Mapping metabolic responses to understand coexistence and community functioning

The metabolism of organisms affects the productivity of populations and communities. However, the relationship between organismal metabolism and species interactions has been scarcely explored. Hence, predicting the rates at which entire communities flux energy and resources remains difficult. My work shows that the metabolism of organisms measured in isolation does not reflect their performance in communities because species interactions alter how organisms uptake and expend resources. Understanding how such interactions affect metabolism is essential to estimate productivity and how it will change with biodiversity loss and global warming. I propose to use marine phytoplankton as a model laboratory system to determine how metabolic responses to competitors affect coexistence and community functioning. My goal is to connect metabolic theory, that studies physical constraints on the metabolism of organisms in isolation, with community ecology, that centres on species interactions and emergent community properties. Based on my preliminary data, I will map metabolic responses between species that compete for similar resources and test whether these responses stabilise coexistence. I will leverage developments in transcriptomics of non-model organisms to identify the metabolic pathways that underpin metabolic responses. From this basis, I will extend my analysis on larger temporal and biological scales – I will determine how warming modifies metabolic responses and community productivity and, finally, how metabolism evolves in communities. Altogether, this project will demonstrate how metabolic adjustments influence the diversity and functioning of communities. I will use a system that is ecologically important because phytoplankton support 50% of global oxygen production. These results will have broad implications for our understanding of biological systems because the metabolic impact of species interactions shapes the physiology and evolution of all organisms.