population growth rates
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2022 ◽  
Vol 2 ◽  
Author(s):  
Lalasia Bialic-Murphy ◽  
Tiffany M. Knight ◽  
Kapua Kawelo ◽  
Orou G. Gaoue

The reintroduction of rare species in natural preserves is a commonly used restoration strategy to prevent species extinction. An essential first step in planning successful reintroductions is identifying which life stages (e.g., seeds or large adults) should be used to establish these new populations. Following this initial establishment phase, it is necessary to determine the level of survival, growth, and recruitment needed to maintain population persistence over time and identify management actions that will achieve these goals. In this 5-year study, we projected the short- and long-term population growth rates of a critically endangered long-lived shrub, Delissea waianaeensis. Using this model system, we show that reintroductions established with mature individuals have the lowest probability of quasi-population extinction (10 individuals) and the highest increase in population abundance. However, our results also demonstrate that short-term increases in population abundances are overly optimistic of long-term outcomes. Using long-term stochastic model simulations, we identified the level of natural seedling regeneration needed to maintain a positive population growth rate over time. These findings are relevant for planning future reintroduction efforts for long-lived species and illustrate the need to forecast short- and long-term population responses when evaluating restoration success.


Author(s):  
Mohammad Taghi Sheykhi

The two variables of population and development affect each other in an indirect manner in which when population increase happens, development is reduced. The two effectively impact quality of life. It is strongly recommended to control population in order to achieve development. Sociologists are widely responsible to create the balance of population and development. As resources are limited in each country, an organized and planned population is needed towards any development. The phenomenon development being multi-lateral, needs an appropriate population size. It is worth mentioning that population naturally grows, but resources for development do not. Overall, Asia, Africa, and Latin America had very high population growth rate of 2.1% between 1955 and 1975. Fortunately, increase of literacy and education has caused population growth rates to decline in the past two decades in many parts of the developing countries. The only part of the developing world with high population growth rate is Africa in which the population will increase to over 4.2 billion by the year 2100; threatening other parts of the world. Such a situation will widely endanger quality of life.


Dharma LPPM ◽  
2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Saiful Rahman Yuniarto ◽  
Gunawan Eko Nurtjahjono ◽  
Raden Rustam Hidayat ◽  
Edy Yulianto ◽  
Muhammad Faisal Riza

The high unemployment rate is a fundamental problem in employment in our country, where the new workforce that is added is far greater than the increase in employment. Unemployment is a problem for countries with high population growth rates, and unemployment can also affect the level of the economy. At the beginning of 2020, world economic growth experienced a decline due to the coronavirus disease outbreak, this coronavirus (covid-19) had an impact on economic growth in the form of a decline in the level of the world economy, including Indonesia. Seeing conditions like this, special attention is needed for alumni to prepare students for the world of work. This community service is carried out in the form of training on strategies for finding and applying for jobs, the problem solving framework provided is by providing training so that it can increase knowledge and insight to job seekers college alumni about srategies for finding and applying for jobs.The purpose of this community service activity is to provide training to college alumni so that they have the readiness to find and apply for jobs. This community service activity is carried out virtually online online in the form of training and guidance. The target is college alumni who will definitely be involved in the activity of finding and applying for jobs, at the initial stage the presenter will deliver a theoretical presentation accompanied by realistic examples. The results of the implementation of community service by providing the training are expected that college alumni as prospective job seekers already have the knowledge, insight and readiness in finding and applying for jobs, then to provide knowledge and insight about strategies for finding and applying for these jobs, as well as the factors that must be considered.The high unemployment rate is a fundamental problem in employment in our country, where the new workforce that is added is far greater than the increase in employment. Unemployment is a problem for countries with high population growth rates, and unemployment can also affect the level of the economy. At the beginning of 2020, world economic growth experienced a decline due to the coronavirus disease outbreak, this coronavirus (covid-19) had an impact on economic growth in the form of a decline in the level of the world economy, including Indonesia. Seeing conditions like this, special attention is needed for alumni to prepare students for the world of work. This community service is carried out in the form of training on strategies for finding and applying for jobs, the problem solving framework provided is by providing training so that it can increase knowledge and insight to job seekers college alumni about srategies for finding and applying for jobs.The purpose of this community service activity is to provide training to college alumni so that they have the readiness to find and apply for jobs.This community service activity is carried out virtually online online in the form of training and guidance. The target is college alumni who will definitely be involved in the activity of finding and applying for jobs, at the initial stage the presenter will deliver a theoretical presentation accompanied by realistic examples. The results of the implementation of community service by providing the training are expected that college alumni as prospective job seekers already have the knowledge, insight and readiness in finding and applying for jobs, then to provide knowledge and insight about strategies for finding and applying for these jobs, as well as the factors that must be considered.


2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Hanna Kokko

Fisher's fundamental theorem states that natural selection improves mean fitness. Fitness, in turn, is often equated with population growth. This leads to an absurd prediction that life evolves to ever-faster growth rates, yet no one seriously claims generally slower population growth rates in the Triassic compared with the present day. I review here, using non-technical language, how fitness can improve yet stay constant (stagnation paradox), and why an unambiguous measure of population fitness does not exist. Subfields use different terminology for aspects of the paradox, referring to stasis, cryptic evolution or the difficulty of choosing an appropriate fitness measure; known resolutions likewise use diverse terms from environmental feedback to density dependence and ‘evolutionary environmental deterioration’. The paradox vanishes when these concepts are understood, and adaptation can lead to declining reproductive output of a population when individuals can improve their fitness by exploiting conspecifics. This is particularly readily observable when males participate in a zero-sum game over paternity and population output depends more strongly on female than male fitness. Even so, the jury is still out regarding the effect of sexual conflict on population fitness. Finally, life-history theory and genetic studies of microevolutionary change could pay more attention to each other.


2021 ◽  
Vol 9 ◽  
Author(s):  
Binu Timsina ◽  
Pavel Kindlmann ◽  
Zuzana Münzbergová ◽  
Maan B. Rokaya

Studies on population dynamics are helpful for understanding the factors determining population development and predicting the effects of disturbances, such as harvesting of plant species. In an investigation of the demography of a terrestrial medicinal orchid known as Crepidium acuminatum, the effects of harvesting on its population dynamics were recorded. Data on recruitment, growth and survival were collected in three populations of C. acuminatum over a 6-year period (2012–2017) in central Nepal. A matrix modeling method was used to determine the effect of different harvesting regimes on the population growth and survival of this species. Population growth rates (λ) of unharvested populations were relatively similar and stable in different years of the study. Harvesting significantly reduced λ. The results of this study indicate that the sustainable survival of a population that is subject to harvesting can only occur when it is either selective (only flowering individuals or only small amounts of vegetative individuals) or rotational (once every 3–5 or more years). This study demonstrates the necessity of using a sustainable method when harvesting natural populations. Our results are useful for developing efficient management strategies for this species. As each species has a different biology, similar studies are needed for other rare and/or economically important species in the Himalayan region and in other understudied parts of the world.


2021 ◽  
Vol 880 (1) ◽  
pp. 012050
Author(s):  
Azreen Harina Azman ◽  
Nurul Nadrah Aqilah Tukimat ◽  
M.A. Malek ◽  
Ros Faizah Che

Abstract Malaysia as an emerging country, increasing population, gross domestic product (GDP) growth and enhanced access to electricity lead to an expanding of demand. The crucial parameters to determine future energy demand and generation projections are GDP, population growth rates and weather implications due to climate change. The study aims to forecast the future trends based on the historical values and also to project the future electricity demand and generation. The electricity demand and generation growth evaluated based on 2 main elements which are population growth and weather parameters (maximum temperature and rainfall). The future trends are forecasted based on the historical values of population and weather parameters. There is 152.9% of population growth in 32 years. The population will keep on developing yet with the lower rate. The GDP trend and the population growth mirrors the pattern of emissions. The findings from Statistical Downscaling Model (SDSM) analysis shows that the rainfall distribution will diminish while the temperature will expand that depict the climate change impact as time passes by. In 2020, the most extreme temperature recorded is 31.7 °C while in 2040, the estimated greatest temperature is 32.3 °C. There will be a 0.6 °C increase in temperature in 20 years. The demand in 2040 will be expanded 50.3% more than demand in 2020. The estimated electricity demand per capita will continue expanding because of the augmentation of the populace and the significance of electricity in daily activities. The pattern shows that electricity demand and generation in Malaysia will be expanding massively year by year.


2021 ◽  
Author(s):  
Daniel S Fisher

Evolution in complex high-dimensional phenotype spaces can be very different than the caricature of uphill evolutionary trajectories in a low-dimensional fitness landscape. And slight modifications of the environment can have large consequences for the future evolution. Here, the simplest approximation of evolution, an almost-always clonal population evolving by small effect mutations under deterministic "adaptive" dynamics, is studied. The complexities of organisms and their interactions with their environments are caricatured by population growth rates being smoothly varying random functions in very high dimensional phenotype spaces. In a fixed environment, there are huge numbers of fitness maxima, yet evolutionary trajectories wander around amongst saddles, gradually slowing down but still wandering widely and without committing to any maximum. But with even very small changes of the environment caused by the phenotypic changes, after an initial transient the evolution continues forever without further slowing down. In this Red Queen "phase" the apparent rate of increase of the fitness saturates (at a feedback strength-dependent rate) and the trajectories perpetually wander over large phenotypic distances. Organismic complexities, caricatured by a large number of constraints on the molecular-level phenotype, together with the simplest possible interactions of the organisms with their environment, are shown to be sufficient to cause such Red Queen dynamics. Arguments are made for the ubiquity of such behavior.


2021 ◽  
Author(s):  
Corey J. A. Bradshaw ◽  
Salvador Herrando-Perez

Analysis of long-term trends in abundance provide insights into population dynamics. Population growth rates are the emergent interplay of fertility, survival, and dispersal, but the density feedbacks on some vital rates (component) can be decoupled from density feedback on population growth rates (ensemble). However, the mechanisms responsible for this decoupling are poorly understood. We simulated component density feedbacks on survival in age-structured populations of long-living vertebrates and quantified how imposed nonstationarity (density-independent mortality and variation in carrying-capacity) modified the ensemble feedback signal estimated from logistic-growth models to the simulated abundance time series. The statistical detection of ensemble density feedback was largely unaffected by density-independent processes, but catastrophic and proportional mortality eroded the effect of density-dependent survival on ensemble-feedback strength more strongly than variation in carrying capacity. Thus, phenomenological models offer a robust approach to capture density feedbacks from nonstationary census data when density-independent mortality is low.


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