Action: Reduce grazing intensity on pastures
Key messagesRead our guidance on Key messages before continuing
One replicated trial has shown that reducing the intensity of summer cattle grazing can increase the abundance, but not the species richness of cavity-nesting bees and wasps.
Supporting evidence from individual studies
In a comparison of six intensively (5.5 cattle/ha) and six lightly (1.5 cattle/ha) cattle-grazed meadows with six ungrazed meadows in Germany, meadows with light grazing had a greater number of individual cavity-nesting bees, wasps and their brood parasites than meadows with intensive grazing (Kruess & Tscharntke 2002). There was an average of 47 emerging individuals/lightly grazed site, compared to 27 emerging individuals/intensively grazed site. Reduced intensity of grazing did not significantly increase the number of bee and wasp species.
Both abundance and total species richness of these insects were significantly higher on ungrazed grassland (11.5 species) than on intensively (4.7 species) or lightly (6.2 species) grazed pastures. These results were linked to an increase in vegetation height as grazing intensity is reduced.