Hedgerows and perennial flower strips are complementary in supporting wild bees in orchards by offering constant resources throughout the growing season, according to research from the University of Freiburg. The findings are published in The Journal of Applied Ecology by the British Ecological Society.
According to research on the pollination needs of wild bee populations there, hedgerows and perennial flower strips have complementary flowering times that work together to increase the diversity and abundance of wild bees in intensively farmed orchards.
Early in the season, wild bees went to flowering hedges from March to June. Later in the season, they went to perennial flower strips from June to August the first year they were planted and from April on in the years after that.
Based on what they found, the researchers suggest that farmers plant a network of perennial flower strips and flower-rich hedges to help wild bees.
“For enhancing wild bees in intensive agricultural landscapes, one should provide a network of perennial flower strips and some well-maintained hedges to create a continuous flower offer over the entire growing season,” said Dr. Vivien von Königslöw, the study’s lead author.
Also, the researchers say that annual flower mixtures should be avoided in favor of perennial flower mixtures, which include plants like viper’s bugloss and mallow.
“Our findings imply that perennial flower strips should be planted more frequently than annual flower strips because they flower much earlier in the second year of establishment than in the first year of sowing and draw in various bee communities over time. They are therefore better suited to increasing bee diversity. Dr. von Königslöw said.
Despite the fact that hedges and flower strips were found to work well together, the researchers concluded that flower strips provided the greatest benefits to wild bees because they bloomed during times when other flowers were in short supply. Hedges, on the other hand, mostly encircle apple trees and spring-blooming orchard ground vegetation.
Wild bees are scarce in areas of intensive agriculture due to the scarcity of flowers that serve as sources of nectar and pollen. Since crop systems like apple crop systems rely on pollination, this is a problem for farmers.
Wild bee populations need to have access to flowers that bees like all through the growing season. However, in mass-flowering monocultures like fruit trees, flowers are usually only in bloom for a short time.
In the 2018–2020 study, 18 apple orchards in Germany’s Lake Constance region—a significant apple-growing region—were compared for flower resources and wild bee populations. Orchards had different parts, such as a mix of perennial flower strip, improved hedges, and sown herbs.
