Population Dynamics and Economic Development: Age-Specific Population Growth Rates and Economic Growth in Developing Countries, 1965 to 1990

1997 ◽  
Vol 62 (6) ◽  
pp. 974 ◽  
Author(s):  
Edward M. Crenshaw ◽  
Ansari Z. Ameen ◽  
Matthew Christenson
2014 ◽  
Vol 71 (8) ◽  
pp. 1198-1208 ◽  
Author(s):  
Douglas C. Braun ◽  
John D. Reynolds

Understanding linkages among life history traits, the environment, and population dynamics is a central goal in ecology. We compared 15 populations of sockeye salmon (Oncorhynchus nerka) to test general hypotheses for the relative importance of life history traits and environmental conditions in explaining variation in population dynamics. We used life history traits and habitat variables as covariates in mixed-effect Ricker models to evaluate the support for correlates of maximum population growth rates, density dependence, and variability in dynamics among populations. We found dramatic differences in the dynamics of populations that spawn in a small geographical area. These differences among populations were related to variation in habitats but not life history traits. Populations that spawned in deep water had higher and less variable population growth rates, and populations inhabiting streams with larger gravels experienced stronger negative density dependence. These results demonstrate, in these populations, the relative importance of environmental conditions and life histories in explaining population dynamics, which is rarely possible for multiple populations of the same species. Furthermore, they suggest that local habitat variables are important for the assessment of population status, especially when multiple populations with different dynamics are managed as aggregates.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Patrick Giraudoux ◽  
Petra Villette ◽  
Jean-Pierre Quéré ◽  
Jean-Pierre Damange ◽  
Pierre Delattre

Abstract Rodent outbreaks have plagued European agriculture for centuries, but continue to elude comprehensive explanation. Modelling and empirical work in some cyclic rodent systems suggests that changes in reproductive parameters are partly responsible for observed population dynamics. Using a 17-year time series of Microtus arvalis population abundance and demographic data, we explored the relationship between meteorological conditions (temperature and rainfall), female reproductive activity, and population growth rates in a non-cyclic population of this grassland vole species. We found strong but complex relationships between female reproduction and climate variables, with spring female reproduction depressed after cold winters. Population growth rates were, however, uncorrelated with either weather conditions (current and up to three months prior) or with female reproduction (number of foetuses per female and/or proportion of females reproductively active in the population). These results, coupled with age-structure data, suggest that mortality, via predation, disease, or a combination of the two, are responsible for the large multi-annual but non-cyclic population dynamics observed in this population of the common vole.


1993 ◽  
Vol 62 (1) ◽  
pp. 57-62 ◽  
Author(s):  
G. Namkoong ◽  
J. Bishir ◽  
J. H. Roberds

SummaryThe evolution of traits that affect genotypic responses to density regulated resources can be strongly affected by population dynamics in ways that are unpredictable from individual viability or reproduction potentials. Genotypes that are most efficient in utilizing energy may not always displace less efficient ones, and the evolution of energy allocation strategies may not always favour reproductive fitness because of their effects on destabilizing population growth rates. Furthermore, genetic polymorphisms in single loci that affect such traits can be maintained in populations with stable, periodic changes in population size and gene frequencies in the absence of heterozygote superiority. In fact, in the models investigated in this paper, the polymorphism is maintained, even in the absence of equilibrium genotypic frequencies.


2002 ◽  
Vol 357 (1425) ◽  
pp. 1307-1319 ◽  
Author(s):  
H. Charles J. Godfray ◽  
Mark Rees

Current issues in population dynamics are discussed in the context of The Royal Society Discussion Meeting 'Population growth rate: determining factors and role in population regulation'. In particular, different views on the centrality of population growth rates to the study of population dynamics and the role of experiments and theory are explored. Major themes emerging include the role of modern statistical techniques in bringing together experimental and theoretical studies, the importance of long-term experimentation and the need for ecology to have model systems, and the value of population growth rate as a means of understanding and predicting population change. The last point is illustrated by the application of a recently introduced technique, integral projection modelling, to study the population growth rate of a monocarpic perennial plant, its elasticities to different life-history components and the evolution of an evolutionarily stable strategy size at flowering.


2002 ◽  
Vol 357 (1425) ◽  
pp. 1185-1195 ◽  
Author(s):  
Bernt–Erik Sæther ◽  
Steinar Engen

A central question in population ecology is to understand why population growth rates differ over time. Here, we describe how the long–term growth of populations is not only influenced by parameters affecting the expected dynamics, for example form of density dependence and specific population growth rate, but is also affected by environmental and demographic stochasticity. Using long–term studies of fluctuations of bird populations, we show an interaction between the stochastic and the deterministic components of the population dynamics: high specific growth rates at small densities r 1 are typically positively correlated with the environmental variance σ e 2 . Furthermore, θ, a single parameter describing the form of the density regulation in the theta–logistic density–regulation model, is negatively correlated with r 1 . These patterns are in turn correlated with interspecific differences in life–history characteristics. Higher specific growth rates, larger stochastic effects on the population dynamics and stronger density regulation at small densities are found in species with large clutch sizes or high adult mortality rates than in long–lived species. Unfortunately, large uncertainties in parameter estimates, as well as strong stochastic effects on the population dynamics, will often make even short–term population projections unreliable. We illustrate that the concept of population prediction interval can be useful in evaluating the consequences of these uncertainties in the population projections for the choice of management actions.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252748
Author(s):  
Nathan J. Hostetter ◽  
Nicholas J. Lunn ◽  
Evan S. Richardson ◽  
Eric V. Regehr ◽  
Sarah J. Converse

Understanding the influence of individual attributes on demographic processes is a key objective of wildlife population studies. Capture-recapture and age data are commonly collected to investigate hypotheses about survival, reproduction, and viability. We present a novel age-structured Jolly-Seber model that incorporates age and capture-recapture data to provide comprehensive information on population dynamics, including abundance, age-dependent survival, recruitment, age structure, and population growth rates. We applied our model to a multi-year capture-recapture study of polar bears (Ursus maritimus) in western Hudson Bay, Canada (2012–2018), where management and conservation require a detailed understanding of how polar bears respond to climate change and other factors. In simulation studies, the age-structured Jolly-Seber model improved precision of survival, recruitment, and annual abundance estimates relative to standard Jolly-Seber models that omit age information. Furthermore, incorporating age information improved precision of population growth rates, increased power to detect trends in abundance, and allowed direct estimation of age-dependent survival and changes in annual age structure. Our case study provided detailed evidence for senescence in polar bear survival. Median survival estimates were lower (<0.95) for individuals aged <5 years, remained high (>0.95) for individuals aged 7–22 years, and subsequently declined to near zero for individuals >30 years. We also detected cascading effects of large recruitment classes on population age structure, which created major shifts in age structure when these classes entered the population and then again when they reached prime breeding ages (10–15 years old). Overall, age-structured Jolly-Seber models provide a flexible means to investigate ecological and evolutionary processes that shape populations (e.g., via senescence, life expectancy, and lifetime reproductive success) while improving our ability to investigate population dynamics and forecast population changes from capture-recapture data.


2018 ◽  
Vol 7 (4.34) ◽  
pp. 123
Author(s):  
Mohd Khairul Amri Kamarudin ◽  
Noorjima Abd Wahab ◽  
Mahadzirah Mohamad ◽  
Ahmad Shakir Mohd Saudi ◽  
Mohamad Shaharudin Samsurijan ◽  
...  

This research examines the effects of population growth on the economic development between the two developed and developing countries which is Singapore and Malaysia. They were many previous studies that have sought to gauge the effects or impact of population growth along the economic development. It was said that there was a strong relationship between the effects of population growth and the economic development, which is the growth of population is depending on the economic growth. Singapore was well known worldwide as a highly developed free-market economy. The economy of Singapore has been ranked as the most open in the world and the most-pro business. The population in the country is estimated at 5.5 million recently. As for Malaysia, it is known as the most competitive developing countries and is ranked on the 5th largest in South Asia. The population estimated at 31.63 million in Malaysia.  


1993 ◽  
Vol 32 (4I) ◽  
pp. 411-431
Author(s):  
Hans-Rimbert Hemmer

The current rapid population growth in many developing countries is the result of an historical process in the course of which mortality rates have fallen significantly but birthrates have remained constant or fallen only slightly. Whereas, in industrial countries, the drop in mortality rates, triggered by improvements in nutrition and progress in medicine and hygiene, was a reaction to economic development, which ensured that despite the concomitant growth in population no economic difficulties arose (the gross national product (GNP) grew faster than the population so that per capita income (PCI) continued to rise), the drop in mortality rates to be observed in developing countries over the last 60 years has been the result of exogenous influences: to a large degree the developing countries have imported the advances made in industrial countries in the fields of medicine and hygiene. Thus, the drop in mortality rates has not been the product of economic development; rather, it has occurred in isolation from it, thereby leading to a rise in population unaccompanied by economic growth. Growth in GNP has not kept pace with population growth: as a result, per capita income in many developing countries has stagnated or fallen. Mortality rates in developing countries are still higher than those in industrial countries, but the gap is closing appreciably. Ultimately, this gap is not due to differences in medical or hygienic know-how but to economic bottlenecks (e.g. malnutrition, access to health services)


2021 ◽  
Vol 257 ◽  
pp. 109104
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Taylor K. Chapple ◽  
Scot D. Anderson ◽  
Timothy D. White ◽  
...  

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