The Secret Life Of Plants🌱Mar 30, 2025
Statistische Belege für die Reduzierung der Wildbienenpopulation im Botanischen Garten #München durch #Honigbienenkonkurrenz
Der Anstieg der Zahl kultivierter #Honigbienen ( #Apismellifera ) in vielen europäischen Städten hat durch Konkurrenzeffekte unbekannte Auswirkungen auf die #Wildbienendichte.
Es fanden sich klare Belege dafür, dass eine hohe #Honigbienendichte zu einer Konkurrenzsituation bei zahlreichen Blumenarten führt.
https://link.springer.com/article/10.1007/s00442-021-04862-6
#Bienen #Honig #Wildbienen #Honigbienen #hymenoptera #Beewashing #Hummel #biodiversität #Bienenliebe #Bienenschutz #artenschutz #Artenvielfalt #Wildpflanzen
High honeybee abundances reduce wild bee abundances on flowers in the city of Munich - Oecologia

The increase in managed honeybees (Apis mellifera) in many European cities has unknown effects on the densities of wild bees through competition. To investigate this, we monitored honeybees and non-honeybees from 01 April to 31 July 2019 and 2020 at 29 species of plants representing diverse taxonomic and floral-functional types in a large urban garden in the city of Munich in which the same plant species were cultivated in both years. No bee hives were present in the focal garden, and all bee hives in the adjacent area were closely monitored by interviewing the relevant bee keepers in both 2019 and 2020. Honeybee numbers were similar in April of both years, but increased from May to July 2020 compared to 2019. The higher densities correlated with a significant increase in shifts from wild bee to honeybee visits in May/June/July, while visitor spectra in April 2019 and 2020 remained the same. Most of the species that experienced a shift to honeybee visits in 2020 were visited mostly or exclusively for their nectar. There were no shifts towards increased wild bee visits in any species. These results from a flower-rich garden have implications for the discussion of whether urban bee keeping might negatively impact wild bees. We found clear support that high honeybee densities result in exploitative competition at numerous types of flowers.

SpringerLink
The Secret Life Of Plants🌱Jan 26, 2025
#Honigbienen - Stöcke verringern die Anzahl der #Wildbienen, den #Artenreichtum und die Fruchtanzahl auf Bauernhöfen, ungeachtet der #Wildblumenstreifen.
Die Ergebnisse unserer #Studie deuten darauf hin, dass die Ergänzung von Farmen durch #Bienenstöcke unter bestimmten Umständen die Fruchtanzahl in bestäuberabhängigen Kulturpflanzen verringern und die Anzahl und #Artenvielfalt der #Wildbienen verringern kann. Obwohl Wildblumenstreifen die Fruchtanzahl in begrenztem Umfang steigerten, linderten sie nicht die mit Bienenstöcken verbundenen Abnahmen der #Fruchtanzahl oder der #Wildbienen auf Farmen. Weitere Bemühungen zur Ermittlung angemessener Schwellenwerte für die #Honigbienendichte im Verhältnis zu den wilden Bestäuberpopulationen würden den Erzeugern bei ihren Managemententscheidungen zugutekommen und ihnen helfen, finanzielle Kosten oder sogar #Ertragseinbußen durch die unnötige Miete von #Bienen-stöcken zu vermeiden
https://www.nature.com/articles/s41598-021-81967-1 #honig #Imker #Massentierhaltung #Artenvielfalt #biodiversität
Honey bee hives decrease wild bee abundance, species richness, and fruit count on farms regardless of wildflower strips - Scientific Reports

Pollinator refuges such as wildflower strips are planted on farms with the goals of mitigating wild pollinator declines and promoting crop pollination services. It is unclear, however, whether or how these goals are impacted by managed honey bee (Apis mellifera L.) hives on farms. We examined how wildflower strips and honey bee hives and/or their interaction influence wild bee communities and the fruit count of two pollinator-dependent crops across 21 farms in the Mid-Atlantic U.S. Although wild bee species richness increased with bloom density within wildflower strips, populations did not differ significantly between farms with and without them whereas fruit counts in both crops increased on farms with wildflower strips during one of 2 years. By contrast, wild bee abundance decreased by 48%, species richness by 20%, and strawberry fruit count by 18% across all farm with honey bee hives regardless of wildflower strip presence, and winter squash fruit count was consistently lower on farms with wildflower strips with hives as well. This work demonstrates that honey bee hives could detrimentally affect fruit count and wild bee populations on farms, and that benefits conferred by wildflower strips might not offset these negative impacts. Keeping honey bee hives on farms with wildflower strips could reduce conservation and pollination services.

Nature