Introduced and native bumble bee species respond differently to floral resources, land cover and trace lead (Pb) concentration along a gradient of urbanization

Pollinators, such as bumble bees (Bombus spp.), provide essential ecosystem services by pollinating a variety of native and non-native plants and helping to maintain wild plant diversity and crop productivity. Variable land‐use activities across the landscape introduce trace metals into our environment. As insect pollinators forage for resources, they interact with the environment, thereby actively and passively collecting trace metals. For a heavy metal like lead (Pb), this is of great concern because of its toxicity and persistence in the soil. Since bumble bees nest in the ground, it is worth investigating their exposure to trace metals in various land‐use settings.  

My research investigated the concentration of select trace metals within bumble bee bodies. The research sites covered various land‐use types (e.g. urban, agricultural) to examine how proximity to anthropogenic activities affect bumble bee trace metal concentrations. In the summer of 2019, I began collecting bumble bee specimens and floral nectar. We found that trace lead (Pb) concentration within bumble bee bodies increased as impervious cover increased. In addition, an introduced bumble bee species, Bombus impatiens, also increased with greater impervious cover, possibly indicating a competitive advantage for this species.  

This interdisciplinary research collaborated with two UBC researcher groups: Dr. Juli Carrillo and Dr. Dominique Weis in the Faculty of Land and Food Systems and the Department of Earth, Ocean and Atmospheric Sciences, respectively. Furthermore, my project included collaboration with two community organizations: Hives for Humanity and Bumble Bee Watch.