For this purpose, Benjamin Rutschmann and Patrick Kohl set up twelve normally-sized honeybee nests in observation hives across the Steigerwald– the respective proportion of forest in the surroundings varied for each bee colony. The unexpected result was that the bees utilized the forest far less than anticipated based on its contribution to landcover.” Especially in late summer, the supply of pollen in the forest was not guaranteed or inadequate, besides this being an especially important time for the bee colonies and their brood,” says Rutschmann. Barely any plants can cope with the light conditions in beech forests after the canopy closes, so a diverse herb layer that would be so crucial for bees is missing out on,” according to the biologist.
Honeybees need a more varied forest as an environment.
A honeybee (Apis mellifera) gathers honeydew on a fir tree. The research study shows that the beech-dominated Steigerwald provides inadequate food resources for honeybees. Credit: Ingo Arndt
The western honeybee (Apis mellifera) is generally thought of as populating flowering meadows, nevertheless, its original environment was in fact woodland, which provides nesting sites in tree cavities. A recent research study performed by researchers at Julius-Maximilians-Universität Würzburg (JMU) explored the suitability of contemporary deciduous forests as foraging premises for these busy bugs.
For this function, Benjamin Rutschmann and Patrick Kohl set up twelve normally-sized honeybee colonies in observation hives across the Steigerwald– the particular percentage of forest in the environments differed for each bee nest. The two researchers perform research at JMU in the Chair of Animal Ecology and Tropical Biology (Zoology III), which is headed by Professor Ingolf Steffan-Dewenter. The latter was likewise included in the research study, which has just recently appeared in the Journal of Applied Ecology.
Eavesdropping on bee dances
The unexpected outcome was that the bees used the forest far less than expected based on its contribution to landcover. Colonies that lived deep in the forest typically had to take a trip long ranges to find food.
Wild garlic (Allium urisnum) blooming in the forest at springtime. Varied vegetation is essential for the survival of honeybees. Credit: Ingo Arndt
” Especially in late summertime, the supply of pollen in the forest was not guaranteed or insufficient, besides this being a particularly vital time for the bee colonies and their brood,” says Rutschmann. One of the main reasons for this, he states, is the tree types beech, that makes up more than 40 percent of the tree population in the Steigerwald: “Beech forests are dark, there is not much growing on the ground. Hardly any plants can handle the light conditions in beech forests after the canopy closes, so a varied herb layer that would be so crucial for bees is missing,” according to the biologist.
Bees need more diverse forests
Honeydew or blooming tree species, such as linden, black locust, and chestnut, or shrubs such as blackberry and raspberry, do provide bees with an essential source of carbohydrates and, sometimes, pollen as a source of protein during short periods of the year; nevertheless, bees require a well balanced food supply throughout the season. “For a more bee-friendly environment, forests ought to be diversified with insect-pollinated trees– cherry, linden, maple, willow, horse chestnut, or sweet chestnut,” Rutschmann advises. Permitting secondary succession in forest spaces, the natural return of plants and fauna common of a site might assist.
Gloomy outlook: little sunshine permeates through the dense canopy of the beech forest. Credit: Ingo Arndt
As if the lack of food were insufficient of a problem, wild honeybee colonies in handled forests are likewise hampered by the low availability of tree hollows.
In a possible next action, the comparison with other European forest locations with various tree species structure and management could be examined: “Especially the contrast with protected locations, where greater disruptions happen, would be fascinating,” says Benjamin Rutschmann. More natural disruption and less optimization for wood production need to not just increase flower diversity in the forest but likewise enhance the chances of survival of wild-living honeybee nests.
Not just honeybees advantage
Honeybees need a more diverse forest as a habitat. The honeybee, in turn, is one of the most crucial pollinators, along with various other species of wild bees.
A more varied forest benefits not only the honeybee but ultimately the forest itself– a diverse community is a healthy community and less susceptible to pest invasion, for example. “Converting forests to species-rich blended deciduous forests not just promotes biodiversity, however also adjustment to future climate conditions,” highlights Ingolf Steffan-Dewenter.
Recommendation: “Foraging ranges, habitat preferences and seasonal colony performance of honeybees in Central European forest landscapes” by Benjamin Rutschmann, Patrick L. Kohl and Ingolf Steffan-Dewenter, 10 April 2023, Journal of Applied Ecology.DOI: 10.1111/ 1365-2664.14389.