Weed flora in paved areas in relation to environment, pavement characteristics and weed control

By 2015, all herbicide use on public pavements in Flanders (northern region of Belgium) will be phased out. Currently, little is known about weed flora in these pavements or their interactions with different weed control methods. The objectives of this study were to explore the species composition of pavements in relation to various abiotic factors and applied weed control methods. A vegetation survey was conducted on 163 public pavements constructed with small paving elements across Flanders. Botanical composition was determined, and a score for street scene perception was calculated. For each pavement, a set of environmental conditions and technical characteristics was determined, and data on the applied weed control methods were collected. Apart from Musci (mosses), the most important plant species were Poa annua, Sagina procumbens, Conyza canadensis, Taraxacum officinale and Plantago major. Weed species composition and street scene perception were affected by intensity of use, joint width and light intensity. Weed prevention measures may be built into the construction of pavements by manipulating light, joints and use in their design. Repeated use of a single weed control method caused shifts in weed flora. This suggests that more optimal weed control on pavements is likely to be achieved by alternating weed control methods