Importance of resource diversity to stingless bees in Australia

• Applicant: Professorin Dr. Sara Diana Leonhardt
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 186358927

Biodiversity is known to be crucial for ecosystem functioning and stability. Moreover, species rich systems provide a diversity of resources to be exploited with diversity on one level (e.g., primary producers/resources) strongly affecting other levels (e.g., consumers). But how resource diversity affects other species/ higher trophic levels that depend on these resources has been poorly investigated and shall be addressed in the study proposed here. We attempt to unravel the mechanisms by which resource diversity affects eusocial stingless bees of Australia. Stingless bees collect both floral resources (pollen and nectar) for nutrition, but also other plant materials (e.g.; plant resins) for nest construction, nest defense and to build up their chemical body and nest profiles. We have shown that they collect all these resources from various (albeit not all) plant species available, but it is unclear whether this broad resource collection is by chance or adaptive and whether bees collecting in diverse ecosystems (e.g.; rainforests, suburban habitats) gain a fitness advantage over bees collecting in less diverse habitats or even monocultures (e.g.; timber plantations, eucalypt forests). Whereas it is known that a variety of pollen is needed to sustain a healthy larval development in honeybees and bumblebees, hitherto, no study exists on the effect of pollen diversity on stingless bee larval development. Resin affects colony health (by e.g., reducing the growth of bacteria and fungi), nest properties (such as resilience and stability to temperature), defensive properties (against microbes and predators) as well as chemical communication and recognition within and between colonies. Due to a potential synergistic effect of mixtures, we expect these physiological and chemical functions to be even more pronounced when resins from different tree species are used (instead of resin from only a single tree species). Australia is unique in providing the opportunity to study the same common and widespread stingless bee species in a broad range of ecosystems including both artificial and natural monocultures of crops or trees (representing monotonous pollen, nectar and/or resin sources) and natural and disturbed habitats (e.g.; rainforests or suburban areas with abundant sources of the three resources collected). Therefore, stingless bees in Australia provide the most promising preconditions to compare the consequences of resource diversity vs. resource monotony and unravel the underlying mechanisms.

• DFG Programme: Research Grants
• International Connection: Australia
• Participating Persons: Professor Dr. Nico Blüthgen; Professor Dr. Thomas Schmitt; Professorin Helen Wallace, Ph.D.