Suchergebnisse

Climate change is expected to alter the geographic distribution of many plant species worldwide. However, there is still no clear evidence showing a generalised direction and magnitude of these distribution shifts. Here, we have surveyed, in nine mountainous regions in Spain, an array of tree species along entire elevational ranges, as surrogates of their global climatic ranges, to test for elevational shifts towards cooler locations. We analysed the distribution recruitment patterns of five dominant tree species, recording the abundance and measuring the primary growth of juveniles in 306 plots. Three of the species have a temperate-boreal distribution with populations at their southern edge in the Mediterranean mountain ranges: Pinus sylvestris, Pinus uncinata and Fagus sylvatica; and the other two species have a Mediterranean distribution: Quercus ilex and Pinus nigra. Despite the contrasting phylogenies and biogeographies, we identified a similar pattern in recruitment abundance across species, with an asymmetric distribution of juveniles (more recruits in the middle-upper elevation of their range), but higher annual growths at lower elevations. This survival-growth trade-off at the early recruitment stage may potentially counterbalance at population level the negative effect of global warming on recruit survival at the lower edge of species ranges. These findings suggest a demographic stabilisation process at the early recruitment stage of these tree species, and highlight the importance of considering the different demographic stages across the whole climatic range to understand the effects that climate change may exert on species distributions and population dynamics. ; RB was funded by a Marie Curie IEF fellowship (FP7-PEOPLE-2011-IEF). Funding also was provided by the Spanish Ministry for Innovation and Science with the grant Consolider-Montes (CSD2008_00040), VULGLO (CGL2010 22180 C03 03), MOUNTAINS (CGL-2012-38427), the Community of Madrid grant REMEDINAL 2 (CM S2009 AMB 1783) and the European Union with the projects BACCARA (CE: FP7-226299, 7FP) and FunDivEUROPE (CE: FP7-ENV-2010. 265171).

© 2015 Geobotanisches Institut ETH, Stiftung Ruebel. Climate change is expected to alter the geographic distribution of many plant species worldwide. However, there is still no clear evidence showing a generalised direction and magnitude of these distribution shifts. Here, we have surveyed, in nine mountainous regions in Spain, an array of tree species along entire elevational ranges, as surrogates of their global climatic ranges, to test for elevational shifts towards cooler locations. We analysed the distribution recruitment patterns of five dominant tree species, recording the abundance and measuring the primary growth of juveniles in 306 plots. Three of the species have a temperate-boreal distribution with populations at their southern edge in the Mediterranean mountain ranges: Pinus sylvestris, Pinus uncinata and Fagus sylvatica; and the other two species have a Mediterranean distribution: Quercus ilex and Pinus nigra. Despite the contrasting phylogenies and biogeographies, we identified a similar pattern in recruitment abundance across species, with an asymmetric distribution of juveniles (more recruits in the middle-upper elevation of their range), but higher annual growths at lower elevations. This survival-growth trade-off at the early recruitment stage may potentially counterbalance at population level the negative effect of global warming on recruit survival at the lower edge of species ranges. These findings suggest a demographic stabilisation process at the early recruitment stage of these tree species, and highlight the importance of considering the different demographic stages across the whole climatic range to understand the effects that climate change may exert on species distributions and population dynamics. ; Funding also was provided by the Spanish Ministry for Innovation and Science with the grant Consolider-Montes (CSD2008 00040), VULGLO (CGL201022180 C03 03), MOUNTAINS (CGL-2012-38427), the Community of Madrid grant REMEDINAL 2 (CM S2009 AMB 1783) and the European Union with the projects BACCARA (CE: FP7-226299, 7FP) and FunDivEUROPE (CE: FP7-ENV-2010. 265171). ; RB was funded by a MarieCurie IEF fellowship (FP7-PEOPLE-2011-IEF). ; Peer Reviewed

Die starke Zuwanderung der letzten Jahre hat zu einer deutlichen Verschiebung der demografischen Strukturen in Deutschland geführt. So wären die Zahl der 20- bis 29-Jährigen ohne die seit 2007 Zugewanderten im Jahr 2017 um 1,26 Millionen und ihr Anteil an der Gesamtbevölkerung um 0,9 Prozentpunkte niedriger gewesen. Auch bei den 0- bis 9-Jährigen und den 30- bis 39-Jährigen zeigen sich durch die Neuzuwanderer und ihre in Deutschland geborenen Kinder deutliche Gewinne. Hingegen ergeben sich bei den 10- bis 19-Jährigen und den 40- bis 49-Jährigen keine maßgeblichen Veränderungen und bei den Älteren Rückgänge der Bevölkerungsanteile. Dabei besteht aus demografischer Sicht gerade bei den im Jahr 2017 im Teenageralter befindlichen Personen ein besonders großer Bedarf an Zuwanderern, da diese die geburtenstarken Jahrgänge am Arbeitsmarkt ersetzen müssen. Die Potenziale der Mobilität innerhalb der EU, die eine tragende Säule der Zuwanderung der letzten Jahre war, sind hier sehr begrenzt. Denn in den Herkunftsländern der europäischen Zuwanderer in dieser Altersgruppe bestehen ebenfalls große demografische Lücken. Daher muss die Zuwanderungspolitik ihren Fokus in den nächsten Jahren vermehrt auf demografiestarke Drittstaaten richten. Der Schwerpunkt sollte dabei auf der Erwerbs- und Bildungsmigration liegen, da das Gelingen der Integration in den deutschen Arbeitsmarkt darüber entscheidet, welchen Beitrag die Zuwanderung zur Bewältigung der mit dem demografischen Wandel einhergehenden Herausforderungen tatsächlich leisten kann. ; The high level of immigration in recent years has led to a significant shift in Germany's demographic structure. Without the immigrants and their children born in Germany since 2007, the share of 20-to29-year-olds in the total population in 2017 would have been 11.1 per cent - with them it was 12.0 per cent. There are also clear gains from new immigration among 0-to-9 and 30-to-39-year-olds, whereas it has not led to any significant changes among 10-to-19 and 40-to-49-year-olds. The proportion of older people has declined as a result of immigration. From a demographic point of view, there is still a great need for immigrants, especially among those who were in their teens in 2017, as they will be needed to replace the baby boomers in the labour market. Mobility within the EU, which has been a mainstay of immigration in recent years, has little more to offer in this respect because the countries European immigrants have traditionally come from have themselves large demographic gaps in this age group. For this reason, immigration policy in the coming years will need to focus increasingly on third countries with still-growing populations. The focus should be on immigrants intent upon working or studying, since the contribution they actually make to meeting the challenges posed by the demographic transition will be determined by how successfully they can be integrated into the German labour market.

Abstract
This review essay discusses Welcome to the Desert of Post-Socialism: Radical Politics After Yugoslavia. This volume, edited by Srećko Horvat and Igor Štiks, critiques a reductive neoliberal narrative regarding the Balkans in relation to Western Europe by examining the disastrous consequences of the transition of post-socialist countries to capitalism. The volume provides a critical engagement with socialist Yugoslavia and an affirmation of the possibilities of radical anti-capitalist struggles. This review examines the critique of transition politics by focusing on concepts of stability, racism and questions of temporality.

Current local and national demographic trends have deepened the existing and formed new global demographic processes that have received a new historical reasoning that requires deep scientific research taking into account the influence of the multifactorial global dimension of the modern society development. The purpose of the article is to study the development of global demographic processes and to define the causes of their occurrence, manifestations, implications and prospects for implementation in the first half of the 21st century. The authors have identified and characterized four global demographic processes, namely population growth, migration, increase of tourism, and change in population structure. It is projected that in the 30's of the 21st century, the number and growth rates of the world population will reach the objective growth and these dynamics over the next two decades will begin to change in the direction of reducing the growth rates, which will lead to gradual stabilization, and eventually reduce the size of the world population. By the middle of the 21st century, one can observe the preservation of the growth rates of international and domestic migration, the growth of international migration flows from the South to the North and from the East to the West, the strengthening of new economically developed centers of gravity (Canada, Australia and New Zealand), the increase in migration of rural population to cities, as well as urbanization and activation of the metropolises development. The share of international tourists in comparison with the world population will be constantly increasing, and the annual growth rate of the number of international tourists will significantly depend on the world economy and may vary at the several percent level. Permanent change will occur in the age, religious-cultural and socio-economic structure of the population.