February 8 2017

12:00 158 HH

Beth Pringle
School of Natural Sciences
University of Nevada, Reno

From micro to macro, the trophic regulation of a multispecies protective mutualism


Mutualism is pervasive in ecological systems, and most mutualisms are consumer-resource interactions. The nature of these consumer-resource interactions determines why and where mutualisms form and persist, as well as how they shape whole ecosystems. In this talk, I will discuss my work on ant-plant-hemipteran protection mutualisms in tropical and temperate systems. My work in the dry forests of Central America suggested that trees pay symbiotic ants more to defend their leaves when the climate is drier. But when trees pay ants indirectly, via the hemipteran honeydew that the ants consume, how does this strategy work\? I will discuss evidence from this system that numerous microbes are shared among symbiotic macroorganisms. Moving to a temperate legume-aphid system, I will show that microbes can affect the chemical composition of hemipteran honeydew. In a temperate ant-plant-aphid mutualism, I will show that the chemical composition of honeydew also depends on the plant\'s genotype and can drive changes in ant defensive behavior. Finally, looping back to macro-patterns in the Brazilian Amazon, I will show that the physiological trade-offs imposed on trees by climate could affect community-scale patterns of plant defense and protective mutualisms. This work is assembling evidence that climatic stress and indirect mutualisms can together select for changes in phytochemistry, with implications for feedbacks to nutrient cycles and climate itself.















































































































































































































































































































































































































































































































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