Articles de revues : « Metapopulation dynamics model »

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Wang, Shaopeng, Bart Haegeman et Michel Loreau. « Dispersal and metapopulation stability ». PeerJ 3 (1 octobre 2015) : e1295. http://dx.doi.org/10.7717/peerj.1295.

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Metapopulation dynamics are jointly regulated by local and spatial factors. These factors may affect the dynamics of local populations and of the entire metapopulation differently. Previous studies have shown that dispersal can stabilize local populations; however, as dispersal also tends to increase spatial synchrony, its net effect on metapopulation stability has been controversial. Here we present a simple metapopulation model to study how dispersal, in interaction with other spatial and local processes, affects the temporal variability of metapopulations in a stochastic environment. Our results show that in homogeneous metapopulations, the local stabilizing and spatial synchronizing effects of dispersal cancel each other out, such that dispersal has no effect on metapopulation variability. This result is robust to moderate heterogeneities in local and spatial parameters. When local and spatial dynamics exhibit high heterogeneities, however, dispersal can either stabilize or destabilize metapopulation dynamics through various mechanisms. Our findings have important theoretical and practical implications. We show that dispersal functions as a form of spatial intraspecific mutualism in metapopulation dynamics and that its effect on metapopulation stability is opposite to that of interspecific competition on local community stability. Our results also suggest that conservation corridors should be designed with appreciation of spatial heterogeneities in population dynamics in order to maximize metapopulation stability.

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Taylor, Caz M., et Richard J. Hall. « Metapopulation models for seasonally migratory animals ». Biology Letters 8, n^o 3 (16 novembre 2011) : 477–80. http://dx.doi.org/10.1098/rsbl.2011.0916.

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Metapopulation models are widely used to study species that occupy patchily distributed habitat, but are rarely applied to migratory species, because of the difficulty of identifying demographically independent subpopulations. Here, we extend metapopulation theory to describe the directed seasonal movement of migratory populations between two sets of habitat patches, breeding and non-breeding, with potentially different colonization and extinction rates between patch types. By extending the classic metapopulation model, we show that migratory metapopulations will persist if the product of the two colonization rates exceeds the product of extinction rates. Further, we develop a spatially realistic migratory metapopulation model and derive a landscape metric—the migratory metapopulation capacity—that determines persistence. This new extension to metapopulation theory introduces an important tool for the management and conservation of migratory species and may also be applicable to model the dynamics of two host–parasite systems.

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SARDANYÉS, JOSEP, et ERNEST FONTICH. « ON THE METAPOPULATION DYNAMICS OF AUTOCATALYSIS : EXTINCTION TRANSIENTS RELATED TO GHOSTS ». International Journal of Bifurcation and Chaos 20, n^o 04 (avril 2010) : 1261–68. http://dx.doi.org/10.1142/s0218127410026460.

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One of the theoretical approaches to study spatially-extended ecosystems is given by metapopulation models, which consider fragmented populations inhabiting discrete patches linked by migration. Most of the metapopulation models assume exponential growth of the local populations and few works have explored the role of cooperation in fragmented ecosystems. In this letter, we study the dynamics and the bifurcation scenarios of a minimal, two-patch metapopulation Turing-like model given by nonlinear differential equations with an autocatalytic reaction term together with diffusion. We also analyze the extinction transients of the metapopulations focusing on the effect of coupling two local populations undergoing delayed transition phenomena due to ghost saddle remnants. We find that increasing diffusion rates enhance the delaying capacity of the ghosts. We finally propose the saddle remnant as a new class of transient generator mechanism for ecological systems.

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Anderson, B. J., H. R. Akçakaya, M. B. Araújo, D. A. Fordham, E. Martinez-Meyer, W. Thuiller et B. W. Brook. « Dynamics of range margins for metapopulations under climate change ». Proceedings of the Royal Society B : Biological Sciences 276, n^o 1661 (25 février 2009) : 1415–20. http://dx.doi.org/10.1098/rspb.2008.1681.

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We link spatially explicit climate change predictions to a dynamic metapopulation model. Predictions of species' responses to climate change, incorporating metapopulation dynamics and elements of dispersal, allow us to explore the range margin dynamics for two lagomorphs of conservation concern. Although the lagomorphs have very different distribution patterns, shifts at the edge of the range were more pronounced than shifts in the overall metapopulation. For Romerolagus diazi (volcano rabbit), the lower elevation range limit shifted upslope by approximately 700 m. This reduced the area occupied by the metapopulation, as the mountain peak currently lacks suitable vegetation. For Lepus timidus (European mountain hare), we modelled the British metapopulation. Increasing the dispersive estimate caused the metapopulation to shift faster on the northern range margin (leading edge). By contrast, it caused the metapopulation to respond to climate change slower , rather than faster, on the southern range margin (trailing edge). The differential responses of the leading and trailing range margins and the relative sensitivity of range limits to climate change compared with that of the metapopulation centroid have important implications for where conservation monitoring should be targeted. Our study demonstrates the importance and possibility of moving from simple bioclimatic envelope models to second-generation models that incorporate both dynamic climate change and metapopulation dynamics.

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Uchmański, Janusz. « Zmienność osobnicza a dynamika metapopulacji : model osobniczy ». Studia Ecologiae et Bioethicae 9, n^o 3 (30 septembre 2011) : 47–84. http://dx.doi.org/10.21697/seb.2011.9.3.04.

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The individual-based model is presented for describing the dynamics of metapopulations. The model of the local population describes the dynamics of the population with non-overlapping generations. The growth of the individuals is followed in every generation. The growth rate of individuals is affected by the level of resources. The individuals compete for these resources, which are therefore not evenly distributed among the individuals. The persistence of a local population in which the individuals could not disperse was compared to the persistence of the metapopulation. Metapopulation models differed in the conditions under which individuals disperse. In some versions of the model the individuals that dispersed were the weaker individuals in the local population - they dispersed because they could not acquire any resources in the original local habitat, or because they could not acquire enough resources to reproduce. In another version, the individuals that dispersed were the stronger individuals. They migrated immediately before the extinction of the local population. In the last version of the model, the dispersing individuals were selected at random. The model showed that the reason for which the individuals dispersed affected the persistence of the metapopulation. In contrast to classic models, one cannot assume that dispersion could be adequately described in terms of the diffusion equation. The effect of the reproduction rate and the variability of the individuals in the population on the persistence of different version of the metapopulation model was also analyzed.

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Yeakel, Justin D., Jean P. Gibert, Thilo Gross, Peter A. H. Westley et Jonathan W. Moore. « Eco-evolutionary dynamics, density-dependent dispersal and collective behaviour : implications for salmon metapopulation robustness ». Philosophical Transactions of the Royal Society B : Biological Sciences 373, n^o 1746 (26 mars 2018) : 20170018. http://dx.doi.org/10.1098/rstb.2017.0018.

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The spatial dispersal of individuals plays an important role in the dynamics of populations, and is central to metapopulation theory. Dispersal provides connections within metapopulations, promoting demographic and evolutionary rescue, but may also introduce maladapted individuals, potentially lowering the fitness of recipient populations through introgression of heritable traits. To explore this dual nature of dispersal, we modify a well-established eco-evolutionary model of two locally adapted populations and their associated mean trait values, to examine recruiting salmon populations that are connected by density-dependent dispersal, consistent with collective migratory behaviour that promotes navigation. When the strength of collective behaviour is weak such that straying is effectively constant, we show that a low level of straying is associated with the highest gains in metapopulation robustness and that high straying serves to erode robustness. Moreover, we find that as the strength of collective behaviour increases, metapopulation robustness is enhanced, but this relationship depends on the rate at which individuals stray. Specifically, strong collective behaviour increases the presence of hidden low-density basins of attraction, which may serve to trap disturbed populations, and this is exacerbated by increased habitat heterogeneity. Taken as a whole, our findings suggest that density-dependent straying and collective migratory behaviour may help metapopulations, such as in salmon, thrive in dynamic landscapes. Given the pervasive eco-evolutionary impacts of dispersal on metapopulations, these findings have important ramifications for the conservation of salmon metapopulations facing both natural and anthropogenic contemporary disturbances. This article is part of the theme issue ‘Collective movement ecology’.

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Huang, Yu, et Xingfu Zou. « Impact of Dispersion on Dynamics of a Discrete Metapopulation Model ». Open Systems & ; Information Dynamics 14, n^o 04 (décembre 2007) : 379–96. http://dx.doi.org/10.1007/s11080-007-9063-1.

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We propose and analyze a discrete time model for metapopulation on two patches with local logistic dynamics. The model carries a delay in the dispersion terms, and our results on this model show that the impact of the dispersion on the global dynamics of the metapopulation is complicated and interesting: it can affect the existence of a positive equilibrium; it can either drive the metapopulation to global extinction, or prevent the metapopulation from going to global extinction and stabilize a positive equilibrium; it can also destabilize a positive equilibrium or a periodic orbit.

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Hanski, Ilkka. « A Practical Model of Metapopulation Dynamics ». Journal of Animal Ecology 63, n^o 1 (janvier 1994) : 151. http://dx.doi.org/10.2307/5591.

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Gotelli, Nicholas J., et Walter G. Kelley. « A General Model of Metapopulation Dynamics ». Oikos 68, n^o 1 (octobre 1993) : 36. http://dx.doi.org/10.2307/3545306.

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Bosi, Stefano, et David Desmarchelier. « An economic model of metapopulation dynamics ». Ecological Modelling 387 (novembre 2018) : 196–204. http://dx.doi.org/10.1016/j.ecolmodel.2018.09.013.

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Hale, Robin, Eric A. Treml et Stephen E. Swearer. « Evaluating the metapopulation consequences of ecological traps ». Proceedings of the Royal Society B : Biological Sciences 282, n^o 1804 (7 avril 2015) : 20142930. http://dx.doi.org/10.1098/rspb.2014.2930.

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Ecological traps occur when environmental changes cause maladaptive habitat selection. Despite their relevance to metapopulations, ecological traps have been studied predominantly at local scales. How these local impacts scale up to affect the dynamics of spatially structured metapopulations in heterogeneous landscapes remains unexplored. We propose that assessing the metapopulation consequences of traps depends on a variety of factors that can be grouped into four categories: the probability of encounter, the likelihood of selection, the fitness costs of selection and species-specific vulnerability to these costs. We evaluate six hypotheses using a network-based metapopulation model to explore the relative importance of factors across these categories within a spatial context. Our model suggests (i) traps are most severe when they represent a large proportion of habitats, severely reduce fitness and are highly attractive, and (ii) species with high intrinsic fitness will be most susceptible. We provide the first evidence that (iii) traps may be beneficial for metapopulations in rare instances, and (iv) preferences for natal-like habitats can magnify the effects of traps. Our study provides important insight into the effects of traps at landscape scales, and highlights the need to explicitly consider spatial context to better understand and manage traps within metapopulations.

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Bertassello, L. E., E. Bertuzzo, G. Botter, J. W. Jawitz, A. F. Aubeneau, J. T. Hoverman, A. Rinaldo et P. S. C. Rao. « Dynamic spatio-temporal patterns of metapopulation occupancy in patchy habitats ». Royal Society Open Science 8, n^o 1 (13 janvier 2021) : 201309. http://dx.doi.org/10.1098/rsos.201309.

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Spatio-temporal dynamics in habitat suitability and connectivity among mosaics of heterogeneous wetlands are critical for biological diversity and species persistence in aquatic patchy landscapes. Despite the recognized importance of stochastic hydroclimatic forcing in driving wetlandscape hydrological dynamics, linking such effects to emergent dynamics of metapopulation poses significant challenges. To fill this gap, we propose here a dynamic stochastic patch occupancy model (SPOM), which links parsimonious hydrological and ecological models to simulate spatio-temporal patterns in species occupancy in wetlandscapes. Our work aims to place ecological studies of patchy habitats into a proper hydrologic and climatic framework to improve the knowledge about metapopulation shifts in response to climate-driven changes in wetlandscapes. We applied the dynamic version of the SPOM (D-SPOM) framework in two wetlandscapes in the US with contrasting landscape and climate properties. Our results illustrate that explicit consideration of the temporal dimension proposed in the D-SPOM is important to interpret local- and landscape-scale patterns of habitat suitability and metapopulation occupancy. Our analyses show that spatio-temporal dynamics of patch suitability and accessibility, driven by the stochasticity in hydroclimatic forcing, influence metapopulation occupancy and the topological metrics of the emergent wetlandscape dispersal network. D-SPOM simulations also reveal that the extinction risk in dynamic wetlandscapes is exacerbated by extended dry periods when suitable habitat decreases, hence limiting successful patch colonization and exacerbating metapopulation extinction risks. The proposed framework is not restricted only to wetland studies but could also be applied to examine metapopulation dynamics in other types of patchy habitats subjected to stochastic external disturbances.

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Driscoll, D. A. « How to find a metapopulationThis review is one of a series dealing with some aspects of the impact of habitat fragmentation on animals and plants. This series is one of several virtual symposia focussing on ecological topics that will be published in the Journal from time to time. » Canadian Journal of Zoology 85, n^o 10 (octobre 2007) : 1031–48. http://dx.doi.org/10.1139/z07-096.

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Where habitat loss and fragmentation is severe, many native species are likely to have reduced levels of dispersal between remnant populations. For those species to avoid regional extinction in fragmented landscapes, they must undergo some kind of metapopulation dynamics so that local extinctions are countered by recolonisation. The importance of spatial dynamics for regional survival means that research into metapopulation dynamics is essential. In this review I explore the approaches taken to examine metapopulation dynamics, highlight the analytical methods used to get the most information out of field data, and discover some of the major research gaps. Statistical models, including Hanski’s incidence function model (IFM) are frequently applied to presence–absence data, an approach that is often strengthened using long-term data sets that document extinctions and colonisations. Recent developments are making the IFM more biologically realistic and expanding the range of situations for which the model is relevant. Although accurate predictions using the IFM seem unlikely, it may be useful for ranking management decisions. A key weakness of presence–absence modelling is that the mechanisms underlying spatial dynamics remain inferential, so combining modelling approaches with detailed demographic research is warranted. For species where very large data sets cannot be obtained to facilitate statistical modelling, a demographic approach alone or with stochastic modelling may be the only viable research angle to take. Dispersal is a central process in metapopulation dynamics. Research combining mark–recapture or telemetry methods with model-selection procedures demonstrate that dispersal is frequently oversimplified in conceptual and statistical metapopulation models. Dispersal models like the island model that underlies classic metapopulation theory do not approximate the behaviour of real species in fragmented landscapes. Nevertheless, it remains uncertain if additional biological realism will improve predictions of statistical metapopulation models. Genetic methods can give better estimates of dispersal than direct methods and take less effort, so they should be routinely explored alongside direct ecological methods. Recent development of metacommunity theory (communities connected by dispersal) emphasises a range of mechanisms that complement metapopulation theory. Taking both theories into account will enhance interpretation of field data. The extent of metapopulation dynamics in human modified landscapes remains uncertain, but we have a powerful array of field and analytical approaches for reducing this knowledge gap. The most informative way forward requires that many species are studied in the same fragmented landscape by applying a selection of approaches that reveal complementary aspects of spatial dynamics.

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Secor, David H., Lisa A. Kerr et Steven X. Cadrin. « Connectivity effects on productivity, stability, and persistence in a herring metapopulation model ». ICES Journal of Marine Science 66, n^o 8 (8 juin 2009) : 1726–32. http://dx.doi.org/10.1093/icesjms/fsp154.

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Abstract Secor, D. H., Kerr, L. A., and Cadrin, S. X. 2009. Connectivity effects on productivity, stability, and persistence in a herring metapopulation model. – ICES Journal of Marine Science, 66: 1726–1732. Diverse and interacting spawning groups of Atlantic herring (Clupea harengus) have varying degrees of independence to environmental conditions. How these population components respond independently to the same set of environmental conditions, and are connected through straying or entrainment, will contribute to the aggregate metapopulation dynamics. The consequences of connectivity for productivity, stability, and persistence were evaluated in an age-structured model of a two-component metapopulation. Simulation scenarios of straying and entrainment were developed to examine the effects of component interchange and recruitment covariance on metapopulation attributes. Asynchronous component responses should result in reduced variance in metapopulation dynamics, which was measured as the portfolio effect (PE). Most types and magnitudes of connectivity reduced metapopulation productivity and stability. Increased connectivity tended to increase instability of a component by distributing the effect of strong year classes among components and disrupting the “storage effect” within components. Density-dependent straying and entrainment, respectively, showed stabilizing and destabilizing feedback cycles on metapopulation stability and persistence. Furthermore, high rates of connectivity tended to result in increased synchronous responses between components and depressed metapopulation productivity, stability, and PE. Exploitation on a metapopulation should similarly depress independence among components because high mortality will dampen component responses to environmental forcing.

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FENG, ZHILAN, LIBIN RONG et ROBERT K. SWIHART. « DYNAMICS OF AN AGE-STRUCTURED METAPOPULATION MODEL ». Natural Resource Modeling 18, n^o 4 (28 juin 2008) : 415–40. http://dx.doi.org/10.1111/j.1939-7445.2005.tb00166.x.

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McVinish, R., P. K. Pollett et Y. S. Chan. « A metapopulation model with Markovian landscape dynamics ». Theoretical Population Biology 112 (décembre 2016) : 80–96. http://dx.doi.org/10.1016/j.tpb.2016.08.005.

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Gyllenberg, Mats, et Ilkka Hanski. « Single-species metapopulation dynamics : A structured model ». Theoretical Population Biology 42, n^o 1 (août 1992) : 35–61. http://dx.doi.org/10.1016/0040-5809(92)90004-d.

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Mietchen, Matthew S., Christopher T. Short, Matthew Samore et Eric T. Lofgren. « Examining the impact of ICU population interaction structure on modeled colonization dynamics of Staphylococcus aureus ». PLOS Computational Biology 18, n^o 7 (25 juillet 2022) : e1010352. http://dx.doi.org/10.1371/journal.pcbi.1010352.

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Background Complex transmission models of healthcare-associated infections provide insight for hospital epidemiology and infection control efforts, but they are difficult to implement and come at high computational costs. Structuring more simplified models to incorporate the heterogeneity of the intensive care unit (ICU) patient-provider interactions, we explore how methicillin-resistant Staphylococcus aureus (MRSA) dynamics and acquisitions may be better represented and approximated. Methods Using a stochastic compartmental model of an 18-bed ICU, we compared the rates of MRSA acquisition across three ICU population interaction structures: a model with nurses and physicians as a single staff type (SST), a model with separate staff types for nurses and physicians (Nurse-MD model), and a Metapopulation model where each nurse was assigned a group of patients. The proportion of time spent with the assigned patient group (γ) within the Metapopulation model was also varied. Results The SST, Nurse-MD, and Metapopulation models had a mean of 40.6, 32.2 and 19.6 annual MRSA acquisitions respectively. All models were sensitive to the same parameters in the same direction, although the Metapopulation model was less sensitive. The number of acquisitions varied non-linearly by values of γ, with values below 0.40 resembling the Nurse-MD model, while values above that converged toward the Metapopulation structure. Discussion Inclusion of complex population interactions within a modeled hospital ICU has considerable impact on model results, with the SST model having more than double the acquisition rate of the more structured metapopulation model. While the direction of parameter sensitivity remained the same, the magnitude of these differences varied, producing different colonization rates across relatively similar populations. The non-linearity of the model’s response to differing values of a parameter gamma (γ) suggests simple model approximations are appropriate in only a narrow space of relatively dispersed nursing assignments. Conclusion Simplifying assumptions around how a hospital population is modeled, especially assuming random mixing, may overestimate infection rates and the impact of interventions. In many, if not most, cases more complex models that represent population mixing with higher granularity are justified.

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Castorani, Max C. N., Daniel C. Reed, Peter T. Raimondi, Filipe Alberto, Tom W. Bell, Kyle C. Cavanaugh, David A. Siegel et Rachel D. Simons. « Fluctuations in population fecundity drive variation in demographic connectivity and metapopulation dynamics ». Proceedings of the Royal Society B : Biological Sciences 284, n^o 1847 (25 janvier 2017) : 20162086. http://dx.doi.org/10.1098/rspb.2016.2086.

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Demographic connectivity is vital to sustaining metapopulations yet often changes dramatically through time due to variation in the production and dispersal of offspring. However, the relative importance of variation in fecundity and dispersal in determining the connectivity and dynamics of metapopulations is poorly understood due to the paucity of comprehensive spatio-temporal data on these processes for most species. We quantified connectivity in metapopulations of a marine foundation species (giant kelp Macrocystis pyrifera ) across 11 years and approximately 900 km of coastline by estimating population fecundity with satellite imagery and propagule dispersal using a high-resolution ocean circulation model. By varying the temporal complexity of different connectivity measures and comparing their ability to explain observed extinction–colonization dynamics, we discovered that fluctuations in population fecundity, rather than fluctuations in dispersal, are the dominant driver of variation in connectivity and contribute substantially to metapopulation recovery and persistence. Thus, for species with high variability in reproductive output and modest variability in dispersal (most plants, many animals), connectivity measures ignoring fluctuations in fecundity may overestimate connectivity and likelihoods of persistence, limiting their value for understanding and conserving metapopulations. However, we demonstrate how connectivity measures can be simplified while retaining utility, validating a practical solution for data-limited systems.

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Shima, Jeffrey S., Erik G. Noonburg et Stephen E. Swearer. « Consequences of variable larval dispersal pathways and resulting phenotypic mixtures to the dynamics of marine metapopulations ». Biology Letters 11, n^o 2 (février 2015) : 20140778. http://dx.doi.org/10.1098/rsbl.2014.0778.

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Larval dispersal can connect distant subpopulations, with important implications for marine population dynamics and persistence, biodiversity conservation and fisheries management. However, different dispersal pathways may affect the final phenotypes, and thus the performance and fitness of individuals that settle into subpopulations. Using otolith microchemical signatures that are indicative of ‘dispersive’ larvae (oceanic signatures) and ‘non-dispersive’ larvae (coastal signatures), we explore the population-level consequences of dispersal-induced variability in phenotypic mixtures for the common triplefin (a small reef fish). We evaluate lipid concentration and otolith microstructure and find that ‘non-dispersive’ larvae (i) have greater and less variable lipid reserves at settlement (and this variability attenuates at a slower rate), (ii) grow faster after settlement, and (iii) experience similar carry-over benefits of lipid reserves on post-settlement growth relative to ‘dispersive’ larvae. We then explore the consequences of phenotypic mixtures in a metapopulation model with two identical subpopulations replenished by variable contributions of ‘dispersive’ and ‘non-dispersive’ larvae and find that the resulting phenotypic mixtures can have profound effects on the size of the metapopulation. We show that, depending upon the patterns of connectivity, phenotypic mixtures can lead to larger metapopulations, suggesting dispersal-induced demographic heterogeneity may facilitate metapopulation persistence.

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Nareddy, Vahini Reddy, Jonathan Machta, Karen C. Abbott, Shadisadat Esmaeili et Alan Hastings. « Dynamical Ising model of spatially coupled ecological oscillators ». Journal of The Royal Society Interface 17, n^o 171 (octobre 2020) : 20200571. http://dx.doi.org/10.1098/rsif.2020.0571.

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Long-range synchrony from short-range interactions is a familiar pattern in biological and physical systems, many of which share a common set of ‘universal’ properties at the point of synchronization. Common biological systems of coupled oscillators have been shown to be members of the Ising universality class, meaning that the very simple Ising model replicates certain spatial statistics of these systems at stationarity. This observation is useful because it reveals which aspects of spatial pattern arise independently of the details governing local dynamics, resulting in both deeper understanding of and a simpler baseline model for biological synchrony. However, in many situations a system’s dynamics are of greater interest than their static spatial properties. Here, we ask whether a dynamical Ising model can replicate universal and non-universal features of ecological systems, using noisy coupled metapopulation models with two-cycle dynamics as a case study. The standard Ising model makes unrealistic dynamical predictions, but the Ising model with memory corrects this by using an additional parameter to reflect the tendency for local dynamics to maintain their phase of oscillation. By fitting the two parameters of the Ising model with memory to simulated ecological dynamics, we assess the correspondence between the Ising and ecological models in several of their features (location of the critical boundary in parameter space between synchronous and asynchronous dynamics, probability of local phase changes and ability to predict future dynamics). We find that the Ising model with memory is reasonably good at representing these properties of ecological metapopulations. The correspondence between these models creates the potential for the simple and well-known Ising class of models to become a valuable tool for understanding complex biological systems.

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Ross, J. V. « A stochastic metapopulation model accounting for habitat dynamics ». Journal of Mathematical Biology 52, n^o 6 (6 mars 2006) : 788–806. http://dx.doi.org/10.1007/s00285-006-0372-8.

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Reed, J. Michael, et Stephen H. Levine. « A model for behavioral regulation of metapopulation dynamics ». Ecological Modelling 183, n^o 4 (mai 2005) : 411–23. http://dx.doi.org/10.1016/j.ecolmodel.2004.02.025.

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Xu, Dashun, Zhilan Feng, Linda J. S. Allen et Robert K. Swihart. « A spatially structured metapopulation model with patch dynamics ». Journal of Theoretical Biology 239, n^o 4 (avril 2006) : 469–81. http://dx.doi.org/10.1016/j.jtbi.2005.08.012.

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Groeneveld, Rolf, et Hans-Peter Weikard. « Terrestrial metapopulation dynamics : a nonlinear bioeconomic model analysis ». Journal of Environmental Management 78, n^o 3 (février 2006) : 275–85. http://dx.doi.org/10.1016/j.jenvman.2005.04.023.

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Xia, Bjørnstad et Grenfell. « Measles Metapopulation Dynamics : A Gravity Model for Epidemiological Coupling and Dynamics ». American Naturalist 164, n^o 2 (2004) : 267. http://dx.doi.org/10.2307/3473444.

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Xia, Yingcun, Ottar N. Bjørnstad et Bryan T. Grenfell. « Measles Metapopulation Dynamics : A Gravity Model for Epidemiological Coupling and Dynamics ». American Naturalist 164, n^o 2 (août 2004) : 267–81. http://dx.doi.org/10.1086/422341.

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Dockstader, Zachary, Chris Bauch et Madhur Anand. « Interconnections Accelerate Collapse in a Socio-Ecological Metapopulation ». Sustainability 11, n^o 7 (28 mars 2019) : 1852. http://dx.doi.org/10.3390/su11071852.

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Over-exploitation of natural resources can have profound effects on both ecosystems and their resident human populations. Simple theoretical models of the dynamics of a population of human harvesters and the abundance of a natural resource being harvested have been studied previously, but relatively few models consider the effect of metapopulation structure (i.e., a population distributed across discrete patches). Here we analyze a socio-ecological metapopulation model based on an existing single-population model used to study persistence and collapse in human populations. Resources grow logistically on each patch. Each population harvests resources on its own patch to support population growth, but can also harvest resources from other patches when their own patch resources become scarce. We show that when populations are allowed to harvest resources from other patches, the peak population size is higher, but subsequent population collapse is significantly accelerated and across a broader parameter regime. As the number of patches in the metapopulation increases, collapse is more sudden, more severe, and occurs sooner. These effects persist under scenarios of asymmetry and inequality between patches. Our model makes simplifying assumptions in order to facilitate insight and understanding of model dynamics. However, the robustness of the model prediction suggests that more sophisticated models should be developed to ascertain the impact of metapopulation structure on socio-ecological sustainability.

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Manica, Vanderlei, et Jacques Aveline Loureiro da Silva. « The Influence of Temporal Migration in the Synchronization of Populations ». TEMA (São Carlos) 16, n^o 1 (29 mai 2015) : 31. http://dx.doi.org/10.5540/tema.2015.016.01.0031.

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A discrete metapopulation model with temporal dependent migration is proposed in order to study the stability of synchronized dynamics. During each time step, we assume that there are two processes involved in the population dynamics: local patch dynamics and migration process between the patches that compose the metapopulation. We obtain an analytical criterion that depends on the local patch dynamics (Lyapunov number) and on the whole migration process. The stability of synchronized dynamics depends on how individuals disperse among the patches.

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BICHSEL, MANUEL, A. D. BARBOUR et ANDREAS WAGNER. « DYNAMICS OF AN INSERTION SEQUENCE INFECTION IN A SPATIALLY STRUCTURED ENVIRONMENT ». Journal of Biological Systems 26, n^o 01 (mars 2018) : 133–66. http://dx.doi.org/10.1142/s0218339018500079.

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Bacterial insertion sequences (ISs), the simplest form of autonomous mobile DNA, depend on their prokaryote hosts to spread in a spatially structured environment. We use a spatially explicit metapopulation model to simulate the spread of an IS that can have both detrimental and beneficial effects on its host cell. We find that, on the one hand, the spatial structure of the metapopulation and cell dispersal between subpopulations have no strong effect on the time to full infection of the metapopulation. On the other hand, factors that influence the IS infection dynamics within a subpopulation have a strong effect on that time. These factors are mainly the fitness benefit of an IS and the rate of horizontal gene transfer. We also find that the infection process of a metapopulation is very erratic in its early phase. Finally, we show that the infection’s success depends critically on the initially infected subpopulation.

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Bolzoni, Luca, Rossella Della Marca, Maria Groppi et Alessandra Gragnani. « Dynamics of a metapopulation epidemic model with localized culling ». Discrete & ; Continuous Dynamical Systems - B 25, n^o 6 (2020) : 2307–30. http://dx.doi.org/10.3934/dcdsb.2020036.

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Feng, Zhilan, Robert Swihart, Yingfei Yi et Huaiping Zhu. « Coexistence in a metapopulation model with explicit local dynamics ». Mathematical Biosciences and Engineering 1, n^o 1 (mars 2004) : 131–45. http://dx.doi.org/10.3934/mbe.2004.1.131.

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Elías-Wolff, F., A. Eriksson, A. Manica et B. Mehlig. « How Levins’ dynamics emerges from a Ricker metapopulation model ». Theoretical Ecology 9, n^o 2 (24 septembre 2015) : 173–83. http://dx.doi.org/10.1007/s12080-015-0271-y.

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Uchmański, Janusz. « Individual variability and metapopulation dynamics : An individual-based model ». Ecological Modelling 334 (août 2016) : 8–18. http://dx.doi.org/10.1016/j.ecolmodel.2016.04.019.

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Nagatani, Takashi, et Genki Ichinose. « Diffusively-Coupled Rock-Paper-Scissors Game with Mutation in Scale-Free Hierarchical Networks ». Complexity 2020 (9 octobre 2020) : 1–8. http://dx.doi.org/10.1155/2020/6976328.

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We present a metapopulation dynamic model for the diffusively-coupled rock-paper-scissors (RPS) game with mutation in scale-free hierarchical networks. We investigate how the RPS game changes by mutation in scale-free networks. Only the mutation from rock to scissors (R-to-S) occurs with rate μ. In the network, a node represents a patch where the RPS game is performed. RPS individuals migrate among nodes by diffusion. The dynamics are represented by the reaction-diffusion equations with the recursion formula. We study where and how species coexist or go extinct in the scale-free network. We numerically obtained the solutions for the metapopulation dynamics and derived the transition points. The results show that, with increasing mutation rate μ, the extinction of P species occurs and then the extinction of R species occurs, and finally only S species survives. Thus, the first and second dynamical phase transitions occur in the scale-free hierarchical network. We also show that the scaling law holds for the population dynamics which suggests that the transition points approach zero in the limit of infinite size.

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Calvetti, Daniela, Alexander P. Hoover, Johnie Rose et Erkki Somersalo. « Modeling Epidemic Spread among a Commuting Population Using Transport Schemes ». Mathematics 9, n^o 16 (5 août 2021) : 1861. http://dx.doi.org/10.3390/math9161861.

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Understanding the dynamics of the spread of COVID-19 between connected communities is fundamental in planning appropriate mitigation measures. To that end, we propose and analyze a novel metapopulation network model, particularly suitable for modeling commuter traffic patterns, that takes into account the connectivity between a heterogeneous set of communities, each with its own infection dynamics. In the novel metapopulation model that we propose here, transport schemes developed in optimal transport theory provide an efficient and easily implementable way of describing the temporary population redistribution due to traffic, such as the daily commuter traffic between work and residence. Locally, infection dynamics in individual communities are described in terms of a susceptible-exposed-infected-recovered (SEIR) compartment model, modified to account for the specific features of COVID-19, most notably its spread by asymptomatic and presymptomatic infected individuals. The mathematical foundation of our metapopulation network model is akin to a transport scheme between two population distributions, namely the residential distribution and the workplace distribution, whose interface can be inferred from commuter mobility data made available by the US Census Bureau. We use the proposed metapopulation model to test the dynamics of the spread of COVID-19 on two networks, a smaller one comprising 7 counties in the Greater Cleveland area in Ohio, and a larger one consisting of 74 counties in the Pittsburgh–Cleveland–Detroit corridor following the Lake Erie’s American coastline. The model simulations indicate that densely populated regions effectively act as amplifiers of the infection for the surrounding, less densely populated areas, in agreement with the pattern of infections observed in the course of the COVID-19 pandemic. Computed examples show that the model can be used also to test different mitigation strategies, including one based on state-level travel restrictions, another on county level triggered social distancing, as well as a combination of the two.

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Sun, Bo, et Yi Zhao. « Impact of dispersion on dynamics of a discrete metapopulation model ». Journal of Computational and Applied Mathematics 200, n^o 1 (mars 2007) : 266–75. http://dx.doi.org/10.1016/j.cam.2005.12.031.

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Mann Manyombe, M. L., B. Tsanou, J. Mbang et S. Bowong. « A metapopulation model for the population dynamics of anopheles mosquito ». Applied Mathematics and Computation 307 (août 2017) : 71–91. http://dx.doi.org/10.1016/j.amc.2017.02.039.

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Schmidt, Daniel J., Joel A. Huey, Nick R. Bond et Jane M. Hughes. « Population structure of sexually reproducing carp gudgeons : does a metapopulation offer refuge from sexual parasitism ? » Marine and Freshwater Research 64, n^o 3 (2013) : 223. http://dx.doi.org/10.1071/mf12305.

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Australian carp gudgeons (Hypseleotris spp.) of the Murray–Darling basin are a species complex including sexually reproducing taxa and unisexual hybrid lineages that reproduce via hybridogenesis. Unisexual fish require gametes of a sexual species to propagate themselves and can be regarded as ‘sexual parasites’ capable of driving closed populations to extinction. Metapopulation dynamics have been proposed as a mechanism that could facilitate coexistence between a sexual parasite and its ‘host’. This study evaluates whether patterns of spatial genetic variation are compatible with metapopulation dynamics for a sexually reproducing member of the carp gudgeon complex (Hypseleotris sp. HA), in the Granite Creeks system of central Victoria. Genetic differentiation of fish among all study sites was accommodated by a model of migration-drift equilibrium using decomposed pairwise regression analysis. Given that the population was divided into discrete patches in the form of refugial waterholes during the time of this study, we infer that spatially constrained source–sink metapopulation dynamics may be responsible for producing this pattern. It is therefore possible that metapopulation dynamics contribute to coexistence in the Granite Creeks carp gudgeon hybridogenetic system, and further analysis is required to determine the relative importance of environmental versus demographic factors towards patch extinction.

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Wang, Yi, et Zhen Jin. « Epidemic Threshold for Metapopulation Networks with Demographical Dynamics ». Advanced Materials Research 268-270 (juillet 2011) : 2097–100. http://dx.doi.org/10.4028/www.scientific.net/amr.268-270.2097.

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In this paper, we investigate the dynamics of an epidemic model with birth anddeath and reaction-di usion processes in heterogeneous metapopulation networks. By mean- eld analysis, we obtain the conditions that the disease will outbreak on networks for somespeci c cases. This reminds us both the structure of the networks and population demographyplay an important role on the spread of infectious disease.

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Dearlove, Bethany, et Daniel J. Wilson. « Coalescent inference for infectious disease : meta-analysis of hepatitis C ». Philosophical Transactions of the Royal Society B : Biological Sciences 368, n^o 1614 (19 mars 2013) : 20120314. http://dx.doi.org/10.1098/rstb.2012.0314.

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Genetic analysis of pathogen genomes is a powerful approach to investigating the population dynamics and epidemic history of infectious diseases. However, the theoretical underpinnings of the most widely used, coalescent methods have been questioned, casting doubt on their interpretation. The aim of this study is to develop robust population genetic inference for compartmental models in epidemiology. Using a general approach based on the theory of metapopulations, we derive coalescent models under susceptible–infectious (SI), susceptible–infectious–susceptible (SIS) and susceptible–infectious–recovered (SIR) dynamics. We show that exponential and logistic growth models are equivalent to SI and SIS models, respectively, when co-infection is negligible. Implementing SI, SIS and SIR models in BEAST, we conduct a meta-analysis of hepatitis C epidemics, and show that we can directly estimate the basic reproductive number ( R 0 ) and prevalence under SIR dynamics. We find that differences in genetic diversity between epidemics can be explained by differences in underlying epidemiology (age of the epidemic and local population density) and viral subtype. Model comparison reveals SIR dynamics in three globally restricted epidemics, but most are better fit by the simpler SI dynamics. In summary, metapopulation models provide a general and practical framework for integrating epidemiology and population genetics for the purposes of joint inference.

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Camaclang, Abbey E., Janelle M. R. Curtis, Ilona Naujokaitis-Lewis, Mark S. Poesch et Marten A. Koops. « Modelling the impact of poaching on metapopulation viability for data-limited species ». Canadian Journal of Fisheries and Aquatic Sciences 74, n^o 6 (juin 2017) : 894–906. http://dx.doi.org/10.1139/cjfas-2015-0508.

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We developed a spatially explicit simulation model of poaching behaviour to quantify the relative influence of the intensity, frequency, and spatial distribution of poaching on metapopulation viability. We integrated our model of poaching with a stochastic, habitat-based, spatially explicit population model, applied it to examine the impact of poaching on northern abalone (Haliotis kamtschatkana) metapopulation dynamics in Barkley Sound, British Columbia, Canada, and quantified model sensitivity to input parameters. While demographic parameters remained important in predicting extinction probabilities for northern abalone, our simulations indicate that the odds of extinction are twice as high when populations are subjected to poaching. Viability was influenced by poaching variables that affect the total number of individuals removed. Of these, poaching mortality was the most influential in predicting metapopulation viability, with each 0.1 increase in mortality rate resulting in 22.6% increase in the odds of extinction. By contrast, the location and spatial correlation of events were less important predictors of viability. When data are limited, simulation models of poaching combined with sensitivity analyses can be useful in informing management strategies and future research directions.

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Lipcius, Romuald N., William T. Stockhausen et David B. Eggleston. « Marine reserves for Caribbean spiny lobster : empirical evaluation and theoretical metapopulation recruitment dynamics ». Marine and Freshwater Research 52, n^o 8 (2001) : 1589. http://dx.doi.org/10.1071/mf01193.

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Field data on spiny-lobster abundance, habitat quality, and hydrodynamic transport patterns for a reserve (ECLSP) and three exploited sites (CI, EI, LSI) were used to assess reserve success in reducing fishing mortality and increasing theoretical metapopulation recruitment. Fishing mortality was estimated empirically by quantification of lobster density at ECLSP and the three exploited sites before and after the start of the fishing season in two years. Fishing mortality was estimated to be 47–98% lower at the reserve. Using a circulation model , we theoretically assessed effectiveness of ECLSP and nominal reserves at the exploited sites in augmenting recruitment through redistribution of larvae to all sites. Larvae discharged from ECLSP and EI recruited throughout Exuma Sound, whereas those from LSI and CI recruited only to CI and LSI. Hence, only reserves at EI and ECLSP would be suitable for metapopulation recruitment. In selecting an optimal reserve for metapopulation recruitment, use of information on habitat quality or adult density did not yield a higher probability of success than did determining the reserve location by chance. The only successful strategy was one that used information on transport processes. Designation of effective marine reserves therefore requires careful attention to metapopulation dynamics and recruitment processes.

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Citron, Daniel T., Carlos A. Guerra, Andrew J. Dolgert, Sean L. Wu, John M. Henry, Héctor M. Sánchez C. et David L. Smith. « Comparing metapopulation dynamics of infectious diseases under different models of human movement ». Proceedings of the National Academy of Sciences 118, n^o 18 (29 avril 2021) : e2007488118. http://dx.doi.org/10.1073/pnas.2007488118.

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Newly available datasets present exciting opportunities to investigate how human population movement contributes to the spread of infectious diseases across large geographical distances. It is now possible to construct realistic models of infectious disease dynamics for the purposes of understanding global-scale epidemics. Nevertheless, a remaining unanswered question is how best to leverage the new data to parameterize models of movement, and whether one’s choice of movement model impacts modeled disease outcomes. We adapt three well-studied models of infectious disease dynamics, the susceptible–infected–recovered model, the susceptible–infected–susceptible model, and the Ross–Macdonald model, to incorporate either of two candidate movement models. We describe the effect that the choice of movement model has on each disease model’s results, finding that in all cases, there are parameter regimes where choosing one movement model instead of another has a profound impact on epidemiological outcomes. We further demonstrate the importance of choosing an appropriate movement model using the applied case of malaria transmission and importation on Bioko Island, Equatorial Guinea, finding that one model produces intelligible predictions of R0, whereas the other produces nonsensical results.

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Sutherland, C., D. A. Elston et X. Lambin. « Accounting for false positive detection error induced by transient individuals ». Wildlife Research 40, n^o 6 (2013) : 490. http://dx.doi.org/10.1071/wr12166.

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Context In metapopulations, colonisation is the result of dispersal from neighbouring occupied patches, typically juveniles dispersing from natal to breeding sites. When occupancy dynamics are dispersal driven, occupancy should refer to the presence of established, breeding populations. The detection of transient individuals at sites that are, by definition, unoccupied (i.e. false positive detections), may result in misleading conclusions about metapopulation dynamics. Until recently, the issue of false positives has been considered negligible and current efforts to account for such error have been restricted to the context of species misidentification. However, the detection of transient individuals visiting multiple sites while dispersing is a distinct source of false positives that can bias estimates of occupancy because visited sites do not contribute to metapopulation dynamics in the same way as do sites occupied by established, reproducing populations. Although transient-induced false positive error presents a challenge to occupancy studies aiming to account for all sources of detection error and estimate occupancy without bias, accounting for it has received little attention. Aims Using a novel application of an existing occupancy model, we sought to account for false positives that result from transient individuals being observed at truly unoccupied sites (i.e. where no establishment has occurred). Methods We applied a Bayesian multi-season occupancy model correcting for false negative and false positive errors, to 3 years of detection or non-detection data from a metapopulation of water voles, Arvicola amphibious, in which both types of patch-state misclassification are suspected. Key results We provide evidence that transient individuals can cause false positive detection errors. We then demonstrate the flexibility of the occupancy model to account for both false negative and false positive detection errors beyond the typical application to species misidentification. Accounting for both types of observation error reduces the bias in estimates of occupancy and avoids misleading conclusions about the status of (meta) populations by allowing for the distinction to be made between resident and transient occupancy. Conclusion In many species, transience may result in patch-state misclassification which needs to be accounted for so as to draw correct inference about metapopulation status. Making the distinction between occupancy by established populations and visitation by transients will influence how we interpret patch occupancy dynamics, with important implications for the management of wildlife. Implications The ability to estimate occupancy free of bias induced by false positive detections can help ensure that downward trends in occupancy are detected despite such declines being accompanied by increasing frequency of transients associated with, for example, reductions in mate availability or failure to establish. Our approach can be applied to any occupancy study in which false positive detections are suspected because of the behaviour of the focal species.

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Beyer, Hawthorne L., Katie Hampson, Tiziana Lembo, Sarah Cleaveland, Magai Kaare et Daniel T. Haydon. « Metapopulation dynamics of rabies and the efficacy of vaccination ». Proceedings of the Royal Society B : Biological Sciences 278, n^o 1715 (15 décembre 2010) : 2182–90. http://dx.doi.org/10.1098/rspb.2010.2312.

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Spatial structure in a host population results in heterogeneity in transmission dynamics. We used a Bayesian framework to evaluate competing metapopulation models of rabies transmission among domestic dog populations in villages in Tanzania. A proximate indicator of disease, medical records of animal-bite injuries, is used to infer the occurrence (presence/absence) of suspected rabid dog cases in one month intervals. State-space models were used to explore the implications of different levels of reporting probability on model parameter estimates. We find evidence for a relatively high rate of infection of these populations from neighbouring districts or from other species distributed throughout the study area, rather than from adjacent wildlife protected areas, suggesting wildlife is unlikely to be implicated in the long-term persistence of rabies. Stochastic simulation of our highest ranked models in vaccinated and hypothetical unvaccinated populations indicated that pulsed vaccination campaigns occurring from 2002 to 2007 reduced rabies occurrence by 57.3 per cent in vaccinated villages in the 1 year following each pulse, and that a similar regional campaign would deliver an 80.9 per cent reduction in occurrence. This work demonstrates how a relatively coarse, proximate sentinel of rabies infection is useful for making inferences about spatial disease dynamics and the efficacy of control measures.

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Belyaev, Alexander, Irina Bashkirtseva et Lev Ryashko. « Stochastic variability of regular and chaotic dynamics in 2D metapopulation model ». Chaos, Solitons & ; Fractals 151 (octobre 2021) : 111270. http://dx.doi.org/10.1016/j.chaos.2021.111270.

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Liu, Maoxing, Xinjie Fu, Jie Zhang et Donghua Zhao. « Global Dynamics of an SIS Model on Metapopulation Networks with Demographics ». Complexity 2021 (20 septembre 2021) : 1–9. http://dx.doi.org/10.1155/2021/8884236.

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In this paper, we propose a susceptible-infected-susceptible (SIS) epidemic model with demographics on heterogeneous metapopulation networks. We analytically derive the basic reproduction number, which determines not only the existence of endemic equilibrium but also the global dynamics of the model. The model always has the disease-free equilibrium, which is globally asymptotically stable when the basic reproduction number is less than unity and otherwise unstable. We also provide sufficient conditions on the global stability of the unique endemic equilibrium. Numerical simulations are performed to illustrate the theoretical results and the effects of the connectivity and diffusion. Furthermore, we find that diffusion rates play an active role in controlling the spread of infectious diseases.

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Liu, Wei-chung, Louise Matthews, Margo Chase-Topping, Nick J. Savill, Darren J. Shaw et Mark E. J. Woolhouse. « Metapopulation dynamics of Escherichia coli O157 in cattle : an exploratory model ». Journal of The Royal Society Interface 4, n^o 16 (13 mars 2007) : 917–24. http://dx.doi.org/10.1098/rsif.2007.0219.

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Livestock movement is thought to be a risk factor for the transmission of infectious diseases of farm animals. Simple mathematical models were constructed for the transmission of Escherichia coli serogroup O157 between Scottish cattle farms, and the models were used in a preliminary exploration of factors contributing to the levels of infection reported in the field. The results suggest that cattle movement can make a significant contribution to the observed prevalence of E. coli O157-positive farms, but is not by itself sufficient for the persistence of E. coli O157. The results also suggest that cattle movements involving infected farms with cattle shedding an exceptional amount of E. coli O157, ‘super-shedders’, also make a substantial contribution to the prevalence of infected farms. Simulations indicate that E. coli O157 could have reached the currently observed prevalence levels in less than a decade. Implications and findings from our models are discussed in relation to possible control of E. coli O157 in Scottish cattle.

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Hanski, Ilkka, et Chris D. Thomas. « Metapopulation dynamics and conservation : A spatially explicit model applied to butterflies ». Biological Conservation 68, n^o 2 (1994) : 167–80. http://dx.doi.org/10.1016/0006-3207(94)90348-4.

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