Rate Of Population Change Research Articles

The Impact of Population Shrinkage on Economic Resilience in Mountain Cities: A Case Study of Guizhou Province, China

With the recent changes in population structure and continuous urbanization, the degree of population shrinkage in mountain cities has increased, especially under the impact of the COVID-19 epidemic, and the economic development of such mountain cities has become a prominent issue. The epidemic has not only exposed the vulnerability of these cities to economic development but also aggravated the negative impact of population contraction, bringing about new challenges and pressures related to regional population development and economic resilience. This change has become an important topic in the study of mountain cities. Therefore, taking Guizhou Province as a case study, this work applies the population change rate, the entropy method, and a mediation effect model to study the spatiotemporal evolution of population shrinkage and economic resilience, and it explores how population shrinkage influences economic resilience. The results reveal the following: (1) Few counties experienced population shrinkage in Guizhou Province from 2013 to 2017, indicating a sporadic distribution pattern, whereas the degree of population shrinkage increased rapidly from 2018 to 2022, revealing an east–west symmetrical distribution pattern, with Guiyang city located on the central axis. (2) There are significant regional differences in the spatial distribution of the level of economic resilience between the two periods. Under the impact of COVID-19, from 2019 to 2022, although the overall level of economic resilience increased, the level of resilience in most counties tended to decrease. (3) Regarding the mediating effect, population shrinkage affected the level of economic resilience through general public budget expenditure, foreign trade investment, new urban employment, and GDP. The abovementioned findings are helpful for providing theoretical support and empirical guidance for the sustainable development of mountain cities in the face of population contraction, economic challenges, and promoting regional coordination.

Effects of industrial pollution and ambient air temperature on larval performance and population dynamics of Eriocrania leafminers (Lepidoptera)

Pollution is an integral part of global environmental change, yet the combined and interactive effects of pollution and climate on terrestrial ecosystems remain inadequately understood. This study aims to explore whether pollution alters the impacts of ambient air temperature on the population dynamics of herbivorous insects. Between 1995 and 2005, we studied populations of two closely related moths, Eriocrania semipurpurella and E. sangii, at eight sites located 1 to 64 km from a large copper‑nickel smelter in Monchegorsk, Russia. We found that pollution and temperature influence the performance of Eriocrania larvae mining in the leaves of mountain birch, Betula pubescens var. pumila, through multiple pathways. This is evident from the unconsistent changes observed in larval and frass weight, mine area, and leaf size. We found increases in both leaf quality and larval weight with decreasing pollution levels at both spatial and temporal scales and attributed these to the impact of sulphur dioxide, rather than trace elements (nickel and copper). The quality of birch leaves increased with spring (May) temperatures, enabling Eriocrania larvae to achieve greater weight while consuming less biomass. During the larval growth period (early June to early July), Eriocrania larvae increased their consumption with rising temperatures, presumably to compensate for increased metabolic expenses. Contrary to our expectations, the per capita rate of population change did not correlate with larval weight and did not vary along the pollution gradient. Nevertheless, we detected interactive effects of pollution and climate on the rate of population change. This rate decreased with rising winter temperatures in slightly polluted and unpolluted sites but remained unchanged in heavily polluted sites. We conclude that pollution disrupts mechanisms regulating the natural population dynamics of Eriocrania moths.

Automated Geospatial Approach for Assessing SDG Indicator 11.3.1: A Multi-Level Evaluation of Urban Land Use Expansion across Africa

Geospatial data has proven useful for monitoring urbanization and guiding sustainable development in rapidly urbanizing regions. The United Nations’ (UN) Sustainable Development Goal (SDG) Indicator 11.3.1 leverages geospatial data to estimate rates of urban land and population change, providing insight on urban land use expansion patterns and thereby informing sustainable urbanization initiatives (i.e., SDG 11). Our work enhances a UN proposed delineation method by integrating various open-source datasets and tools (e.g., OpenStreetMap and openrouteservice) and advanced geospatial analysis techniques to automate the delineation of individual functional urban agglomerations across a country and, subsequently, calculate SDG Indicator 11.3.1 and related metrics for each. We applied our automated geospatial approach to three rapidly urbanizing countries in Africa: Ethiopia, Nigeria, and South Africa, to conduct multi-level examinations of urban land use expansion, including identifying hotspots of SDG Indicator 11.3.1 where the percentage growth of urban land was greater than that of the urban population. The urban agglomerations of Ethiopia, Nigeria, and South Africa displayed a 73%, 14%, and 5% increase in developed land area from 2016 to 2020, respectively, with new urban development being of an outward type in Ethiopia and an infill type in Nigeria and South Africa. On average, Ethiopia’s urban agglomerations displayed the highest SDG Indicator 11.3.1 values across urban agglomerations, followed by those of South Africa and Nigeria, and secondary cities of interest coinciding as SDG Indicator 11.3.1 hotspots included Mekelle, Ethiopia; Benin City, Nigeria; and Polokwane, South Africa. The work presented in this study contributes to knowledge of urban land use expansion patterns in Ethiopia, Nigeria, and South Africa, and our approach demonstrates effectiveness for multi-level evaluations of urban land expansion according to SDG Indicator 11.3.1 across urbanizing countries.

Geographic principles applied to population dynamics: A spatially interpolated integrated population model

Abstract A major impediment to wildlife conservation and management, from a quantitative perspective, is dealing with high degrees of uncertainty associated with population estimates. Integrated population models (IPMs) can help alleviate that challenge, but they are often limited to narrow spatial or temporal windows owing to the financial and logistical burdens of acquiring requisite datasets. To expand the spatiotemporal scope of practical IPM implementation, we developed a novel method that expresses demographic relatedness among sampled and unsampled locations using geographic principles of spatial autocorrelation. We interpolated demographic parameters at unsampled locations using parameter estimates from data‐informed locations. Errors attributable to the interpolative process were corrected using a joint likelihood and locally recorded count data (‘cheaper’ and broadly distributed). We evaluated the spatially interpolated IPM (SIIPM) for precision and accuracy under variable levels of spatial autocorrelation using simulated data and a Leave‐One‐Out Cross‐Validation (LOOCV) technique. Conventional IPMs and state‐space models (SSM) were fit to the same simulated datasets to provide a comparative assessment of the novel method. In a final, empirical demonstration we fit the SIIPM to data collected from Greater Sage‐Grouse (Centrocercus urophasianus; sage‐grouse) populations located in Nevada, U.S.A. during 2013–2021. SIIPMs outperformed conventional IPMs when fit to data possessing moderate‐to‐high levels of spatial autocorrelation. Under moderate levels of autocorrelation, the average improvement in parameter estimation was 13.6% for survival, 65.3% for recruitment and 23.7% for rate of population change (). When spatial autocorrelation was low, the SIIPM still outperformed contemporary approaches in areas that were geographically close (<67 km) to sampling locations. Under low autocorrelation‐near distance scenarios, we observed SIIPM parameters that were 30.8% (recruitment), 32.5% (; IPM comparison) and 54.0% (; SSM comparison) more precise than contemporary models. Spatial autocorrelation is often assumed but rarely tested when comparing population dynamics across regions of large geographic extent. We demonstrated that SIIPMs can improve precision of species' vital rate estimation when extrapolating model inference beyond populations for which long‐term monitoring data exists. Specific to sage‐grouse, these results support previous conclusions of broad‐scale spatial autocorrelation in population dynamics and a reproductive‐survival trade‐off previously documented at smaller scales.

The population trend of the largest breeding colony of the Indian Swiftlet Aerodramus unicolor: is it on the verge of extinction?

Fluctuations in animal populations are indicators of environmental change. Populations of the Indian Swiftlet Aerodramus unicolor on the Burnt and Old Lighthouse islands of Vengurla rocks, Sindhudurg district, Maharashtra were assessed using the logistic growth model. The study used secondary literature and primary surveys to estimate breeding population sizes on both islands. To understand population dynamics, we calculated the carrying capacity (K) using the Verhulst population growth model, and the percent rate of change in populations. Swiftlet populations on both islands are considered to be the maximum size their habitat can sustain, not exceeding 5,000 and 246 birds on Burnt and Old Lighthouse islands, respectively. These populations were observed to fluctuate between 2020 and 2023, with change rates of 5.5% on Burnt Island, and -53% on Old Lighthouse Island. The logistic growth model indicates that these Indian Swiftlet populations are fluctuating near the carrying capacities of their habitats, which could gradually lead to extinction. This highlights the urgent need for conservation and regular monitoring of these populations in Vengurla rocks.

A Nonlinear ODE Model for a Consumeristic Society

In this paper, we introduce an ODE system to model the interaction between natural resources and human exploitation in a rich consumeristic society. In this model, the rate of change in population depends on wealth per capita, and the rate of consumption has a quadratic growth with respect to population and wealth. We distinguish between renewable and non-renewable resources, and we introduce a replenishment term for non-renewable resources. We first obtain some information on the asymptotic behavior of wealth and population, then we compute all system equilibria and study their stability when the resource exploitation parameter is low. Some numerical simulations confirm the theoretical results and suggest directions for future research.

The Local Regression Approach as a Tool to Improve Place-Based Policies: The Case of Molise (Southern Italy)

The implementation of place-based policies entails the construction of intervention areas (spatially contiguous areas in which the policies are adopted). Many approaches can be adopted for the definition of such areas. This paper reflects on the use of geographically weighted regression (GWR) models as a tool capable of supporting the definition process. The case study concerns Molise, a region in Southern Italy particularly affected by persistent and deep-rooted processes of depopulation. The dependent variable is the average annual rate of population change of municipalities of Molise across the 2011–2019. The independent variables are related to socio-economic profiles of each municipality. The results, contextualised using a broad overview of the Italian case, show that a key variable in the demographic dynamics of the municipalities of Molise is the labour market activity rate of women and that this variable drives a spatial instability that cannot be detected using global approaches and models. This proves the urgent need to expand the use of local thinking for the benefit of both applied demography and society.

How Do Population Changes and Land Use Policies Affect the Relationship between the Urban Economy and Public Services?

In recent years, an increasing number of Chinese cities have experienced population decline, impacting the urban economy, public services, and paid use of state-owned land (PUL). This paper employs a coupled coordination degree model and the gray correlation coefficient method to examine the relationship between the rate of population change from 1990 to 2020, the rate of PUL change from 2000 to 2020, and the coupled coordination of economy and public services. The study arrives at several conclusions: (1) Cities with declining populations exhibit a lower PUL rate than those without population shrinkage, indicating reduced activity in the land market. (2) Population growth plays a significant role in the coordinated development of the urban economy and public services, fostering urbanization. (3) The economy and public services in shrinking cities rely heavily on revenue generated from the transfer of PUL rights to support their coordinated development. This research provides an insightful comparison between shrinking and non-shrinking cities by integrating the unique compensated land transfer system in China with the critical variable of population change.

Spatial and temporal evolution of habitat quality and its shrinkage effect in shrinking cities: Evidence from Northeast China

Continued population loss in the context of urban shrinkage has led to the transformation and reconfiguration of urban land use space, which in turn has had a major impact on regional habitats and ecosystem services. To explore the status of habitat quality (HQ) in shrinking cities, based on land use data from 2010 to 2020, this study uses the InVEST model to analyze the spatiotemporal characteristics of HQ in shrinking cities. Then, we reveal the shrinkage effect of HQ in shrinking cities from the perspective of population change rate, and detect the dominant influencing factors of HQ in different types of shrinking cities with the help of geographical detector. The results show that:(1) From 2010 to 2020, the primary land use types in both shrinking and non-shrinking cities of the three northeastern provinces were forestland and cropland. However, there were significant differences in the area of construction land between the two categories of cities. (2) The HQ in both shrinking and non-shrinking cities showed a declining trend, yet the HQ index of shrinking cities was higher than that of non-shrinking cities. (3) The distribution of HQ in shrinking cities has a significant shrinkage effect, and HQ index gradually strengthens as urban shrinkage intensifies. Low-quality habitats have a strong distributional advantage in slightly shrinking cities, while severely shrinking cities tend to be dominated by high-quality habitats. (4) Population profile, economic development, industrial structure and built environment are important factors influencing the spatial heterogeneity of HQ in shrinking cities. However, the spatial determinants of HQ vary significantly among different types of shrinking cities in terms of dimensions and indicators, with two-factor interactions exerting a stronger influence than single-factor impacts. Based on the findings of this study, the government can formulate differentiated habitat protection measures, dynamically adjust, and optimize them according to the distribution characteristics of HQ grades in shrinking cities.

Adaptation and establishment of Habrobracon hebetor Say in the population of stored moths pests of date, Ephestia kuehniella Zeller and Plodia interpunctella Hübner

BackgroundHabrobracon hebetor (Hymenoptera: Braconidae) is a larval ectoparasitoid, mainly of pyralid moths of the stored pests of date, Plodia interpunctella Hübner and Ephestia kuehniella Zeller. It has some suitable characteristics for use in biological control of stored moth pests. The aim of this study was to compare the ability of H. hebetor establishment in the population of two important date storage moth pests P. interpunctella and E. kuehniella, and its role in their population fluctuations.ResultsThe population growth trends of two host species increased in the first 6 weeks and in the 17th to 22nd weeks of the 6-month period of conducting tests. The peaks of larval population of the two species were in the 10th and 21st weeks under temperature of 25 ± 2 °C, RH of 60 ± 5% and a photoperiod of 12:12, D:L. The pattern of fluctuation in the parasitism percentage in the larval population of the two moth species host was inconsistent with each other. The parasitism percentage was higher on the larval population of E. kuehniella than larval population of P. interpunctella. In E. kuehniella, the host population change rates were − 0.1 in the 10th and 15th weeks, while the highest rates were 0.1 and 0.8 in the 12th and 3rd weeks. The lowest level of parasitoid balance in the larval population of E. kuehniella and P. interpunctella was recorded in the 11th and 15th weeks, and the highest levels were recorded in the 20th and 24th weeks, respectively. The maximum probability rate of parasitoid non-establishment in E. kuehniella larval population was zero during the entire period and for P. interpunctella until the 22nd week.ConclusionIn fact, there was a strong correlation between establishment success and the severity of host and parasitoid populations. Only in the larval population of P. interpunctella, the maximum probability of failure of establishment was 11.5%, due to the occurrence of the maximum population of parasitized larvae and the minimum ratio of non-parasitic and parasitic larvae.

Diminishing numbers of male southern elephant seals (Mirounga leonina Pinnipedia: Phocidae, Linnaeus, 1758) at the Vestfold Hills, East Antarctica (1957–2022)

Abstract A proportion of the southern elephant seal (Mirounga leonina) population that breeds in the Kerguelen Plateau region seasonally migrates between their natal sub-Antarctic islands and moult haul-out locations on the Antarctic coastline. Analyses of survey data collated for one moult location at the Vestfold Hills, East Antarctica, showed that there had been no appreciable change in the timing (phenology) of maximum seal arrivals between 1974 and 2022; however, the maximum number of seals moulting at that site had declined by ~90% over the same time interval. Spatial analyses showed rates of population change were survey area dependent, as seal numbers decreased most rapidly at haul-out areas closest to the permanently occupied Davis Station, suggesting that a relationship exists between seal numbers and human activities. The range of potential factors that contribute to population change for southern elephant seals moulting at the Vestfold Hills includes changes in status at primary source populations, one of which has not been surveyed since the 1990s, and species relocation. Should numbers of southern elephant seals in the Vestfold Hills continue to decrease at the current average rate of change (-7.78 seals/year) the species could vanish from the area by c. 2040.

Bolivian River Dolphin trends: A long-term analysis in the Mamore basin.

South American river dolphins face significant threats from intense human activities, resulting in habitat loss, fragmentation of their natural connectivity, overfishing, pollution, and incidental and intentional catches for use as bait for fisheries. From 1998 to 2022, 12 surveys were conducted in a river system in the Mamore River (Ibare-Tijamuchi-Mamore) basin, one of the primary distribution areas of the Bolivian river dolphin (BRD - Inia geoffrensis boliviensis). Generalized linear models (GLMs) were used to assess population trends. The most supported model does not definitively indicate a decline in population. The estimated mean annual rate of population change for BRDs over the 24-year monitoring period was -0.0115 per year. The average count of BRDs in the Ibare River is lower (mean = 20, n = 4) compared to the mean of Tijamuchi (mean = 260, n = 4), and the same pattern is observed with the Mamore River (mean = 76, n = 4). There is tentative visual evidence of negative trend for the count of BRD based on the GLM curves, but the statistics are still inconclusive to the sub-basin of the Mamore River. This study highlights the importance of continue with monitoring efforts on river dolphin populations. Similar population dynamics are observed in other river dolphin species in the Amazon region, requiring immediate actions to reduce mortality and reverse the concerning decreasing trend exhibited by these populations.

Municipal solid waste (MSW) under the population shrinking and aging: Spatio-temporal patterns, driving forces, and the impact of smart city development

The phenomenon of shrinking and aging populations has profound implications for socioeconomic sustainability and presents unique challenges for managing municipal solid waste (MSW). These challenges have yet to be comprehensively understood thus far. In this study, we focus on the Circum-Bohai-Sea area in China (CBS) to investigate the spatiotemporal patterns of MSW generation under the population shrinking and aging. Results showed that the MSW growth rate reduced from 3.2% (2011–2015) to 1.6% (2016–2020) with population shrinking and aging. Geographical and temporal weighted regression (GTWR) revealed that disposable personal income and total population are the predominant drivers of MSW growth. In contrast, the population change rate and the proportion of elderly were the key factors for MSW reduction. Urban MSW reduction exhibited higher sensitivity to population shrinking, resulting in a 141.6% greater reduction compared to rural MSW for every 1% population shrinking. Conversely, rural MSW reduction displayed a greater response to population aging, with a 19.7% reduction more than urban MSW for every 1% increase in the proportion of the elderly. Based on scenario analysis, the smart city development will curb population shrinking (7.6%), while increasing the well-being, life expectancy, and population share of the elderly (3.4%). Future population shrinking and aging is expected to contribute to the growth of MSW, and this trend is further amplified by the development of smart city. However, smart city development led to MSW reduction overall with an MSW amount of 76.8 Mt (7.5% lower than in the business-as-usual scenario) by 2040, mainly attributed to smart sanitation technology. This study offers valuable insights for decision-makers in MSW management, not only in China but also for other countries grappling with population regression challenges.

Demographics of Palmer amaranth (Amaranthus palmeri) in annual and perennial cover crops

AbstractPalmer amaranth (Amaranthus palmeri S. Watson) is the most problematic weed of cotton (Gossypium hirsutum L.)-cropping systems in the U.S. Southeast. Heavy reliance on herbicides has selected for resistance to multiple herbicide mechanisms of action. Effective management of this weed may require the integration of cultural practices that limit germination, establishment, and growth. Cover crops have been promoted as a cultural practice that targets these processes. We conducted a 2-yr study in Georgia, USA, to measure the effects of two annual cover crops (cereal rye [Secale cereale L.] and crimson clover [Trifolium incarnatum L.]), a perennial living mulch (‘Durana®’ white clover [Trifolium repens L.]), and a bare ground control on A. palmeri population dynamics. The study was conducted in the absence of herbicides. Growth stages were integrated into a basic demographic model to evaluate differences in population trajectories. Cereal rye and living mulch treatments suppressed weed seedling recruitment (seedlings seed−1) 19.2 and 13 times and 12 and 25 times more than the bare ground control, respectively. Low recruitment was correlated positively with low light transmission (photosynthetic active radiation: above canopy photosynthetically active radiation [PAR]/below cover crop PAR) at the soil surface. Low recruitment rates were also negatively correlated with high survival rates. Greater survival rates and reduced adult plant densities resulted in greater biomass (g plant−1) and fecundity (seeds plant−1) in cereal rye and living mulch treatments in both years. The annual rate of population change (seeds seed−1) was equivalent across all treatments in the first year but was greater in the living mulch treatment in the second year. Our results highlight the potential of annual cover crops and living mulches for suppressing A. palmeri seedling recruitment and would be valuable tools as part of an integrated weed management strategy.

The Exclusiveness of Smart Cities—Myth or Reality? Comparative Analysis of Selected Economic and Demographic Conditions of Polish Cities

The Smart City concept is perceived as a method of dynamic development of cities and an opportunity to improve the quality of life of the urban community. Nevertheless, it is not without its disadvantages, among which the possibility of exclusion (economic, social or digital) is most often mentioned. However, the literature on the subject lacks empirical research verifying this allegation. For this reason, the purpose of this article is to conduct a comparative analysis of economic and social conditions in 17 Polish cities, 3 of which are recognized as Smart Cities in international rankings. By analyzing the economic and demographic conditions in the long term, an attempt is made to answer the question of whether Smart Cities offer better living conditions, and if so, how big is the imbalance and the risk of excluding other cities? In the course of the research, the following are taken into account: tax revenue per capita, unemployment rate, population density and level, as well as the share of working and post-working age population. These parameters are analyzed using descriptive statistics and systematized using multi-criteria analysis. The collective comparison of all the surveyed provincial cities shows that the best economic and demographic conditions apply to cities recognized as smart. The average annual rate of changes in tax revenues in the surveyed cities ranges from 5% to almost 8% and is the highest in Warsaw, Kraków and Wrocław. These cities are also characterized by the lowest unemployment rate, ranging from 3% to 4% (in other cities, from 4% to almost 7%). The mentioned cities and Gdańsk are the only ones with a positive rate of population change (from 0.62% to 1.08%). Other studied cities are systematically depopulating (annual rate of change from −0.37% to −7.09%). In Warsaw, Wrocław and Kraków, the share of the working-age population is also decreasing the slowest (the annual rate of change below −1.0%). The cities recognized as smart (Warsaw, Kraków and Wrocław) are matched by Gdańsk and Poznań, which can be considered strong contenders for being smart. Unfortunately, the remaining cities are far from the leaders of the ranking, which may expose them to economic and social exclusion, all the more so that the parameters examined in them are characterized by negative tendencies. It can, therefore, be concluded that striving to be smart can be a cause of increasing the economic and demographic distance. Therefore, it may increase unbalance and generate exclusion in the analyzed areas.

THE AVIAN SONG OVER TIME: VARIABILITY AND STABILITY

Information is reviewed on the dynamics of bird singing over time, analyzing the rate of change in individual and population repertoires, and considering the factors affecting the rate of such changes. The available data indicate very significant periods of persistence of vocal patterns (song types) in songbird populations. The rate of change in population and individual repertoires is higher in species with an unlimited period of imprinting a song compared to species with a fixed period. The population repertoire of song types in numerous populations inhabiting vast and continuous habitats is more stable than in small and isolated populations occupying structurally fragmented habitats. The most common vocal patterns are the most conserved from year to year, while rare variants often disappear from the population repertoire over time. Abnormal climatic phenomena that cause significant changes in the age composition of populations contribute to rapid changes of dialects. The cases of rapid synchronous changes in vocal repertoires in individuals in local populations, as well as in populations separated from each other by a great distance, are considered in detail. The causes that give rise to this need further research. The most likely reasons may be an exchange of vocal models at wintering grounds or the simultaneous introduction of a large number of migrants into the study populations, which in species with an open training period may cause changes in the repertoire of local individuals also borrowing new vocal models.

Temporal patterns of the burden of Alzheimer's disease and their association with Sociodemographic Index in countries with varying rates of aging 1990-2019.

To we examine the temporal patterns of the burden of Alzheimer's disease and their association with Sociodemographic Index in countries with varying rates of aging. Data were obtained from Global Burden of Diseases studies (GBD) 2019 and were used to compare countries with different rates of change in aging population from 1990 to 2019. We collected the data of the age-standardized rates per 100,000 of disability-adjusted life years (DALYs), incidence, prevalence of Alzheimer's disease and other dementias, and the age-specific population rates per 100,000. Countries with high rates of change in their aging populations had an increase in DALYs, incidence, and prevalence of Alzheimer's disease and other dementias over the last 30 years. Countries with a high rate of change in aging population had a significantly positive association among DALYs, incidence, and prevalence of Alzheimer's disease and other dementias. In contrast, countries with a medium and low rate of change in aging population had negative associations between DALYs and incidence of Alzheimer's disease and other dementias. This study highlights the significant impact of demographic changes on the burden, prevalence, and incidence of Alzheimer's disease and other dementia. The study also found that robust health care and social systems, as reflected by a higher Sociodemographic Index, can contribute to reducing the burden of Alzheimer's disease and other dementias in medium to low rates of aging populations. The findings underscore the importance of investing in health care and social systems to address the growing burden of these conditions, especially in countries with a high rate of change in the aging population.

Identification and Classification of Urban Shrinkage in Northeast China

The phenomenon of shrinking cities is a significant challenge faced by many cities today. To more accurately identify the leading factors driving urban shrinkage and develop rational recommendations, precise identification and classification of urban shrinkage has become an indispensable part of the process. This paper focuses on the typical population loss region of China’s three northeastern provinces, using 497 identified physical cities as the basic research unit. Based on multi-source geographical big data and utilizing the geographically weighted regression (GWR) model, spatial modeling of population in the three provinces of northeast China was conducted, resulting in spatialized population data, followed by identification and classification of shrinking cities among the physical cities. Cities with a total population change rate of less than 0 are defined as shrinking cities. In cities where the total population change rate is greater than 0, cities with both a city shrinking area ratio and a decreased population ratio greater than 5% are defined as locally shrinking cities. Based on this, 90 (18.1%) shrinking cities and 118 (23.7%) locally shrinking cities were identified within the three provinces of northeast China. The phenomenon of urban shrinkage is distributed throughout various regions, mainly in smaller cities located near larger cities. According to the standards of the urban shrinkage classification model, the spatial pattern of population loss regions was divided into four types, identifying 13 (6.3%) global type, 111 (53.4%) concentrated type, 64 (30.7%) perforated type, and 20 (9.6%) edge type. Analysis of shrinking cities based on their classification revealed that the main reasons for urban shrinkage are the decline and dissolution of large industrial enterprises, abandonment and neglect of buildings, and unreasonable design planning in cities. Economic development and inward population flow can be promoted in shrinking cities by creating job opportunities, improving living standards, developing transportation, adjusting urban planning or concentrating urban population, as well as vigorously developing urban center areas. These measures can provide support for the revival and development of shrinking cities.

Single-industry towns: Grouping and identification of factors influencing the demographic situation

Subject. This article considers single-industry towns of the Russian Federation as specific settlements. Objectives. The article aims to analyze the distribution of single-industry towns by category for 2014–2022, and model the rate of population change in single-industry towns. Methods. For the study, we used statistical, regression, and comparative analyses. Results. The article finds that social and economic factors, as well as the distance from a single-industry town to the capital of the region, affect the population growth of single-industry towns. Conclusions. The results of the study can be taken into account by government agencies when designing a strategy for the development of single-industry towns.

Change in monarch winter abundance over the past decade: A Red List perspective

Abstract Assessing invertebrate species for the IUCN Red List under Criterion A frequently involves fitting an appropriate statistical model to available abundance data and calculating a 10‐year change (TYC) estimate from predicted abundances. When the rate of change has not been constant across the entire time series, models that accommodate variable change rates are recommended. The monarch butterfly (Danaus plexippus) was recently added to the IUCN Red List (A2ab Endangered) based on analysis of data on winter abundances in Mexico and the western USA between 1993 and 2020. TYC estimates in the monarch assessment came from models that assumed constant change rates. We conducted a Bayesian analysis of the same data using models that accommodated variable change rates and used those models to compute TYC estimates. Our results suggested that monarch population change rates have not been constant over the study period. The analysis yielded a model‐averaged TYC estimate of +5.23%, which was not statistically distinguishable from 0% and was considerably different from values of −46% and −72% in the assessment. The Bayesian posterior probability of a TYC value below −30% (A2ab Vulnerable) was 0.15 and that of a TYC value below −50% (A2ab Endangered) was 0.03. We recommend that researchers evaluating monarch conservation status consider using abundance models with variable change rates, as models with constant change rates may not accurately predict the trajectory of monarch abundances into the future.