Dr Ian Vaughan
My research focuses on the processes that shape communities over ecological and evolutionary timescales, and how they respond to environmental change. Much of this focusses upon river systems, for their rich diversity, importance and because they are an excellent model system for asking general ecological questions. This encompasses processes acting across a wide range of scales, from individual trophic interactions and food resource dynamics, through management interventions, land cover and fluvial geomorphology, to large-scale climatic effects. A variety of approaches is used to address these questions, including novel field studies, analysis of large data sets, null models, network analysis, experiments and molecular analyses.
Course Director: MSc Global Ecology and Conservation
Module Leader: BIT051 Assessing Biodiversity and Ecosystems
I read Biology at Bristol University (1997–2000) before making the trip over the Severn bridge to Cardiff to undertake a PhD (2000–4) with Prof. Steve Ormerod. The PhD focused on species distribution modelling, with river birds as a model system. Two years of post-doctoral work in Cardiff followed, contributing to the understanding of how ecology interacts with physical habitat in rivers.
In September 2006, I was awarded a Research Councils UK fellowship allowing me to pursue my research interests in river systems and quantitative methods, before moving onto a lectureship in September 2011. I was awarded a Cardiff University Research Leave Fellowship for the academic year (2016-17) and was a Visiting Research Scholar at the University of Vermont in 2016.
Current projects include:
Null model analysis of ecological networks
Null models are valuable tools for analysing community structure, and can help distinguish the roles of different processes in structuring ecological networks including food webs and pollinator networks. A fundamental question is the extent to which structure results from chance (e.g. interactions occur more frequently with common species cf. rare species) as opposed to choice (e.g. dietary preferences). In collaboration with Bill Symondson, we developed a null model for separating these two processes in prey choice and recently generalised this to whole network structure (Agusti et al. 2003; Pearson et al. 2018). This is now being applied in the research group to studies of diet, pollination and food web structure across a range of systems.
I wrote and maintain the econullnetr package for R (Vaughan et al. 2018), available from the Comprehensive R Archive Network (https://CRAN.R-project.org/package=econullnetr), which makes it possible to run these analyses with a range of different data sets. My GitHub site hosts the most recent development version (https://github.com/ivaughan).
Long term changes in British rivers
Many UK rivers have changed greatly over recent decades. In and around urban areas, the news in generally good, with large scale-recovery from historical water quality problems, whilst elsewhere the news is less positive, with stressors such as fine sediments becoming increasingly important. Trying to understand the effects of a changing climate further complicates the mix. Work in this area has helped to elucidate the changes in river communities that have occurred, both nationally and more locally (e.g. Vaughan & Ormerod 2012, 2014), and continues to grapple with the challenge of determining the roles of different stressors (e.g. Vaughan & Gotelli, in press).
Land use impacts on streams
Rivers reflect their catchments and land use can impact river ecosystems in manifold ways, including effects on the hydrology, water quality and availability of food resources. This opens up possibilities for managing the riparian zone and wider catchment for the benefit of river ecosystems. Combining large data sets, fieldwork and molecular analysis of predator diets, we are investigating the mechanisms by which land cover affects stream ecosystems, and the implications for long-term resilience (e.g. Pearson et al. 2016; 2018).
Current students (lead or co-supervisor)
- Fiona Joyce: ‘Does riparian woodland increase the resilience of stream ecosystems to floods and droughts?’ (NERC)
- Rowena Diamond: ‘Diagnosing and mitigating the adverse effects of extreme winter climate on salmonoid spawning’ (EU KESS)
- Max Tercel: ‘The effects of invasive ants on island food webs’ (NERC)
- Nick Tew: ‘Urban Buzz: quantifying and manipulating the resources available to pollinators in urban gardens’ (NERC)
- Jordan Cuff: ‘Nutrient-specific foraging and the role of spiders as aphid predators’ (BBSRC)
- Sarah Davies: ‘Projecting the effects of climate change on prey selection and dietary competition between reed bed warbler species’ (NERC)
- Richard Facey: ‘The effects of local weather variation on the seasonal fecundity of the barn swallow Hirundo rustia’
- Jez Smith: ‘Impacts of climate change on pied flycatchers (Ficedula hypoleuca); from individual behaviour to population change’ (NERC)
- Ewan Stenhouse: ‘Is food availability and choice a limiting factor for declining UK Hawfinch populations?’ (NERC)
- Rebecca Young: ‘Saving an iconic species from extinction in the UK: interactions between diet, parasites and environmental change’ (NERC)
- Richard Burger: ‘Reticulated pythons in the Kinabatangan: coping with an altered landscape’. (Danau Girang Field Centre)
NERC (including the recent £3.1m Diversity in upland rivers for ecosystem service sustainability (DURESS) project: http://nerc-duress.org/)
EU (including the €9m Managing aquatic ecosystems and water resources under multiple stressors (MARS) project)
Natural Resources Wales