Delayed mowing promotes planthoppers, leafhoppers and spiders in extensively managed meadows

Abstract

Biodiversity‐rich grasslands have been severely impacted by agricultural intensification. Although agri‐environment schemes (AES) have been launched partly to combat grassland biodiversity erosion, they could neither halt nor revert it, and this calls for alternative solutions. We carried out controlled experiments on the effects of three mowing regimes on the arthropod biodiversity of extensively managed meadows, testing whether alternative mowing regimes can improve AES effectiveness: (i) mowing according to the Swiss AES prescriptions, i.e. first cut not before 15 June (control meadows); (ii) first cut not before 15 July (delayed mowing); (iii) refuge left uncut on 10–20% of the meadow area, otherwise first cut not before 15 June. Leaf‐ and planthoppers (Auchenorrhyncha) and spiders (Araneae) were sampled before and after mowing during 3 years, which enabled testing for immediate (within season) and carry‐over (1 year to the next) effects. Regarding immediate effects, Auchenorrhyncha and Araneae increased in abundance under the delayed mowing regime, with densities 3.5 and 1.8 times higher, respectively, than in control meadows. Furthermore, a positive carry‐over effect was detected for Araneae density under the delayed mowing regime. The refuge mowing regime had no effect on abundance. Finally, no statistically significant changes were detected for species richness and diversity (Shannon index) after 2 years of manipulations. We conclude that delaying the first cut in extensively managed meadows promotes these two taxa. It could be easily implemented by slight adjustments of the extant grassland AES.

Urban meadows as an alternative to short mown grassland: effects of composition and height on biodiversity

“…, Buri et al. ). Urban meadows, however, warrant separate attention as conditions, and constraints, differ substantially from agricultural systems.…”

“…While the potential benefits to people and wildlife are widely articulated, and there are some studies of human responses (Jiang andYuan 2017, Southon et al 2017), there is little work quantifying the ecological effects of different types of urban meadows in public greenspaces (Klaus 2013). This contrasts with the more extensive examination of the ecological effects of increasing wildflower coverage in agricultural systems (Knop et al 2006, Haaland et al 2011, Buri et al 2016. Urban meadows, however, warrant separate attention as conditions, and constraints, differ substantially from agricultural systems.…”

Larval and phenological traits predict insect community response to mowing regime manipulations

“…) and spiders (Buri et al. ) remained high in the uncut delayed meadows, compared to control meadows mown mid‐June (Appendix : Table S4). Delaying mowing allows more individuals to reproduce before the first cut, leading to higher abundances in the next spring.…”

“…Appendices 1 and 2 in Buri et al. () provide a map and the coordinates of the study sites, respectively.…”

“…The elevation of the sites ranged from 390 to 826 m, annual precipitation from 845 to 1,148 mm, and mean annual temperature from 13.7°to 16.3°C. Appendices 1 and 2 in Buri et al (2016) provide a map and the coordinates of the study sites, respectively.…”