Pollinators are the key component of global biodiversity shaping natural-plant communities and supporting human food production. However, pollinating insects, especially bees, are faced with growing pressures
Bees thrive in biodiverse environments, where biodiversity is ultimately linked with plant species diversity and thus the diversity of available food resources. However, the link between floral diversity and composition, the nutritional composition of floral resources and finally bee health is still unclear, particularly in wild bees which are likely less resilient to environmental changes than honeybees. Nor do we understand the differential contribution of different nutrients or nutrient groups to the bees’ health status. Are there species-specific key nutrients or nutrient ratios linked to health? Are such key nutrients associated with specific key plant species? Can increased bee health (as e.g. typically found in more diverse environments) be better predicted by ‘optimal’ amounts and ratios of (critical) nutrients, the mitigation of toxic compounds (e.g. plant secondary compounds, pesticides) and/or the mitigation of infections?
Answering these questions will not only shed light on the mechanisms underlying the known positive correlation between biodiversity and bee health, but also enable us to design better strategies for conserving or restoring biodiversity for bees and thus combat ongoing bee declines.
Bees are essential pollinators of most flowering plants and of many crop plant species. They also contribute to additional ecosystem services, such as biodiversity conservation and landscape aesthetics. Alarmingly, many wild bee populations are in decline. Their decline puts at risk the multiple ecosystem functions and services they are associated with. It is therefore of large concern to scientists and many stakeholders and policy makers alike.
Scientists assume that the loss of floral diversity is a major driver of the observed bee decline. In fact, bees seem to thrive in biodiverse environments, which typically provide a continuous supply of diverse food resources. Moreover, studies conducted in the laboratory have shown that honeybees fed diverse floral diets are healthier than honeybees fed monotone floral diets. However, equivalent field observations are still lacking. And the precise relationship between floral diversity, nutritional intake and bee health is still largely unknown. This is particularly true for wild bees, which have received much less research and attention than managed honeybees.
We combine our expertise in various fields of bee research, including taxonomy, nutritional and chemical ecology, community ecology, physiology, behavior, biostatistics, epidemiology and modeling to elucidate the link between floral biodiversity, nutrition and bee health.
Main objectives of the project are:
- To study how the composition and diversity of food resources collected across environments varying in floral diversity affects the nutritional composition and toxicity (e.g. due to toxic compounds typically found in flowers) of allocated food
- To study how food nutritional composition and toxicity relate to health of different wild bee species
- To determine whether key nutrients can be linked with specific key plant species and habitats, which shall then be targeted by mitigation and conservation actions
The ultimate aim of NutriB2 is to support effectively the health of different wild bee species through protecting/providing nutritionally diverse and appropriate floral resources particularly in low diversity environments. In fact, many wild bee species frequently ignore plants generally used in flower strips, indicating that they do not meet their nutritional needs. Nutritionally appropriate and diverse floral communities will thus not only benefit bee communities, but most likely also other animals depending on plants as resources as well as higher trophic levels. Our approach will consequently enable us to restore overall biodiversity particularly in impoverished landscapes (i.e. landscapes with low resource quantity and quality for bees).
Our work plan:
- We will identify plant species visited by different wild bee species in grasslands differing in floral diversity. To that end we will use next-generation-sequencing
- We will analyze the complete chemical composition including nutrients and toxic compounds of pollen of those plant species
- We will measure differences in the health status of bees within and between species. Health will be quantified through morphometric, physiological and stoichiometric measures
- We will additionally measure bee pathogen e.g. viruses, protozoa loads to capture interactions between nutrition, health and infections in relation to floral diversity
- We will then define species-specific nutritional niches and determine critical key nutrients and plant species and habitats beyond grasslands that cover the nutritional needs of a large fraction of bee species
Specific activities for dissemination of the project’s outputs, knowledge transfer and involvement of stakeholders / policy-makers:
We will closely collaborate with farmers, seed companies, beekeepers and local and international NGOs. We will first reveal informational gaps on the importance of floral resources and nutrition for bees as well as on whether stakeholders have the means to support floral enhancement. We will implement communication platforms, e.g. website, workshops, policy-briefs, newspapers and booklets.
Total requested funding budget is 1.328.784 EUR.