Population dynamics in northwestern China

AbstractThis article analyzes the population dynamics in northwestern China from roughly 2010 to 2020. The area’s dynamics showed a slow, stable increase in population size, a stable increase in the population of non-Han ethnic groups, which increased at a more rapidly than the Han population, and population rejuvenation coupled with a population structure that aged. The biological sex structure fluctuated within a balanced range in northwestern China. Urbanization advanced in northwestern China, throughout this period, but the area’s level of urbanization is still significantly lower than the average level of urbanization nationally.

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Population Dynamics Among the Totos of West Bengal: A Positive Response to Culture Contact

Journal of Biosocial Science ◽

10.1017/s0021932000014528 ◽

1983 ◽

Vol 15 (2) ◽

pp. 237-245 ◽

Cited By ~ 1

Author(s):

Debasish Sinha ◽

Bikas Chandra Pal

Keyword(s):

Population Dynamics ◽

Population Structure ◽

Death Rate ◽

Birth Rate ◽

West Bengal ◽

Positive Response ◽

Developmental Change ◽

Demographic Data ◽

Culture Contact ◽

Sex Structure

SummaryThe population structure of the Toto tribe at Totopara, a small village in West Bengal, District Jalpaiguri, was studied, for since 1951 the Totos have been coming more and more in contact with the outside world and undergoing a process of cultural and developmental change. Demographic data presented include the age-sex structure, marital status, fertility, birth rate, death rate and population growth trends in the pre-contact and contact era. At present the population shows a trend towards increase.

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How Do the Population Structure Changes of China Affect Carbon Emissions? An Empirical Study Based on Ridge Regression Analysis

Sustainability ◽

10.3390/su13063319 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3319

Author(s):

Chulin Pan ◽

Huayi Wang ◽

Hongpeng Guo ◽

Hong Pan

Keyword(s):

Population Structure ◽

Regression Analysis ◽

Population Size ◽

Carbon Emissions ◽

Ridge Regression ◽

Employment Structure ◽

Consumption Structure ◽

Structure Changes ◽

Size Population ◽

Ridge Regression Analysis

This study focuses on the impact of population structure changes on carbon emissions in China from 1995 to 2018. This paper constructs the multiple regression model and uses the ridge regression to analyze the relationship between population structure changes and carbon emissions from four aspects: population size, population age structure, population consumption structure, and population employment structure. The results showed that these four variables all had a significant impact on carbon emissions in China. The ridge regression analysis confirmed that the population size, population age structure, and population employment structure promoted the increase in carbon emissions, and their contribution ratios were 3.316%, 2.468%, 1.280%, respectively. However, the influence of population consumption structure (−0.667%) on carbon emissions was negative. The results showed that the population size had the greatest impact on carbon emissions, which was the main driving factor of carbon emissions in China. Chinese population will bring huge pressure on the environment and resources in the future. Therefore, based on the comprehensive analysis, implementing the one-child policy will help slow down China’s population growth, control the number of populations, optimize the population structure, so as to reduce carbon emissions. In terms of employment structure and consumption structure, we should strengthen policy guidance and market incentives, raising people’s low-carbon awareness, optimizing energy-consumption structure, improving energy efficiency, so as to effectively control China’s carbon emissions.

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

Brazilian Journal of Biology ◽

10.1590/1519-6984.10014 ◽

2016 ◽

Vol 76 (1) ◽

pp. 45-54 ◽

Cited By ~ 2

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.

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Legacy of draught cattle breeds of South India: Insights into population structure, genetic admixture and maternal origin

PLoS ONE ◽

10.1371/journal.pone.0246497 ◽

2021 ◽

Vol 16 (5) ◽

pp. e0246497

Author(s):

Vandana Manomohan ◽

Ramasamy Saravanan ◽

Rudolf Pichler ◽

Nagarajan Murali ◽

Karuppusamy Sivakumar ◽

...

Keyword(s):

Population Structure ◽

Population Size ◽

Effective Population Size ◽

South India ◽

Genetic Admixture ◽

Zebu Cattle ◽

Effective Population ◽

Cattle Breeds ◽

South Indian ◽

Indian Cattle

The present study is the first comprehensive report on diversity, population structure, genetic admixture and mitochondrial DNA variation in South Indian draught type zebu cattle. The diversity of South Indian cattle was moderately high. A significantly strong negative correlation coefficient of -0.674 (P<0.05) was observed between the effective population size of different breeds and their estimated FIS. The genetic structure analysis revealed the distinctness of Kangayam, Vechur and Punganur cattle from the rest of the zebu breeds. The results showed the influence of Hallikar breed in the development of most Mysore type cattle breeds of South India with the exception of Kangayam. Bayesian clustering analysis was performed to assess the taurine admixture in South Indian zebu cattle using purebred Jersey and Holstein-Friesian as reference genotypes. Relatively high levels of taurine admixture (>6.25%) was observed in Punganur, Vechur, Umblachery and Pulikulam cattle breeds. Two major maternal haplogroups, I1 and I2, typical of zebu cattle were observed, with the former being predominant than the later. The pairwise differences among the I2 haplotypes of South Indian cattle were relatively higher than West Indian (Indus valley site) zebu cattle. The results indicated the need for additional sampling and comprehensive analysis of mtDNA control region variations to unravel the probable location of origin and domestication of I2 zebu lineage. The present study also revealed major concerns on South Indian zebu cattle (i) risk of endangerment due to small effective population size and high rate of inbreeding (ii) lack of sufficient purebred zebu bulls for breeding and (iii) increasing level of taurine admixture in zebu cattle. Availability of purebred semen for artificial insemination, incorporation of genomic/molecular information to identify purebred animals and increased awareness among farmers will help to maintain breed purity, conserve and improve these important draught cattle germplasms of South India.

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Population structure of Czech cold-blooded breeds of horses

Archives Animal Breeding ◽

10.5194/aab-54-1-2011 ◽

2011 ◽

Vol 54 (1) ◽

pp. 1-9

Author(s):

L. Vostrý ◽

Z. Čapková ◽

J. Přibyl ◽

B. Hofmanová ◽

H. Vostrá Vydrová ◽

...

Keyword(s):

Population Structure ◽

Genetic Variability ◽

Population Size ◽

Effective Population Size ◽

Inbreeding Coefficient ◽

Effective Population ◽

The Czech Republic ◽

Generation Interval ◽

Average Value ◽

Inbreeding Coefficients

Abstract. In order to estimate effective population size, generation interval and the development of inbreeding coefficients (Fx) in three original breeds of cold-blooded horses kept in the Czech Republic: Silesian Noriker (SN), Noriker (N) and Czech-Moravian Belgian horse (CMB) all animals of the particular breeds born from 1990 to 2007 were analysed. The average values of generation interval between parents and their offspring were: 8.53 in SN, 8.88 in N and 8.56 in CMB. Average values of effective population size were estimated to be: 86.3 in SN, 162.3 in N and 104.4 in CMB. The average values of inbreeding coefficient were 3.13 % in SN stallions and 3.39 % in SN mares, in the N breed 1.76 % and 1.26 % and in the CMB breed 3.84 % and 3.26 % respectively. Overall averages of Fx were: 3.23 %, 1.51 % and 3.55 % for the breeds SN, N and CMB. The average value of inbreeding coefficient Fx increased by 1.22 % in SN, by 0.35 % in N and by 1.01 % in CMB, respectively. This may lead to a reduction in genetic variability. Reduction in genetic variability could be either controlled in cooperation with corresponding populations of cold-blooded breeds in other European countries or controlled by number of sires used in population

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Population dynamics of mantis shrimp Harpiosquilla harpax and Oratosquillina sp. in the waters south of Madura Island, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d210425 ◽

2020 ◽

Vol 21 (4) ◽

Author(s):

Yenni Arista ◽

ZAIRION ◽

YUSLI WARDIATNO

Keyword(s):

Population Dynamics ◽

Population Structure ◽

Life Span ◽

Fishery Resource ◽

Growth Coefficient ◽

Mantis Shrimp ◽

Exploitation Rate ◽

L Value ◽

Males And Females

Abstract. Ekalaturrahmah YAC, Zairon, Wardiatno Y. 2020. Population dynamics of mantis shrimp Harpiosquilla harpax and Oratosquillina sp. in the waters south of Madura Island, Indonesia. Biodiversitas 21: 1458-1466. Mantis shrimps are a potential fishery resource in Indonesia, but information about their population dynamics in the southern waters of Madura is limited. This study aimed to determine the population structure, growth, life span, and rate of exploitation for two taxa of mantis shrimp (Harpiosquilla harpax and Oratosquillina sp.). The research was conducted from September 2018 to February 2019 in the southern waters of Madura. The results showed that for H. harpax the majority of males caught ranged in length between 132.50 and 139.37 mm while the majority of females were between 153.45 and 160.22 mm. For Oratosquillina sp., the majority of males caught ranged from 84.70 and 89.60 mm while the majority of females were between 89.85 and 95.30 mm. The Growth Coefficient (K) for H. harpax was estimated to be 0.65 per year for males and 0.60 per year for females; while for Oratosquillina sp. the estimates were 0.81 and 0.78 per year, respectively. The L∞ value for H. harpax males was 183.00 mm and for females 250.55 mm, while the L∞ values for Oratosquillina sp. were 112.64 mm for males and 137.02 for females. The life span of H. harpax was estimated at 5 years, while for Oratosquillina sp. it was 4 years. The exploitation rate (E) for H. harpax males and females was 0.65 and 0.67 respectively, while for Oratosquillina sp. it was 0.54 and 0.58. These estimations indicated overexploitation of the resource, particularly in the case of H. harpax.

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Genetic diversity, population structure, and effective population size in two yellow bat species in south Texas

PeerJ ◽

10.7717/peerj.10348 ◽

2020 ◽

Vol 8 ◽

pp. e10348

Author(s):

Austin S. Chipps ◽

Amanda M. Hale ◽

Sara P. Weaver ◽

Dean A. Williams

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

North America ◽

Wind Energy ◽

Population Size ◽

Effective Population Size ◽

Microsatellite Loci ◽

South Texas ◽

Population Substructure ◽

Effective Population

There are increasing concerns regarding bat mortality at wind energy facilities, especially as installed capacity continues to grow. In North America, wind energy development has recently expanded into the Lower Rio Grande Valley in south Texas where bat species had not previously been exposed to wind turbines. Our study sought to characterize genetic diversity, population structure, and effective population size in Dasypterus ega and D. intermedius, two tree-roosting yellow bats native to this region and for which little is known about their population biology and seasonal movements. There was no evidence of population substructure in either species. Genetic diversity at mitochondrial and microsatellite loci was lower in these yellow bat taxa than in previously studied migratory tree bat species in North America, which may be due to the non-migratory nature of these species at our study site, the fact that our study site is located at a geographic range end for both taxa, and possibly weak ascertainment bias at microsatellite loci. Historical effective population size (NEF) was large for both species, while current estimates of Ne had upper 95% confidence limits that encompassed infinity. We found evidence of strong mitochondrial differentiation between the two putative subspecies of D. intermedius (D. i. floridanus and D. i. intermedius) which are sympatric in this region of Texas, yet little differentiation using microsatellite loci. We suggest this pattern is due to secondary contact and hybridization and possibly incomplete lineage sorting at microsatellite loci. We also found evidence of some hybridization between D. ega and D. intermedius in this region of Texas. We recommend that our data serve as a starting point for the long-term genetic monitoring of these species in order to better understand the impacts of wind-related mortality on these populations over time.

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POPULATION DYNAMICS OF SEX-DETERMINING ALLELES IN HONEY BEES AND SELF-INCOMPATIBILITY ALLELES IN PLANTS

Genetics ◽

10.1093/genetics/91.3.609 ◽

1979 ◽

Vol 91 (3) ◽

pp. 609-626 ◽

Cited By ~ 1

Author(s):

Shozo Yokoyama ◽

Masatoshi Nei

Keyword(s):

Population Dynamics ◽

Population Size ◽

Honey Bee ◽

Honey Bees ◽

Finite Population ◽

Large Population ◽

Allele Frequencies ◽

Self Incompatibility ◽

Overdominant Selection ◽

Incompatibility Alleles

ABSTRACT Mathematical theories of the population dynamics of sex-determining alleles in honey bees are developed. It is shown that in an infinitely large population the equilibrium frequency of a sex allele is l/n, where n is the number of alleles in the population, and the asymptotic rate of approach to this equilibrium is 2/(3n) per generation. Formulae for the distribution of allele frequencies and the effective and actual numbers of alleles that can be maintained in a finite population are derived by taking into account the population size and mutation rate. It is shown that the allele frequencies in a finite population may deviate considerably from l/n. Using these results, available data on the number of sex alleles in honey bee populations are discussed. It is also shown that the number of self-incompatibility alleles in plants can be studied in a much simpler way by the method used in this paper. A brief discussion about general overdominant selection is presented.

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Flood disturbance and shade stress shape the population structure of açaí palm Euterpe precatoria, the most abundant Amazon species

Botany ◽

10.1139/cjb-2019-0090 ◽

2020 ◽

Vol 98 (3) ◽

pp. 147-160

Author(s):

Heloisa Dantas Brum ◽

Alexandre F. Souza

Keyword(s):

Population Structure ◽

Population Size ◽

Size Distribution ◽

Amazon Basin ◽

Habitat Type ◽

Forest Products ◽

Life Stages ◽

Disturbance Regime ◽

Human Settlements ◽

Human Management

Euterpe precatoria Mart. is the most abundant plant species in the Amazon basin, and one of the main non-timber forest products on the continent. A thorough understanding of the ecology of this species is needed to support sustainable management initiatives. Resource availability, disturbance regime, and human management are some of the main factors influencing population structure. We described the species’ life stages, evaluated its allometric relationships, and assessed the effects of habitat type (floodplain and upland) and proximity to human settlements on population size distribution in the Central Amazon near the Purus River. The height:diameter ratio increased from Seedlings to Juvenile 2, but decreased from Juvenile 2 to Reproductive 2, indicating changing height investment for any given diameter along these life stages. There was a marked habitat dependency in both the density and population size distribution, with populations in upland forests dominated by juveniles, whereas populations in the floodplains were dominated by reproductive palms. Proximity to human settlements was not related to population structure parameters. Our results suggest that the disturbance regime may have opposite meanings in várzea forests, where it limits recruitment under increased light levels, and in terra firme forests, where it may stimulate recruitment under limited light conditions.

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