Using pollen meta-barcoding to understand pollinator preferences in urban greenspaces

Miss Katherine Berthon¹, Dr Freya Thomas³, Dr Liz Miller², Professor Sarah Bekessy¹, Dr Francisco Encinas-Viso²

¹Royal Melbourne University of Technology, Melbourne, Australia, ²Centre of Australian National Biodiversity Research, CSIRO, Canberra, Australia, ³Urban Forest and Ecology Team, The City of Melbourne, Melbourne, Australia

Abstract:

Urban green spaces form important habitats for animals in an increasingly urbanised world. Recommendations on plant species combinations for use in urban green space is likely to be highly context dependent, but information is lacking on the use of urban plant resources at the level of specific plant-animal interactions. Using a pollen DNA metabarcoding approach, we investigate the plant preferences of three dominant groups of pollinators (honeybees, hoverflies and solitary native Australian bees) in native and non-native planted garden beds in Melbourne CBD. We describe the overlap in plant taxa between pollinator groups and analyse for structural changes in plant-pollinator networks in relation to garden bed origin, floral density and floral diversity.

Network analysis revealed very little structural difference in networks constructed for native and non-native beds, nor did the type of garden bed influence species level metrics such as specialisation. Instead, the diversity of flowering genera and differences between pollinator types influenced patterns in specialisation (d’), linkage density, pollen richness and vulnerability to extinction. There was a large overlap in the plants used by pollinators, with plant families such as Asteraceae being highly attractive to all groups. Some native grasses such as Poa were also present in pollen samples from native bees and hoverflies but not honeybees. Heterogeneity in diversity of flowering plants across sites and the plethora of weeds present in pollen samples indicate the importance of management practices in designing garden beds that provide useful foraging habitat for urban pollinators.

Biography:

Katherine is an urban ecologist interested promoting co-existence between people and nature in cities. Grounded with a diverse research background in animal behaviour and ecology, her PhD research focuses on informing design guidelines for enhancing biodiversity in urban areas.