Resilience in marine ecosystems: the effects of environmental and ecological context on ecosystem multifunctioning and multistability

Background and significance of research: -

The lack of knowledge regarding how biodiversity simultaneously contributes to ecosystem stability and functioning in complex ecological networks is a key challenge in ecology. We now know that biodiversity is important because different species are capable of simultaneously maintaining multiple ecosystem processes through time and space (Gamfeldt et al. Ecology 2008, Isbell et al. Nature 2011). A similar understanding of how species contribute to multiple forms of stability, e.g. variability, resilience, resistance, and persistence is lacking, yet similar mechanisms may prevail (Donohue et al. Ecology Letters 2013). This project is focused on assessing how species simultaneously contribute to a range of different ecosystem stabilities, rather than functions. Specifically, the project will assess how species traits, e.g. body mass or food web connectedness, explain variation in their contribution to multiple forms of stability.

The project will employ a newly commissioned large-scale marine mesocosm facility based at Queen’s University Marine Laboratory. The mesocosm facility employs over 100 x 45 litre mesocosms that emulate intertidal rock pools and provides an unparalleled scale of replication. The multiple stabilities of assembled rock pool food webs will be experimentally assessed experimentally in relation to species traits, such as body size, linkage density and trophic level. The PhD is aligned with the Marine Ecosystem Research Program (MERP) see http://www.marine-ecosystems.org.uk/, and will contribute to an ongoing collaboration with partners in Switzerland, Spain and Ireland, there will be extensive opportunities for collaboration with these groups. The project will combine experimental and computer simulation based approaches to assess the stability of model marine food webs, developing new mathematical models to explore the relationship between biodiversity and multiple forms of ecosystem stability.

Research aims: -

1. How do species traits affect multiple forms of ecosystem stability (variability, resistance, resilience, robustness and persistence)?
2. How do species traits affect multiple forms of ecosystem functioning (primary and secondary-production, nutrient dynamics, and respiration)?
3. How do concepts developed for ecosystem multifunctioning apply to multiple forms of stability?
4. Assess using computer simulations the role of traits for food web stability (reflecting experimental tests in mesocosms).

This project will be supervised by Professor Mark Emmerson and Dr Nessa O’Connor of Queen’s University Belfast.