There have been increasing concerns over the decline of insect populations and protecting their biodiversity. New collaborative research reveals how wild bee populations increased after faba bean cultivation while bumblebees benefited from semi-natural habitats.
To help preserve biodiversity, the EU's Common Agricultural Policy has developed methods called greening measures. However, actions such as cultivating nitrogen-fixing legumes like faba beans have been questioned because of lacking evidence supporting their role in biodiversity.
The University of Göttingen, the Julius Kühn Institute, and the Thuenen Institute in Braunschweig published their findings in the Journal of Applied Ecology. Cultivation is inclusive of planting, improving, tending, and harvesting crops.
Also known as fava beans or broad beans, the crop has proved to be beneficial for bumblebees. The team has analyzed wild bees from 30 different agricultural landscapes across Germany. Fifty percent of the landscapes used conventional methods to cultivate faba beans while the rest did not have bean fields.
Nicole Beyer from the Functional Agrobiodiversity Group at the University of Göttingen explained that faba bean nectar could only be accessed by bees with longer tongues, like bumblebees, because it lays deep inside the flowers. The team "wanted to investigate how groups of wild bees, which differ in their external appearance, react to the cultivation of faba beans and whether they can benefit from it."
Bee Tongue Size
In 2014, a study from the Ecological Society of America revealed tongue lengths of various bee species are crucial for pollination. Although bees are generalists, meaning that they can drink nectar and collect pollen from a range of flower species, some bees and plants match better due to various tongue lengths of wild bee species.
For example, short-tongued European bumblebees are better suited for pollinating tomatoes. On the other hand, the Bombus dahlbomii from Patagonia, Argentina, are long-tongued bees favoring flowers like honeysuckle and columbine.
However, bees with longer tongues don't necessarily have an advantage since it hinders them from efficiently collecting nectar and pollen from short flowers. Determining the tongue length of various species can help ecologists keep track of the resilience, invasiveness, and other behavior to preserve bee populations.
FIND OUT MORE: How Do Bees Drink Nectar Exactly?
Thriving Bee Populations
In the recent study, landscapes with faba beans had twice the population of bumblebees than landscapes that had other crops and did not affect other wild bees. The wild bee populations thrived better in semi-natural habitats or agricultural areas that support ecosystems.
Professor Catrin Westphal from the University of Göttingen's Functional Agrobiodiversity shared that their results clearly showed that similar measures in farmed areas could support certain bee species. However, how the wild bees benefited from the agricultural landscapes depended on the types of crops and type of pollinator.
For the best biodiversity, the team proposed "a combination of measures: the cultivation of various flowering arable crops such as faba beans and the promotion or preservation of semi-natural habitats with a diverse range of flowers and nesting sites for many other wild bees."
READ: New Study Traces the African Carder Bee in Western Australia
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