%0 Journal Article %J Ecological Modelling %D 2020 %T Quantitative food web modeling unravels the importance of the microphytobenthos-meiofauna pathway for a high trophic transfer by meiofauna in soft-bottom intertidal food webs. %A van der Heijden, L.H. %A Nathalie Niquil %A Haraldsson, M. %A Asmus, R.M. %A Pacella, S.R. %A Graeve, M. %A Rzeznik-Orignac, J. %A Asmus, H. %A Saint-Béat, B. %A Lebreton, B. %K Carbon %K Carbon flow networks %K deposit feeder %K Deposits %K Ecological network analysis %K Ecological process %K Ecosystems %K Feeding %K Feeding ecology %K food web %K Food web model %K intertidal community %K intertidal habitats %K Inverse problems %K linear inverse model %K Linear inverse models %K Markov chain Monte Carlo techniques %K Markov chains %K Meiofauna %K Microphytobenthos %K Monte Carlo methods %K Phytobenthos %K quantitative analysis %K Sediment organic matters %K soft-bottom environment %K stable isotope mixing models %K trophic level %K Trophic relationships %K Trophic structure %X Meiofauna are known to have an important role on many ecological processes, although, their role in food web dynamics is often poorly understood, partially as they have been an overlooked and under sampled organism group. Here, we used quantitative food web modeling to evaluate the trophic relationship between meiofauna and their food sources and how meiofauna can mediate the carbon flow to higher trophic levels in five contrasting soft-bottom intertidal habitats (including seagrass beds, mudflats and sandflats). Carbon flow networks were constructed using the linear inverse model-Markov chain Monte Carlo technique, with increased resolution of the meiofauna compartments (i.e. biomass and feeding ecology of the different trophic groups of meiofauna) compared to most previous modeling studies. These models highlighted that the flows between the highly productive microphytobenthos and the meiofauna compartments play an important role in transferring carbon to the higher trophic levels, typically more efficiently so than macrofauna. The pathway from microphytobenthos to meiofauna represented the largest flow in all habitats and resulted in high production of meiofauna independent of habitat. All trophic groups of meiofauna, except for selective deposit feeders, had a very high dependency on microphytobenthos. Selective deposit feeders relied instead on a wider range of food sources, with varying contributions of bacteria, microphytobenthos and sediment organic matter. Ecological network analyses (e.g. cycling, throughput and ascendency) of the modeled systems highlighted the close positive relationship between the food web efficiency and the assimilation of high-quality food sources by primary consumers, e.g. meiofauna and macrofauna. Large proportions of these flows can be attributed to trophic groups of meiofauna. The sensitivity of the network properties to the representation of meiofauna in the models leads to recommending a greater attention in ecological data monitoring and integrating meiofauna into food web models. © 2020 Elsevier B.V. %B Ecological Modelling %V 430 %G eng %R 10.1016/j.ecolmodel.2020.109129 %0 Journal Article %J Marine Environmental Research %D 2019 %T Modelling the functioning of a coupled microphytobenthic-EPS-bacterial system in intertidal mudflats %A Rakotomalala, C %A Katell Guizien %A Karine Grangeré %A Sébastien Lefebvre %A Christine Dupuy %A Francis Orvain %K Bacillariophyta %K bacteria %K Bacteria (microorganisms) %K bacterial growth %K bacterium %K Biogeochemical modeling %K biogeochemistry %K Biomass %K Carbon %K Carbon and nitrogen %K Carbon and nitrogen ratios %K Diatom %K diel vertical migration %K exopolymer %K Experimental conditions %K Extracellular polymeric substances %K intertidal environment %K intertidal zone %K light %K mesocosm %K microbial community %K Microphytobenthos %K Migration %K modeling %K mudflat %K Nitrogen %K nonhuman %K Nutrient availability %K Nutrients %K nutritional requirement %K organic carbon %K organismal interaction %K Photosynthesis %K Phytobenthos %K Phytoplankton %K polymer %K Review %K simulation %K tide %K vertical migration %X A mechanistic and biogeochemical model was developed to analyze the interactions between microphytobenthos (MPB), bacteria and nutrients in a tidal system. Behavioral vertical migration was hypothesized as being controlled by exogenous factors (tide and light) but also by endogenous factors (carbon and nitrogen requirements). The secretion of Extracellular Polymeric Substances (EPS) during photosynthesis (overflow metabolism) and migration of diatoms was also formulated. Similarities in MPB dynamics between observations and simulations support the assumption that carbon and nitrogen ratios are additional key processes behind the vertical migration of diatoms in the sediment. The model satisfactorily reproduced the three growth phases of the MPB development observed in a mesocosm (the lag phase, the logarithmic growth, and the plateau). Besides, nutrient availability, which could be induced by faunal bioturbation, significantly determined the extent of MPB biomass and development. The plateau phase observed in the last days of simulations appeared to be attributed to a nutrient depletion in the system, emphasizing the importance of nutrient availability. The model, although improvable especially on the formulation of the EPS excretion and bacteria development, already updated understanding of several aspects of benthic-system functioning during experimental conditions. © 2019 Elsevier Ltd %B Marine Environmental Research %V 150 %G eng %U https://www.sciencedirect.com/science/article/abs/pii/S0141113619300704 %R 10.1016/j.marenvres.2019.104754