Description:

Shalene Jha, PhD,
Assistant Professor,
Section of Integrative Biology,University of Texas, Austin,

Location: Chicago Botanic Garden

Abstract:

More than 60% of earth’s terrestrial surface is managed by humans as agriculture, pasture, or urbanized areas, and land conversion continues to be the primary driver of global biodiversity loss. Despite this, little is known about the impacts of land management on multi-species interactions, gene flow, and ecosystem function. My research program investigates ecological and evolutionary processes from genes to landscapes, to quantify global change impacts on plant-animal interactions, movement ecology, and the provisioning of ecosystem services. Specifically, we study the complex and dynamic nature of wild bee foraging and dispersal, with implications for pollination success and plant gene flow. We show that wild bumble bee foraging is far more plastic and extensive than previously believed and does not follow a simple optimal foraging strategy; instead wild bees exhibit a multi-scalar, risk-averse, and phenologically-driven foraging strategy. By looking at fine-scale patterns of spatial genetic structure in wild bees, we provide evidence of highly localized dispersal (1-9km) and also reveal that genetic structure is responding to human land-use at very short time scales, indicating a sensitivity to land-conversion events within decades of alteration. Finally, using a pollinator species-specific mapping of pollen movement across multiple landscapes, we provide evidence that long-distance dispersal is facilitated by small-bodied bee species almost to the same degree as large-bodied species, likely through pollen carry-over. This work contradicts conventional wisdom that large-bodied pollinators should be prioritized for the conservation of long-distance pollination services and suggests that pollen-carryover may be playing a more important role in pollen-mediated gene flow than previously expected.