Biodiversity Research Seminar Series (BRS)
BRS Lauren Ponisio: Disease in plant-pollinator communities
January 25, 2023, 12:00 pm to 1:00 pm
Zoom webinar link for remote attendees:
https://ubc.zoom.us/j/66364136696?pwd=OVp2UW10Ulp5eCtncTVzQ3pvWmFZUT09
Passcode: 202209
host: Risa Sargent
Title: Disease in plant-pollinator communities
Abstract:
Infectious disease prevalence is among the top five drivers of global extinction, including in wild bees. With the global decline of wild bees, our work aims to contribute to understanding how community characteristics shape infectious disease prevalence in plant-pollinator communities. Infectious parasites can influence host immunity, physiology, and reproduction. The sharing of floral resources is a common mode of disease transmission among pollinators. Increasing host aggregation on floral resources can increase disease prevalence (i.e., ``amplification"). Conversely, high host species diversity---even if accompanied by host aggregation---may dilute infection (`dilution"). Because bees pick up parasites from flowers, but not all flowers transmit parasites equally, flower abundance and diversity may further contribute to parasite dilution. In three systems, mass-blooming sunflower in Yolo Co., CA, harvested forests in Coast Range, OR, and high elevation meadows across the Southwestern U.S., I examine how the factors that shape plant-pollinator abundance and diversity and the ramifications for parasite prevalence in wild bee communities. Across all systems, ~40% of bees have at one parasite. Both natural (phenology) and human-induced (years post-harvest, mass-blooming crops) modification of the bee and floral communities indirectly affected parasitism by altering host community characteristics. I found a consistent amplification effect of host (bee) abundance and detected dilution through either host diversity or floral diversity in each system.