Ground beetle (Coleoptera: Carabidae) communities on green roofs in Switzerland: synthesis and perspectives

Urban Ecosystems - Green roofs have recently gained recognition for their potential contribution to urban ecosystems by providing, among other services, habitat for plants and animals, and stepping...     

Rainfall interception capacity of tree species used in urban afforestation

Afforestation is inserted in the urban environment and interferes directly in the surface runoff. In order to quantify the rainfall interception by tree species, an experiment was carried out in the city of Uruaçu, Goiás, Brazil, with the four most common tree species in the urban afforestation of the region. The species chosen were the Mangifera indica (mango tree), the Caesalpinia peltophoroides (sibipiruna tree), the Pachira aquatica (munguba tree) and the Licania tomentosa (oiti). In order to register precipitation, ten pluviographs were used. They are capable of measuring precipitation over time in terms of duration, volume, and intensity. For events with a mean cumulative precipitation of 16.7 mm, the mean values of interception found in each species were: Mangifera indica - 8.0 mm; Pachira aquatica - 7.4 mm; Licania tomentosa - 7.2 mm; and Caesalpinia peltophoroides - 4.8 mm. The research confirms the importance of studies related to the identification of the species’ individual characteristics that interfere in the rainfall interception capacity and that can consequently contribute to urban drainage actions. In addition, it proves the existence of variations of rainfall interception in relation to rainfall events and during their occurrences and emphasizes the need for a careful definition of the species that will compose the urban afforestation.     

Coming in like a wrecking-ball: are native Eurasian red squirrels displacing invasive Siberian chipmunks? A study from an urban park

Alien squirrels may seriously threaten native species by means of interspecific competition. In our work, we analysed whether the distribution of alien Siberian chipmunks within the Sigurtà Garden urban park (north-eastern Italy) changed after the natural spread of native Eurasian red squirrels in a 20-year period. Distribution of both squirrels was estimated through a citizen-science approach, in the first 10-year after red squirrel arrival 1 (i.e. Decade 1: 1997–2006) and in the second 10-year interval (i.e. Decade 2: 2007–2017). We compared habitat use of both species and we assessed whether a vertical segregation occurred through a dissimilarity index. Woodlands were selected by both species in both decades. Red squirrels also selected tree lines in Decade 1. A vertical segregation was apparent in Decade 1, whereas in Decade 2 both squirrel species were observed on the lowest branches or on the ground, where they are fed by humans. This was also confirmed by the habitat niche-overlap index, which increased in Decade 2. The extent of occurrence of Sciurus vulgaris increased throughout the park, whereas those of Eutamias sibiricus decreased. Differently from what is usually observed with alien squirrels, the spread of the native species appears to be halting and reversing the expansion of the non-native one.     

Development of urban behaviour is associated with time since urbanization in a reed-nesting waterbird

Behavioural adaptations are recognized as crucial determinants for successful establishment and persistence of animal populations in a novel urban environment. Here, we examined mechanisms responsible for the development of urban behavioural type in a common waterbird, the Eurasian coot Fulica atra. We compared the behaviour of coots from a rural population and two urban populations that differed in the timing of colonization event (1960s vs. 2000s). We found that some behavioural characters associated with urban life (aggression during nest defence and boldness towards humans during foraging) were more strongly expressed in the older urban population when compared with the recently established urban population. By contrast, coots from the two urban populations showed a similar likelihood of exploiting human-derived food resources, as well as they showed similar levels of physiological stress. Urban coots were generally more aggressive, bolder, and less stressed than their rural conspecifics. Large behavioural and physiological divergence of coots from the recently established urban population and their rural conspecifics suggested that phenotypic plasticity and phenotype sorting may play a key role in the initial stages of urban colonization. On the other hand, increasing expression of boldness and aggression with the time since urbanization may suggest the role of microevolutionary adaptation in response to novel selective forces associated with the urban environment. Our results indicate that a combination of different processes (phenotypic plasticity, phenotype sorting, and microevolution) can determine successful colonization of urban areas by the Eurasian coots, and possibly other bird species.     

The role of grandparenting in early childcare and child outcomes

This paper examines the short and medium term impact of early childcare provision by grandparents and formal care settings on child cognitive outcomes, using data from the Millennium Cohort Study (UK). Compared with children placed in formal childcare, children cared for by their grandparents are better at naming objects, but perform worse on tests of basic concept development and non-verbal reasoning. These results mask strong heterogeneities. On the one hand, the positive association between grandparental care and child outcomes is stronger for children from more advantaged households; on the other, the negative association is only significant for those from more disadvantaged households. The results of OLS estimations used for our analysis are confirmed using panel methods and an instrumental variable approach.     

Do childbirth grants increase the fertility rate? Policy impacts in South Korea

In response to a low fertility rate, a number of municipalities in South Korea have been providing family benefits in the form of childbirth grants and child allowances. Using panel data for 230 municipalities that spans the years 2001–2014, this paper examines the impacts of family benefits on the fertility rate in Korea. I use the fact that different municipalities began providing the family benefits at different times to estimate the impact of family benefits on fertility rates using a difference-in-differences approach. This study finds a positive effect of family benefits on total fertility rate. Moreover, it finds little evidence of an anticipatory response within municipalities that adopted the policy. Given that a 10 million Korean won increase in family benefits is associated with a 3.5% increase in the total fertility rate, an increase in family benefits of about 44 million Korean won per child would be required to raise the total fertility rate to a safe zone above 1.5 children per woman, where population declines are gradual and easily reversed.     

Life satisfaction in China and consumption and income inequalities

This research uses nationally representative data to study how economic resources and inequalities are associated with life satisfaction of Chinese residents. We construct economic resource and inequality measures from expenditure rather than from income, after confirming that expenditure inequality is a better measure in the Chinese context. We find that economic inequalities in general are negatively associated with life satisfaction, and that this association is larger for inequalities in the lower half of the distribution than those in the upper half of the distribution. We further explore the mechanisms under which inequality can be associated with life satisfaction, and find that aspiration is potentially one important channel.     

Precautionary saving in Spain during the great recession: evidence from a panel of uncertainty indicators

The aim of this paper is to empirically study the effect of uncertainty on private consumption using a sample of Spanish households, and therefore, to test the existence of a precautionary motive for saving. Using data provided by the Spanish Survey of Household Finances and the Labour Force Survey we construct several uncertainty measures that are commonly used in the literature and an additional indicator based on job insecurity data, and we consequently estimate different econometric models under the life-cycle/permanent income hypothesis, including these measures of uncertainty. Our results are twofold: first, we find evidence in favour of the precautionary saving hypothesis. Secondly, we find that, unlike other variables related to the performance of the labour market (such as the unemployment rate) the job insecurity indicator is an appropriate variable to approximate income uncertainty in any macroeconomic context.     

Wealth and inheritance in Britain from 1896 to the present

Personal wealth has grown since the 1970s twice as fast in real terms as national income. Has this rise in the wealth-income ratio led to a corresponding increase in the wealth being passed on from one generation to the next? Are we returning to the levels of inheritance found in the 19th century? The aim of this paper is to construct UK evidence on the extent of the transmission of wealth in the form of estates and gifts inter vivos. It takes a long-run view of inheritance, starting from 1896, when the modern Estate Duty was introduced, and exploits the extensive estate data published over the years. Construction of a long-run time series for more than a century is challenging, and there are important limitations. The resulting time-series demonstrates the major importance of inheritance in the UK before the First World War, when the total transmitted wealth represented some 20 per cent of net national income. In the inter-war period, the total was around 15 per cent, falling to some 10 per cent after the Second World War, and then falling further to below 5 per cent in the late 1970s. Since then, there has indeed been an upturn: a rise from 4.8 per cent in 1977 to 8.2 per cent in 2006. This increase was more or less in line with the increase in personal wealth, and has to be interpreted in the light of the changing net worth of the corporate and public sectors of the economy.     

Banking crises in the US: the response of top income shares in a historical perspective

This paper examines the response of income concentration in the US to the occurrence of major systemic banking crises since the beginning of the twentieth century. In doing so, the paper analyzes the shape of the upper income tail as well as the national income shares accruing to different groups within the richest decile. The findings suggest that systemic banking crises reduce income concentration within the top decile of the US pre–tax and transfers income distribution, and more generally, that the effect is highly heterogeneous across different top income groups. While the richest income group loses ground, the lower half of the top decile appears to gain in relative terms. However, evidence suggests that the estimated short-term effect of market forces stemming from banking crises can be relatively small in magnitude and even temporary in nature, as it may be quickly reabsorbed. These findings lend indirect support to the idea that only substantial changes in government policies and institutional frameworks can bring about radical changes in income distribution.