Ecological and economic benefits of low‐intensity urban lawn management

Abstract

Intensive management of urban lawns is globally widespread, predominantly for aesthetic reasons. However, a growing body of knowledge demonstrates negative ecological and environmental effects of this practice. We present a meta‐analysis of North American and European studies from 2004 to 2019, which incorporates three previously unpublished datasets from eastern Canada, to investigate how mowing intensity impacts the ecology of urban lawns. The meta‐analysis provides aggregated evidence that invertebrate and plant diversity is lower in urban lawns under increased mowing intensity. This decline is independent of the level of contrast between mowing ‘treatment’ and ‘control’ (e.g. height or frequency of mowing), which differed considerably between studies. Intensive mowing also increases the occurrence of pest species (e.g. herbivorous beetle larvae and allergenic plants), though studies in this group were limited to northern environments. Changes in ecosystem‐level variables (soil temperature, soil moisture deficit and carbon deficit) were less evident and suggest changes in abiotic processes may take longer to become apparent. An economic case study of the mowing costs in Trois‐Rivières, Canada, suggests that cost savings of 36% may be possible with a modest reduction of mowing frequency. Synthesis and Applications. Increasing urban biodiversity and reducing greenhouse gas emissions are strong motivators for reducing lawn management intensity. We also suggest that the benefits of reducing pest species while saving lawn management costs may provide additional social and economic incentives for decision makers to review urban greenspace management practices.

Flower power in the city: Replacing roadside shrubs by wildflower meadows increases insect numbers and reduces maintenance costs

“…Although our cost estimates are therefore not directly transferable to other communities, the cost differences between the vegetation types we studied are consistent with other sources of information, which indicate-for roadside vegetation-considerably lower costs for the maintenance of "landscape lawns" than for frequently mown "utility lawns" (three times more expensive than landscape lawns) or woody areas (six times more expensive) [159]. Therefore, our cost estimates confirmed that wildflower meadows can be a promising option not only to increase the value of green spaces for biodiversity [18], but also to reduce maintenance costs [26,48,160]. This fact may lead to an increased planting of urban flower meadows in the future, since in addition to positive effects on biodiversity and contextdependent considerations of aesthetics and public perception, human resources and economic sustainability are important [48].…”

Socio‐psychological factors, beyond knowledge, predict people’s engagement in pollinator conservation

“…In particular, reduced mowing of lawns is a simple action that can benefit pollinators by increasing the availability of floral and larval food sources (Watson et al, 2020). Whilst reduced mowing is perceived as untidy by some portions of the public, a recent…”

Public attitudes toward biodiversity‐friendly greenspace management in Europe

“…Urban grasslands encompass a wide range of different types, from short-cut and sometimes irrigated lawns with ornamental and recreational functions to less-intensively managed tall-grass meadows (Figure 1; Tables S1 and S2; Rudolph et al, 2017;Sehrt, Bossdorf, Freitag, & Bucharova, 2020). Tall-grass meadows are typically mown once or twice per year in late summer and can provide habitat for native plants and animals (Cilliers et al, 2004;Norton et al, 2019;Watson, Carignan-Guillemette, Turcotte, Maire, & Proulx, 2020). Converting lawns to meadows significantly increases their value for biodiversity (Chollet, Brabant, Tessier, & Jung, 2018;Wastian, Unterweger, & Betz, 2016) and bene-fits ecosystem functions such as pollination or heat regulation (Ignatieva & Hedblom, 2018).…”