Animal teamwork: Bees, bats and birds work together to promote macadamia production

International research team investigates sustainable increase in macadamia nut production

An international research team led by the Universities of Göttingen and Hohenheim has gained new insights into how the interaction between bees, bats and birds significantly increases the quantity and quality of macadamia nuts. In addition, the effectiveness of their ecosystem services (pollination and biological pest control) depends on the altitude of the area and whether there are natural habitats there. In addition to the German universities of Göttingen and Hohenheim, the University of the Free State and the University of Venda in South Africa also took part in the research. The results of the study have been published in the journal Ecological Applications.

"We used both observations and experiments to find out how pollination and pest control - individually and together - influence plant production," explains first author Mina Anders from the Functional Agrobiodiversity and Agroecology research group at the University of Göttingen. Pollination by insects increased the number of nuts fourfold compared to plants without pollinators, which significantly increased yields. At the same time, bats and birds, which feed on insect pests, reduced insect infestation by an average of 40 percent, which improved the overall quality of the nuts. Ingo Grass, Head of the Department of Ecology of Tropical Agricultural Systems at the University of Hohenheim, emphasized the importance of the landscape framework for improving these ecosystem services: ,,Macadamia tree rows aligned perpendicular to natural habitats showed the greatest pollination effects. At the same time, biological pest control decreased at higher elevations, but was enhanced by nearby natural habitats," he noted.

The research results show that pollination and biological pest control are important and complementary ecosystem services that can be optimized through intelligent plantation design and the protection of natural habitats. Catrin Westphal, Professor of Functional Agrobiodiversity and Agroecology at the University of Göttingen, emphasizes the far-reaching implications of the study for sustainable agriculture: ,,By managing these ecosystem services together, we can transition to a more sustainable agriculture. This promotes agricultural productivity and at the same time reduces the need for chemical inputs that endanger biodiversity."

Original publication: Mina Anders et al. Complementary effects of pollination and biocontrol services enable ecological intensification in macadamia orchards. Ecological Applications 2024. https://doi. org/10.1002/eap.3049