@article{EmaryMalchow2022, author = {Emary, Clive and Malchow, Anne-Kathleen}, title = {Stability-instability transition in tripartite merged ecological networks}, series = {Journal of mathematical biology}, volume = {85}, journal = {Journal of mathematical biology}, number = {3}, publisher = {Springer}, address = {Heidelberg}, issn = {0303-6812}, doi = {10.1007/s00285-022-01783-7}, pages = {18}, year = {2022}, abstract = {Although ecological networks are typically constructed based on a single type of interaction, e.g. trophic interactions in a food web, a more complete picture of ecosystem composition and functioning arises from merging networks of multiple interaction types. In this work, we consider tripartite networks constructed by merging two bipartite networks, one mutualistic and one antagonistic. Taking the interactions within each sub-network to be distributed randomly, we consider the stability of the dynamics of the network based on the spectrum of its community matrix. In the asymptotic limit of a large number of species, we show that the spectrum undergoes an eigenvalue phase transition, which leads to an abrupt destabilisation of the network as the ratio of mutualists to antagonists is increased. We also derive results that show how this transition is manifest in networks of finite size, as well as when disorder is introduced in the segregation of the two interaction types. Our random-matrix results will serve as a baseline for understanding the behaviour of merged networks with more realistic structures and/or more detailed dynamics.}, language = {en} } @article{ReilRosenfeldImholtetal.2017, author = {Reil, Daniela and Rosenfeld, Ulrike M. and Imholt, Christian and Schmidt, Sabrina and Ulrich, Rainer G. and Eccard, Jana and Jacob, Jens}, title = {Puumala hantavirus infections in bank vole populations}, series = {BMC ecology}, volume = {17}, journal = {BMC ecology}, publisher = {BioMed Central}, address = {London}, issn = {1472-6785}, doi = {10.1186/s12898-017-0118-z}, pages = {13}, year = {2017}, abstract = {Background In Europe, bank voles (Myodes glareolus) are widely distributed and can transmit Puumala virus (PUUV) to humans, which causes a mild to moderate form of haemorrhagic fever with renal syndrome, called nephropathia epidemica. Uncovering the link between host and virus dynamics can help to prevent human PUUV infections in the future. Bank voles were live trapped three times a year in 2010-2013 in three woodland plots in each of four regions in Germany. Bank vole population density was estimated and blood samples collected to detect PUUV specific antibodies. Results We demonstrated that fluctuation of PUUV seroprevalence is dependent not only on multi-annual but also on seasonal dynamics of rodent host abundance. Moreover, PUUV infection might affect host fitness, because seropositive individuals survived better from spring to summer than uninfected bank voles. Individual space use was independent of PUUV infections. Conclusions Our study provides robust estimations of relevant patterns and processes of the dynamics of PUUV and its rodent host in Central Europe, which are highly important for the future development of predictive models for human hantavirus infection risk}, language = {en} } @article{RadchukJohstGroeneveldetal.2014, author = {Radchuk, Viktoriia and Johst, Karin and Groeneveld, J{\"u}rgen and Turlure, Camille and Grimm, Volker and Schtickzelle, Nicolas}, title = {Appropriate resolution in time and model structure for population viability analysis: Insights from a butterfly metapopulation}, series = {: an international journal}, volume = {169}, journal = {: an international journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0006-3207}, doi = {10.1016/j.biocon.2013.12.004}, pages = {345 -- 354}, year = {2014}, abstract = {The importance of a careful choice of the appropriate scale for studying ecological phenomena has been stressed repeatedly. However, issues of spatial scale in metapopulation dynamics received much more attention compared to temporal scale. Moreover, multiple calls were made to carefully choose the appropriate model structure for Population Viability Analysis (PVA). We assessed the effect of using coarser resolution in time and model structure on population dynamics. For this purpose, we compared outcomes of two PVA models differing in their time step: daily individual-based model (dIBM) and yearly stage-based model (ySBM), loaded with empirical data on a well-known metapopulation of the butterfly Boloria eunomia. Both models included the same environmental drivers of population dynamics that were previously identified as being the most important for this species. Under temperature change scenarios, both models yielded the same qualitative scenario ranking, but they quite substantially differed quantitatively with dIBM being more pessimistic in absolute viability measures. We showed that these differences stemmed from inter-individual heterogeneity in dIBM allowing for phenological shifts of individual appearance. We conclude that a finer temporal resolution and an individual-based model structure allow capturing the essential mechanisms necessary to go beyond mere PVA scenario ranking. We encourage researchers to carefully chose the temporal resolution and structure of their model aiming at (1) depicting the processes important for (meta)population dynamics of the species and (2) implementing the environmental change scenarios expected for their study system in the future, using the temporal resolution at which such changes are predicted to operate.}, language = {en} } @misc{SchneiderSchroederEsselbach2012, author = {Schneider, Anne-Kathrin and Schr{\"o}der-Esselbach, Boris}, title = {Perspectives in modelling earthworm dynamics and their feedbacks with abiotic soil properties}, series = {Applied soil ecology : a section of agriculture, ecosystems \& environment}, volume = {58}, journal = {Applied soil ecology : a section of agriculture, ecosystems \& environment}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0929-1393}, doi = {10.1016/j.apsoil.2012.02.020}, pages = {29 -- 36}, year = {2012}, abstract = {Effects of earthworms on soil abiotic properties are well documented from several decades of laboratory and mesocosm experiments, and they are supposed to affect large-scale soil ecosystem functioning. The prediction of the spatiotemporal occurrence of earthworms and the related functional effects in the field or at larger scales, however, is constrained by adequate modelling approaches. Correlative, phenomenological methods, such as species distribution models, facilitate the identification of factors that drive species' distributions. However, these methods ignore the ability of earthworms to select and modify their own habitat and therefore may lead to unreliable predictions. Understanding these feedbacks between earthworms and abiotic soil properties is a key requisite to better understand their spatiotemporal distribution as well as to quantify the various functional effects of earthworms in soil ecosystems. Process-based models that investigate either effects or responses of earthworms on soil environmental conditions are mostly applied in ecotoxicological and bioturbation studies. Process-based models that describe feedbacks between earthworms and soil abiotic properties explicitly are rare. In this review, we analysed 18 process-based earthworm dynamic modelling studies pointing out the current gaps and future challenges in feedback modelling. We identify three main challenges: (i) adequate and reliable process identification in model development at and across relevant spatiotemporal scales (individual behaviour and population dynamics of earthworms), (ii) use of information from different data sources in one model (laboratory or field experiments, earthworm species or functional type) and (iii) quantification of uncertainties in data (e.g. spatiotemporal variability of earthworm abundances and soil hydraulic properties) and derived parameters (e.g. population growth rate and hydraulic conductivity) that are used in the model.}, language = {en} } @article{LiuSiblyGrimmetal.2013, author = {Liu, Chun and Sibly, Richard M. and Grimm, Volker and Thorbek, Pernille}, title = {Linking pesticide exposure and spatial dynamics an individual-based model of wood mouse (Apodemus sylvaticus) populations in agricultural landscapes}, series = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, volume = {248}, journal = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-3800}, doi = {10.1016/j.ecolmodel.2012.09.016}, pages = {92 -- 102}, year = {2013}, abstract = {The wood mouse is a common and abundant species in agricultural landscape and is a focal species in pesticide risk assessment. Empirical studies on the ecology of the wood mouse have provided sufficient information for the species to be modelled mechanistically. An individual-based model was constructed to explicitly represent the locations and movement patterns of individual mice. This together with the schedule of pesticide application allows prediction of the risk to the population from pesticide exposure. The model included life-history traits of wood mice as well as typical landscape dynamics in agricultural farmland in the UK. The model obtains a good fit to the available population data and is fit for risk assessment purposes. It can help identify spatio-temporal situations with the largest potential risk of exposure and enables extrapolation from individual-level endpoints to population-level effects. Largest risk of exposure to pesticides was found when good crop growth in the "sink" fields coincided with high "source" population densities in the hedgerows.}, language = {en} }