| 1. |
- Chauvet, Eric, et al.
(författare)
-
Litter decomposition as an indicator of stream ecosystem functioning at local-to-continental scales : insights from the European RivFunction project
- 2016
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Ingår i: Large-scale ecology. - London : Academic Press. - 9780081009352 ; 55, s. 99-182
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Bokkapitel (refereegranskat)abstract
- RivFunction is a pan-European initiative that started in 2002 and was aimed at establishing a novel functional-based approach to assessing the ecological status of rivers. Litter decomposition was chosen as the focal process because it plays a central role in stream ecosystems and is easy to study in the field. Impacts of two stressors that occur across the continent, nutrient pollution and modified riparian vegetation, were examined at > 200 paired sites in nine European ecoregions. In response to the former, decomposition was dramatically slowed at both extremes of a 1000-fold nutrient gradient, indicating nutrient limitation in unpolluted sites, highly variable responses across Europe in moderately impacted streams, and inhibition via associated toxic and additional stressors in highly polluted streams. Riparian forest modification by clear cutting or replacement of natural vegetation by plantations (e.g. conifers, eucalyptus) or pasture produced similarly complex responses. Clear effects caused by specific riparian disturbances were observed in regionally focused studies, but general trends across different types of riparian modifications were not apparent, in part possibly because of important indirect effects. Complementary field and laboratory experiments were undertaken to tease apart the mechanistic drivers of the continental scale field bioassays by addressing the influence of litter, fungal and detritivore diversity. These revealed generally weak and context-dependent effects on decomposition, suggesting high levels of redundancy (and hence potential insurance mechanisms that can mitigate a degree of species loss) within the food web. Reduced species richness consistently increased decomposition variability, if not the absolute rate. Further field studies were aimed at identifying important sources of this variability (e.g. litter quality, temporal variability) to help constrain ranges of predicted decomposition rates in different field situations. Thus, although many details still need to be resolved, litter decomposition holds considerable potential in some circumstances to capture impairment of stream ecosystem functioning. For instance, species traits associated with the body size and metabolic capacity of the consumers were often the main driver at local scales, and these were often translated into important determinants of otherwise apparently contingent effects at larger scales. Key insights gained from conducting continental scale studies included resolving the apparent paradox of inconsistent relationships between nutrients and decomposition rates, as the full complex multidimensional picture emerged from the large-scale dataset, of which only seemingly contradictory fragments had been seen previously.
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| 2. |
- Chauvet, Eric, et al.
(författare)
-
Litter decomposition as an indicator of stream ecosystem functioning at local-to-continental scales : insights from the European RivFunction project
- 2016
-
Ingår i: Large-scale ecology. - London : Academic Press. ; 55, s. 99-182
-
Bokkapitel (populärvet., debatt m.m.)abstract
- RivFunction is a pan-European initiative that started in 2002 and was aimed at establishing a novel functional-based approach to assessing the ecological status of rivers. Litter decomposition was chosen as the focal process because it plays a central role in stream ecosystems and is easy to study in the field. Impacts of two stressors that occur across the continent, nutrient pollution and modified riparian vegetation, were examined at > 200 paired sites in nine European ecoregions. In response to the former, decomposition was dramatically slowed at both extremes of a 1000-fold nutrient gradient, indicating nutrient limitation in unpolluted sites, highly variable responses across Europe in moderately impacted streams, and inhibition via associated toxic and additional stressors in highly polluted streams. Riparian forest modification by clear cutting or replacement of natural vegetation by plantations (e.g. conifers, eucalyptus) or pasture produced similarly complex responses. Clear effects caused by specific riparian disturbances were observed in regionally focused studies, but general trends across different types of riparian modifications were not apparent, in part possibly because of important indirect effects. Complementary field and laboratory experiments were undertaken to tease apart the mechanistic drivers of the continental scale field bioassays by addressing the influence of litter, fungal and detritivore diversity. These revealed generally weak and context-dependent effects on decomposition, suggesting high levels of redundancy (and hence potential insurance mechanisms that can mitigate a degree of species loss) within the food web. Reduced species richness consistently increased decomposition variability, if not the absolute rate. Further field studies were aimed at identifying important sources of this variability (e.g. litter quality, temporal variability) to help constrain ranges of predicted decomposition rates in different field situations. Thus, although many details still need to be resolved, litter decomposition holds considerable potential in some circumstances to capture impairment of stream ecosystem functioning. For instance, species traits associated with the body size and metabolic capacity of the consumers were often the main driver at local scales, and these were often translated into important determinants of otherwise apparently contingent effects at larger scales. Key insights gained from conducting continental scale studies included resolving the apparent paradox of inconsistent relationships between nutrients and decomposition rates, as the full complex multidimensional picture emerged from the large-scale dataset, of which only seemingly contradictory fragments had been seen previously.
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| 3. |
- Ferreira, C. S. S., et al.
(författare)
-
Conclusions
- 2022
-
Ingår i: Nature-Based Solutions for Flood MitigationHEC,volume 107. - Cham : Springer Nature. ; , s. 507-513
-
Bokkapitel (refereegranskat)abstract
- Mitigating and adapting to increasing flood risk driven by climate change and growing urbanization is still a challenge for humanity. Over the last decades, the Nature Based Solutions (NBS) approach has received increasing interest from governments, academia and society, but its implementation is still in its infancy. This volume presented an up-to-date compilation about the current knowledge on NBS regarding their potential to mitigate several types of floods recorded in different environments, the associated advantages and limitations, and the barriers affecting their wider implementation. This concluding chapter provides a synthesis of the main messages of the chapters included in this volume, and it highlights the relevant aspects that must be considered for an effective and broader application of NBS. In this regard, particular attention is given to the need to maximize their multifunctionality and to consider the transdisciplinary nature of the NBS approach.
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| 4. |
- Ferreira, Carla S. S., et al.
(författare)
-
Introduction : Nature-Based Solutions for Flood Mitigation
- 2022
-
Ingår i: Nature-Based Solutions for Flood Mitigation. - Cham : Springer Nature. ; , s. 1-7, s. 1-7
-
Bokkapitel (refereegranskat)abstract
- Floods are one of the most common natural disasters affecting numerous people worldwide. Over the last years, Nature-Based Solutions (NBS) have gained attention as an emerging approach for flood mitigation that can complement traditional grey infrastructures. NBS provide several ecosystem services, including flood mitigation and improved water quality. Increasing political awareness and interest from the scientific community have led to the implementation of NBS worldwide. This contribution provides an overview of the concept of NBS for flood mitigation, focusing on (1) the environmental impacts of NBS, (2) the effectiveness of NBS in flood mitigation based on several case studies, and (3) the socio-economic aspects of NBS. Compiling the latest research, this book furthers our understanding of the role of NBS for flood mitigation and its relation to environmental aspects, to guide students, managers, practitioners, policy-makers, and scientists in future NBS projects.
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| 5. |
- Hawkins, Stephen J., et al.
(författare)
-
The Intertidal Zone of the North-East Atlantic Region
- 2019
-
Ingår i: Interactions in the Marine Benthos: Global Patterns and Processes (Systematics Association Special Volume Series, pp. 7-46). - : Cambridge university press. - 9781108416085
-
Bokkapitel (refereegranskat)abstract
- The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
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| 6. |
- Verdés, Ramón I., et al.
(författare)
-
Accurate Position Regulation of an Electro-Hydraulic Actuator via Uncertainty Compensation-Based Controller
- 2021
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Ingår i: Emerging Trends in Sliding Mode Control. - Singapore : Springer. - 9789811586125 - 9789811586132 ; , s. 279-303
-
Bokkapitel (refereegranskat)abstract
- Electro-hydraulic actuators are complex systems with uncertainties in their parameters and disregarded dynamics due to its complexity. This paper presents a disturbance observer-based controller method for the accurate position regulation of an electro-hydraulic actuator. To this aim, a super-twisting algorithm-based observer identifies the plant uncertainties and neglected dynamics, theoretically, in finite-time. Thus, a compensation based controller is designed to counteract the uncertainty and neglected dynamics effects through feedback, improving the position regulation accuracy. The closed-loop analysis is carried out using Lyapunov theory. The feasibility of the controller is validated through high-fidelity simulations and experiments in a forestry crane.
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