Population density and temperature correlate with long-term trends in somatic growth rates and maturation schedules of herring and sprat

Density-dependent population growth regulates long-term urban expansion and shapes distinctive socioeconomic trends. Despite a marked heterogeneity in the spatial distribution of the resident population, Mediterranean European countries are considered more homogeneous than countries in other European regions as far as settlement structure and processes of metropolitan growth are concerned. However, rising socioeconomic inequalities among Southern European regions reflect latent demographic and territorial transformations that require further investigation. An integrated assessment of the spatio-temporal distribution of resident populations in more than 1000 municipalities (1961–2011) was carried out in this study to characterize density-dependent processes of metropolitan growth in Greece. Using geographically weighted regressions, the results of our study identified distinctive local relationships between population density and growth rates over time. Our results demonstrate that demographic growth rates were non-linearly correlated with other variables, such as population density, with positive and negative impacts during the first (1961–1971) and the last (2001–2011) observation decade, respectively. These findings outline a progressive shift over time from density-dependent processes of population growth, reflecting a rapid development of large metropolitan regions (Athens, Thessaloniki) in the 1960s, to density-dependent processes more evident in medium-sized cities and accessible rural regions in the 2000s. Density-independent processes of population growth have been detected in the intermediate study period (1971–2001). This work finally discusses how a long-term analysis of demographic growth, testing for density-dependent mechanisms, may clarify the intrinsic role of population concentration and dispersion in different phases of the metropolitan cycle in Mediterranean Europe.

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CO2 variability in the Mexico City region from in situ measurements at an urban and a background site

10.20937/atm.52956 ◽

2020 ◽

Author(s):

Eugenia González del Castillo ◽

Noémie Taquet ◽

Alejandro Bezanilla ◽

Wolfgang Stremme ◽

Michel Ramonet ◽

...

Keyword(s):

Mexico City ◽

Growth Rates ◽

Urban Areas ◽

Layer Growth ◽

Dry Season ◽

University Campus ◽

City Region ◽

Air Masses ◽

Long Term Trends

Urban areas are important contributors to the increase of global CO2levels due to human activities, but continuous records of CO2concentration in cities are scarce, especially in the developing world. In this study we present five years of simultaneous, in-situmeasurements at a university campus in the south of Mexico City (UNAM) and at a high-altitude station, the Altzomoni atmospheric observatory (ALTZ), 60 km apart from the first site. The characteristics of the daily cycles, seasonality, and long-term trends were extracted from both time series. The features of the daily and seasonal cycles at UNAM are dominated by the dynamics of the boundary layer growth, while the seasonality at Altzomoni is determined by both the local meteorology and the photosynthetic activity of the vegetation. Annual CO2 growth rates of 2.4 and 2.6 ppm yr-1 were estimated for UNAM and Altzomoni, respectively, in close agreement with reported global growth rates and with previous estimates of total column CO2trends. The simultaneous monitoring at the urban and the mountain sites revealed a regular exchange of air masses between the city and its vicinities. The annual cycle at UNAM shows a secondary CO2maximum at the end of the dry season likely due to incoming air parcels enriched with emissions from agricultural burnings. Likewise, the daily CO2cycle at ALTZ during the dry season shows evidence of a daily afternoon arrival of polluted air masses from the neighboring urban areas. This study lays the foundation of an upcoming expansion in the CO2measurement sites and capabilities in the metropolitan area of Mexico City.

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Carcass records of autumn-slaughtered reindeer as indicator of long-term changes in animal condition

Rangifer ◽

10.7557/2.31.1.1830 ◽

2011 ◽

Vol 31 (1) ◽

pp. 7-20 ◽

Cited By ~ 3

Author(s):

Anna Olofsson ◽

Öje Danell ◽

Birgitta Åhman ◽

Pär Forslund

Keyword(s):

Population Density ◽

Body Condition ◽

Skeletal Development ◽

Strongly Correlated ◽

Range Use ◽

Long Term Changes ◽

Long Term Trends ◽

Reindeer Population

This study investigates the possibility of using carcass records from the commercial slaughter of reindeer as indicator of long-term changes in animal condition and, thus, the condition and use of their snow-free pasture. The aim was to assess the suitability of this indicator for use within adaptive management programmes for reindeer husbandry grazing resources. Data comprising measurements of carcass weight, conformation and fatness taken from commercial reindeer slaughter between 1994 and 2007, were analysed in relation to year, slaughter date, herding district, population density, and three categories of animals selected for slaughter. The carcass measures were significantly affected by year, and the effects were strongly correlated among the three animal categories. There were generally positive trends over the 14-year period studied. We identified several factors that should be considered when using carcass data to indicate long-term changes in animal body condition: (i) slaughter date had different effects depending on animal category; (ii) reindeer population density negatively affected female and calf carcasses, but not male carcasses. The effects of herding district were similar for carcasses of calves and females, but differed between females and males. Some of the differences between animal categories may be due to differing timing of slaughter (point i above), by different slaughter selection among districts, or have ecological explanations, e.g. sex differences in range use. Uncertainties in the classification of animals when using skeletal development to discriminate between calf and yearling carcasses, may also add to differences among districts. That population density effects on body condition were detectable together with the similarities in the effects of year and general long-term trends between animal categories support the suggestion that carcass measures can be used to indicate general changes in reindeer body condition and range use.

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Delineating Long-Term Trends in Beach Change, Central California

California and the World Ocean '02 ◽

10.1061/40761(175)3 ◽

2005 ◽

Author(s):

Cope M. Willis ◽

Gary B. Griggs

Keyword(s):

Central California ◽

Long Term Trends

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The Reproduction Vector of the Russian Economy: 1999-2007

Voprosy Ekonomiki ◽

10.32609/0042-8736-2008-4-94-109 ◽

2008 ◽

pp. 94-109 ◽

Cited By ~ 1

Author(s):

D. Sorokin

Keyword(s):

Economic Policy ◽

Human Capital ◽

Growth Rates ◽

Developed Countries ◽

Gdp Per Capita ◽

Real Sector ◽

Russian Economy ◽

Per Capita ◽

The Developed Countries

The problem of the Russian economy’s growth rates is considered in the article in the context of Russia’s backwardness regarding GDP per capita in comparison with the developed countries. The author stresses the urgency of modernization of the real sector of the economy and the recovery of the country’s human capital. For reaching these goals short- or mid-term programs are not sufficient. Economic policy needs a long-term (15-20 years) strategy, otherwise Russia will be condemned to economic inertia and multiplying structural disproportions.

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