Earthquake hazard and vulnerability in the northeastern Mediterranean: the Corinth earthquake sequence of February-March 1981

Population density, building type and earthquake magnitude are the main factors on which the total building damage following an earthquake depend. For the Greece - Turkey region quantitative relations between these factors have been developed, which, in spite of the inaccuracies in the available data, allow crude estimates of the damage following a particular size earthquake to be made. This is demonstrated retrospectively for the Gulf of Corinth earthquakes in 1981.     

Is the environment becoming more hazardous?—A global survey 1947 to 1980

This paper examines the assertion that natural disasters are increasingly destructive using evidence from disaster reports during the period 1947–1980. The criteria for judging the impact of a given natural disaster are chiefly loss of life and the extent of the geographical area affected. In spite of uneveness and bias in the reporting of sudden impact disasters the conclusions are that both the frequency of disasters and number of people killed are increasing. Further research into the social consequences of disasters and the need for disaster preparedness training programmes are recommended.     

Intraspecific competition and high food availability are associated with insular gigantism in a lizard

Resource availability, competition, and predation commonly drive body size evolution. We assess the impact of high food availability and the consequent increased intraspecific competition, as expressed by tail injuries and cannibalism, on body size in Skyros wall lizards (Podarcis gaigeae). Lizard populations on islets surrounding Skyros (Aegean Sea) all have fewer predators and competitors than on Skyros but differ in the numbers of nesting seabirds. We predicted the following: (1) the presence of breeding seabirds (providing nutrients) will increase lizard population densities; (2) dense lizard populations will experience stronger intraspecific competition; and (3) such aggression, will be associated with larger average body size. We found a positive correlation between seabird and lizard densities. Cannibalism and tail injuries were considerably higher in dense populations. Increases in cannibalism and tail loss were associated with large body sizes. Adult cannibalism on juveniles may select for rapid growth, fuelled by high food abundance, setting thus the stage for the evolution of gigantism.     

Biased sex ratio and low population density increase male mating success in the bug Nysius huttoni (Heteroptera: Lygaeidae)

Demographic factors such as operational sex ratio (OSR) and local population density (LPD) are temporally and spatially dynamic in the natural environment but the influence of these variables on male mating success and the mechanisms behind it are still poorly understood and highly controversial. Here, we manipulated the OSR and LPD of a seed bug, Nysius huttoni, and carried out a series of mating trials to test how these variables affected male mating success. The two demographic factors had no significant interactions, suggesting that they affect male mating success independently in N. huttoni. In this species male mating success was significantly higher in both male- and female-biased OSR than in even OSR. It is suggested that, in male-biased OSR, the increased intensity of competition and interference does not result in lower male mating success; rather, males may make more effort in courting and females may have more chance to encounter better males, resulting in higher male mating success. In female-biased OSR, females may become less choosy and less likely to reject male mating attempt, leading to the higher male mating success. Lower male mating success in N. huttoni in high LPD may be due to increased interference between males and/or delayed female receptiveness for mating. OSR had a stronger effect on male mating success than LPD in N. huttoni, suggesting that OSR and LPD affect mating success in different ways and intensities.     

Lyapunov stability for an age-structured population model

This is a short notice on the McKendrick equation that I actually learned from Yu.M. Svirezhev in the 1990s. This McKendrick equation modelling the evolution in time of an age-structured population has received attention recently from mathematicians. The initial and boundary conditions for the McKendrick equation imposed by the population model are not the standard side conditions one sees in PDE theory for an evolution equation. In the simplest case, the problem reduces to a well-known model in demography, the Lotka integral equation.     

A methodological approach to develop “contaminant migration–population effects” models

The main aim of the present work is to discuss the methodological approaches that underpin the “contaminant migration–population effects” models for the evaluation of the detriment to populations of moving organisms in environmental systems with spatial and time dependent pollution levels. A technique to couple the equations controlling the population dynamics and the pollutant dispersion is described and discussed. The domain of application and the limitations of the methodology are analysed and illustrated by some examples. Possible alternative approaches are briefly presented.     

Reaching a forest land per capita milestone in the United States

During April 2007, forest land per capita in the United States dropped below 1 ha. This is the result of a rather static area of forest land in the United States for the past 100 years combined with population growth. The US now joins the ranks of most countries (77%) having forest land per capita below 1 ha. The combination of an increasing human population with stable or increasing per capita natural resource utilization may place even more demand on resources derived from forest land in the future. The forest land per capita should be expected to continue its downward trend unless substantive demographic, resource utilization, and land-use changes occur.     

Population collapses in the pre-modern period: case study of the Fuping County,Northwest China

The pre-modern history of population change in the Fuping County (Shaanxi Province, China) during the Ming and Qing Dynasties (AD 1368–1911) was reconstructed using historical sources. The Fuping County experienced two major population collapses, i.e. the late Ming Dynasty (1550–1640s) and the 1860–1880s. The first one was caused by the great AD 1556 earthquake and the extreme droughts and warfare in the 1630–1640s. The second one was caused by warfare and extreme droughts. As a whole, natural disasters, including extreme drought and great earthquake, were the key direct causes of population collapse, and climatic cooling would be a potential indirect cause. It is very interesting that population collapses occurred almost synchronously in the Fuping County and whole China, and the trends of population change were also very similar. Climate–population relationship in China would be valid at finer geographic level, and climatic cooling could be a potential indirect cause of population collapse.     

Menus of price-quantity contracts for inducing the truth in environmental regulation

Many authors have proposed mechanisms to induce regulated polluting firms to truthfully reveal their private information. This paper proposes an alternative scheme in which the regulator offers each firm a menu of linear price-quantity contracts; faced with this menu, each firm′s dominant strategy is to truthfully report its private information and self-select the contract that is ex post efficient. The proposed menu schedule that is more elastic than the firm′s residual marginal damage function engenders a positive quantity effect, thereby counterbalancing the firm′s incentive to misreport prompted by the linearity of price. Due to its built-in price quantity structure, the scheme performs as designed regardless of the elasticities of marginal damage and demand functions.