Predicting the dynamics of community biomass and size distributions in freshwater communities exposed to long-term warming. PhD in Biosciences (NERC FRESH)

Lead supervisor:
Prof Gabriel Yvon-Durocher, Department of Biosciences, College of Life and Environmental Sciences, University of Exeter

Additional supervisors:
Dr Ben Ashby, University of Bath

Dr Jeremy Biggs, Freshwater Habitats Trust

Prof Isabelle Durance, Cardiff University

The NERC Centre for Doctoral Training in Freshwater Biosciences and Sustainability (GW4 FRESH CDT) provides a world-class doctoral research and training environment, for the next generation of interdisciplinary freshwater scientists equipped to tackle future global water challenges. GW4 FRESH harnesses freshwater scientists from four of the UK’s most research-intensive universities (Bath, Bristol, Cardiff and Exeter) plus world-class research organisations the Centre for Ecology and Hydrology (CEH) and British Geological Survey (BGS).

For an overview of the GW4 FRESH CDT please see website http://www.gw4fresh.co.uk

Note, the research projects listed are in competition with other studentship projects available across the GW4 FRESH CDT Partnership. Up to 14 studentships will be awarded to the best applicants.

Project Description
Rapid evolution is predicted to be an important driver of microbial responses to climate change; but its role in shaping the emergent structure and functioning of novel communities is unknown. This project will integrate experiments with theory to generate a predictive framework to understand how warming affects the structure, functioning and assembly of aquatic communities through interaction between ecological and evolutionary processes. The project will capitalise on an existing long-term experiment, comprising 20 artificial freshwater ponds, half of which have been experimentally warmed (+ 4°C above ambient temperature) for 10 years. By combining measurements of community-wide trait distributions, species interaction networks and ecosystem function in this unique long-term experiment, we will quantify feedbacks between ecological and evolutionary processes across levels of organisation in shaping the assembly of novel communities under climate warming.

We have recently demonstrated that rapid evolutionary change in metabolic traits underpin adaptive responses to warming in a wide range of microbes – including isolates from the long-term warming experiment (Padfield et al., 2015; Schaum et al., in-press). We predict that feedbacks between levels of organisation (individual, population, ecosystem), emerging from the interactions among species in food webs are critical for scaling metabolic traits to ecosystem functioning. This project will break new ground in quantifying the mechanisms that shape the emergence of novel communities and the ecosystem functions they mediate in a warmer world.

The student will begin by quantifying the distributions of metabolic traits within and among species across the metacommunity in the existing 10-year to determine the extent to which rapid evolution has driven trait variation within species relative to variation in the regional species pool. They will then carry out a series of experiments on isolated taxa with strains adapted to both the warmed and ambient treatments to quantify how mismatches in metabolic traits influence biotic interactions. These strains will then be used to seed a new mesocosm warming experiment enabling the student to assess how evolved differences between warm- and ambient-adapted isolates influence the trajectory of community assembly and ecosystem succession. This experimental approach will be complemented by the development of new theory that integrates ecological, evolutionary and metabolic theories.

This is an ambitious and innovative project that spans disciplines (mathematics, ecology, evolution), scales (time and space), and levels of biological organisation (phenotypes to ecosystems). It therefore has great potential to break new ground in understanding the mechanisms through which ecological and evolutionary dynamics shape ecosystem responses to environmental change.

Project specific enquiries should be directed to the lead supervisor, Prof. Gabriel Yvon-Durocher: [Email Address Removed]