The effects of late cutting on threatened bumblebees Bombus spp. in sea wall grassland at Goldhanger creek, Essex, England.
Sea wall flood defences provide important grassland habitats for bumblebees in the UK but cutting in July and August could be deleterious for declining species, such as the shrill carder-bee Bombus sylvarum. The effect on the abundance of bee species of changing the timing of cutting to an annual late cut (after 15 September) on a sea wall at Goldhanger Creek on the Essex coast was compared with a control sward which was cut annually in July or August from 2013-18. On the late cut sea wall there was a significant increase in the overall abundance of threatened bee species, probably because the later mowing avoided the destruction of nests constructed close to the ground. The increase in bee numbers did not correspond with a change in overall forage plant species richness or red clover Trifolium pratense abundance. Late-nesting bumblebees are likely to be favoured by delaying the timing of cutting to later in the season.