-the-ground management of roadside vegetation, while some counties use other staff. Compared to engineers, roadside managers more strongly agreed that using the ecological principles of integrated roadside vegetation management (IRVM) provided environmental benefits. Engineers in counties with a roadside manager more strongly agreed that IRVM practices reduce the spread of invasive species and provide attractive roadsides. Both engineers and roadside managers mentioned challenges to managing roadside vegetation, including interference with some native plantings by adjacent landowners, and ranked safety and soil erosion concerns as the highest priorities when making decisions. Four in ten roadside managers said their counties had protected native plant community remnants on secondary roadsides. Our findings can inform conservation outreach efforts to those responsible for managing roadside vegetation, and emphasize the importance of addressing safety and soil erosion concerns in roadside research and communications.