A recent Safeguard study published in the Conservation Evidence Journal investigates how the different mowing frequency of urban lawn spaces in the United Kingdom is interlinked with pollinator abundance, suggesting better lawn management practices.
The loss of habitat and foraging resources for pollinators is one of the major drivers of the decline of pollinator populations. As urban green spaces can serve as critical hotspots for pollinator biodiversity and conservation, one way to address pollinator declines is proper management of the floral resources within lawns in urban areas.
Focusing on this issue, Safeguard researchers Morgan A. Morrison and Mark J.F. Brown from the Royal Holloway, University of London tested the effectiveness of different mowing frequencies on the availability of floral resources to pollinators and whether this could increase pollinator communities in urban and suburban building complexes.
To do that, the research group selected the Ministry of Justice prison and court sites, containing four patches: one control patch was mown as normal every two weeks, and then three patches were mown every four, six, or 12 weeks.
Results show that reducing mowing frequency from the typical two-week regime being used at sites before the study, to mowing either every six or 12 weeks, can increase the number of pollinators visiting flowers on lawns by over 170%. Floral species richness was also doubled on patches mown every 12 weeks compared to patches mown every two weeks, and, in turn, pollinator abundance and taxonomic richness were higher on patches with higher floral species richness.
To improve floral resources and pollinator abundance, contributing to a pollinator-friendly future, the authors recommend that lawns within commercial and governmental building complexes are mown at an interval of at least six, but ideally 12, weeks.
Figure: Plot of total pollinator abundance observed against floral species richness in each of the 12 weekly surveys carried out across four locations during June-August 2023.