Dr Isabelle Durance
Reader and Director of the Water Research Institute
Freshwaters are hot spots of biodiversity and also vital natural resources on which human well-being depends. However, multiple and often conflicting uses of these waters and their catchments have significantly degraded freshwater ecosystems worldwide. Evidence and tools are urgently needed to guide the management of freshwaters and their catchments within safe environmental limits.
Using an ecosystem approach, my work blends large scale empirical analysis with smaller scale in-situ manipulations, to address pressing questions on:
- The role of river biodiversity in sustaining key ecosystem services
- The role of landscape processes in regulating freshwater biodiversity
- The impact of global changes on freshwater ecosystem
Following a degree in Natural Sciences and a Masters in Engineering (Ingenieur Agronome, Agrotech Paris), I worked in Research & Development in an industrial context (Danone Belgium). I then embarked on a PhD in Landscape Ecology working in Ukraine and France, and developed my research increasingly using freshwater ecosystems as a model during a 10 year lectureship in France (Rouen).
With the support of the Daphne Jackson charity, a charity established to help women back into science, I obtained 3 independent research fellowships after my career break, before being recently awarded a senior lectureship in Cardiff School of Biosciences.
In turn, over the past 5 years in Cardiff, I have had the chance to contribute to academic and public life through involvement in:
- Working groups on biodiversity and ecosystem services, for example by joining the Ecosystem Service Partnership steering committee (ESP), contributing to two chapters of the UK National Ecosystem Assessment, and to the Future Earth working group on biodiversity monitoring.
- Peer reviewing processes for example as part of the NERC peer-review college, NERC and Horizon 2020 panels, and journal associate editorship of the International Journal of Biodiversity Science, Ecosystem Services & Management.
- Training and mentoring of early career researchers.
Currently I also lead 2 interdisciplinary initiatives, the Duress project and the Cardiff Water URI.
My current research focuses on three key areas: the role of river biodiversity in sustaining key ecosystem services, the role of landscape processes in driving freshwater ecosystems, the impact of global changes on freshwater ecosystems.
The role of river biodiversity in sustaining ecosystem services
Since June 2012, I have been leading Duress – Diversity of Upland Rivers for Ecosystem Service Sustainability. The project is part of a major Research Council initiative called BESS - Biodiversity and Ecosystem Service Sustainability - to assess the role of biodiversity in delivering the key ecosystem services on which we rely. This £3.1 million project brings together a consortium of 28 researchers from a range of disciplines and institutions, and is actively supported by seven key stakeholders.
Sustainable management of river ecosystem services depends on understanding the processes that underpin them. For example, we lack quantitative understanding of how river processes contribute to the clarification, purification and cost of clean water. Through in situ experiments and long-term big data analysis (e.g. Raffaelli et al 2014), the NERC-DURESS project is seeking to assess quantitatively how river services such as fish production or water quality regulation depend on river organisms, and whether there are biodiversity thresholds under which a service cannot be delivered or is compromised (Figure 1).
Landscape processes and biodiversity conservation
The spatial distribution and persistence of patches of different habitat quality can determine population viability and species composition within ecosystems. This perspective from landscape ecology is increasingly valued in the conservation or restoration of threatened organisms, particularly where the underlying ecological processes can be identified. Links between landscape pattern, process and biodiversity formed much of my work prior to joining Cardiff University (e.g. Durance & Baudry, Eds. 2003), and this theme continues. Typical approaches combine ordination, linear models and variance analysis with geo-statistics, GIS and remotely sensed data, and these are active areas of both my research and teaching (e.g. Leuven, Durance and Teuuw, Eds. 2002, UKNEA Wales chapter 2011) (Figure 2).
By comparison with terrestrial ecosystems, landscape ecological applications to freshwaters have been few. Previous collaborative work with researchers in Nijmegen (NL), Rouen (F), and CEMAGREF (F) brought landscape and system perspectives to river restoration and ecological risk assessment in the Seine and Rhine, illustrating the importance of scale and spatial pattern in river restoration or fisheries management (e.g. Durance et al 2002; Leuven & Durance 2002, Durance et al. 2006). Similarly, EA/NERC sponsored research into the ecology of three Red-listed snails on English grazing marshes showed how connectivity between suitable ditches has a major influence on distribution (Durance et al. 2006; Niggebrugge et al. 2007, Ormerod, Durance et al. 2010). Recent work has also highlighted the role of spatial distribution and land use on river birds (Morrisey et al 2013, 2014).
Global change impacts on river function
By directly affecting temperature and hydrology, climate affects a range of major processes in river systems. As a result, organisms here may be among the most sensitive of all to climate forcing. Long-term data from the Llyn Brianne experimental catchments (1981-2005) have revealed clear climatic effects on invertebrate assemblages in headstreams (Durance & Ormerod 2007). Results highlighted in the journal Nature suggested that in the most species-rich streams, the abundance of invertebrates in the spring-time could decline by one-fifth for every degree of temperature gain, with major consequences on energy flows. Cooler-water species are most at risk. In the long-term Llyn Brianne catchments, we found evidence for the role of climate in the local extinction of a cool-water triclad Crenobia alpina (Durance & Ormerod 2010). Other species are also at risk. In the adjacent Wye, our research using Environment Agency data showed that populations of Atlantic salmon and brown trout fell respectively, by 50% and 67% between 1985 and 2004, a decrease correlated with mixed models representing a trend towards hotter, drier summers (Clews, Durance et al in 2010). This work is currently complemented by research on the impact of droughts (PhD Ifan Jams)
In river ecosystems, climate change interacts with other stressors such as recovery from pollution and catchment land use (e.g. Watts et al. 2015). Our work on how climate change interacts with other stressors has for example shown that climate affected the recovery pattern of streams affected by acid deposition (Ormerod & Durance 2009) and that recent winter-biased warming in the chalk streams had been insufficient to affect invertebrates negatively over a period of improving water quality (Durance & Ormerod 2009). Current work (e.g. PhD by Marian Pye, is also highlighting the role of land energetics inputs in regulating river ecosystem function.
This research is funded by:
NERC under the BESS programme, I am the lead PI of the DURESS project - Diversity in Upland Rivers for Ecosystem Service Sustainability, a £3.1million consortium project involving 28 researchers across 9 institutions and 7 key stakeholder partners. For more information visit the DURESS website.
The Esmee Fairbairn Foundation which funds the Llyn Brianne Stream Observatory, a 5 year project to provide data and evidence about how best to manage upland stream landscapes.
The European funded MARS project on Managing Aquatic ecosystems and water Resources under multiple Stress. As part of this €9 million consortium, we are studying responses of river biodiversity and ecosystem services to multiple stressors.