Weed occurrence on pavements in five North European towns

Abstract

Weeds on pavements in urban areas are unwanted mainly because they cause an untidy appearance or sometimes structural damage. Glyphosate has been the principal weed control method for years, but policies in several European towns have changed to lower dependence on herbicides. Instead, less effective and more speciesdependent non-chemical methods are used, but little is known about the pavement flora. Consequently, we surveyed the flora on pavements in five North European towns [Braunschweig (DE), Malmo¨(SE), Naestved (DK), Royal Leamington Spa (UK) and Wageningen (NL)] by recording weed species and their coverage in 56 recording points randomly placed in each town. Weeds were recorded at several dates in 2005 and 2006 and no weed control was applied apart from sweeping. Weed coverage increased during the survey (averaging 1.4% in late 2006) and was highest in the towns having the strictest policies limiting herbicide use. Most coverage (averaging 2%) was found along the pavement edge away from the road. Poa annua was the most frequently recorded species, followed by bryophytes (mainly mosses), Sagina procumbens and perennial grasses. Grasses and some other species frequently found, notably Taraxacum officinale, should receive particular attention when planning a non-chemical weed control campaign on pavements.

Richness of vascular flora in Lublin city, east Poland, under different urban pressure

“…The number of native species in the study area is comparable in all habitat types. Despite high percentages of AS, widespread generalist native species remain the most common component of urban floras of central Europe, similar to cities in Britain (Roy et al 1999) and northern Europe (Melander et al 2009). The number of AS increases in highly transformed areas and is maintained at the same level in A and F areas.…”

Green Roofs and Green Walls for Biodiversity Conservation: A Contribution to Urban Connectivity?

“…The most common annual species show very competitive strategies for reproduction, such as non-seasonal reproduction, fast germination, and the absence of seed dormancy. Like the flora on stone walls, plant cover is also highly fragmented (e.g., joints between paving-stones) [90,91].…”

“…However, like roofs, they show very extreme environmental conditions, with flora adapted to a hostile environment that includes limited nutrients, water, and soil accumulation due to highly compacted and thin substrates, extreme light and temperature conditions, a variable soil pH, changing water conditions, eutrophication, and disturbances (trampling, intensive management, pets) [88][89][90][91]. Locally, even in this harsh environment, the heterogeneity of abiotic conditions can enhance species diversity [92].…”

Caucalido platycarpi-Vicietum michauxii — a new weed association from crop fields of Kyrgyzstan (Middle Asia)

“…The increasing needs in weed conservation gave inspiration and involved botanists in many conservation projects focused on extinct or disappearing taxa [45]. Biological attributes of endangered species of weeds responsible for their regression [46] or expansion [47] have received less attention. Thus it is really surprising that in Middle Asia, one of the most important regions as far as the weed diversity and richness is concerned, hardly any conservation studies focused on weed flora have been conducted.…”