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Chemical effects on ecological interactions within a model-experiment loopuse asterix (*) to get italics
Dominique LAMONICA, Sandrine CHARLES, Bernard CLÉMENT, Christelle LOPES
<p style="text-align: justify;">We propose in this paper a method to assess the effects of a contaminant on a micro-ecosystem, integrating the population dynamics and the interactions between species. For that, we developed a dynamic model to describe the functioning of a microcosm exposed to a contaminant and to discriminate direct and indirect effects. Then, we get back from modelling to experimentation in order to identify which of the collected data have really been necessary and sufficient to estimate model parameters in order to propose a more efficient experimental design for further investigations. We illustrated our approach using a 2-L laboratory microcosm involving three species (the duckweed <em>Lemna minor</em>, the microalgae <em>Pseudokirchneriella subcapitata</em> and the daphnids <em>Daphnia magna</em>) exposed to cadmium contamination. We modelled the dynamics of the three species and their interactions using a mechanistic model based on coupled ordinary differential equations. The main processes occurring in this three-species microcosm were thus formalized, including growth and settling of algae, growth of duckweeds, interspecific competition between algae and duckweeds, growth, survival and grazing of daphnids, as well as cadmium effects. We estimated model parameters by Bayesian inference, using simultaneously all the data issued from multiple laboratory experiments specifically conducted for this study. Cadmium concentrations ranged between 0 and 50 µg.L-1. For all parameters of our model, we obtained biologically realistic values and reasonable uncertainties. The cascade of cadmium effects, both direct and indirect, was identified. Critical effect concentrations were provided for the life history traits of each species. An example of experimental design adapted to this kind a microcosm was also proposed. This approach appears promising when studying contaminant effects on ecosystem functioning.</p> should fill this box only if you chose 'All or part of the results presented in this preprint are based on data'. URL must start with http:// or https:// should fill this box only if you chose 'Scripts were used to obtain or analyze the results'. URL must start with http:// or https:// should fill this box only if you chose 'Codes have been used in this study'. URL must start with http:// or https://
Bayesian inference ; microcosm ; experimental design optimisation ; cadmium ; daphnid ; duckweed ; microalgae
Aquatic ecotoxicology, Environmental risk assessment, Modelling, Species interactions-webs
Peter Vermieren, Elise Billoir, Nele Schuwirth, Gaëlle Triffault-Bouchet, Tido Strauss, Sylvain Bart No need for them to be recommenders of PCI Ecotox Env Chem. Please do not suggest reviewers for whom there might be a conflict of interest. Reviewers are not allowed to review preprints written by close colleagues (with whom they have published in the last four years, with whom they have received joint funding in the last four years, or with whom they are currently writing a manuscript, or submitting a grant proposal), or by family members, friends, or anyone for whom bias might affect the nature of the review - see the code of conduct
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2022-05-30 11:05:59
Volker Grimm
Charles Hazlerigg, Peter Vermeiren