Temporal scales of resource variability: Effects on population dynamics of structured populations

2014 ◽  
Vol 18 ◽  
pp. 6-9 ◽  
Author(s):  
Alan Hastings
Author(s):  
Anna Clara Balbina Silva ◽  
Afonso Pelli

Compreender os mecanismos que regulam a dinâmica das populações espacialmente estruturadas é um desafio crítico para os ecólogos e gestores de conservação. A dinâmica de populações é um ramo da ecologia que estuda as populações como sistema em atividades, relacionando as influências ambientais com a distribuição e abundância dos indivíduos e suas interações com o ambiente. O presente artigo é uma revisão bibliográfica, com o objetivo de identificar produções científicas relevantes sobre dinâmica populacional. Para isso, foram utilizados periódicos revisados por pares, na base de Periódicos Capes. A pesquisa foi realizada em junho de 2019, utilizando-se as palavras-chave para título contendo: "population dynamics" e no assunto “ecology”, a partir de 2014, quando o texto completo estava disponível. Foram considerados como critérios de exclusão os artigos publicados antes de 2014. Após a leitura dos títulos dos artigos, foram selecionados 34 artigos que foram lidos na íntegra. Em livros disponíveis no acervo da biblioteca da Universidade Federal do Triângulo Mineiro, foram selecionados quatro livros no tema dinâmica populacional. O referencial teórico aborda os aspectos da dinâmica de populações, tabela de vida, formas de crescimento e interações populacionais. Ressalta-se a necessidade de novos estudos que ainda possuem lacunas, que venha complementar e contribuir para o conhecimento de organismos que faltam ou ainda não possuem registros de estudos. Palavras-chave: Taxas de Natalidade e Mortalidade. Atributos Populacionais. Dispersão. AbstractUnderstanding the mechanisms that regulate the dynamics of spatially structured populations is a critical challenge for ecologists and conservation managers. Population dynamics is a branch of ecology that studies populations as a system in activities, relating environmental influences to the individuals’ distribution and abundance and their interactions with the environment. This article is a bibliographic review, aiming to identify relevant scientific productions about population dynamics. Thus. peer-reviewed journals were used in the Capes Periodicals base, the research was conducted in June 2019, using the keywords for title containing "population dynamics" and in the subject "ecology", from 2014, when the full text was available. Exclusion criteria were: articles published before 2014, after reading the article titles, 34 articles were selected that met the initially proposed criteria and were read in full. In books available in the library collection of the Federal University of Triângulo Mineiro, with a search for the dynamic population theme, 4 books were used. The theoretical framework addresses the aspects of population dynamics, life table, forms of growth and population interactions. It is emphasized  the need for further studies that still have gaps, which will complement and contribute to the knowledge of organisms that are missing or do not have study records. Keywords: Birth and Mortality Rates. Population Attributes. Dispersion.


2021 ◽  
pp. 341-350
Author(s):  
Maria Paniw ◽  
Gabriele Cozzi ◽  
Stefan Sommer ◽  
Arpat Ozgul

In socially structured animal populations, vital rates such as survival and reproduction, are affected by complex interactions among individuals of different social ranks and among social groups. Due to this complexity, mechanistic approaches to model vital rates may be preferred over commonly used structured population models. However, mechanistic approaches come at a cost of increased modelling complexity, computational requirements, and reliance on simulated metrics, while structured population models are analytically tractable. This chapter compares different approaches to modelling population dynamics of socially structured populations. It first simulates individual-based data based on the life cycle of a hypothetical cooperative breeder and then projects population dynamics using a matrix population model (MPM), an integral projection model (IPM), and an individual-based model (IBM). The authors demonstrate that, when projecting population size or structure, the relatively simpler MPM can outperform both the IPM and IBM. However, mechanistic details parametrised in the more complex IBM are required to accurately project interactions within social groups. The R scripts in this chapter provide a roadmap to both simulate data that best describe a socially structured system and assess the level of model complexity needed to capture the dynamics of the system.


2010 ◽  
Vol 20 (7) ◽  
pp. 1926-1935 ◽  
Author(s):  
Perry de Valpine ◽  
Katherine Scranton ◽  
Clifford P. Ohmart

1998 ◽  
Vol 44 (4) ◽  
pp. 399-404 ◽  
Author(s):  
Ralf Wilhelm ◽  
Olaf Heller ◽  
Manuela Bohland ◽  
Cordula Tomaschewski ◽  
Inge Klein ◽  
...  

Cell volume distribution patterns were used to characterize the status of physiologically heterogeneous monospecific populations of bacteria. Such physiologically structured populations typically consist of subpopulations of cells in different metabolic and regulatory states. During recovery from starvation the differentiation of active (growing, proliferating) and quiescent (nonproliferating) subpopulations becomes detectable. Since cell volume distributions may be distorted by background noise or debris, we developed a method to extrapolate size distributions from a reduced set of reliable data. The extrapolation procedure is based upon a lognormal distribution of cell sizes. By the same approach we were able to differentiate between subpopulations even when their size ranges overlapped. The analyses of size distributions were also used, partly in combination with fluorescence microscopy, to investigate the population dynamics of Pseudomonas fluorescens and Nitrosomonas europaea during recovery from energy deprivation.Key words: physiologically heterogeneous populations, cell volume distribution, population dynamics, Pseudomonas fluorescens, Nitrosomonas europaea.


2019 ◽  
Author(s):  
Hugo Cayuela ◽  
Richard A. Griffiths ◽  
Nurul Zakaria ◽  
Jan W. Arntzen ◽  
Pauline Priol ◽  
...  

ABSTRACTIdentifying the drivers of population fluctuations in spatially distinct populations remains a significant challenge for ecologists. Whereas regional climatic factors may generate population synchrony (i.e., Moran effect), local factors including the level of density-dependence may reduce the level of synchrony. Although divergences in the scaling of population synchrony and spatial environmental variation have been observed, the regulatory factors that underlie such mismatches are poorly understood.No previous studies have investigated how density-dependent processes and population-specific responses to weather variation influence spatial synchrony at both local and continental scales. We addressed this issue in a pond-breeding amphibian, the great crested newt (Triturus cristatus). We used capture-recapture data collected through long-term surveys in five T. cristatus populations in Western Europe.We found a low level of demographic synchrony at both local and continental levels. Weather has weak and spatially variable effects on survival, recruitment and population growth rate. In contrast, density-dependence was a common phenomenon (at least for population growth) in almost all populations and subpopulations.Our findings support the idea that Moran’s effect is low in species where the population dynamics more closely depends on local factors (e.g. population density and habitat characteristics) than on large-scale environmental fluctuation (e.g. regional climatic variation). Those demographic feature likely have far-reaching consequences for the long-term viability of the spatially structured populations and their ability to response to large-scale climatic anomalies.


2021 ◽  
Vol 441 ◽  
pp. 109408
Author(s):  
Emily B. Dennis ◽  
Marc Kéry ◽  
Byron J.T. Morgan ◽  
Armin Coray ◽  
Michael Schaub ◽  
...  

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Nicola F Müller ◽  
Gytis Dudas ◽  
Tanja Stadler

Abstract Population dynamics can be inferred from genetic sequence data by using phylodynamic methods. These methods typically quantify the dynamics in unstructured populations or assume migration rates and effective population sizes to be constant through time in structured populations. When considering rates to vary through time in structured populations, the number of parameters to infer increases rapidly and the available data might not be sufficient to inform these. Additionally, it is often of interest to know what predicts these parameters rather than knowing the parameters themselves. Here, we introduce a method to  infer the predictors for time-varying migration rates and effective population sizes by using a generalized linear model (GLM) approach under the marginal approximation of the structured coalescent. Using simulations, we show that our approach is able to reliably infer the model parameters and its predictors from phylogenetic trees. Furthermore, when simulating trees under the structured coalescent, we show that our new approach outperforms the discrete trait GLM model. We then apply our framework to a previously described Ebola virus dataset, where we infer the parameters and its predictors from genome sequences while accounting for phylogenetic uncertainty. We infer weekly cases to be the strongest predictor for effective population size and geographic distance the strongest predictor for migration. This approach is implemented as part of the BEAST2 package MASCOT, which allows us to jointly infer population dynamics, i.e. the parameters and predictors, within structured populations, the phylogenetic tree, and evolutionary parameters.


1998 ◽  
Vol 08 (05) ◽  
pp. 905-925 ◽  
Author(s):  
O. ARINO ◽  
W. V. SMITH

We introduce a linear model for age structured populations which migrate between several locations or patches. Birth is allowed in each patch. Existence, uniqueness and positivity of solutions is proved. A certain North Atlantic fishery is given as an example. Asymptotic solutions are characterized in a general system with periodic coefficients by spectral theory techniques and the results are applied to the example.


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