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Littérature scientifique sur le sujet « Metapopulation dynamics model »

Auteur : Grafiati

Publié le 9 mars 2023

Mis à jour le 10 mars 2023

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Articles de revues sur le sujet "Metapopulation dynamics model"

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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Thèses sur le sujet "Metapopulation dynamics model"

Snäll, Tord. « Distribution Patterns and Metapopulation Dynamics of Epiphytic Mosses and Lichens ». Doctoral thesis, Uppsala University, Department of Evolutionary Biology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3904.

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This thesis examines the relative importance of local conditions, dispersal and dynamics of the trees on epiphyte distribution patterns and colonization-extinction dynamics. Study species are the mosses Orthotrichum speciosum and O. obtusifolium, and the red-listed Neckera pennata. The thesis also includes an attempt to parameterize a model for a lichen metapopulation (Lobaria pulmonaria) in a dynamic landscape, based on only presence/absence data of the epiphyte and its host trees.

The results show that epiphyte colonization of trees is affected by both local conditions, and by connectivity to occupied trees. The positive effect of connectivity, implying a restricted dispersal range, was established by both demographic and genetic studies. The important local conditions were tree diameter and vitality, and shade. Local extinctions from trees occurred among small trees with low local epiphyte abundance, but more often, were the results of tree fall.

The observed importance of connectivity on epiphyte colonization agrees with the assumptions of the classic metapopulation model. However, the classic metapopulation model assumes that the landscape is static, and that local extinctions occur for stochastic reasons. The dynamics of epiphytes are different. A new conceptual model is therefore suggested, the patch-tracking metapopulation model. It differs from the classic metapopulation model in that it includes dynamics of the patches, and in that local extinctions only occur as patches are destroyed.

Simulations of the dynamics of N. pennata showed that its future metapopulation size will be overestimated unless the dynamics of the trees are accounted for. The simulation results further suggest that the dynamics of N. pennata can be characterised by the patch-tracking metapopulation model.

The attempt to parameterize the L. pulmonaria metapopulation model showed that more information are required for rigorous parameterization, preferably of the past historic fire regime.

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Teissier, Yoann. « Metapopulation dynamics of dengue epidemics in French Polynesia ». Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB008.

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La dengue circule en Polynésie française sur un mode épidémique depuis plus de 35 ans. Néanmoins, en dépit de la taille relativement faible de la population de Polynésie française, la circulation de la dengue peut persister à de faibles niveaux pendant de nombreuses années. L’objectif de ce travail de thèse est de déterminer si l'épidémiologie de la dengue dans le système insulaire de la Polynésie française répond aux critères d’un contexte de métapopulation. Après avoir constitué une base de données regroupant les cas de dengue répertoriés sur les 35 dernières années, nous avons réalisé des analyses épidémiologiques descriptives et statistiques. Celles-ci ont révélé des disparités spatio-temporelles distinctes pour l’incidence de la dengue des archipels et des îles, mais la structure de l'épidémie globale à l’échelle de la Polynésie française pour un même sérotype ne semble pas être affectée. Les analyses de la métapopulation ont révélé l'incidence asynchrone de la dengue dans un grand nombre d’îles. Celle-ci s’observe plus particulièrement par la différence de dynamique de l’incidence entre les îles plus peuplées et celles ayant une population plus faible. La taille critique de la communauté nécessaire à la persistance de la dengue n’est même pas atteinte par la plus grande île de Polynésie Française, Tahiti. Ce résultat suggère que la dengue peut uniquement persister grâce à sa propagation d’île en île. L'incorporation de la connectivité des îles à travers des modèles de migration humaine dans un modèle mathématique a produit une dynamique de la dengue davantage en adéquation avec les données observées, que les tentatives de modélisation traitant la population dans son ensemble. Le modèle de la métapopulation a été capable de simuler la même dynamique que les cas de dengue observés pour l'épidémie et la transmission endémique qui a suivi pour la période de 2001 à 2008. Des analyses complémentaires sur la différenciation de l'incidence de la maladie et de l'infection seront probablement instructives pour affiner le modèle de métapopulation de l'épidémiologie de la dengue en Polynésie française
Dengue has been epidemic in French Polynesia for the past 35 years. Despite the relatively small population size in French Polynesia, dengue does not disappear and can persist at low levels for many years. In light of the large number of islands comprising French Polynesia, this thesis addresses the extent to which a metapopulation context may be the most appropriate to describe the epidemiology and persistence of dengue in this case. After compiling a database of dengue cases over the last 35 years, we used a number of descriptive and statistical epidemiological analyses that revealed distinct spatio-temporal disparity in dengue incidence for archipelago and islands. But the global structure of the epidemics of the same serotype were not affected. Metapopulation analyses revealed asynchronous dengue incidence among many of the islands and most notably larger islands lagged behind the smaller islands. The critical community size, which determines dengue persistence, was found to exceed even the largest island of Tahiti, suggesting that dengue can only exist by island-hopping. Incorporation of island connectedness through patterns of human migration into a mathematical model enabled a much better fit to the observed data than treating the population as a whole. The metapopulation model was able to capture to some extent the epidemic and low level transmission dynamics observed for the period of 2001-2008. Further analyses on differentiating incidence of disease and infection will likely prove informative for the metapopulation model of dengue epidemiology in French Polynesia

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New, Cherie Lynn. « A metapopulation dynamics model for black bear recolonization in the Trans-Pecos region of Texas ». Thesis, Sul Ross State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1526975.

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West Texas, especially the Trans-Pecos region, mainly consists of desert shrubs and grasslands with patches of higher elevation (1,500 – 2,000 m) mountain ranges. Black bears (Ursus americanus) were extirpated from this area by the 1940s because of predator control and over hunting. In the 1980s, black bears returned to west Texas in a natural recolonization movement from Mexico, where they had survived. The black bear populations of the Trans-Pecos region and northern Mexico fit a mainland-island metapopulation model. Based on previously published research on this recolonization event, I identified several likely habitat recolonization sites and corridor routes for use in predicting possible black bear dispersal throughout the area. Then, using these corridor and recolonization scenarios, I produced a black bear metapopulation model for the Trans-Pecos region.

The possible habitat recolonization site map was created by combining 2 habitat suitability index (HSI) maps and using these HSI maps to define 'core' and 'useable' black bear habitat within the Trans-Pecos region. Using these locations, along with dispersal probabilities and black bear demographic parameters, I created a corridor dispersal map of the area using the program Circuitscape.

The metapopulation model was created using STELLA modeling software. Each recolonization location in the Trans-Pecos region (Big Bend National Park, Black Gap Wildlife Management Area, and the Davis Mountains) has its own black bear subpopulation. The metapopulation model is a stochastic compartment model based on a yearly time step (Δt = 1 yr). This model was tested for the effects of: carrying capacity per site, immigration rates from Mexico, rates of dispersal from Black Gap Wildlife Management Area to the Davis Mountains, and the recovery time for the area after complete extirpation from the Trans-Pecos. This information will help local biologists conserve and manage these returning black bears in the Trans-Pecos region.

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Sahlsten, Jonas. « Impact of Geographical and Environmental Structures on Habitat Choice, Metapopulation Dynamics and Genetic Structure for Hazel Grouse (Bonasa bonasia) ». Doctoral thesis, Uppsala universitet, Institutionen för ekologi och evolution, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7911.

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In this work suitable habitats for hazel grouse (Bonasa bonasia) were identified using ecological niche factor analysis (ENFA). The results from ENFA reveal that hazel grouse utilize a different and more restricted niche than what is generally available in the study area. When a landscape is fragmented the amount of edge increases, which is negative for many species and thus will affect the amount of available area. The perimeter-area ratio was used to analyze the relative importance of geometric shape. In order to estimate a correlation between incidence of hazel grouse and landscape features census data and land cover maps were analyzed with logistic regression models. It is concluded that hazel grouse is tied to coniferous forest and avoid open areas. However, the result indicates that there is a scale effect that should be considered. The amount of edge in a landscape seems to be important and shape of patches could be a better measure in metapopulation dynamics. In this study the Incidence function model was used to estimate occupancy levels and capacity of a landscape to sustain a metapopulation according to four different area measurement scenarios. Results from the simulations indicate that perimeter-area related measures of patch size combined with capacity could be a more important measure for estimation of population dynamics compared to a basic area measurement. Using a landscape genetic approach, hazel grouse genetic structure, neighbourhood size and dispersal distance were estimated. Genetic estimates of dispersal were in concordance with previous ecological estimates. The results indicate evidence of a population structure reminiscent of what has been found in many other Scandinavian animals with a basic north-south divide. No evidence was found that geographic and environmental structures affected gene flow and dispersal patterns for the hazel grouse.

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Lloyd, Alun Lewis. « Mathematical models for spatial heterogeneity in population dynamics and epidemiology ». Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337603.

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BORRELLO, DAVIDE. « Interacting particle systems : stochastic order, attractiveness and random walks on small world graphs ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7467.

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The main subject of the thesis is concerned with interacting particle systems, which are classes of spatio-temporal stochastic processes describing the evolution of particles in interaction with each other. The particles move on a finite or infinite discrete space and on each element of this space the state of the configuration is integer valued. Configurations of particles evolve in continuous time according to a Markov process. Here the space is either the infinite deterministic d-dimensional lattice or a random graph given by the finite d-dimensional torus with random matchings. In Part I we investigate the stochastic order in a particle system with multiple births, deaths and jumps on the d-dimensional lattice: stochastic order is a key tool to understand the ergodic properties of a system. We give applications on biological models of spread of epidemics and metapopulation dynamics systems. In Part II we analyse the coalescing random walk in a class of finite random graphs modeling social networks, the small world graphs. We derive the law of the meeting time of two random walks on small world graphs and we use this result to understand the role of random connections in meeting time of random walks and to investigate the behavior of coalescing random walks.

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Brown, Natasha A. « Evaluating and Improving Current Metapopulation Theory for Community and Species-level Models ». University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535633560485168.

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Lalechère, Etienne. « Apports des modèles de métapopulation hors équilibre : application à l'évaluation de la dynamique des plantes forestières ». Thesis, Université Clermont Auvergne‎ (2017-2020), 2017. http://www.theses.fr/2017CLFAC057/document.

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Les modèles de métapopulations permettent de prédire l'occupation des habitats au sein desquels elles évoluent en fonction de la configuration spatiale du paysage. La destruction et la création d'habitats peuvent induire une dette d'extinction ou un crédit d'immigration, c'est-à-dire des dynamiques d'espèces qui ne sont pas immédiates mais décalées dans le temps par rapport cette rotation des habitats. La présence d'un délai temporel signifie que les espèces ne sont pas à l'équilibre avec les paysages actuels. Cette thèse a pour objectif d'évaluer l'apport de modèles de métapopulations hors équilibre pour comprendre ces dynamiques décalées dans le temps de façon théorique et à partir de données empiriques sur les plantes forestières. A ces fins, nous avons évalué la robustesse d'une méthode d'inférence de paramètres de dynamique de métapopulations hors équilibre, adaptée à l'échelle régionale. Elle a ensuite été appliquée sur des données contemporaines de plantes forestières et de séries temporelles de cartographies des forêts dans les départements de la Seine-et-Marne et de l'Eure-et-Loir. A partir des modèles utilisés, nous avons pu reproduire certaines caractéristiques de la répartition des espèces qui sont dues à l'évolution historique des surfaces forestières. En effet, certaines espèces sont plus fréquentes en forêt anciennes et d'autres en forêt récentes, ce qui s'explique en partie par les traits des espèces et leurs affinités pour des conditions environnementales spécifiques. A partir de projections à long-terme de leurs dynamiques, nous avons montré que les délais de réponse de ces espèces peuvent être de plusieurs siècles et dépendent fortement de la connectivité fonctionnelle des habitats. Des scénarios virtuels de rotation des habitats ont été simulés pour pallier l'analyse des seules zones d'études. Associé à des projections de dynamiques de métapopulations, qui permettent de contrôler les paramètres à étudier, nous avons testé l'importance relative de la distance de dispersion des espèces et de la configuration spatiale de la rotation des habitats sur ces dynamiques. Le temps de retour à l'équilibre des métapopulations ne s'explique pas uniquement par l'amplitude de la dette d'extinction ou du crédit d'immigration mais dépend aussi de ces deux facteurs. Ces résultats mettent en évidence l'importance d'approfondir nos connaissances sur les effets de perturbations successives qui rendent le retour théorique à l'équilibre des espèces très incertain
Metapopulation models are used to predict the occupancy of habitats from landscape spatial configuration. Habitat destruction and creation can lead to an extinction debt or an immigration credit that are time-delayed species dynamics following habitat turnover. Such delays mean that species are not in equilibrium with the current landscape structures. The aim of this thesis is to evaluate the contribution of non-equilibrium metapopulation models to understand time-delayed dynamics theoretically and from empirical datasets about forest plants. For this purpose, we assessed the robustness of the method used to infer metapopulation parameters at the regional scale. Then, we applied this method from contemporary plant inventories and time-series of forest maps of the Seine-et-Marne and the Eure-et-Loir french regions. Models satisfactorily reproduced some characteristics of forest plant spatial structure that are due to historical changes in forest areas. Indeed, some species are more frequent in ancient forests and some others are more frequent in recent forests notably due to species traits and their affinity for specific environmental characteristics. From long-term projections of species dynamics, we showed that the delays in forest plant dynamics are several centuries following habitat turnover and strongly depend on habitat functional connectivity. Virtual scenarios of habitat turnover were simulated to assess other study cases than the two study areas. We projected metapopulation dynamics, while controlling for some metapopulation parameters, to test the relative effects of species dispersal distance and the spatial configuration of habitat turnover on these dynamics. Metapopulation return time towards equilibrium not only depends on the magnitude of the extinction debt or on the magnitude of the immigration credit but also on these two variables.These results put forward the need to improve our knowledge on the effects of successive perturbations that make species return towards equilibrium unsure

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« Epidemic Dynamics of Metapopulation Models ». Doctoral diss., 2014. http://hdl.handle.net/2286/R.I.21041.

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abstract: Mathematical modeling of infectious diseases can help public health officials to make decisions related to the mitigation of epidemic outbreaks. However, over or under estimations of the morbidity of any infectious disease can be problematic. Therefore, public health officials can always make use of better models to study the potential implication of their decisions and strategies prior to their implementation. Previous work focuses on the mechanisms underlying the different epidemic waves observed in Mexico during the novel swine origin influenza H1N1 pandemic of 2009 and showed extensions of classical models in epidemiology by adding temporal variations in different parameters that are likely to change during the time course of an epidemic, such as, the influence of media, social distancing, school closures, and how vaccination policies may affect different aspects of the dynamics of an epidemic. This current work further examines the influence of different factors considering the randomness of events by adding stochastic processes to meta-population models. I present three different approaches to compare different stochastic methods by considering discrete and continuous time. For the continuous time stochastic modeling approach I consider the continuous-time Markov chain process using forward Kolmogorov equations, for the discrete time stochastic modeling I consider stochastic differential equations using Wiener's increment and Poisson point increments, and also I consider the discrete-time Markov chain process. These first two stochastic modeling approaches will be presented in a one city and two city epidemic models using, as a base, our deterministic model. The last one will be discussed briefly on a one city SIS and SIR-type model.
Dissertation/Thesis
Ph.D. Applied Mathematics for the Life and Social Sciences 2014

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Day, Jemery R. (Jemery Robert). « Mathematical models of metapopulation dynamics / Jemery R. Day ». 1995. http://hdl.handle.net/2440/18540.

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Bibliography: p. 269-279.
viii, 279 p. : ill. ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 1995

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Livres sur le sujet "Metapopulation dynamics model"

Spromberg, Julann A. Metapopulation dynamics as a model for toxicant impacts in patchy environments. Bellingham, WA : Huxley College of Environmental Studies, Western Washington University, 1995.

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Macovsky, Louis M. The effects of toxicant related mortality upon metapopulation dynamics : A laboratory model. 1999.

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U. S Forest U.S Forest Service et Department of Agriculture, United States. Developing a Decision-Support Process for Landscape Conservation Design : Topics : Conservation under Global Change, Landscape Models and Data, Projecting Urban Growth, Dynamic-Landscape MetaPopulation. Independently Published, 2022.

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Chapitres de livres sur le sujet "Metapopulation dynamics model"

Burton, Jennifer L., Ewan Robinson et Sheng Ye. « Spatially Explicit Agent-Based Model of Striped Newt Metapopulation Dynamics Under Precipitation and Forest Cover Scenarios ». Dans Ecologist-Developed Spatially-Explicit Dynamic Landscape Models, 63–83. Boston, MA : Springer US, 2012. http://dx.doi.org/10.1007/978-1-4614-1257-1_5.

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Burton, Jennifer L., Richard F. Lance, James D. Westervelt et Paul L. Leberg. « An Individual-Based Model for Metapopulations on Patchy Landscapes-Genetics and Demography (IMPL-GD) ». Dans Ecologist-Developed Spatially-Explicit Dynamic Landscape Models, 197–209. Boston, MA : Springer US, 2012. http://dx.doi.org/10.1007/978-1-4614-1257-1_11.

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Botsford, Louis W., J. Wilson White et Alan Hastings. « Spatial population dynamics ». Dans Population Dynamics for Conservation, 214–46. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198758365.003.0009.

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This chapter considers populations structured in a different dimension: space. This begins by representing population dynamics with a spatial continuity equation (analogous to the M’Kendrick/von Foerster model for continuity in age or size). If organisms move at random, this motion can be approximated as diffusion. This proves useful for modeling spreading populations, such as the expansion of sea otter populations along the California coast. Adding directional advection represents a population in a flowing stream. Metapopulation models are then introduced using a simple model of the fraction of occupied patches; these are made more realistic by accounting for inter-patch distance using incidence function models. The next level of complexity is models with population dynamics in each patch. These are used to examine how metapopulations can persist as a network even if no patch would persist by itself. Finally, the consequences of synchrony (or lack thereof) among spatially separated populations is described.

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« Community Ecology of Stream Fishes : Concepts, Approaches, and Techniques ». Dans Community Ecology of Stream Fishes : Concepts, Approaches, and Techniques, sous la direction de Jeffrey A. Falke et Kurt D. Fausch. American Fisheries Society, 2010. http://dx.doi.org/10.47886/9781934874141.ch10.

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Abstract.—Stream fishes carry out their life histories across broad spatial and temporal scales, leading to spatially structured populations. Therefore, incorporating metapopulation dynamics into models of stream fish populations may improve our ability to understand mechanisms regulating them. First, we reviewed empirical research on metapopulation dynamics in the stream fish ecology literature and found 31 papers that used the metapopulation framework. The majority of papers applied no specific metapopulation model, or included space only implicitly. Although parameterization of spatially realistic models is challenging, we suggest that stream fish ecologists should incorporate space into models and recognize that metapopulation types may change across scales. Second, we considered metacommunity theory, which addresses how trade-offs among dispersal, environmental heterogeneity, and biotic interactions structure communities across spatial scales. There are no explicit tests of metacommunity theory using stream fishes to date, so we used data from our research in a Great Plains stream to test the utility of these paradigms. We found that this plains fish metacommunity was structured mainly by spatial factors related to dispersal opportunity and, to a lesser extent, by environmental heterogeneity. Currently, metacommunity models are more heuristic than predictive. Therefore, we propose that future stream fish metacommunity research should focus on developing testable hypotheses that incorporate stream fish life history attributes, and seasonal environmental variability, across spatial scales. This emerging body of research is likely to be valuable not only for basic stream fish ecological research, but also multispecies conservation and management.

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Gravel, Dominique, et François Massol. « Toward a general theory of metacommunity ecology ». Dans Theoretical Ecology, 195–220. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198824282.003.0012.

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Investigation of how spatial processes affect the maintenance of biodiversity and its geographic distribution has led to landmark contributions in community ecology. Theory has followed a logical complexification of the objects of study, with specific models at each step, from populations connected by dispersal to ecosystems connected by flows of energy and material. This large body of theory is not only diverse in the questions it addresses, and the scales and organization levels it encompasses, but also in the types of models used to represent spatial dynamics. Unfortunately, this makes it hard to establish clear, standard, quantitative predictions stemming from a coherent mathematical formalism. Here our objectives are : i) to propose a general metacommunity model that allows the investigation of spatial ecology from populations to entire food webs ; ii) use the model to review a set of principles driving coexistence in all types of metacommunities; iii) reveal how these principles constrain the spatial distribution of diversity, with a particular emphasis on species co-distribution. The model is based on the well-established representation of spatial dynamics through colonization and extinction processes. We generalize Levins’ metapopulation model to all types of ecological interactions, using a formalism akin to Lotka–Volterra equations for local community dynamics. Doing so, we revisit coexistence mechanisms proposed for competitive metacommunities, along with the assembly dynamics for spatial food webs and mutualistic interactions.

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Bonsall, Michael B., et Michael P. Hassell. « Predator–prey interactions ». Dans Theoretical Ecology. Oxford University Press, 2007. http://dx.doi.org/10.1093/oso/9780199209989.003.0008.

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Predation is a widespread population process that has evolved many times within the metazoa. It can affect the distribution, abundance, and dynamics of species in ecosystems. For instance, the distribution of western tussock moth is known to be affected by a parasitic wasp (Maron and Harrison, 1997; Hastings et al., 1998), the abundance of different competitors can be shaped by the presence or absence of predators (e.g. Paine, 1966), and natural enemies (such as many parasitoids) can shape the dynamics of a number of ecological interactions (Hassell, 1978, 2000). The broad aim of this chapter is to explore the dynamical effects of predators (including the large groupings of insect parasitoids) and show how our understanding of predator–prey interactions scales from knowledge of the behaviour and local patch dynamics to the population and regional (metapopulation) levels. We draw on a number of approaches including behavioural studies, population dynamics, and time-series analysis, and use models to describe the data and dynamics of the interaction between predators and prey. Predator–prey interactions have an inherent tendency to fluctuate and show oscillatory behaviour. If predators are initially rare, then the size of the prey population can increase. As prey population size increases, the predator populations also begins to increase, which in turn has a detrimental effect on the prey population leading to a decline in prey numbers. As prey become scarce then the predator population size declines and the cycle starts again. These intuitive dynamics can be captured by one of the simplest mathematical descriptions of a predator–prey interaction: the Lotka–Volterra model (Lotka, 1925; Volterra, 1926). Specifically, the Lotka–Volterra model for an interaction between a predator (P) and its prey (N) is a continuous-time model and has the form : where r is the prey-population growth rate in the absence of predators, α is the predator attack rate, c is the (positive) impact of prey on predators, and d is the death rate of predators in the absence of their prey resource.

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Quintana-Ascencio, Pedro F., Eric S. Menges, Geoffrey S. Cook, Johan Ehrlén et Michelle E. Afkhami. « Drivers of demography : past challenges and a promise for a changed future ». Dans Demographic Methods across the Tree of Life, 115–30. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198838609.003.0006.

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There is an urgent need to understand how populations and metapopulations respond to shifts in the environment to mitigate the consequences of human actions and global change. Identifying environmental variables/factors affecting population dynamics and the nature of their impacts is fundamental to improve projections and predictions. This chapter examines how environmental drivers, both continuous (stress) and episodic (disturbance), are incorporated in demographic modelling across many types of organisms and environments, using both observational and experimental approaches to characterise drivers. It critically summarises examples of the main approaches and identifies major accomplishments, challenges, and limitations. The chapter points to promising approaches and possible future developments. In the initial sections, models in closed systems without migration among populations are considered. The chapter then focuses on metapopulation models, emphasising the importance of understanding drivers affecting migration and differential extinction among populations. Finally, it concludes with a discussion of some important and general problems associated with assessing how population dynamics may be affected by environmental drivers that are dynamic, nonlinear, and with indirect and/or interacting effects with other drivers..

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« Pacific Salmon Environmental and Life History Models : Advancing Science for Sustainable Salmon in the Future ». Dans Pacific Salmon Environmental and Life History Models : Advancing Science for Sustainable Salmon in the Future, sous la direction de Scott G. Leibowitz et Denis White. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781934874097.ch12.

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Abstract.—Simulation modeling can be a valuable tool for improving scientific understanding of the mechanisms that affect fish abundance and sustainability. Spatially explicit models, in particular, can be used to study interactions between fish biology and spatiotemporal habitat patterns and to study the significance of fish movement to population growth and abundance. In this chapter, we present a novel approach for modeling fish populations that generalizes across systems rather than being site-specific. We describe a spatially explicit coho (Oncorhynchus kisutch) simulation model that uses randomly generated stream networks. The use of random landscapes has been extremely valuable for the study of movement, metapopulation dynamics, and extinction risk in terrestrial populations, and should allow similar insights into long-term dynamics and sustainability of salmonids and other aquatic organisms. In particular, random stream networks can help test specific hypotheses by controlling for stream characteristics that could confound analytical results. In addition, random stream networks can allow for more robust inferences across stream networks by addressing network-level variability. We also include in our model a number of different mechanisms for representing fish movement. This allows us to examine how these different mechanisms affect model output, which will be useful for species where these mechanisms are poorly understood. We describe this model in detail, and include results from a number of simple analyses that are meant to examine the novel features of the model. These demonstrate how properties of the stream network can affect model output, and how different ways of representing fish movement can influence results.

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HASTINGS, ALAN. « Structured models of metapopulation dynamics ». Dans Metapopulation Dynamics : Empirical and Theoretical Investigations, 57–71. Elsevier, 1991. http://dx.doi.org/10.1016/b978-0-12-284120-0.50007-3.

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« Eels at the Edge : Science, Status, and Conservation Concerns ». Dans Eels at the Edge : Science, Status, and Conservation Concerns, sous la direction de Giulio A. De Leo, Paco Melià, Marino Gatto et Alain J. Crivelli. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781888569964.ch22.

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Abstract.—We critically review population dynamics models developed for Anguilla spp. eels. Despite the (quasi) panmictic nature of temperate eel species, most modeling effort has focused on subpopulations within specific brackish or inland water bodies. Models have been developed along three major lines: cohort approaches, input-output models that directly relate juvenile recruit abundance to migrating mature eels, and stage- or size-structured population models, or both, some of which explicitly account for the observed variability of eel life traits. More recently, attempts have been made to extend demographic analyses to the oceanic phase of the eel life cycle. We discuss eel population models in terms of mathematical complexity and usability, amount and quality of data required for calibration, realism in the description of life cycle and demographic parameters, potential for analyzing different fisheries management strategies, and inclusion of environmental and interindividual stochasticity and uncertainty in parameter estimation. While site-specific analyses are needed to understand eel life history in the continental phase, the generalized decline of eel recruitment requires a global assessment of metapopulation viability under different hypotheses and scenarios. Given the high number of unknowns and untested hypotheses, we emphasize the need to explicitly model uncertainty in parameter estimation and environmental and interindividual stochasticity (e.g., by using bootstrap techniques and Monte Carlo simulations). There is an urgent need for population models that can be used for conservation-based eel management in broad geographic areas where few data are available.

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Actes de conférences sur le sujet "Metapopulation dynamics model"

Jianxin, Chen. « Metapopulation Model of the Banking Risk Contagion --- Dynamic Simulation Based on Cellular Automata ». Dans 2010 International Conference on Computational and Information Sciences (ICCIS). IEEE, 2010. http://dx.doi.org/10.1109/iccis.2010.328.

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