Population Dynamics with Endogenous Birth and Mortality Rates

2020 ◽  
pp. 119-146
Author(s):  
Wei-Bin Zhang
Keyword(s):  
Population Dynamics ◽  
Mortality Rates

scholarly journals The influence of microhabitat on the population dynamics of four herbaceous species in a semiarid area of northeastern Brazil

2016 ◽  
Vol 76 (1) ◽  
pp. 45-54 ◽  
Author(s):  
K. A. Silva ◽  
J. M. F. F. Santos ◽  
J. R. Andrade ◽  
E. N. Lima ◽  
U. P. Albuquerque ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Mortality Rates ◽  
Dry Forest ◽  
Northeastern Brazil ◽  
Annual Rainfall ◽  
Herbaceous Species ◽  
Forest Fragment ◽  
Experimental Station ◽  
Over Time

Abstract Variation in annual rainfall is considered the most important factor influencing population dynamics in dry environments. However, different factors may control population dynamics in different microhabitats. This study recognizes that microhabitat variation may attenuate the influence of climatic seasonality on the population dynamics of herbaceous species in dry forest (Caatinga) areas of Brazil. We evaluated the influence of three microhabitats (flat, rocky and riparian) on the population dynamics of four herbaceous species (Delilia biflora, Commelina obliqua, Phaseolus peduncularis and Euphorbia heterophylla) in a Caatinga (dry forest) fragment at the Experimental Station of the Agronomic Research Institute of Pernambuco in Brazil, over a period of three years. D. biflora, C. obliqua and P. peduncularis were found in all microhabitats, but they were present at low densities in the riparian microhabitat. There was no record of E. heterophylla in the riparian microhabitat. Population size, mortality rates and natality rates varied over time in each microhabitat. This study indicates that different establishment conditions influenced the population size and occurrence of the four species, and it confirms that microhabitat can attenuate the effect of drought stress on mortality during the dry season, but the strength of this attenuator role may vary with time and species.

scholarly journals Estado Atual de Conhecimento de Dinâmica de Populações

2019 ◽  
Vol 23 (3) ◽  
pp. 256
Author(s):  
Anna Clara Balbina Silva ◽  
Afonso Pelli
Keyword(s):  
Population Dynamics ◽  
Full Text ◽  
Mortality Rates ◽  
Structured Populations ◽  
Exclusion Criteria ◽  
Spatially Structured Populations ◽  
The Subject ◽  
Population Interactions ◽  
Dynamic Population ◽  
Critical Challenge

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.

Cycle de développement, croissance et production de Pisidium amnicum (Mollusca: Bivalvia) dans le Saint-Laurent (Québec)

1981 ◽  
Vol 59 (12) ◽  
pp. 2350-2359 ◽  
Author(s):  
B. Vincent ◽  
G. Vaillancourt ◽  
N. Lafontaine
Keyword(s):  
Population Dynamics ◽  
Sexual Maturity ◽  
Dry Weight ◽  
Mortality Rates ◽  
The Other ◽  
Annual Production ◽  
Bithynia Tentaculata ◽  
The Mean ◽  
Total Dry Weight ◽  
St Lawrence River

The population dynamics of Pisidium amnicum have been studied in one population of the St. Lawrence River over a 2-year period during which 19 samples were taken. The species can live up to 3 years and it is iteroparous; individuals generally attain sexual maturity after 1 year and they reproduce twice, once at 2 and once at 3 years of age. In adults, mortality is lower in winter than during the rest of the year and mortality rates are twice as high during the 1st year than during the 2nd year. Total dry weight (PT, in milligrams) is related to maximum length (L, in millimetres) according to the equation PT = 0.0283∙L3,80 and flesh dry weight (PC, in milligrams) is related to length as follows: PC = 0.007∙L3,18. The annual production to mean biomass (P/B) ratio is 1.4, the mean annual production being 1.298 mg/m2 of total dry weight and 107 mg/m2 of flesh weight. Comparing these results with those obtained for the gastropod Bithynia tentaculata in the same environment and at the same period of the year has shown that the growth of Pisidium amnicum is far less influenced by the temperature regime than that of the other species and that its production is at least 10 times lower.

Larval mortality rates and population dynamics of Lesser Sandeel (Ammodytes marinus) in the northwestern North Sea

2012 ◽  
Vol 93 ◽  
pp. 47-57 ◽  
Author(s):  
Michael R. Heath ◽  
Jens Rasmussen ◽  
Martin C. Bailey ◽  
John Dunn ◽  
John Fraser ◽  
...  
Keyword(s):  
Population Dynamics ◽  
North Sea ◽  
Larval Mortality ◽  
Mortality Rates

Production and Population Dynamics of the Crayfish Orconectes virilis in Three Michigan Lakes

1977 ◽  
Vol 34 (11) ◽  
pp. 2030-2040 ◽  
Author(s):  
Walter T. Momot ◽  
Howard Gowing
Keyword(s):  
Population Dynamics ◽  
Growth Rates ◽  
Age Groups ◽  
Mortality Rates ◽  
Reproductive Age ◽  
Annual Production ◽  
Effective Density ◽  
Orconectes Virilis ◽  
Brood Stock ◽  
Density Dependent

Fluctuations in mortality rather than in growth rates produced most of the year-to-year differences in biomass accumulation of three different populations of the crayfish Orconectes virilis. Yearly biomass changes resulted from density-dependent control of mortality and fecundity during certain portions of the life cycle. Density-dependent changes in mortality rates controlled population size for adults in all lakes and for young-of-the-year in two of the three study lakes. Growth rates were much less responsive to fluctuating densities. Disparity between the number of ovarian and attached eggs increased as density of age I+ crayfish increased. This provided a strong density regulator on fecundity. Differences occurred in the number of recruits produced by a brood stock that survive to the end of the first growing season in the various lakes. Yet the number of females surviving to reproductive age 2 yr later was strongly regulated. Strong population regulation produced two female recruits of breeding age for every two–six parental breeding females. The high biomass and production levels of crayfish discovered in West Lost Lake in 1962–63 also occurred in the other area lakes. Higher but variable levels of recruitment resulted in larger standing crops and production in West Lost lake. This resulted from less effective density controls on the mortality rates of younger age-groups in that lake. Despite great variation in biomass of from 46 to 213 kg/ha and annual production from 60 to 142 kg/ha, the annual turnover ratio of the biomass was found to vary only between 0.94 and 1.53. Key words: crayfish, Orconectes virilis, population dynamics, annual production, Michigan lakes

UnexpectedListronotus bonariensis(Coleoptera: Curculionidae) mortality in the presence of parasitoids

2004 ◽  
Vol 94 (5) ◽  
pp. 411-417 ◽  
Author(s):  
S.L. Goldson ◽  
J.R. Proffitt ◽  
M.R. McNeill ◽  
C.B. Phillips ◽  
N.D. Barlow ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Mortality Rates ◽  
Ecological Significance ◽  
Time Intervals ◽  
Larval Parasitoid ◽  
Mortality Effect ◽  
Listronotus Bonariensis ◽  
Field And Laboratory Conditions ◽  
The Impact ◽  
Microctonus Hyperodae

AbstractField enclosure and laboratory cage experiments designed to measure the impact of the parasitoidMicroctonus hyperodaeLoan on the Argentine stem weevil,Listronotus bonariensis(Kuschel) have shown that under high parasitoid pressure, there is significant weevil mortality without obvious parasitism. Parasitoid-exposed, but unparasitized portions of caged populations died at rates significantly higher than both the parasitized weevils from the same population and the unexposed controls. Unexpectedly, parasitized weevils had the lowest mortality rates (prior to larval parasitoid emergence). It was of ecological significance that this mortality effect was detected under field conditions using several years of empirically-collected population dynamics data. Under both field and laboratory conditions this mortality was found to occur within shorter time intervals than that required for full parasitoid larval development; thus it could not be attributed to the mortality that occurs after the emergence of prepupal parasitoids. The mechanism for this mortality remains undetermined, although it could possibly be linked to pseudoparasitism.

scholarly journals Short Communication: Population dynamics of double-spined rock lobster (Panulirus penicillatus Olivier, 1791) in Southern Coast of Yogyakarta

2018 ◽  
Vol 19 (1) ◽  
pp. 337-342
Author(s):  
RAKHMA FITRIA LARASATI ◽  
SUADI SUADI ◽  
EKO SETYOBUDI
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Short Communication ◽  
Mortality Rates ◽  
Southern Coast ◽  
Rock Lobster ◽  
Wild Stock ◽  
Fishing Activity ◽  
Males And Females ◽  
Asymptotic Point

Larasati RF, Suadi, Setyobudi E. 2018. Short Communication: Population dynamics of double-spined rock lobster (Panulirus penicillatus Olivier, 1791) in Southern Coast of Yogyakarta. Biodiversitas 19: 337-342. The southern coast of Yogyakarta, Indonesia, near to the Indian Ocean borders is a preferable habitat for lobster. Double-spined rock lobster (Panulirus penicillatus) is one of the prevalent species caught by fishermen. However the increased number of capture activities had an effect on the sustainability of global lobster fisheries. In order to sustain these fisheries resource, the preservation management of lobster should include wild stock assessments. Currently, the effect of fishing pressures on populations of P. penicillatus is limited. The objective of this research was to identify several factors affecting lobster population in terms of growth (carapace length (CL) and mass), recruitment, mortality rates, and exploitation rates in this species. Results showed that double-spined rock lobster had a longer size (CL) (45.2-55.1 mm) than that of females (55.2 mm-65.1 mm). While the growth rate (K) of males lobster is 0.85 year-¹ and its CL reached an asymptotic point at 125 mm (12 years old). Growth rate of females double-spined rock lobster was 0.55 year-¹ and its CL reached an asymptotic point at 125.5 mm (15 years old). The total estimation of mortality rates of double-spined rock lobster was 2.46, wherein 2.56 year-¹ for males and females, respectively. The estimated values of M were 1.08, 0.81 year-¹ for males and females, respectively while the respective values of F were 1.38 year-¹ and 1.75 year-¹ for males and females. The exploitation rate of males was 0.56 and females was 0.68. It has exceeded the optimal level (0.5) and reached overfishing value. Based on these results, it suggest that the time management of fishing activities such as by several approaches including the restricted time of fishing activity in spawning and recruitment season, the management of catching effort by the development of environment-friendly fishing gear, and the development of the lobster hatchery to reproduce and maintain their population naturally.

scholarly journals Effects of phenological synchronization on caterpillar early-instar survival under a changing climate

2018 ◽  
Vol 48 (3) ◽  
pp. 247-254 ◽  
Author(s):  
Emma Despland
Keyword(s):  
Population Dynamics ◽  
Host Plants ◽  
Larval Mortality ◽  
Mortality Rates ◽  
Chemical Defenses ◽  
Population Fluctuations ◽  
Density Dependent ◽  
Early Instar ◽  
Species Specific ◽  
Very High

Early-instar caterpillars experience very high and often very variable mortality; if it is density dependent, it can be a key factor in outbreak dynamics. Plant physical and chemical defenses can be extremely effective against young caterpillars, even of specialists. Phenological asynchrony with host plants can lead to dispersal and mortality in the early instars and increased predation or poor nutrition in later instars. Predation on early-instar larvae (including cannibalism) can be extremely high, parasitism appears generally low, and pathogens acquired early in larval development can lead to high mortality in later stadia. Four well-studied species reveal very different roles of early-instar mortality in population dynamics. In spruce budworm and gypsy moth, early-instar mortality rates can be very high; they do not drive outbreak cycles because density dependence is weak, but can modulate cycles and contribute to outbreak size and duration. For the autumnal moth, early-instar survival depends on host plant synchrony, but may or may not be density dependent. For monarch butterflies, the relative importance of larval mortality rates in population dynamics remains unclear. Tritrophic interactions between herbivores, host plants, natural enemies, and microbes play complex and species-specific roles in early-instar ecology, leading to emergent dynamics in population fluctuations. The phenology of these relationships is often poorly understood, making their responses to climate change unpredictable.

SIMULATION MODEL FOR THE POPULATION DYNAMICS OF THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (LECONTE) (COLEOPTERA: CURCULIONIDAE)

1991 ◽  
Vol 123 (1) ◽  
pp. 63-76 ◽  
Author(s):  
D.X. Zhao ◽  
G. Boivin ◽  
R.K. Stewart
Keyword(s):  
Population Dynamics ◽  
Simulation Model ◽  
Mortality Rates ◽  
Egg Parasitoid ◽  
Adult Density ◽  
Larval Population ◽  
Listronotus Oregonensis ◽  
The Mean ◽  
Carrot Weevil ◽  
The Impact

AbstractA simulation model was developed for the population dynamics of a carrot weevil, Listronotus oregonensis (LeConte), population on muck-grown carrots. The model includes mortality rates of eggs, larvae, and pupae for different sowing dates of carrots. It also incorporates the overwintered adult density, the temperature-dependent growth rates of the above-mentioned life stages, the age-, temperature-, and phenology-dependent oviposition rates, and the impact of an egg parasitoid, Anaphes sordidatus (Girault), on egg mortality rates. Model output was evaluated by comparing simulated results with observed results on the seasonal totals and time of population peaks of the egg and larval populations. The mean percentage differences between the simulated and observed seasonal egg totals were 3.1 ± 0.66 (SE) in 1987 and 1988, and 4.2 ± 0.05 in 1989. They were not statistically different. The mean percentage differences between the simulated and observed seasonal larval totals were 10 ± 3.33 in 1987 and 1988 and 29.8 ± 0.66 in 1989. Independent data sets (i.e. field data in 1989) showed a significant increase in the simulation error of the larval population. Sensitivity analysis indicated that A. sordidatus had a large influence on the population dynamics of L. oregonensis.

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