scholarly journals How can we augment the few that remain? Using stable population dynamics to aid reintroduction planning of an iteroparous species

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6873
Author(s):  
Brenda J. Hanley ◽  
Elizabeth M. Bunting ◽  
Krysten L. Schuler
Keyword(s):  
Population Dynamics ◽  
Real Life ◽  
Life History Strategies ◽  
Stable Population ◽  
Interactive Software ◽  
Vital Rates ◽  
Transient Population ◽  
Selection Of Species ◽  
Iteroparous Species ◽  
Stable Population Theory

Restoration of depleted populations is an important method in biological conservation. Reintroduction strategies frequently aim to restore stable, increasing, self-sustaining populations. Knowledge of asymptotic system dynamics may provide advantage in selecting reintroduction strategies. We introduce interactive software that is designed to identify strategies for release of females that are immediately aligned with stable population dynamics from species represented by 2-, 3-, 4-, and 5-stage life history strategies. The software allows managers to input a matrix of interest, the desired number of breeding females, and the desired management timeline, and calls upon stable population theory to give release strategies that are in concert with both stable population status and the management goals. We demonstrate how the software can aid in assessing various strategies ahead of a hypothetical restoration. For the purpose of demonstration of the tool only, we use published vital rates of an ungulate species, but remark that the selection of species for demonstration is not central to the use of this tool. Adaption of this tool to real-life restorations of any 2-, 3-, 4-, or 5-stage iteroparous species may aid in understanding how to minimize undesirable recovery complications that may naturally arise from transient population dynamics. The software is freely available at: https//cwhl.vet.cornell.edu/tools/stapopd.

scholarly journals Inferring forest fate from demographic data: from vital rates to population dynamic models

2018 ◽  
Vol 285 (1874) ◽  
pp. 20172050 ◽  
Author(s):  
Jessica Needham ◽  
Cory Merow ◽  
Chia-Hao Chang-Yang ◽  
Hal Caswell ◽  
Sean M. McMahon
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Dynamic Models ◽  
Demographic Data ◽  
Life Cycles ◽  
Stochastic Simulations ◽  
Life History Strategies ◽  
Forest Trees ◽  
Vital Rates ◽  
Passage Times

As population-level patterns of interest in forests emerge from individual vital rates, modelling forest dynamics requires making the link between the scales at which data are collected (individual stems) and the scales at which questions are asked (e.g. populations and communities). Structured population models (e.g. integral projection models (IPMs)) are useful tools for linking vital rates to population dynamics. However, the application of such models to forest trees remains challenging owing to features of tree life cycles, such as slow growth, long lifespan and lack of data on crucial ontogenic stages. We developed a survival model that accounts for size-dependent mortality and a growth model that characterizes individual heterogeneity. We integrated vital rate models into two types of population model; an analytically tractable form of IPM and an individual-based model (IBM) that is applied with stochastic simulations. We calculated longevities, passage times to, and occupancy time in, different life cycle stages, important metrics for understanding how demographic rates translate into patterns of forest turnover and carbon residence times. Here, we illustrate the methods for three tropical forest species with varying life-forms. Population dynamics from IPMs and IBMs matched a 34 year time series of data (albeit a snapshot of the life cycle for canopy trees) and highlight differences in life-history strategies between species. Specifically, the greater variation in growth rates within the two canopy species suggests an ability to respond to available resources, which in turn manifests as faster passage times and greater occupancy times in larger size classes. The framework presented here offers a novel and accessible approach to modelling the population dynamics of forest trees.

Quasi-Stable Estimates of the Vital Rates of Pakistan

1965 ◽  
Vol 5 (4) ◽  
pp. 638-658
Author(s):  
Warren C. Robinson ◽  
William Seltzer ◽  
Sultan S. Hashmi
Keyword(s):  
Present Note ◽  
Population Models ◽  
Stable Population ◽  
Stable Model ◽  
Vital Rates ◽  
Recent Past ◽  
Population Theory ◽  
Demographic Theory ◽  
Stable Population Theory

The emergence of stable and quasi-stable population theory has been one of the most interesting developments of demographic theory in the recent past. Zelnik and Rahman Khan writing in the Spring 1965 issue of this Review have applied this methodology to Pakistani data with rather interesting resultsJ. The purpose of this present note is two-fold. First, is to discuss the assumptions and procedures of the Zelnik-Rahman Khan use of the quasi-stable model. In other words, accepting the validity of the model and also its applicability to Pakistan, have the authors made good use of it? Second, and more basically, is the quasistable methodology in fact relevant for Pakistan, given the data available? Let us begin with a brief review of the stable and quasi-stable population models as they have developed in the last ten years.

scholarly journals Demographic effects of interacting species: exploring stable coexistence under increased climatic variability in a semiarid shrub community

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana I. García-Cervigón ◽  
Pedro F. Quintana-Ascencio ◽  
Adrián Escudero ◽  
Merari E. Ferrer-Cervantes ◽  
Ana M. Sánchez ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Species Coexistence ◽  
Climatic Factors ◽  
Demographic Data ◽  
Climatic Variability ◽  
Biotic Interactions ◽  
Vital Rates ◽  
Climatic Fluctuations ◽  
Demographic Models ◽  
Shrub Community

AbstractPopulation persistence is strongly determined by climatic variability. Changes in the patterns of climatic events linked to global warming may alter population dynamics, but their effects may be strongly modulated by biotic interactions. Plant populations interact with each other in such a way that responses to climate of a single population may impact the dynamics of the whole community. In this study, we assess how climate variability affects persistence and coexistence of two dominant plant species in a semiarid shrub community on gypsum soils. We use 9 years of demographic data to parameterize demographic models and to simulate population dynamics under different climatic and ecological scenarios. We observe that populations of both coexisting species may respond to common climatic fluctuations both similarly and in idiosyncratic ways, depending on the yearly combination of climatic factors. Biotic interactions (both within and among species) modulate some of their vital rates, but their effects on population dynamics highly depend on climatic fluctuations. Our results indicate that increased levels of climatic variability may alter interspecific relationships. These alterations might potentially affect species coexistence, disrupting competitive hierarchies and ultimately leading to abrupt changes in community composition.

scholarly journals Within- and among-population variation in vital rates and population dynamics in a variable environment

2016 ◽  
Vol 26 (7) ◽  
pp. 2086-2102 ◽  
Author(s):  
Simone Vincenzi ◽  
Marc Mangel ◽  
Dusˇan Jesensˇek ◽  
John C. Garza ◽  
Alain J. Crivelli
Keyword(s):  
Population Dynamics ◽  
Population Variation ◽  
Vital Rates ◽  
Variable Environment

Understanding historical summer flounder (Paralichthys dentatus) abundance patterns through the incorporation of oceanography-dependent vital rates in Bayesian hierarchical models

2019 ◽  
Vol 76 (8) ◽  
pp. 1275-1294 ◽  
Author(s):  
Cecilia A. O’Leary ◽  
Timothy J. Miller ◽  
James T. Thorson ◽  
Janet A. Nye
Keyword(s):  
Population Dynamics ◽  
Gulf Stream ◽  
Stock Assessment ◽  
Deviance Information Criterion ◽  
Information Criterion ◽  
Natural Mortality ◽  
Vital Rates ◽  
Summer Flounder ◽  
Paralichthys Dentatus ◽  
Abundance Patterns

Climate can impact fish population dynamics through changes in productivity and shifts in distribution, and both responses have been observed for many fish species. However, few studies have incorporated climate into population dynamics or stock assessment models. This study aimed to uncover how past variations in population vital rates and fishing pressure account for observed abundance variation in summer flounder (Paralichthys dentatus). The influences of the Gulf Stream Index, an index of climate variability in the Northwest Atlantic, on abundance were explored through natural mortality and stock–recruitment relationships in age-structured hierarchical Bayesian models. Posterior predictive loss and deviance information criterion indicated that out of tested models, the best estimates of summer flounder abundances resulted from the climate-dependent natural mortality model that included log-quadratic responses to the Gulf Stream Index. This climate-linked population model demonstrates the role of climate responses in observed abundance patterns and emphasizes the complexities of environmental effects on populations beyond simple correlations. This approach highlights the importance of modeling the combined effect of fishing and climate simultaneously to understand population dynamics.

scholarly journals EXPLORATION OF STYLIZED FACTS IN THE ARTIFICIAL LIFE SYSTEM AVIDA

2016 ◽  
Vol 4 ◽  
pp. 791-795
Author(s):  
Shinta Koyano ◽  
Lukáš Pichl
Keyword(s):  
Population Dynamics ◽  
Power Law ◽  
Artificial Life ◽  
Real Life ◽  
Central Processing Unit ◽  
Processing Unit ◽  
Full Width ◽  
Logic Function ◽  
Central Processing ◽  
Clique Graph

Population dynamics in the evolution, extinction, and re-evolution of various logic-function performing organisms is studied in the artificial life system, Avida. Following the work of Yedid (2009), we design an experiment involving two extinction regimes, pulse-extinction (corresponding to a random-kill event) and press-extinction (corresponding to a prolonged episode of rare resources). In addition, we study the effect of environmental topology (toroidal grid and clique graph). In the study of population dynamics, logarithmic returns are generally applied. The resulting distributions display a fat tail form of the power law: the more complex the logic function (in terms of NAND components), the broader the full width at half a maximum of the histogram. The power law exponents were in sound agreement with those of “real-life” populations and distributions. The distributions of evolutionary times, as well as post-extinction recovery periods, were very broad, and presumably had no standard deviations. Using 100 runs of 200,000 updates for each of the four cases (about 1 month of central processing unit time), we established the dynamics of the average population, with the effect of world topology.

Integral projection models

2021 ◽  
pp. 181-196
Author(s):  
Edgar J. González ◽  
Dylan Z. Childs ◽  
Pedro F. Quintana-Ascencio ◽  
Roberto Salguero-Gómez
Keyword(s):  
Population Dynamics ◽  
Environmental Variables ◽  
Linear Models ◽  
Vital Rates ◽  
Matrix Population Models ◽  
Generalised Linear Models ◽  
Integral Projection Models ◽  
Integral Projection ◽  
Over Time

Integral projection models (IPMs) allow projecting the behaviour of a population over time using information on the vital processes of individuals, their state, and that of the environment they inhabit. As with matrix population models (MPMs), time is treated as a discrete variable, but in IPMs, state and environmental variables are continuous and are related to the vital rates via generalised linear models. Vital rates in turn integrate into the population dynamics in a mechanistic way. This chapter provides a brief description of the logic behind IPMs and their construction, and, because they share many of the analyses developed for MPMs, it only emphasises how perturbation analyses can be performed with respect to different model elements. The chapter exemplifies the construction of a simple and a more complex IPM structure with an animal and a plant case study, respectively. Finally, inverse modelling in IPMs is presented, a method that allows population projection when some vital rates are not observed.

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