Bumble bees and honey bee abundances collected in agricultural landscapes with and without flower strips and honey bee hives
Wild bee declines in agricultural landscapes have led farmers to supplement crops with honey bees. Simultaneously, environmental subsidy and conservation programmes have incentivized farmers to establish flower strips to support wild and managed pollinators. To find out if flower strips enhance, and competition from honey bees suppresses, wild bees in the landscape and across seasons, we surveyed bumble bee and honey bee abundances in 16 sites in Sweden in summer 2018 and spring 2019. The centre of each site (2 km radius) was with or without an annual flower strip, and with or without added honey bee hives. We surveyed bees in each flower strip and in linear habitats in the landscape around each site, such as field edges and road verges. In the following spring, we surveyed bumble bee queen abundance in each site. We show that adding flower strips benefits bumble bee queen abundance the following year, but this effect is diminished if honeybee hives are added. In sites with flower strips, added honey bee hives reduced male bumble bee abundance. Our relatively small flower strip areas bolstered bumble bee population growth across seasons, probably by relieving a resource bottleneck. Adding honey bee hives in combination with flower strips to landscapes with few floral resources should be avoided as it cancelled the positive effect of flower strips.
Bommarco R., S.A.M. Lindström, C.A. Raderschall, V. Gagic, O. Lundin (2021). Flower strips enhance abundance of bumble bee queens and males in landscapes with few honey bee hives. Biological Conservation, 263, 109363.
Queensland Department of Agriculture and Fisheries
Swedish University of Agricultural Sciences
Swedish university of agricultural sciences EkoForsk
Including: Plant Genetics, Agricultural Ecology, Agricultural Technology, Agricultural History
Rearing of animals and/or cultivation of plants.
Environmental resources, protection and conservation.
Geographical areas characterised by specific ecological conditions, processes, structure, and (life support) functions that physically support the organisms that live there. Includes terrestrial and aquatic areas distinguished by geographical, abiotic and biotic features, whether entirely natural or semi-natural.
Territory characterised according to its current and future planned functional dimension or socio-economic purpose (e.g. residential, industrial, commercial, agricultural, forestry, recreational).
Geographical distribution of occurrence of animal and plant species aggregated by grid, region, administrative unit or other analytical unit.