Environmental Research Institute - Journal Articles
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Item Climate models with delay differential equations(AIP Publishing, 2017-10-17) Keane, Andrew; Krauskopf, Bernd; Postlethwaite, Claire M.A fundamental challenge in mathematical modelling is to find a model that embodies the essential underlying physics of a system, while at the same time being simple enough to allow for mathematical analysis. Delay differential equations (DDEs) can often assist in this goal because, in some cases, only the delayed effects of complex processes need to be described and not the processes themselves. This is true for some climate systems, whose dynamics are driven in part by delayed feedback loops associated with transport times of mass or energy from one location of the globe to another. The infinite-dimensional nature of DDEs allows them to be sufficiently complex to reproduce realistic dynamics accurately with a small number of variables and parameters. In this paper, we review how DDEs have been used to model climate systems at a conceptual level. Most studies of DDE climate models have focused on gaining insights into either the global energy balance or the fundamental workings of the El Niño Southern Oscillation (ENSO) system. For example, studies of DDEs have led to proposed mechanisms for the interannual oscillations in sea-surface temperature that is characteristic of ENSO, the irregular behaviour that makes ENSO difficult to forecast and the tendency of El Niño events to occur near Christmas. We also discuss the tools used to analyse such DDE models. In particular, the recent development of continuation software for DDEs makes it possible to explore large regions of parameter space in an efficient manner in order to provide a “global picture” of the possible dynamics. We also point out some directions for future research, including the incorporation of non-constant delays, which we believe could improve the descriptive power of DDE climate models.Item Towards sustainability in transboundary water resources: The role of inter-state solidarity(SAGE Publishing, 2025-01-28) McIntyre, OwenWhile cooperation regarding the management of transboundary water resources continues to improve in terms of the extent and intensity of inter-State engagement, watercourse States will increasingly need to employ flexible arrangements to facilitate the adaptive management of shared waters in response to the likely impacts of climate change. The legal challenges involved in crafting and applying such arrangements will require greater focus upon the community of interest understood to exist amongst co-basin States, and greater reliance upon the principle of solidarity underlying this concept. Though long a feature of international law, solidarity plays a particularly important role in the continuing development and functioning of international water law, and today offers a set of cooperative values to assist international water law in adapting to the looming global water crisis.Item Acute impacts of biologging devices on the diving behaviour of Manx shearwaters(BioMed Central Ltd, 2025) Clairbaux, Manon; Darby, Jamie H.; Caulfield, Emma; Jessopp, Mark J.; Irish Research CouncilBiologging studies rely on the assumption that equipped animal behaviours are representative of the ones displayed by unequipped individuals. Identifying any tagging effects is therefore necessary to correctly interpret recorded data from equipped animals. The majority of seabird studies report an absence of tag effects using broad metrics such as breeding success or foraging trip duration. However, animals may compensate for tag attachment through increased effort or behavioural responses. We compared foraging trip and dive characteristics of 42 breeding Manx shearwaters (Puffinus puffinus) equipped with a range of biologging tags representing 0.9–3.7% body mass. There was no evidence that increasing tag weight affected foraging trip duration, but individuals equipped with heavier tags travelled shorter distances and at slower speed as well as spending more time in Area Restricted Search behaviour. The number of dives performed per hour of foraging trip was not affected by increasing tag weight, but individuals with the heaviest tags conducted shorter and shallower dives with slower ascent rates than those equipped with lighter tags. Additionally, birds equipped with the heaviest tags increased resting time between dives, suggesting a need to recover from a greater physiological cost of diving when equipped. Our study is one of the few that describe acute tagging impacts on seabird diving behaviour and foraging effort, suggesting that deployments should be kept as short as possible to limit cumulative impacts. © The Author(s) 2025.Item End-of-life wind turbine blades and paths to a circular economy(Elsevier, 2025) Deeney, Peter; Leahy, Paul G.; Campbell, Kevin; Ducourtieux, Claire; Mullally, Gerard; Dunphy, Niall P.; Science Foundation Ireland; Irish Research Council; Sustainable Energy Authority of IrelandA structured literature review is used to identify barriers to the recommended methods of processing end-of-life wind turbine blades. The Waste Management Hierarchy recommends firstly avoidance, then repurposing, recycling, energy recovery and lastly, disposal. The review finds that most recent research articles are concerned with recycling, despite its position in third place in the Hierarchy. The review also identifies the following barriers to the first, second and third most recommended processes: misalignment of financial rewards for blade manufacturers making more durable blades; lack of information about blades which could help repurposing and recycling; and lack of financial incentives for any of the top three methods. Based on these findings the following solutions are proposed: alternative payment structures for blade ownership incentivising blade quality and longevity; an information exchange to facilitate the second hand market, repurposing and recycling; and the widespread use of compliance bonds to provide a financial incentive for repurposing and recycling.Item A continuous feast of bramble: Rubus fruticosus agg. is a key cross‐seasonal dietary resource for a fallow deer population(John Wiley & Sons, Inc., 2025-02-09) Gresham, Amy; Pillay, Kirthana; Healey, John R.; Eichhorn, Markus P.; Ellison, Amy M.; Lowe, Abigail; Cordes, Line S.; Creer, Simon; Shannon, Graeme; Natural Environment Research Council; Wales Biodiversity Partnership; European Regional Development FundContext: Deer (Cervidae) populations are increasing in many global regions, leading to concerns about their impacts on temperate forests. Advancing evidence-based management requires a detailed understanding of the dietary habits of deer and how these are shaped by resource availability. Methodology: We studied the diet of fallow deer (Dama dama) in North Wales (United Kingdom), using faecal DNA metabarcoding. Samples were collected monthly from three woodlands during 2019–2021. Tree surveys and seasonal ground flora surveys were conducted in these woodlands and seven additional woodlands. Preference analyses were used to assess the consumption of plant taxa relative to their availability. Results: The fallow deer consumed high proportions of bramble (Rubus fruticosus agg.) across the seasons, especially in the winter months. Diet diversity was significantly lower in winter compared to the other seasons, suggesting that the deer were bulk foraging on a widely available, predictable resource to conserve energy during winter. Grasses did not form a major component of the diet in any season. The preference analysis showed that spatially clustered woody taxa (e.g. Betula sp., Corylus sp. and Fraxinus sp.) occurred less often than expected in the diet, while widespread woody species occurred in the diet more often than expected (e.g. Rosa sp., Prunus sp. and Quercus sp.). Practical implication: The expansion of deer populations in the United Kingdom has occurred alongside the recovery and maturation of degraded or planted forests since the middle of the 20th century. Despite reduced light availability in these closed-canopy forests and increased herbivory pressure, bramble has remained a dominant understory plant compared to other less herbivory-tolerant plant species. Perhaps as a consequence, bramble has become the winter survival resource for this fallow deer population, remaining a prominent dietary component throughout the year. With increasing disturbance from extreme weather and tree diseases leading to a more open canopy structure, bramble cover is set to increase in European forests, which could support further expansion of deer populations. As we work to expand tree cover and enhance forest resilience and biodiversity, we should seek to understand the dynamic interactions of increasing deer populations with rapidly changing treescapes.