YES-27-B-05: Changing floral landscapes: How ecological and environmental conditions shape pollinator food supply across the UK
Pollinators are declining worldwide, driven in large part by the loss and degradation of habitats and the resulting reduction in the floral resources (pollen and nectar) they depend on. Pollen and nectar are the primary food resources for bees and many other pollinators, yet their availability has declined substantially in many landscapes, with nectar availability in the UK falling by more than 30% since 1930 (Baude et al. 2016). As a result, many agri-environment and pollinator conservation schemes focus on increasing floral resources by providing more flowers.
But flower abundance is only part of the story. The quantity and quality of floral resources produced by a flower can vary greatly, even within the same plant species. The same species growing in a cool, wet meadow and a hot, drought-stressed landscape may provide very different quantities and nutritional qualities of pollen and nectar. This variation can be driven by differences in soil conditions, temperature, water availability, and other environmental conditions, with important consequences for pollinator foraging and population dynamics, and plant reproduction. Yet this within-species variation is largely ignored in pollinator conservation because we still know remarkably little about what drives it.
This is a major gap in our understanding of pollinator food supplies. If floral resource production changes with environmental conditions, then current approaches that estimate pollen and nectar availability from the abundance and identity of flowering plants may substantially over- or underestimate the food available to pollinators. It also limits our ability to predict how floral resource supplies and pollinator populations will respond to ongoing climatic and land-use change, including warming, drought and shifts in habitat management and soil condition.
The project will determine what drives floral resource quantity and quality, how this affects pollinator visitation and plant reproductive success, and scale these relationships up to UK landscapes. Its aim is to understand how pollinator food resources respond to environmental change, providing crucial evidence for conservation, land management and policy.
Research questions
- Which environmental and ecological factors influence the quantity and quality of floral resources produced by a plant?
- How do the quantity, nutritional quality and complementarity of floral resources influence pollinator visitation and plant reproductive success?
- How can this information be used to predict the effects of environmental and land-use change on pollen and nectar availability for pollinators across the UK?
Research approach
The project will combine field ecology, controlled experiments and spatial modelling, focusing on ten key plant species that together provide a large proportion of the UK’s floral resources. By concentrating intensive measurements on this small but disproportionately important set of species, the project can generate detailed species-level understanding while scaling these relationships up to UK landscapes. Pollen and nectar will be sampled across replicated environmental gradients, using established methods to quantify resource quantity and nutritional quality and relate these to variation in soils, weather, habitat and land use. Controlled experiments will then grow focal species under contrasting environmental and soil conditions identified as important in the field, testing causal effects on pollen and nectar production, pollinator visitation and seed set. Additional field experiments will examine whether the nutritional composition of pollen, including its complementarity with surrounding floral resources, influences pollinator visitation. Finally, these relationships will be integrated with spatial environmental and vegetation data to model landscape-scale variation in floral resource supply and explore responses to future environmental and land-use change.
Skills and Training
The student will have a background in biological or environmental sciences and an interest in field ecology, pollinator conservation and environmental change. Experience of fieldwork, data analysis or programming would be useful but is not essential.
The student will receive multidisciplinary training in pollination ecology, floral resource sampling and analysis, statistical analysis and spatial modelling, alongside broader training in scientific communication, data analysis and other transferable research skills.
Further Reading
Baude M, Kunin WE, Boatman ND, Conyers S, Davies N, Gillespie MA, Morton RD, Smart SM, Memmott J. (2016) Historical nectar assessment reveals the fall and rise of floral resources in Britain. Nature. https://doi.org/10.1038/nature16532
Vaudo, A.D., Tooker, J.F., Grozinger, C.M. and Patch, H.M., 2015. Bee nutrition and floral resource restoration. Current opinion in insect science, 10, pp.133-141. https://doi.org/10.1016/j.cois.2015.05.008