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- Chaguaceda, Fernando
(author)
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Bottom-up and top-down regulation of heterogeneous lake food webs
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Food webs are networks of organisms linked by trophic interactions that regulate the responses of ecosystems to environmental change. Such regulation is a result of the effects of resources on the abundance of their consumers (i.e. bottom-up effects) and/or the influence of consumers on the abundance of their resources (i.e. top-down effects). Lake food webs comprise pelagic and benthic production pathways and are largely affected by fluxes of resources from/to adjacent terrestrial ecosystems. These pathways are often coupled by mobile generalist consumers, potentially leading to indirect interactions among prey that arise when sharing a predator. In contrast, consumers can also undergo resource specialization that restricts their ability to couple resources at a given time.In this thesis, I observed that top-down control of predators on benthic and pelagic prey at increasing productivity was highly dependent on apparent mutualism that was driven by switching behaviour of generalist fish. That, in addition to bottom-up responses of benthic pathways at increasing productivity, had important consequences for the fluxes of energy and high quality polyunsaturated fatty acids (PUFAs) to terrestrial systems via insect emergence. I also found that PUFAs were highly regulated over the ontogeny of Eurasian perch (Perca fluviatilis). Mismatches with PUFA composition in prey may in turn affect resource specialization and the timing of ontogenetic diet shifts, altering the role of perch in the food web. Finally, browning, which is a phenomenon affecting many temperate and boreal lakes, did not affect bottom-up and top-down control in open-water lake food webs. Instead, browning affected prey selectivity, probably changing the pathways of energy transfer within the open-water food web. Overall, this thesis demonstrates that predictions of food web responses in lake ecosystems and their exports to adjacent terrestrial systems depend on the coupling of different pathways and subsequent indirect interactions among prey through shared predation. This could not be explained by classic food chain theory, but rather by a framework including resource coupling and resource specialization over the ontogeny of consumers. These observations must not be overlooked when constructing a comprehensive model of food webs across time and space.
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| 2. |
- Chaguaceda, Fernando, et al.
(author)
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Chaguaceda et al. (2020) Oecologia dataset
- 2020
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Other publicationabstract
- Fatty acids (FAs) are key nutrients for fitness which take part in multiple physiological processes over the ontogeny of organisms. Yet, we lack evidence on how FA nutrition mediates life-history trade-offs and ontogenetic niche shifts in natural populations. In a field study, we analyzed ontogenetic changes in the FAs of Eurasian perch (Perca fluviatilis L.), a widespread fish that goes through ontogenetic niche shifts and can have high individual niche specialization. Diet explained most of the variation in the FA composition of perch dorsal muscle over early ontogeny (28%), while the total length explained 23%, suggesting that perch significantly regulated FA composition over early ontogeny. Condition explained 1% of the remaining variation. 18:3n-3 (ALA) and 18:4n-3 (SDA) indicated planktivory; 18:1n-7, benthivory; and 22:6n-3 (DHA), piscivory in perch diet. Conversely, perch regulated long-chained polyunsaturated fatty acids (PUFAs), such as 20:5n-3 (EPA), 20:4n-6 (ARA) and 22:6n-3 (DHA) over ontogeny, emphasizing the role of such FAs in early growth and sexual maturation. Adult perch increasingly retained 16:1n-7 and 18:1n-9 suggesting higher energy storage in older perch. Furthermore, differences in DHA availability in diet correlated with intra-cohort differences in perch growth, potentially hindering the overall use of benthic resources and promoting earlier shifts to piscivory in littoral habitats. Overall, this study indicates that in addition to diet, internal regulation may be more important for FA composition than previously thought. Differences between FA needs and FA availability may lead to life-history trade-offs that affect the ecology of consumers, including their niche
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| 3. |
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| 4. |
- Chaguaceda, Fernando, et al.
(author)
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Regulation of fatty acid composition related to ontogenetic changes and niche differentiation of a common aquatic consumer
- 2020
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In: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 193:2, s. 325-336
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Journal article (peer-reviewed)abstract
- Fatty acids (FAs) are key nutrients for fitness which take part in multiple physiological processes over the ontogeny of organisms. Yet, we lack evidence on how FA nutrition mediates life-history trade-offs and ontogenetic niche shifts in natural populations. In a field study, we analyzed ontogenetic changes in the FAs of Eurasian perch (Perca fluviatilis L.), a widespread fish that goes through ontogenetic niche shifts and can have high individual niche specialization. Diet explained most of the variation in the FA composition of perch dorsal muscle over early ontogeny (28%), while the total length explained 23%, suggesting that perch significantly regulated FA composition over early ontogeny. Condition explained 1% of the remaining variation. 18:3n-3 (ALA) and 18:4n-3 (SDA) indicated planktivory; 18:1n-7, benthivory; and 22:6n-3 (DHA), piscivory in perch diet. Conversely, perch regulated long-chained polyunsaturated fatty acids (PUFAs), such as 20:5n-3 (EPA), 20:4n-6 (ARA) and 22:6n-3 (DHA) over ontogeny, emphasizing the role of such FAs in early growth and sexual maturation. Adult perch increasingly retained 16:1n-7 and 18:1n-9 suggesting higher energy storage in older perch. Furthermore, differences in DHA availability in diet correlated with intra-cohort differences in perch growth, potentially hindering the overall use of benthic resources and promoting earlier shifts to piscivory in littoral habitats. Overall, this study indicates that in addition to diet, internal regulation may be more important for FA composition than previously thought. Differences between FA needs and FA availability may lead to life-history trade-offs that affect the ecology of consumers, including their niche.
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| 5. |
- Chaguaceda, Fernando, et al.
(author)
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Short-term apparent mutualism drives responses of aquatic prey at increasing productivity
- 2021
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In: Journal of Animal Ecology. - : John Wiley & Sons. - 0021-8790 .- 1365-2656. ; 90:4, s. 834-845
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Journal article (peer-reviewed)abstract
- According to apparent competition theory, sharing a predator should cause indirect interactions among prey that can substantially influence food-web responses to environmental drivers. However, empirical evidence of apparent competition under ongoing environmental change is still scarce. In an 8-week mesocosm experiment, we found that short-term responses of aquatic food webs to increasing productivity were strongly regulated by apparent mutualism between benthic and pelagic prey in the presence of a generalist fish. Following trends in natural systems, increasing productivity in our mesocosms favored the relative abundance of benthic prey. This elicited a shift in fish selectivity from pelagic to benthic prey driven by fish switching behavior which resulted in lower and delayed top-down control on pelagic prey. Our results highlight that apparent competition theory may explain food-web responses across environmental gradients, whereby resulting prey dynamics and stability may highly depend on the foraging behavior exhibited by generalist predators.
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| 6. |
- Chaguaceda, Fernando, et al.
(author)
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Supportive data for "Short-term apparent mutualism drives responses of aquatic prey to increasing productivity", Chaguaceda et al.
- 2020
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Other publicationabstract
- This dataset contains both biological variables (phytoplankton, periphyton, zooplankton, Chironomidae emergence) and physico-chemical variables (temperature, dissolved oxygen, pH, turbidity) of an aquatic mesocosm experiment that gradually manipulated nutrient additions (10 nutrient steps, 20 – 1000 µg L -1 total P (TP) and 0.45 – 11.3 mg L -1 total N (TN)) and also manipulated the presence or absence of generalist fish (Crucian carp, Carassius carassius), making a total of 10*2=20 mesocosms.Crucian carp feed both on benthic prey (Chironomidae) and on pelagic prey (Cladocera). Based on that, this experiment aimed to test the indirect interactions between Chironomidae and Cladocera prey due to shared predation, and how these interactions changed in response to nutrient additions through changes in benthic and pelagic food-web pathways. In the dataset there are five different sheets:Sheet number 1 shows the summary values of all the variables after the fish were added. Most variables are shown as mean values over a 7-week experimental period (after fish addition). The other sheets show the time-series of food-web variables (Phytoplankton Chla, periphyton biomass, Chironomidae emergence and Cladocera abundance), where the week refers to week relative to fish addition (week 0 is the first week after fish addition).
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| 7. |
- Chaguaceda, Fernando
(author)
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The role of vital dietary biomolecules in eco-evo-devo dynamics
- 2023
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In: Trends in ecology & evolution. - : Elsevier BV. - 0169-5347 .- 1872-8383. ; 38, s. 72-84
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Research review (peer-reviewed)abstract
- The physiological dependence of animals on dietary intake of vitamins, amino acids, and fatty acids is ubiquitous. Sharp differences in the availability of these vital dietary biomolecules among different resources mean that consumers must adopt a range of strategies to meet their physiological needs. We review the emerging work on omega-3 long-chain polyunsaturated fatty acids, focusing predominantly on predator-prey interactions, to illustrate that trade-off between capacities to consume resources rich in vital biomolecules and internal synthesis capacity drives differences in phenotype and fitness of consumers. This can then feedback to impact ecosystem functioning. We outline how focus on vital dietary biomolecules in eco-eco-devo dynamics can improve our understanding of anthropogenic changes across multiple levels of biological organization.
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| 8. |
- Chaguaceda, Fernando, et al.
(author)
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Zooplankton fatty acids across large environmental gradients in Sweden : Raw data for Chaguaceda et al (2024) Limnology & Oceanography
- 2024
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Other publicationabstract
- Zooplankton fatty-fatty acid data from Swedish lakes along a temperature (summer temperatures 6.8–15.9°C), water color (< 0.005–0.51 Abs420), and eutrophication ( mean TP < 1.0–42.3 μg P L−1) gradient encompassing 2002–2010 and 2020–2021 periods (n=100, N=32 lakes). The dataset is divided into two sheets: one with the fatty acid data ("Zooplankton fatty acid data"), and another with the mean lake data ("Lake data"). A third sheet ("metadata") explains the metadata and the abbreviations used in the other two sheets.
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| 9. |
- Chaguaceda, Fernando, et al.
(author)
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Zooplankton in northern lakes show taxon-specific responses in fatty acids across climate-productivity and ecosystem size gradients
- 2024
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In: Limnology and Oceanography. - 0024-3590 .- 1939-5590. ; 69, s. 947-960
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Journal article (peer-reviewed)abstract
- Northern lakes are facing rapid environmental alterations-including warming, browning, and/or changes in nutrient concentrations-driven by climate change. These environmental changes can have profound impacts on the synthesis and trophic transfer of polyunsaturated fatty acids (PUFA), which are important biochemical molecules for consumer growth and reproduction. Zooplankton are a key trophic link between phytoplankton and fish, but their biochemical responses to environmental change are not well understood. In this study, we assess the trends in fatty acid (FA) composition of zooplankton taxa among 32 subarctic and temperate lakes across broad climate-productivity and ecosystem size gradients. We found that genus-level taxonomy explained most FA variability in zooplankton (54%), suggesting that environmental changes that alter the taxonomic composition also affect the FA composition of zooplankton communities. Furthermore, the FA responses and their underlying environmental drivers differed between cladocerans and copepods. Cladocerans, including widespread Bosmina spp. and Daphnia spp., showed pronounced responses across the climate-productivity gradient, with abrupt declines in PUFA, particularly eicosapentaenoic acid and arachidonic acid in warmer, browner, and more eutrophic lakes. Conversely, calanoid copepods had high and relatively stable PUFA levels across the gradient. In addition, all zooplankton taxa increased in stearidonic acid levels in larger lakes where PUFA-rich cryptophytes were more abundant. Overall, our results suggest that climate-driven environmental alterations pose heterogeneous impacts on PUFA levels among zooplankton taxa, and that the negative impacts of climate warming are stronger for cladocerans, especially so in small lakes.
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| 10. |
- Fehlinger, Lena, et al.
(author)
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The ecological role of permanent ponds in Europe : a review of dietary linkages to terrestrial ecosystems via emerging insects
- 2023
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In: Inland Waters. - : Taylor & Francis. - 2044-2041 .- 2044-205X. ; 13:1, s. 30-46
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Research review (peer-reviewed)abstract
- Permanent ponds are valuable freshwater systems and biodiversity hotspots. They provide diverse ecosystem services (ESs), including water quality improvement and supply, food provisioning, and biodiversity support, despite significant pressure from multiple anthropogenic stressors and the impacts of ongoing global change. However, ponds are largely overlooked in management plans and legislation, and ecological research has focused on large freshwater ecosystems, such as rivers or lakes. Protection of ponds is often insufficient or indirectly provided via associated habitats such as wetlands. This situation is likely exacerbated by the lack of a full-scale understanding of the importance of ponds. In this review, we provide a detailed overview of permanent ponds across Europe, including their usages and the biodiversity they support. By discussing the concepts of pondscape and metacommunity theory, we highlight the importance of connectivity among and between ponds and identified fluxes of emerging insects as another ES of ponds. Those insects are rich in essential nutrients such as polyunsaturated fatty acids (PUFAs), delivered through them to the terrestrial environment; however, the extent and impact of this ES remains largely unexplored. Several potential stressors, especially related to ongoing global change, that influence pond diversity and integrity are discussed. We provide our insights on future pond management. Adaptive measures, taking into account the pond system per se within the pondscape, are the most promising to mitigate the loss of natural ponds and restore and conserve natural small waterbodies as refuges and diversity hotspots in increasingly urbanized landscapes.
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