Friborg (Dpa) – At the edge of orchards, hedges in combination with perennial flowers can create better conditions for wild bees, which are important for pollination. This is what a team led by Vivien von Königslöw of the University of Freiburg writes in the “Journal of Applied Ecology”. The researchers took a closer look at 18 conventional apple orchards in the Lake Constance region over a three-year period.
“In intensive agricultural landscapes, wild bees have often become rare, as only a few flowers are usually available as sources of nectar and pollen,” said von Königslöw of the Institute of Geographical and Environmental Sciences, according to a university statement. For this reason, fruit growers have planted hedges or so-called flower strips near their growing areas.
However, the additional supply of nectar, depending on the flowering stage, is often limited in time. To maintain a diverse and stable community of wild bees, plants that are attractive to bees must be available during the growing season, the study says. The researchers then propose some perennial flowers – for example the mallow or the viper bugloss – in combination with some hedges.
“Our results suggest that perennial flower strips should be planted instead of annual flower strips, because these bloom much earlier in the second year than the planting year and encourage diverse bee communities over the years. Like this one from Königslöw.
Freiburg ecologists were able to observe that wild bees mainly visited the hedges in spring and sometimes continued until June. They visited the flowering strips from June to August in the year of planting, but in the second year as early as April. Overall, the number of bees and species diversity in the flower strips were higher than in the hedges. Their flowering overlaps that of apple trees and ground cover in spring.
© dpa-infocom, dpa: 220926-99-898454 / 2
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