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Jaimie T A Dick - One of the best experts on this subject based on the ideXlab platform.
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influence of intra and interspecific variation in predator prey body size ratios on Trophic Interaction strengths
Ecology and Evolution, 2020Co-Authors: Ross N Cuthbert, Tatenda Dalu, Ryan J Wasserman, H Kaiser, Olaf L F Weyl, Jaimie T A DickAbstract:Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of Interaction strengths. However, studies quantifying the combined influence of intra- and interspecific variation in predator-prey body size ratios are lacking.We use a comparative functional response approach to examine Interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra- and interspecific predator-prey body mass ratios on the scaling of attack rates and handling times.Type II functional responses were displayed by both predators across all predator and prey size classes. Largemouth bass consumed more than bluegill at small and intermediate predator size classes, while large predators of both species were more similar. Small prey were most vulnerable overall; however, differential attack rates among prey were emergent across predator sizes. For both bluegill and largemouth bass, small predators exhibited higher attack rates toward small and intermediate prey sizes, while larger predators exhibited greater attack rates toward large prey. Conversely, handling times increased with prey size, with small bluegill exhibiting particularly low feeding rates toward medium-large prey types. Attack rates for both predators peaked unimodally at intermediate predator-prey body mass ratios, while handling times generally shortened across increasing body mass ratios.We thus demonstrate effects of body size ratios on predator-prey Interaction strengths between key fish species, with attack rates and handling times dependent on the relative sizes of predator-prey participants.Considerations for intra- and interspecific body size ratio effects are critical for predicting the strengths of Interactions within ecosystems and may drive differential ecological impacts among invasive species as size ratios shift.
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the influence of microplastics on Trophic Interaction strengths and oviposition preferences of dipterans
Science of The Total Environment, 2019Co-Authors: Ross N Cuthbert, Rana Aljaibachi, Tatenda Dalu, Jaimie T A Dick, Amanda CallaghanAbstract:Microplastic (MP) pollution continues to proliferate in freshwater, marine and terrestrial environments, but with their biotic implications remaining poorly understood. Biotic Interactions such as predation can profoundly influence ecosystem structuring, stability and functioning. However, we currently lack quantitative understandings of how Trophic Interaction strengths and associated behaviours are influenced by MP pollution, and how transference of MPs between Trophic levels relates to consumptive traits. We also lack understanding of key life-history effects of MPs, for example, reproductive strategies such as oviposition. The present study examines the predatory ability of non-biting midge larvae, Chaoborus flavicans, towards larvae of Culex pipiens mosquitoes when the latter are exposed to MPs, using a functional response (FR) approach. Transfer of MPs occurred from larval mosquitoes to larval midges via predation. Microplastics transfer was significantly positively related to predation rates. Predation by C. flavicans followed a Type II FR, with average maximum feeding rates of 6.2 mosquito larvae per hour. These and other FR parameters (attack rates and handling times) were not significantly influenced by the presence of MPs. Further, C. pipiens adults did not avoid ovipositing in habitats with high concentrations of MPs. We thus demonstrate that MPs can move readily through freshwater food webs via biotic processes such as predation, and that uptake correlates strongly with consumption rates. Further, as MPs do not deter adult mosquitoes from ovipositing, our experiments reveal high potential for MP exposure and transference through ecosystems.
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a Trophic Interaction framework for identifying the invasive capacity of novel organisms
Methods in Ecology and Evolution, 2017Co-Authors: Jaimie T A Dick, Marcin R Penk, Wolfchristian Saul, Ian Donohue, Mhairi E Alexander, Stefan M Linzmaier, Jonathan M JeschkeAbstract:The likelihood and impacts of invasions by novel organisms (e.g. non-native species, genetically modified organisms) on the composition and functioning of receiving biological communities hinges on their capacity to exploit resources and/or avoid predation relative to resident counterparts. While assessment of invasion risk based on the comparison of functional responses (per-capita consumption rate as a function of resource density) of novel species with native analogues has been gaining popularity, it may be undermined if alternative prey and potential predators are not represented realistically. Here, we propose a conceptual framework that enables rigorous identification of Trophic traits conducive to invasion success by novel organisms—irrespective of their Trophic position—and their likely ecological impacts, given their arrival and establishment. We focus on consumption here, but our framework can also be used for autoTrophic energy acquisition, and extended to non-Trophic and indirect Interactions. The framework enables a structured and prioritized selection of subsets of Trophic links for invasion risk assessment. It is based on foraging theory and advances in comparative functional responses in invasion ecology. It can even be used in the absence of a resident comparator organism and when resources or predators are only partly known. Our approach enhances the predictive power of species screening, and thus advances prevention and management of invasions under a common framework for all types of novel organisms.
Ross N Cuthbert - One of the best experts on this subject based on the ideXlab platform.
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influence of intra and interspecific variation in predator prey body size ratios on Trophic Interaction strengths
Ecology and Evolution, 2020Co-Authors: Ross N Cuthbert, Tatenda Dalu, Ryan J Wasserman, H Kaiser, Olaf L F Weyl, Jaimie T A DickAbstract:Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of Interaction strengths. However, studies quantifying the combined influence of intra- and interspecific variation in predator-prey body size ratios are lacking.We use a comparative functional response approach to examine Interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra- and interspecific predator-prey body mass ratios on the scaling of attack rates and handling times.Type II functional responses were displayed by both predators across all predator and prey size classes. Largemouth bass consumed more than bluegill at small and intermediate predator size classes, while large predators of both species were more similar. Small prey were most vulnerable overall; however, differential attack rates among prey were emergent across predator sizes. For both bluegill and largemouth bass, small predators exhibited higher attack rates toward small and intermediate prey sizes, while larger predators exhibited greater attack rates toward large prey. Conversely, handling times increased with prey size, with small bluegill exhibiting particularly low feeding rates toward medium-large prey types. Attack rates for both predators peaked unimodally at intermediate predator-prey body mass ratios, while handling times generally shortened across increasing body mass ratios.We thus demonstrate effects of body size ratios on predator-prey Interaction strengths between key fish species, with attack rates and handling times dependent on the relative sizes of predator-prey participants.Considerations for intra- and interspecific body size ratio effects are critical for predicting the strengths of Interactions within ecosystems and may drive differential ecological impacts among invasive species as size ratios shift.
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the influence of microplastics on Trophic Interaction strengths and oviposition preferences of dipterans
Science of The Total Environment, 2019Co-Authors: Ross N Cuthbert, Rana Aljaibachi, Tatenda Dalu, Jaimie T A Dick, Amanda CallaghanAbstract:Microplastic (MP) pollution continues to proliferate in freshwater, marine and terrestrial environments, but with their biotic implications remaining poorly understood. Biotic Interactions such as predation can profoundly influence ecosystem structuring, stability and functioning. However, we currently lack quantitative understandings of how Trophic Interaction strengths and associated behaviours are influenced by MP pollution, and how transference of MPs between Trophic levels relates to consumptive traits. We also lack understanding of key life-history effects of MPs, for example, reproductive strategies such as oviposition. The present study examines the predatory ability of non-biting midge larvae, Chaoborus flavicans, towards larvae of Culex pipiens mosquitoes when the latter are exposed to MPs, using a functional response (FR) approach. Transfer of MPs occurred from larval mosquitoes to larval midges via predation. Microplastics transfer was significantly positively related to predation rates. Predation by C. flavicans followed a Type II FR, with average maximum feeding rates of 6.2 mosquito larvae per hour. These and other FR parameters (attack rates and handling times) were not significantly influenced by the presence of MPs. Further, C. pipiens adults did not avoid ovipositing in habitats with high concentrations of MPs. We thus demonstrate that MPs can move readily through freshwater food webs via biotic processes such as predation, and that uptake correlates strongly with consumption rates. Further, as MPs do not deter adult mosquitoes from ovipositing, our experiments reveal high potential for MP exposure and transference through ecosystems.
Oswald J. Schmitz - One of the best experts on this subject based on the ideXlab platform.
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convergence of Trophic Interaction strengths in grassland food webs through metabolic scaling of herbivore biomass
Journal of Animal Ecology, 2011Co-Authors: Oswald J. Schmitz, Jessica R PriceAbstract:Summary 1. Food web theory hypothesizes that Trophic Interaction strengths of consumers should vary with consumer metabolic body mass (mass 0AE75 ) rather than simply with consumer body mass (mass 1AE0 ) owing to constraints on consumption imposed by metabolic demand for and metabolic capacity to process nutrients and energy. Accordingly, species with similar metabolic body masses should have similar Trophic Interaction strengths. 2. We experimentally tested this hypothesis by assembling food webs comprised of species of arthropod predators, small sap-feeding and large leaf-chewing insect herbivores and herbaceous plants in a New England, USA meadow grassland. The experiment comprised of a density-matching treatment where herbivore species were stocked into field mesocosms at equal densities to quantify baseline species identity and metabolic body mass effects. The experiment also comprised of a metabolic biomass-matching treatment where smaller sap-feeding herbivore (SH) species were stocked into mesocosms such that the product of their density and metabolic body mass (metabolic biomass) was equal to the large herbivore (LH) species. We compared the magnitude of the direct effects of herbivore species on plants in the different treatments. We also compared the magnitude of indirect effects between predators and plants mediated by herbivores in the different treatments. 3. Consistent with the hypothesis, we found that increasing metabolic biomass translated into a 9– 14-fold increase in magnitude of herbivore direct effects and up to a fivefold increase in indirect effects on plants. Moreover, metabolic biomass matching caused Interaction strengths among herbivore species to converge. This result came about through increases in the herbivore mean effects as well as decreases in variation in effects among treatment replicates as herbivore metabolic biomass increased. 4. We found, however, that herbivore feeding mode rather than herbivore metabolic biomass explained differences in the sign of indirect effects in the different food webs. 5. We conclude that increasing herbivore metabolic biomass not only strengthened the direct and indirect effects on plants but also made those effects more consistent across space. Nevertheless, metabolic biomass alone could not completely explain variation in the nature of indirect effects in the food web, suggesting that additional consideration of consumer traits like feeding mode will provide a more nuanced understanding of Trophic Interaction strengths in food webs.
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Weather variation and Trophic Interaction strength: sorting the signal from the noise
Oecologia, 2004Co-Authors: Ofer Ovadia, Oswald J. SchmitzAbstract:Weather can have important consequences for the structure and function of ecological communities by substantially altering the nature and strength of species Interactions. We examined the role of intra- and inter-annual weather variability on species Interactions in a seasonal old-field community consisting of spider predators, grasshopper herbivores, and grass and herb plants. We experimentally varied the number of Trophic levels for 2 consecutive years and tested for inter-annual variation in Trophic abundances. Grasshopper emergence varied between years to the extent that the second growing season was 20% shorter than the first one. However, the damage grasshoppers inflicted on plants was greater in the second, shorter growing season. This inter-annual variation in plant abundance could be explained using the foraging-predation risk trade-off displayed by grasshoppers combined with their survival trajectory. Decreased grasshopper survival not only reduced the damage inflicted on plants, it weakened the strength of indirect effects of spiders on grass and herb plants. The most influential abiotic factor affecting grasshopper survival was precipitation. We found a negative association between grasshopper survival and the total yearly precipitation. A finer scale analysis, however, showed that different precipitation modalities, namely, number of rainy days and average precipitation per day, had opposing effects on grasshopper survival, which were inconsistent between years. Furthermore, our results suggest that small changes in these factors should result in changes of up to several orders of magnitude in the mortality rate of grasshoppers. We thus conclude that in this system the foraging-predation risk trade-off displayed by grasshoppers combined with their survival trajectory and relevant weather variability should be incorporated in analytical theory, whose goal is to predict community dynamics.
Tatenda Dalu - One of the best experts on this subject based on the ideXlab platform.
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influence of intra and interspecific variation in predator prey body size ratios on Trophic Interaction strengths
Ecology and Evolution, 2020Co-Authors: Ross N Cuthbert, Tatenda Dalu, Ryan J Wasserman, H Kaiser, Olaf L F Weyl, Jaimie T A DickAbstract:Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of Interaction strengths. However, studies quantifying the combined influence of intra- and interspecific variation in predator-prey body size ratios are lacking.We use a comparative functional response approach to examine Interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra- and interspecific predator-prey body mass ratios on the scaling of attack rates and handling times.Type II functional responses were displayed by both predators across all predator and prey size classes. Largemouth bass consumed more than bluegill at small and intermediate predator size classes, while large predators of both species were more similar. Small prey were most vulnerable overall; however, differential attack rates among prey were emergent across predator sizes. For both bluegill and largemouth bass, small predators exhibited higher attack rates toward small and intermediate prey sizes, while larger predators exhibited greater attack rates toward large prey. Conversely, handling times increased with prey size, with small bluegill exhibiting particularly low feeding rates toward medium-large prey types. Attack rates for both predators peaked unimodally at intermediate predator-prey body mass ratios, while handling times generally shortened across increasing body mass ratios.We thus demonstrate effects of body size ratios on predator-prey Interaction strengths between key fish species, with attack rates and handling times dependent on the relative sizes of predator-prey participants.Considerations for intra- and interspecific body size ratio effects are critical for predicting the strengths of Interactions within ecosystems and may drive differential ecological impacts among invasive species as size ratios shift.
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the influence of microplastics on Trophic Interaction strengths and oviposition preferences of dipterans
Science of The Total Environment, 2019Co-Authors: Ross N Cuthbert, Rana Aljaibachi, Tatenda Dalu, Jaimie T A Dick, Amanda CallaghanAbstract:Microplastic (MP) pollution continues to proliferate in freshwater, marine and terrestrial environments, but with their biotic implications remaining poorly understood. Biotic Interactions such as predation can profoundly influence ecosystem structuring, stability and functioning. However, we currently lack quantitative understandings of how Trophic Interaction strengths and associated behaviours are influenced by MP pollution, and how transference of MPs between Trophic levels relates to consumptive traits. We also lack understanding of key life-history effects of MPs, for example, reproductive strategies such as oviposition. The present study examines the predatory ability of non-biting midge larvae, Chaoborus flavicans, towards larvae of Culex pipiens mosquitoes when the latter are exposed to MPs, using a functional response (FR) approach. Transfer of MPs occurred from larval mosquitoes to larval midges via predation. Microplastics transfer was significantly positively related to predation rates. Predation by C. flavicans followed a Type II FR, with average maximum feeding rates of 6.2 mosquito larvae per hour. These and other FR parameters (attack rates and handling times) were not significantly influenced by the presence of MPs. Further, C. pipiens adults did not avoid ovipositing in habitats with high concentrations of MPs. We thus demonstrate that MPs can move readily through freshwater food webs via biotic processes such as predation, and that uptake correlates strongly with consumption rates. Further, as MPs do not deter adult mosquitoes from ovipositing, our experiments reveal high potential for MP exposure and transference through ecosystems.
Howard I Browman - One of the best experts on this subject based on the ideXlab platform.
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parameterizing and operationalizing zooplankton population dynamic and Trophic Interaction models
Ices Journal of Marine Science, 2014Co-Authors: Stephane Plourde, Howard I BrowmanAbstract:Institute of Marine Research, Austevoll Research Station, Storebo 5392, Norway*Corresponding author: tel: 1-418-775-0676; fax: 1-418-775-0546; e-mail: stephane.plourde@dfo-mpo.gc.caPlourde,S.,andBrowman,H.I.2014.ParameterizingandoperationalizingzooplanktonpopulationdynamicandTrophicInteractionmodels. – ICESJournal of Marine Science, 71: 234–235.Received12 November 2013; accepted14 November 2013.