population changes
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Author(s):  
I. M. Grod ◽  
I. V. Zagorodniuk ◽  
L. O. Shevchyk ◽  
N. Ya. Kravets

Monitoring and predicting the dynamics of abundance of species living in natural habitats is an important component stability analysis of ecosystem as well as dynamics and direction of change of biotic communities under global climate change and pressure of the alien species. The aim of the work was to build a matrix model and study the state of stabilisation of the dynamics of the bank vole population within the Leslie model. The object of the study was the population dynamics of Myodes glareolus Schreber, 1780 = Clethrionomys glareolus auct. The study is based on materials obtained during 2017–2019. This period covered one phase of the long-term population dynamics of the bank vole, named “population growth”. The research was carried out according to generally accepted methods. A total of 6400 trap-days were processed, and 358 forest fistulas were collected and studied. The intensity of harmful activity of rodents is due to the variability of the number of animals in the population. The quantitative population changes are the result of three factors: births, deaths, and migrations. The main condition for the existence of the species is the stability of the population, which is determined by the action of thecompensatory mechanisms. The growth phase of the bank vole lasted all three years of the research, the quantitative indicators were respectively: 2017 – 1.8 individuals per 100 trap-days; 2018 – 2.0 individuals per 100 trap-days; 2019 – 2.7 individuals per 100 trap-days. Low levels of the abundance in the spring of each year of the study, namely at the beginning of the breeding season (3.7 – 2.6 – 8.9 individuals per 100 trap-days). Favourable for the abundance growth was the sex ratio of the population (approximately 1:1), with some rise in the share of females, which decreases on the period of spring 2018 to autumn 2019). Some decrease in the share of immature individuals (4.5 – 3.9 – 3.1 %) is an indirect confirmation of the stability of puberty of animals with subsequent replenishment of the "stock", which led to accelerated reproduction and, consequently, provided prerequisites for further population growth. The causal mechanisms of population control established by us, without a doubt, can serve as a basis for further prognosis, of the number of pests in natural habitats. To predict population changes, the Leslie model, which is widely used in mathematical analyses of the abundance of both plant and animal groups, was chosen. The algorithm for building a matrix model, detailed in the article, has five following steps. The exponential nature of the actual and projected growth of the bank vole population during the five-year cycle (2017–2019 with a prognosis until 2023) revealed in the analysis can be explained not so much by the power of the species' reproductive potential as by the lack of the significant changes in habitat, caused by constant weather conditions, low individual mortality from predators and non-communicable diseases or other accidents. The application of the matrix model allowed to confirm the key role of the main compensatory mechanisms of population dynamics, as they contribute to the stabilisation of the population and, as a consequence, are an important condition for the existence of the species.


2021 ◽  
Vol 12 (6) ◽  
pp. 677-689
Author(s):  
Jin-Uk Kim ◽  
Young-Hwa Byun ◽  
Jin-Won Kim ◽  
Yeon-Hee Kim

2021 ◽  
Vol 3 (2) ◽  
pp. 19-36
Author(s):  
Jinhang Jiang ◽  
Karthik Srinivasan

The COVID-19 pandemic has had a severe effect on all facets of human society, including healthcare. One of the primary concerns in healthcare is understanding and mitigating the impact of the pandemic on pregnancy and childbirth. While several studies have looked at challenges such as contract tracing of positive cases, predicting confirmed cases and deaths in individuals and communities, few studies have examined differences in hospitalization and treatment of pregnant mothers and infant care in large populations. In this study, the prevalence and co-occurrence of pregnancy and childbirth-related diagnoses reported in Arizona State hospitals for three sixth-month periods - before COVID-19 (second half of 2019), COVID-19 onset (first half of 2020), and COVID-19 (second half of 2020) are analyzed using network analysis. The results show that there are considerable differences in ego networks of few diagnoses during these time periods warranting further investigation into the causality of such population changes.


Author(s):  
Alina A. Dzusova

The article deals with the formation of money income of the population, changes in the formation of consumer goods and needs for them, including under the influence of pricing, the structural volumes of goods offered for sale with different consumer properties and values. The problem of dynamics and the level of growth in prices for consumer goods is considered from the standpoint of disclosing the relationship between the emerging incomes of the population, inflation, methods of indexation and compensatory regulation. The formation of the incomes of the population of Russia is characterized not only by an insufficiency in relation to existing needs, but also by many contradictions that restrain their correspondence with the goals of improving welfare. At the same time, the need to identify the changes in trends and patterns taking place in the economy and social practice becomes a condition for the possible improvement of the tasks being solved not only in increasing the income of the population, but also in regulating them in consumption and efficiency of use. In practice and in research results, the lack of a systematic nature of the tasks being solved is recorded (generalized) both in price regulation and in the indexation of income in guaranteed rates corresponding to the dynamics of real inflation indicators, its level positions, which are taken into account not only in the emerging wages in monetary form, but also in various benefits that are paid by the state. The solution of these problems requires further detailed scientific research of the processes actually occurring in economic practice with the use of methods for indexing the income of the population with an increase in consumer prices. The supply of consumer goods on the market, which does not have a profitable orientation towards their purchases, in our opinion, will always exacerbate the problem of choosing methods of price regulation, both on the part of the state and commodity producers.


2021 ◽  
Author(s):  
Thomas Frederick Johnson ◽  
Nick J.B. Isaac ◽  
Agustin Paviolo ◽  
Manuela Gonzalez-Saurez

Land-use and climate change have been linked to wildlife population declines, but the role of socioeconomic factors in driving declines, and promoting population recoveries, remains relatively unexplored despite its likely importance. Here, we evaluate a comprehensive array of potential drivers of population changes observed in some of the world's most charismatic species - large mammalian carnivores. Our results reveal a strong role of human socioeconomic development, which we find has a greater impact on population change than habitat loss and climate change. Increases in socioeconomic development are linked to sharp population declines but, importantly, once development is high, carnivore populations have the potential to recover. These links between human development and wildlife population health highlight the challenges ahead to achieve the different UN Sustainable development goals.


Genus ◽  
2021 ◽  
Vol 77 (1) ◽  
Author(s):  
Yi Zeng ◽  
Hanmo Yang ◽  
Zhenglian Wang ◽  
Lan Li

AbstractThis article presents analyses and projections of the residential energy demands in Hebei Province of China, using the ProFamy extended cohort-component method and user-friendly free software and conventional demographic data as input. The results indicate that the future increase in residential energy demands will be dominated by large increase in small households with 1–2 persons. We found that increase of residential energy demands will be mainly driven by the rapid increase of older adults’ households. Comparisons between residential energy demand projections by household changes and by population changes demonstrate that projections by population changes seriously under-estimate the future residential energy demands. We recommend that China needs to adopt policies to encourage and facilitate older parents and adult children to live together or near-by, and support rural-to-urban family migration. Promoting inter-generation co-residence or living near-by between older parents and young adults would result in a mutually beneficial outcome for both older and younger generations as well as to effectively reduce energy demands. We suggest governments to carefully formulate strategies on efficient residential energy use to cope with the rapid households and population aging, and strengthen data collections/analyses on household residential energy demands for sound policy-making and sustainable development.


2021 ◽  
Vol 29 (2) ◽  
pp. 1-24
Author(s):  
László Musicz ◽  
Sándor Faragó

Abstract The Old Lake of Tata, an important wild goose roosting site in Central Europe, is unique in its location being in the middle of a city with a population of 24,000. Consequently, the site is subject to intensive human disturbances. Goose migration and wintering on the lake was studied for over 37 years (1984–2021). In addition to weather, hydrological, and feeding conditions, particular attention was focused on human influences (which were deemed generally disruptive, but also beneficial in some cases) that can induce significant changes in the population dynamics of the 30,000–50,000 wild geese from 13 species wintering here. Almost without exception, the largest observed changes in the abundance of wild geese roosting overnight on the Old Lake are due to anthropogenic effects. In the majority of cases, the most significant population changes are due to impacts associated with the operation and upkeep of the lake and the New Year’s Eve fireworks. As a result, the winter operation of the Old Lake has been regulated by the Wild Goose Preference Mode since 2011, and the City of Tata has banned the use of fireworks during the winter period since 2018. Consequently, the conditions for wild goose migration have improved significantly. However, the situation of the Old Lake is still quite fragile and more conservation measures are needed to protect it further.


2021 ◽  
Vol 9 ◽  
Author(s):  
Wesley H. Webb ◽  
Michelle M. Roper ◽  
Matthew D. M. Pawley ◽  
Yukio Fukuzawa ◽  
Aaron M. T. Harmer ◽  
...  

Songbirds learn their songs culturally, through imitating tutors. The vocal culture of a songbird population changes as new song units (syllables) are introduced through immigration, copying errors, and innovation, while other syllables fall out of use. This leads to a diversification of the syllable pool across the species, much like the diversification and spatial patterns of human language. Vocal cultures have been well-studied in male songbirds but have been largely overlooked in females. Here we undertake one of the first comparisons of male and female song cultures across a songbird metapopulation—studying New Zealand bellbirds Anthornis melanura spanning a network of six islands. Having classified 20,700 syllables (702 types), we compare population syllable repertoire sizes and overlap between sites and sexes. We show that males and females—both with complex songs—have distinct song cultures, sharing only 6–26% of syllable types within each site. Furthermore, male and female syllable types can be statistically discriminated based on acoustic properties. Despite diverse syllable repertoires within sites, few syllable types were shared between sites (both sexes had highly distinct site-specific dialects). For the few types shared between sites, sharing decreased with distance only for males. Overall, there was no significant difference between sexes in degree of site–site repertoire overlap. These results suggest different cultural processes at play for the two sexes, underlining the inadequacy of male-centric song research and calling for comparisons of male and female song cultures in many more species.


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