Population Change Index Research Articles

The Future Process of Japan’s Population Aging: A Cluster Analysis Using Small Area Population Projection Data

Japan’s population aging is the most advanced in the world today. No nationwide study has been conducted using small area population projection data on Japan’s aging population. This is because such projection data was unavailable for Japan before the 2016 launch of the website ‘The Web System of Small Area Population Projections for the Whole Japan’ (SAPP for Japan). SAPP for Japan opened the small-area and long-term projected population of Japan for the first time on the World Wide Web. The purpose of this study is to quantitatively analyze the future aging process using data from the SAPP for Japan and, based on this analysis, to attempt to present the standard aging process that developed countries will experience after the demographic transition, taking advantage of the fact that Japan has the most aged population in the world. Subsequently, a non-hierarchical cluster analysis was performed using two statistics on aging: the elderly population proportion and the elderly population change index, and the small areas were classified into seven clusters. Furthermore, this study examined the demographic and geographical features of the clusters, introduced a new concept of the stage in the population aging process, and analyzed the relationship between the features and the stages. To conclude, the following findings were obtained regarding the future process of Japan’s population aging. In each area of Japan, first, the total population begins to decline, second, the elderly population begins to decrease, and finally, its proportion begins to decrease. These stage shifts generally proceed earlier in areas with a higher elderly population proportion and are attributed to the reduced size of younger cohorts owing to long-term fertility decline. This process would be the norm in many developed countries after the demographic transition.

Features of the population settlement system in the regions of the China – Mongolia – Russia economic corridor

The article presents an analysis of the existing objective conditions and patterns of population distribution on the territory of the China – Mongolia – Russia economic corridor. The study area covers the Inner Mongolia Autonomous Region of China (Inner Mongolia), the central aimags of Mongolia and the Baikal region (Russia). The settlement system of adjacent regions is highly differentiated in terms of natural and geographical conditions, the level of production development, socioeconomic development, and the state of infrastructure. The average population density of the study area is 10.1 people per km2: there are relatively low indicators in the Baikal region, 2.8 people per km2; 4.2 people per km2 are in the central regions of Mongolia, and 21.2 people per km2 are in Inner Mongolia. The highest population density is observed in areas where highways and railways pass. During the period under review (from 2000 to 2018), the indices of population change in adjacent regions amounted to 93.7% in Russia, 129.0% in Mongolia and 106.7% in China. In the study regions, the population lives mainly in cities and large settlements. In the Baikal region, the level of urbanization is 68.6%, in Mongolia – 67.8% and in Inner Mongolia – 62.7%. The growth of cities is mainly due to internal migration, especially in the Russian and Mongolian territories; the process of depopulation of the countryside is taking place.

Socio-еconomic transformation of Sumadija district (Serbia)

The paper starts from the hypothesis that the examined area is characterized by a process of intensive functional transformation accompanied by certain population changes. The transformation of the settlement structure is shown in the area of Sumadija district. The trend of demographic and economic development was observed with a historical overview. It was upgraded with quantitative analyzes (chain index, population change index, functional classification, index of specialization and localization) for the period 1971-2011. The aim was to determine the degree of socio-economic transformation of Sumadija district and the regularities according to which these changes took place. Industrialization generally brings changes in the functional orientation and redistribution of the population. The deagrarianization was one of the main features, with parallel emigration of the rural population. These changes were intensive in 1961-1981, when the peak of employment in secondary activities was registered. Since then, significant spatial transformation in Sumadija district was visible. Special analyzes were used to confirm the assumption that Kragujevac is a dominant labor center, an administrative and service nucleus, which has a propulsive influence on the development of its immediate surroundings (suburban belt) and the wider area (Sumadija district). The contribution of this paper is in the understanding of the scope, spatial distribution, and intensity of changes that have occurred in Sumadija district. It introduces the historical circumstances and quantitative research into a broader concept as a basis for understanding the trajectories of spatial and socio-economic development, and responds to many social challenges specific for this territory.

Soil nitrogen and phosphorous dynamics by in situ soil experiments along an urban-rural gradient in Shanghai, China

An in situ soil experimental system was designed to determine how urbanization impacts soil nitrogen and phosphorus dynamics. Variables including the road density, normalized difference vegetation index, distance to the nearest highway and industrial area from the soil experimental site, land use impact index, population density, population change index, total population, and percentage of water area were used to quantitatively explain the soil nitrogen and phosphorous contents. The results showed that the total phosphorous in the soil increased slowly after September 2013, indicating a phosphorous accumulation phenomenon in the soil in urban areas. The nitrate nitrogen in the soil had a higher value in September 2013, while the soil ammonium nitrogen content was higher during the winter. Moreover, the soil ammonium nitrogen content was higher than the nitrate nitrogen content during most of the experimental period. The distance from the urban centre, road density, proportion of built-up land, and population density can explain the soil nutrient dynamics quantitatively, showing that 45.4% of the soil nitrate nitrogen content, 84.1% of the soil ammonium nitrogen content, 44.6% of the ratio of NO3/NH4, 58.1% of the ratio of total inorganic nitrogen (TIN)/total phosphorous (TP), and 81.6% of the TIN could be explained by one of these variables at most. The potential factors affecting the changes in soil N contents include changes in human dietary habits as more people migrate to cities and industrial wastewater discharge. This study is helpful in quantitatively understanding the urbanization process and associated environmental impacts.

Analyzing patterns in population dynamics using repeated population surveys with three types of detection data

• We generalize distance sampling with multiple observers and time to detection. • Standard distance sampling can misrepresent population trends in some configurations. • Estimating availability to detection is made easier by combining multiple data types. • That new framework increases the number of parameters and the computing time. To facilitate the use of population counts as an index of population change, we describe a generalization of the distance sampling methodology to analyze, in addition to distance to the observer, two other ways to estimate imperfect detection probability: multiple observers and time-to-detection, in a flexible manner, meaning that not all sites or years need to have distance information or be surveyed in the same way every year. We also account for the effect of partially-observed individual covariates, to account for the effect of group size on detection probability. Finally, we separate the probability of availability to detection from the probability of detection itself. We perform a thorough, illustrated assessment of the pros and cons of this framework with simulations and real case studies. First, we compare to simple linear models, illustrating the magnitude of the bias caused by imperfect detection. Second, we compare to standard distance sampling, illustrating the bias caused by variation in the probability of availability to detection. However, the availability to detection was weakly identifiable, meaning that the ability to separate it from detection probability, and therefore debias the trend estimate, depended on the data configuration. Combining distance with multiple observers and with time-to-detection solved the weak identifiability in an applied case study. We recommend using both the type of analysis we showcase, and a simple regression of the population count against time. Discrepancies between results from simple and complex analyses can help identify sources of bias in the former and loss of precision in the latter within the logistical constraints of local wildlife management schemes.

Concentrations and accumulation rates of polychlorinated biphenyls in soil along an urban-rural gradient in Shanghai.

This study proposed an in situ soil experimental system to quantify concentration and accumulation rates of polychlorinated biphenyl (PCB) congeners in the soil in a rural-urban fringe and correlated them with multiple variables in the area. Variables, including road density, normalized difference vegetation index (NDVI), distance to the nearest highway and industrial area from the soil experimental sites, land-use impact index, population density, population change index (PCI), total population, and percentage of water area, were used to explain the concentration of different PCB congeners in soil during the experimental period. A proportion of 40.1%, 22.6%, 56.9%, and 34.3% accumulation rates of PCB8, PCB18, PCB28, and PCB118, respectively was explained by industrial developments, using stepwise linear regression analysis. NDVI was used to explain 33.6%, 61.5%, 49.1%, and 53.2% accumulation rates of PCB44, PCB101, PCB187, and PCB180, respectively. Filtering and transferring of airborne organic pollutants from atmosphere to soil by forests or tree stands and farmlands were all NDVI-related factors that affected the concentrations and accumulation rates of PCB congeners in soil. The traffic-related particle deposition might be the reason why the concentrations and accumulation rates of PCB congeners in soil were affected by road density. The findings can help quantitatively understand urbanization and the associated environmental effects. Graphic abstract.

Spatial demographic inequalities and regional development in Serbia

The study provides a comprehensive data analysis of demographic and socio-economic characteristics in Serbian regions as factors of uneven regional development. The data were provided by the official population censuses from 1953 to 2011. The study uses the following demographic indicators: population; the index of population change; population density; the share of migrants in the total population; the share of 65+ population; and the average age of the population. The indicators of the regions’ socio-economic development were as follows: the level of development of cities and municipalities; the share of uneducated population; the share of the population with secondary and higher education; the share of welfare recipients; the share of employed population; the share of computer illiterate persons; and the share of the unemployed. The research results have shown significant regional discrepancies: Belgrade, Kosovo and Metohija regions are economically prosperous regions, attractive for migrants from other parts of Serbia, the situation is quite the opposite in Southern and Eastern Serbia, characterized by the outflow of the population and economic underdevelopment, especially in the border areas. The other two regions are within the two extremes, Vojvodina being closer to Belgrade and Sumadija and Western Serbia, to Southern and Eastern Serbia.

Polychlorinated biphenyl concentrations, accumulation rates in soil from atmospheric deposition and analysis of their affecting landscape variables along an urban-rural gradient in Shanghai, China

This study initiated an in-situ soil experimental system to quantify the annual dynamics of polychlorinated biphenyl (PCB) congener's concentrations and accumulation rates in soil from atmosphere deposition in a rural-urban fringe, and correlated them by landscape physical and demographic variables in the area. The results showed that the concentrations of all PCB congeners significantly increased with the sampling time (p < 0.05); nearly all the PCB congener concentrations decreased while moving outwards from the urban center. The moderate average concentrations along the gradient for PCB 8, 18, and 28 were 31.003, 18.825, and 19.505 ng g-1, respectively. Tetra-CBs including PCB 44, 52, 66, and 77 were 10.243, 31.214, 8.330 and 9.530 ng g-1, respectively. Penta-CBs including PCB 101, 105, 118, and 126 were 9.465, 7.896, 17.703, and 6.363 ng g-1, respectively. Hexa-CBs including PCB 128, 138, 153, 170, 180, and 187 were 6.798, 11.522, 4.969, 6.722, 6.317, and 8.243 ng g-1 respectively. PCB 195, 206, and 209 were 8.259, 9.506, and 14.169 ng g-1, respectively. Most of the PCB congeners had a higher accumulation rate approximately 28 km from the urban center. The computed variables were found to affect the soil PCB concentrations with a threshold effect (p < 0.05). Regression analysis showed that the thresholds were 10–20 km, 1 km/km2, 30%, and 20% for distance, road density, population change index, and built-up area percentage, respectively. It was concluded that factors related to industrial development, traffic, and urban sprawling (i.e. built-up areas expanding) were the sources of PCBs.

Integrating Breeding Bird Survey and demographic data to estimate Wood Duck population size in the Atlantic Flyway

ABSTRACT The U.S. Fish and Wildlife Service (USFWS) uses data from the North American Breeding Bird Survey (BBS) to assist in monitoring and management of some migratory birds. However, BBS analyses provide indices of population change rather than estimates of population size, precluding their use in developing abundance-based objectives and limiting applicability to harvest management. Wood Ducks (Aix sponsa) are important harvested birds in the Atlantic Flyway (AF) that are difficult to detect during aerial surveys because they prefer forested habitat. We integrated Wood Duck count data from a ground-plot survey in the northeastern U.S. with AF-wide BBS, banding, parts collection, and harvest data to derive estimates of population size for the AF. Overlapping results between the smaller-scale intensive ground-plot survey and the BBS in the northeastern U.S. provided a means for scaling BBS indices to the breeding population size estimates. We applied these scaling factors to BBS results for portions of ...

Characterizing the physical and demographic variables associated with heavy metal distribution along urban-rural gradient

This paper describes a study of how the demographic and physical variables affected the heavy metal (HM) contamination along the urban-rural gradient in PuDong New District, Shanghai. The road density (RDi) and the percentage of built-up areas (BAi) were calculated for various widths of buffers around the soil sampling sites. Through distance allocation, the demographic values of the population change index (PCI) were assigned, with the value being associated with the nearest town. We initiated the use of the population migration rate from 2000 to 2010, i.e., PCI, to represent the urbanization rate. Regression analysis between the soil HM concentrations and the PCI, the RD, and the BA was estimated. The results indicated that the PCI significantly affected the Cd and Cu distribution (p < 0.05), while the RD of the 3-km buffer affected the Pb concentrations. The BA of 2-km buffers affected the spatial distribution of Cd, Cu, and Zn. Zn was also affected by the RD within the 4-km buffer. Using the median values of the PCI and the BA of the 2-km buffer, and the RD of the 3-km buffer, logistic analysis was performed to identify the priority areas for managing HM hazards. The two identified priority areas were the towns of Kangqiao and Zhuqiao, both of which were rapidly urbanized areas with higher PCI values. Our research demonstrated that understanding the rate of urbanization may be as important as the degree of urbanization when examining associated HM contamination patterns.

Reinstatement of customary seabird harvests after a 50-year moratorium

Seabird eggs, chicks, and adults have significant value for many cultures, but delayed maturation, low reproductive rates, and ease of exploitation at breeding colonies make these species especially vulnerable to overharvest. In New Zealand, indigenous Māori placed a moratorium over the harvest of grey-faced petrel (Pterodroma gouldi) chicks in the 1960s because of concerns about diminished returns. Over the last decade, those tribes have indicated their desire to reinstate a small customary harvest. We used recent estimates of population sizes and demographic parameters to develop population models to investigate the feasibility of reinstating a sustainable harvest of pre-fledgling chicks from 2 island populations: Moutohorā and the Ruamāhua Islands. In the absence of harvest, our simulations predicted mean annual rates of population growth of 1.01 (95% CI 1.010–1.014) for the colony on Moutohorā and 0.983 (0.978–0.989) for the Ruamāhua Islands. The Moutohorā colony could potentially sustain a fixed-quota harvest of up to 6,000 chicks or a fixed-proportion harvest of up to 30% of chicks, annually. A larger-scale harvest would require either a very conservative fixed-quota harvest with strict monitoring of bag limits, or a fixed-proportion harvest with reliable ongoing monitoring of the population size. We propose that Māori authorities use a fixed-quota system up until they develop and use either a scientific assessment or a harvester-derived index of population change. On the basis of our simulations, in 2010, Ngāti Awa, the local tribe, harvested chicks from Moutohorā for the first time in half a century. © 2014 The Wildlife Society.

Mark–recapture and playback surveys reveal a steep decline of European Storm Petrels Hydrobates pelagicus at the largest colony in western Scotland

None of the indices of population change for seabirds in the northeast Atlantic have included European Storm Petrel Hydrobates pelagicus, because their cryptic breeding behaviour makes monitoring difficult. The aim of this paper is to present the results of a long-term project to monitor this species on Priest Island, one of the largest breeding colonies in Scotland. Mark–recapture and playback-response methods both showed a steep decline in the population size between 2001 and 2012. The population estimate at the main study site used for mark–recapture was 8,472 birds ± 1,466 (standard error) in 2001 and has declined by about 460 birds per year to 3,854 ± 437 in 2012. The adult annual survival rate was high in 2001/02 and 2002/03 but has since fluctuated between 0.73 and 0.83; these survival estimates are lower than those for the whole of Britain & Ireland estimated from ring recoveries (0.86 from 1967 to 1996, and above 0.9 since 2007/08). Recaptures of birds at three sites at varying distances from the main site used for this study indicated that only birds at the nearest site (c 90 m away) could be considered to be part of the same breeding population. Thus, the minimum distance between study sites for mark–recapture population estimates should be in excess of 100 m. The decline in population revealed by this study may be due to insufficient recruitment resulting from poor productivity, low survival to breeding age, or emigration, and emphasises the importance of future studies to monitor productivity.

Demographic and functional evaluation of urban areas in Vojvodina region

The article illustrates the procedure of quantitative demographic and functional evaluation of urban areas in Vojvodina region. Evaluation is based on seven indicators such as total population, population change index, aging index, the share of employees in primary sector, the share of employees in total population, the share of economically active population (noncommuters) and the share of commuters in economically active population of all urban settlements in Vojvodina region. Quantitative procedure of demographic and functional valorization of urban areas is based on a rank method. According to the results of applied procedure, the categories of urban areas are determined. Each category demonstrates a level of demographic development and correlation between demographic potential and suitable geographical and traffic position. The article is an attempt to perceive better the demographic processes in settlements. Moreover, we pay attention to a different approach in the research of urban settlements network in Vojvodina region.

Olfactory Cues Used in Host Selection by Frankliniella occidentalis (Thysanoptera: Thripidae) in Relation to Host Suitability

Olfactory responses of Frankliniella occidentalis (Pergande) to odors from six vegetable host plants-cabbage (Brassica oleracea), lettuce (Lactuca sativa), cucumber (Cucumis sativus), eggplant (Solanum melongena), celery (Apium graveolens) and garlic (Allium sativum) - were measured in choice tests in a Y-tube olfactometer, while host suitability of these same plants was assessed based on life table parameters-development time, survival rates, fertility, offspring sex ratio, female longevity, and an index of population change (I) - measured on leaf disks. Olfactory response was measured on both undamaged and mechanically-damaged plants. Regardless of plant damaged, female F. occidentalis responded positively to the odors of cabbage, lettuce, cucumber, and eggplant, but showed negative responses to celery and garlic, when offered a choice of plant odor or clean air. When female thrips were offered choices between each possible pairing of undamaged plants, or pairings of mechanically-damaged plants, the order of preference was cabbage = lettuce = cucumber > eggplant > celery = garlic. Male thrips responded differently, males responded positively only to undamaged lettuce and eggplant compared to clean air, while among mechanically-damaged plants only cucumber elicited a positive response. Given a choice between all possible pairings of undamaged plants, male thrips preferred lettuce to celery, and eggplant to garlic, whereas among pairings of mechanically-damaged plants male thrips preferred lettuce to celery, and cucumber to eggplant. The order of suitability of the six host plants based on life table parameters for F. occidentalis was essentially the same as the order of preference by female thrips. These results indicate that host plant odor is an important cue for female F. occidentalis in recognizing hosts suitable for oviposition. Information on plant attraction and repellency may be useful in thrips pest management. In addition, the correspondence of preference and performance that we found suggests that evolution of local host adaptation and, perhaps, host specialization, is possible.

Spatial modelling of population concentration using geographically weighted regression method

This paper presents possibilities of applying the geographically weighted regression method in mapping population change index. During the last decade, this contemporary spatial modeling method has been increasingly used in geographical analyses. On the example of the researched region of Timočka Krajina (defined for the needs of elaborating the Regional Spatial Plan), the possibilities for applying this method in disaggregation of traditional models of population density, which are created using the choropleth maps at the level of statistical spatial units, are shown. The applied method is based on the use of ancillary spatial predictors which are in correlation with a targeted variable, the population change index. For this purpose, spatial databases have been used such as digital terrain model, distances from the network of I and II category state roads, as well as soil sealing databases. Spatial model has been developed in the GIS software environment using commercial GIS applications, as well as open source GIS software. Population change indexes for the period 1961-2002 have been mapped based on population census data, while the data on planned population forecast have been used for the period 2002-2027.

Mapping population change index in Southern Serbia (1961–2027) as a function of environmental factors

Niche analysis methods developed within the biogeography community are routinely used for species distribution modeling of wildlife and endangered species. So far, such techniques have not been used to explain distribution of people in an area, nor to assess spatio-temporal dynamics of human populations. In this paper, the MaxEnt approach to species distribution modeling and publicly available gridded predictors were used to analyze the population dynamics in Southern Serbia (South Pomoravlje Region) for the period 1961–2027. Population values from the census administrative units were first downscaled to 200 m grid using a detailed map of populated places and dasymetric interpolation. In the second step, a point pattern representing the whole population (468,500 inhabitants in 2002) was simulated using the R package spatstat. MaxEnt was then used to derive habitat suitability index (HSI) as a function of gridded predictors: distance to roads, elevation, slope, topographic wetness index, enhanced vegetation index and land cover classes. HSI and environmental predictors were further used to explain spatial patterns in the population change index (PCI) through regression modeling. The results show that inhabiting preference for year 1961 is mainly a function of topography (TWI, elevation). The HSI for year 2027 shows that large portions of remote areas are becoming less preferred for inhabiting. The results of cross-validation in MaxEnt show that distribution of population is distinctly controlled by environmental factors (AUC > 0.84). Population decrease is particularly significant in areas >25 km distant from the main road network. The results of regression analysis show that 40% of variability in the PCI values can be explained with these environmental maps, distance to roads and urban areas being the main drivers of migration process. This approach allows precise mapping of demographic patterns that otherwise would not be visible from the census data alone.

A népességszám változás települési és megyei szintű egyenlőtlenségeinek néhány mérési lehetősége Magyarországon

A népességszám-változás területi különbségei ugyan jól ismertek Magyarországon, ám néhímy kvantitatív módszer segítségével újabb adalélcok adhatók e témához csupán a települések vándorlási egyenlege, népességszám- változása segítségével is. A legtöbb mutató a szuburbanizáció létét erősíti meg Budapest és a nagyvárosok körül, és e tekintetben is számottevő a főváros előnye a nagyvárosok környékéhez képest.

Harvest rate of sooty shearwaters (Puffinus griseus) by Rakiura Māori: a potential tool to monitor population trends?

Sooty shearwaters (tītī, muttonbird, Puffinus griseus) are highly abundant migratory seabirds, which return to breeding colonies in New Zealand. The Rakiura Māori annual chick harvest on islands adjacent to Rakiura (Stewart Island), is one of the last large-scale customary uses of native wildlife in New Zealand. This study aimed to establish whether the rate at which muttonbirders can extract chicks from their breeding burrows indicates population trends of sooty shearwaters. Harvest rates increased slightly with increasing chick densities on Putauhinu Island. Birders' harvest rates vary in their sensitivities to changing chick density. Therefore a monitoring panel requires careful screening to ensure that harvest rates of the birders selected are sensitive to chick density, and represents a cross-section of different islands. Though harvest rates can provide only a general index of population change, it can provide an inexpensive and feasible way to measure population trends. Detecting trends is the first step to assessing the long-term sustainability of the harvest.

Numbers of wintering waterbirds in Great Britain, 1994/1995–1998/1999: I. Wildfowl and selected waterbirds

Estimates of the number of waterbirds (principally wildfowl) wintering in Great Britain are presented, based on data from the period 1994/1995–1998/1999. These update the previous estimates for 1987/1988–1991/1992. National estimates are used to derive 1% thresholds for waterbird species which in turn form the basis for the identification of nationally important wetland sites for subsequent conservation and protection. Estimates are also used to assess changes in numbers of those species for which monitoring data are insufficient to calculate annual indices of population change. Data for calculating the estimates come from a variety of sources including the Wetland Bird Survey (WeBS, a long-term scheme which counts waterbirds by day at wetlands), goose roost censuses, site-based surveys and published reviews. Generation of the estimates is made difficult by a number of methodological and data quality issues. To account for some of the methodological problems affecting WeBS data, new methods for generating estimates have been used which account for birds missed during the counts in a more comprehensive manner. These result in large increases in the estimated numbers for many of the relevant species, although most are still considered to be underestimates. To assess the biological change in numbers since the last assessment, estimates generated from the same methods used previously are also presented. These indicate that while the majority of species have experienced increases in numbers since the late 1980s there have been some notable declines. There is however scope for improving the accuracy of estimates derived from extensive, volunteer-based monitoring schemes such as WeBS.

Integrated pest management of Ips pini (Col., Scolytidae) populations in south‐eastern Montana

Second growth ponderosa pine forests of the Northern Cheyenne Reservation of south‐eastern Montana sustained a chronic Ips pini outbreak between 1978 and 1994. Studies determined the emergence and seasonal flight patterns of the scolytids with regards to temporal and spatial distribution of host material as well as population changes during the year. These changes related to the dry‐down rate of host material (thinning and logging slash) and the availability of slash; an index of population change (IPC) was developed to estimate seasonal changes in the Ips population from spring to autumn. Principal management components of an integrated pest management system included (1) an emphasis on creating thinning and logging slash between August and December, a time that provides quickly degrading host material for the overwintering Ips population while not providing suitable host material for the subsequent spring flight; (2) restrictions on winter logging as slash produced during this period provided suitable hosts for the first spring flights of I. pini; and (3) restrictions on the use of trap logs or pheromones to lower Ips populations as these materials provide kairomones for the predators (Enoclerus lecontei, Enoclerus spegeus and Temnochila chlorodia) that partition their I. pini host across the spring, summer and autumn.