•This paper develops a framework for urban heat prevention, mitigation and adaptation.•Air-conditioning systems are the dominant cooling facility in both work and living environments.•Urban planning ...and design for heat resilient cities is the most urgent intervention.•50% of the respondents preferred collaborative payment among government, developers, and owners for heat resilient infrastructure.•Heat-related responses and actions towards urban heat challenges were dependent demographic factors and their exposure, habit formation and behavior change, social acceptance.
This study investigates public participation in heat impact reduction by analysing adaptive behaviours, familiarity with urban heat island (UHI) and cooling strategies, the perceived urgency of heat impact actions and citizen's willingness to pay through a questionnaire survey in Chongqing, China. The results indicate that air-conditioning systems are the dominant cooling facility in both work and living environments. Respondents had a moderately familiar understanding of several cooling strategies such as urban vegetation, shading devices, water-based artificial facilities, urban design for shading and ventilation and water bodies. Familiarity with innovative materials and techniques for pavements, roofs and façades was less than moderate. Urban planning and design for heat resilient cities was thought to be the most urgent intervention, followed by the establishment of temporary cooling facilities. Most respondents indicated that cost-sharing mechanisms for urban heat prevention and control systems should at least include the government, whilst 50% of the respondents preferred collaborative payment among government, developers, and owners. Only 41.6% of the interviewees expressed their willingness to pay, with a share varying between <20 and >80 RMB. A conservative estimate indicated that there could be an average payment of 45.95 RMB and 19.10 RMB among the 234 respondents who were willing to pay and all 562 respondents regardless of willingness, respectively. Respondents’ heat-related responses and actions towards urban heat challenges were dependent on a wide range of factors like gender, age, education, economic status, health, exposure, habit formation and behavior change, social acceptance, etc. Moreover, such factors could interact with each other affecting public behavior with different weights. Overall, this study increases our understanding of people's perceptions and proactiveness in reducing urban heat and provides guidance for decision-makers towards a novel user-aware approach to the implementation of urban heat prevention, adaptation, and mitigation strategies.
As the main body to promote economic development, the role of demographic structure on carbon emissions cannot be ignored. Based on data from the three national censuses in 2005, 2010 and 2015, this ...paper constructs urban-level demographic structure indicators and uses the Geographically Weighted Regression Model to study the spatial heterogeneity of demographic structure changes on carbon emissions and the corresponding mechanism at the microlevel. The results show that: (i) there was a negative correlation between household size and carbon emissions; (ii) the effects of labour ratio and dependency ratio on carbon emissions between coastal and northeastern cities are significant differences, for example, there is a significant negative relationship between labour ratio and carbon emissions in most cities in the Northeast. Overall, in most cities, the labour force ratio is positively correlated with carbon emissions, while the juvenile dependency ratio is negatively correlated with carbon emissions; (iii) demographic structure affects carbon emissions through cost mechanisms and consumption upgrade mechanism; and (iv) the medical and housing needs of the elderly are positively correlated with carbon emissions. Therefore, cities should seize the positive aspects of demographic changes. For example, policies dedicated to increasing fertility willingness in the short term are effective measures to deal with the aging population, declining birthrate and environmental challenges. It is necessary to respect the inherent laws of population development, meanwhile, based on the city's functional orientation, to cultivate differentiated leading industries, and build a green and low-carbon city through the coordinated development of population structure and employment structure.
•The spatial heterogeneity of demographic structure affects carbon emissions is investigated.•Demographic structure affects carbon emissions via cost mechanisms and consumption upgrades mechanisms.•There was a negative correlation between household size and carbon emissions.•Fertility affects carbon emissions is more pronounced in the Northeast.•The Chinese government should encourage the concentration of labor force in big cities.
This study comprehensively investigated the impacts of demographic structure on CO2 emissions in China at the national level and the regional level for the first time. Panel cointegration modeling ...was employed to test the long-run relationships between CO2 emissions and six demographic structure variables, namely, dependency ratio, sex ratio, higher education ratio, industrial employment ratio, urbanization ratio, and average household size. The fully modified ordinary least squares method was then applied to estimate the long-run elasticity of CO2 emissions for the six demographic structure variables. The results suggested that long-run relationships between CO2 emissions and demographic structure existed at both the national level and the regional level. Dependency ratio was found to exert negative effects on CO2 emissions in China and its three sub-regions. Positive associations between sex ratio and CO2 emissions were revealed to exist in China and West China, and CO2 emissions elasticity for sex ratio was relatively high in West China. Higher education ratio had a positive effect on CO2 emissions in East China. Industrial employment ratio was found to positively correlate with CO2 emissions in China, East China, and Central China. Urbanization ratio was demonstrated to increase CO2 emissions at the national level and the regional level, and CO2 emissions elasticity for urbanization ratio decreased from West China to Central China, and then to East China. Negative correlations between average household size and CO2 emissions were detected at both the national level and the regional level. Based on the findings of this study, several practical recommendations were proposed, including optimizing age structure, promoting gender equality, advocating low-carbon lifestyles and low-carbon consumption patterns, promoting industrial upgrading and industrial structure optimization, building low-carbon cities and less carbon-intensive public infrastructure systems, and improving residential energy efficiency.
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•The impacts of the demographic structure on CO2 emissions in China were estimated.•Dependency ratio and average household size had negative effects on CO2 emissions.•Urbanization ratio exerted a positive impact on CO2 emissions.•The impacts of other independent variables on CO2 emissions differed across regions.
In context of global change, biodiversity loss poses a serious problem in the Mediterranean basin. In Algeria, degradation problems (logging, deforestation, bush fires and agriculture) affect ...vegetation. Knowledge of vegetation characteristics is necessary to manage disturbed areas. That is why this study focused on demographic structure of main species of Ouled Bechih forest (Quercus canariensis and Quercus suber). On eight plots representing this forest of 900 m2, chosen at random, dendrometric and phytosociological parameters are collected. Results obtained reveal a total specific richness of 41 species. Principal families are Asteraceae (21.95%) and Fabaceae (7.32%). Average woody density is 154 individuals/ha with an average basal area of 27.33 m2/ha. Variance analysis shows that there is a high significant difference between the dendrometric parameters (p<0.001). Diameter and height structures are consistent with Weibull distribution. These structures indicate that trees are moderately stable with predominance of large diameter individuals. Results obtained will allow monitoring the vegetation dynamics and will help foresters to put in place a management plan to preserve this forest.
Purpose: The aim of this study is to examine the long-run and short-run impact of demographic structure and human capital on the economic growth of Turkey.
Theoretical framework: The shift in ...demographic dividend which witness shifts in age structures, have led to positive prospects, which have resulted in the decline in rate of births leading to a decline in a country’s young dependent group, and subsequently caused an increase in the percentage of the workforce working-age numbers. In the past few decades, there has been a noticeable substantial shift in the population structure with regard to the percentage of the cohort of working age population in Turkey that could have consequences on the economy.
Design/Methodology/Approach: The annual time series data of Turkey for the time period 1990 to 2020 was employed through the utilization of Autoregressive Distributed Lag (ARDL) model to investigate the association between the demographic structure, human capital and economic growth.
Findings: The results revealed that variations in the age structure, as manifested by the variations in the age cohorts of the working-age population, possess substantial favorable impacts on economic growth in the short and long run. The research also revealed that human capital impacts on economic growth in a positive way in the short run.
Research, practical & social implications: The study revealed that there is a substantial shift in the population fabric in Turkey. The ongoing changes that have transpired relatively rapidly might have significant economic consequences for the country in the future. Hence, it is therefore recommended that Turkey acquire demographic and economic measures which will stimulate the population to be intensively involved in the workforce. This is to garner the gains of demographic and educational returns as a major method towards the attainment of a high level of economic growth.
Originality/Value: This study utilizes working age population more broadly than most of the literature, using disaggregated age groups based on age. The key motivation for this is to ascertain the role of each age group, and its effect on economic growth.
We propose and study an epidemiological model on a social network that takes into account heterogeneity of the population and different vaccination strategies. In particular, we study how the ...COVID-19 epidemics evolves and how it is contained by different vaccination scenarios by taking into account data showing that older people, as well as individuals with comorbidities and poor metabolic health, and people coming from economically depressed areas with lower quality of life in general, are more likely to develop severe COVID-19 symptoms, and quicker loss of immunity and are therefore more prone to reinfection. Our results reveal that the structure and the spatial arrangement of subpopulations are important epidemiological determinants. In a healthier society the disease spreads more rapidly but the consequences are less disastrous as in a society with more prevalent chronic comorbidities. If individuals with poor health are segregated within one community, the epidemic outcome is less favorable. Moreover, we show that, contrary to currently widely adopted vaccination policies, prioritizing elderly and other higher-risk groups is beneficial only if the supply of vaccine is high. If, however, the vaccination availability is limited, and if the demographic distribution across the social network is homogeneous, better epidemic outcomes are achieved if healthy people are vaccinated first. Only when higher-risk groups are segregated, like in elderly homes, their prioritization will lead to lower COVID-19 related deaths. Accordingly, young and healthy individuals should view vaccine uptake as not only protecting them, but perhaps even more so protecting the more vulnerable socio-demographic groups.
Rached-Kanouni M, Hani I, Bousba R, Beldjazia A, Khammar H. 2020. Structural variability of Aleppo pine stands in two forests in northeastern Algeria. Biodiversitas 21: 2848-2853. The layout of the ...stand can be described as the width of the trees, their reciprocal locations, diametric distinction and height. The goal of this study is to recognize changes in the Pinus halepensis spatial and demographic systems in two Beni Oudjana and Chettaba Forests, located in northeast Algeria. An inventory of trees in these forest formations with P. halepensis dominance was carried out based on dendrometric parameters such as total height, tree diameter at dbh ≥ 5 cm, basal area, total volume, etc., as well as the number of trees in the forest. Tree diameter and height measurements were made on 12 rectangular plots (20 m × 20 m), located in both forests. The results obtained show that the mean stand density, mean diameter, basal area and total volume are higher in Chettaba Forest, the values attributed to these parameters are respectively (422 trees/ha, 27.07 cm, 26, 86 m2, 251.63 m3); while the total height and regeneration rate show significantly higher values in Beni Oudjana Forest (18.97 m, 607 individuals/ha). The structure in diameter and height of the species is bell-shaped to asymmetrically positive with a predominance of small diameter individuals in the Chettaba forest. On the other hand, in the Beni Oudjana Forest, the structure is ‘L’ shaped, showing a predominance of very small diameter individuals. These results indicate that the low regeneration rate of P. halepensis in the Chettaba Forest is due to anthropogenic pressures that favor the degradation of this forest.
Many species exhibit selective foraging behaviour, where consumers use a nonrandom subset of available food types. Yet little is known about how selective foraging behaviour varies with environmental ...conditions and the community level consequences of such selection dynamics. We examined selective foraging by wolves preying primarily on elk in Yellowstone National Park (YNP) over a 12-year period and on moose in Isle Royale National Park (IRNP) over a 47-year period. Specifically, we assessed how selection for calves and senescent adults varied with their frequency in the environment, wolf abundance and winter severity. Selection for senescent adults decreased as the relative abundance of senescent prey increased (i.e. negative frequency-dependent selection) in both study sites. In IRNP, selection for calves was also negatively frequency dependent and declined with increasing wolf abundance. These results are inconsistent with the pattern of positive frequency-dependent selection expected under the prey-switching hypothesis. These results suggest that selection is primarily driven by intraspecific differences in prey vulnerability and wolves’ interest in minimizing their risk of injury, as opposed to maximizing intake rates. Lastly, we ran simulations to evaluate how predator–prey dynamics were influenced by dynamic patterns of selection, like those observed in YNP and IRNP. The simulations indicated that predators are more efficient (i.e. steeper slope of the numerical response) when selection for calves is negatively frequency dependent, which results in a lower mean abundance of prey. More importantly, predation is a stronger destabilizing force when selection for calves is negatively frequency dependent. That stronger destabilizing force is indicated by greater variability in the abundance of prey and predators, prey populations being less resilient and a steeper negative slope of the relationship between predation rate and prey population growth rate. As such, our simulation analyses suggest that some of the observed patterns of negative-frequency dependent selection may have important consequences for predator–prey dynamics.
•Wolves showed negative frequency-dependent selection for calves and senescent prey.•Wolves did not exhibit prey-switching behaviour when preferred prey became rare.•Selection is likely driven by the predator's interest to reduce their risk of injury.•Selection for calves may result in more efficient predators and less resilient prey.
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