The Function and Management of Roadside Vegetation

Abstract

The structure and composition of roadside vegetation vary from frequently mown grass to shrubs and trees and from artificial landscaping to natural plant communities. Roadside vegetation can perform many important functions, including the provision of habitat for rare plants and animals, a source of seeds for adjacent landscapes, a buffer to reduce the penetration of traffic noise and light, carbon sinks and enhanced aesthetics for road users. In certain situations, roadside vegetation can have negative effects, such as attracting wildlife and increasing rates of wildlife-vehicle collisions (WVC), creating movement corridors for weeds and invasive species, obscuring road signs and damaging road surfaces. 1 Roadsides can support rare and threatened species of plants and animals, and these should be managed for conservation. 2 Vegetation that reduces visibility or poses a traffic hazard should be managed to achieve a compromise between safety and biodiversity conservation. 3 Roadside habitats may act as ecological traps: It is preferable to recreate offset or compensation habitats away from roadsides. 4 The drainage of roads and roadsides must be designed to minimise impacts on adjacent vegetation and habitats. 5 Never plant invasive species (environmental weeds) along roads: Use plants native to the region for roadside soil stabilisation, shade, ornamental planting and control of noise and light pollution. 6 Perennial vegetation cover and ongoing management of roadside vegetation are required to control the continuous threat of weed invasion. 7 The reduction of fuel loads on roadsides should be compatible with biodiversity management objectives. The challenge for management is to comprehensively quantify and understand the role and values of roadside vegetation and manage roadsides to enhance their positive impacts and reduce their negative effects.