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Migration Histories (migration + history)
Selected AbstractsCaribbean Transnational Return Migrants as Agents of ChangeGEOGRAPHY COMPASS (ELECTRONIC), Issue 1 2007Dennis Conway This article challenges several of the firmly held convictions drawn from extant research on return migration to the Caribbean. For many contemporary small island societies undergoing rapid change and transformation, modernization and integration into the wider global economy, today's younger and more youthful return migrants are no longer an ineffective demographic cohort. Despite their numerically small size, many are demonstrating they can be influential "agents of change." No longer merely returning retirees, they are more diverse, in terms of age, life-course transitions, class and gendered social positions, family networks, and migration histories. Multiple identities are the rule, rather than the exception, as returnees of different ages choose to live, work (and play) in island society, to give something back to the island home of their parents or of their youth. Many embrace transnational strategies to live in and between two worlds, or more if their family network's reach is multilocal. [source] Environmental signature in the otolith elemental fingerprint of the tapertail anchovy, Coilia mystus, from the Changjiang estuary, ChinaJOURNAL OF APPLIED ICHTHYOLOGY, Issue 5 2006J. Yang Summary The ontogenetic patterns of habitat use and the migratory history of the tapertail anchovy, Coilia mystus, collected in the Changjiang estuary around Chongming Island, China, were studied by examining the environmental signature in the otolith strontium (Sr) and calcium (Ca) fingerprints using electron probe microanalysis (EPMA). Our results suggest that the migration strategy of C. mystus is much more flexible than supposed in the literature to date. The spring spawning population of C. mystus from the studied area was found to consist of individuals with different migration histories. Although the tapertail anchovy seems to be an anadromous fish that spawns and hatches in a freshwater habitat, it can also use a freshwater environment in non-spawning seasons. The otolith EPMA of the elemental fingerprint (Sr x-ray maps and Sr : Ca ratios) is an environmental indicator that can be applied to the migratory ecology of other important diadromous species in China. [source] Intraregional Migration, Direct Action Land Reform, and New Land Settlements in the Brazilian AmazonBULLETIN OF LATIN AMERICAN RESEARCH, Issue 4 2010STEPHEN G. PERZ This article analyses migration histories of residents in rural settlements of the Brazilian Amazon that resulted from direct action land reform (DALR), which involves organised land occupations. Our analysis evaluates two hypotheses. The ,urban migration' expectation asserts that urban experience is important for DALR participation, which links rural and urban areas via migration for land occupations. The ,DALR efficacy' hypothesis argues that migration and DALR are complementary livelihood strategies, such that participation in DALR obviates the need for further migration. Our findings support both hypotheses and bear implications for regional development and environmental change in the Amazon. [source] Phytogeographical evidence for post-glacial dispersal limitation of European beech forest speciesECOGRAPHY, Issue 6 2009Wolfgang Willner The post-glacial migration of European beech Fagus sylvatica has been addressed by many studies using either genetic or fossil data or a combination of both. In contrast to this, only little is known about the migration history of beech forest understorey species. In a review of phytosociological literature, we identified 110 plant species which are closely associated with beech forest. We divided the distribution range of European beech forests into 40 geographical regions, and the presence or absence of each species was recorded for each region. We compared overall species numbers per region and numbers of narrow-range species (species present in <10 regions). A multiple regression model was used to test for the explanatory value of three potential diversity controls: range in elevation, soil type diversity, and distance to the nearest potential refuge area. A hierarchical cluster analysis of the narrow-range species was performed. The frequency of range sizes shows a U-shaped distribution, with 42 species occurring in <10 regions. The highest number of beech forest species is found in the southern Alps and adjacent regions, and species numbers decrease with increasing distance from these regions. With only narrow-range species taken into consideration, secondary maxima are found in Spain, the southern Apennines, the Carpathians, and Greece. Distance to the nearest potential refuge area is the strongest predictor of beech forest species richness, while altitudinal range and soil type diversity had little or no predictive value. The clusters of narrow-range species are in good concordance with the glacial refuge areas of beech and other temperate tree species as estimated in recent studies. These findings support the hypothesis that the distribution of many beech forest species is limited by post-glacial dispersal rather than by their environmental requirements. [source] Refugia, differentiation and postglacial migration in arctic-alpine Eurasia, exemplified by the mountain avens (Dryas octopetala L.)MOLECULAR ECOLOGY, Issue 7 2006INGER SKREDE Abstract Many arctic-alpine organisms have vast present-day ranges across Eurasia, but their history of refugial isolation, differentiation and postglacial expansion is poorly understood. The mountain avens, Dryas octopetala sensu lato, is a long-lived, wind-dispersed, diploid shrub forming one of the most important components of Eurasian tundras and heaths in terms of biomass. We address differentiation and migration history of the species with emphasis on the western and northern Eurasian parts of its distribution area, also including some East Greenlandic and North American populations (partly referred to as the closely related D. integrifolia M. Vahl). We analysed 459 plants from 52 populations for 155 amplified fragment length polymorphisms (AFLP) markers. The Eurasian plants were separated into two main groups, probably reflecting isolation and expansion from two major glacial refugia, situated south and east of the North European ice sheets, respectively. Virtually all of northwestern Europe as well as East Greenland have been colonized by the Southern lineage, whereas northwest Russia, the Tatra Mountains and the arctic archipelago of Svalbard have been colonized by the Eastern lineage. The data indicate a contact zone between the two lineages in northern Scandinavia and possibly in the Tatra Mountains. The two single populations analysed from the Caucasus and Altai Mountains were most closely related to the Eastern lineage but were strongly divergent from the remaining eastern populations, suggesting survival in separate refugia at least during the last glaciation. The North American populations grouped with those from East Greenland, irrespective of their taxonomic affiliation, but this may be caused by independent hybridization with D. integrifolia and therefore not reflect the true relationship between populations from these areas. [source] | |||||||||||||