Research
We study how the environment, including the interactions within and between species, regulates the rate at which organisms use energy and resources - in plain terms, breathe and eat. Our goal is to identify general rules for how organismal physiology shapes communities, keeping into account that physiology is plastic and evolves in response to the environment.
Can plastic and evolutionary changes in physiology explain how species interact, and the biodiversity and productivity of communities?
To answer this question we use marine phytoplankton as a model system — phytoplankton are tiny algae that are key players in ocean productivity and carbon uptake. We combine manipulations of communities and environmental conditions with high-throughput phenotyping of metabolism and growth at different scales, and species traits, such as body size and competitive ability.
Can plastic and evolutionary changes in physiology explain how species interact, and the biodiversity and productivity of communities?
To answer this question we use marine phytoplankton as a model system — phytoplankton are tiny algae that are key players in ocean productivity and carbon uptake. We combine manipulations of communities and environmental conditions with high-throughput phenotyping of metabolism and growth at different scales, and species traits, such as body size and competitive ability.
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Metabolic plasticity to species interactions
Metabolic rate varies between individuals of the same species and size. Some of this variation can be explained by differences in population densities because organisms often reduce metabolism in crowded conditions. But what drives metabolic suppression? Food certainly plays a role but it is not the only cause! Organisms can perceive when they are in crowded conditions and seem to adjust their metabolism accordingly (Lovass et al. 2020). We are studying the mechanisms and consequences of metabolic regulation within and between species - this can ultimately help explain population growth and species coexistence since metabolism affects the ability of an organism to compete and reproduce. |
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Community functioning and scaling patterns
The metabolism of organisms scales predictably with size for many species. These scaling relationships could be valuable tools to infer the metabolism of entire communities. But empirical tests suggest that the metabolism of species in isolation does not reflect what happens in communities. We are exploring two main questions: 1) how much do species interactions matter when scaling from species to communities? 2) How do environmental conditions modify these effects? We aim to find general rules for how species interactions and density-dependent processes affect organismal metabolism and, in turn, the productivity and stability of communities (Fant & Ghedini 2024). |
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Evolution in and of communities
Most organisms adjust their metabolism almost instantaneously in response to varying ecological conditions, e.g. the presence of conspecifics or other species. But how does metabolism evolve in response to species interactions? In a community, multiple competitors can present different selective pressure so it is difficult to anticipate which traits are favoured. We leverage the rapid life cycle of phytoplankton to track the trajectory of species metabolism, size and competitive ability in communities to determine how species evolve and explain changes in community assembly and functioning. See our recent work on this topic: Briddon, Estevens & Ghedini 2025; Briddon, Garcia & Ghedini 2025. |
Funding
2024-2029: ERC Starting Grant 2023 to Giulia Ghedini, project META_FUN: Mapping metabolic responses to understand coexistence and community functioning.
2021-2024: Junior Leader Incoming fellowship to Giulia Ghedini from ”la Caixa” Foundation and from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 847648 (LCF/BQ/PI21/11830001).
2024-2029: ERC Starting Grant 2023 to Giulia Ghedini, project META_FUN: Mapping metabolic responses to understand coexistence and community functioning.
2021-2024: Junior Leader Incoming fellowship to Giulia Ghedini from ”la Caixa” Foundation and from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 847648 (LCF/BQ/PI21/11830001).
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