Search results for "Geografia"
showing 10 items of 1008 documents
Origin and distribution of desert ants across the Gibraltar Straits
2017
The creation of geographic barriers has long been suspected to contribute to the formation of new species. We investigated the phylogeography of desert ants in the western Mediterranean basin in order to elucidate their mode of diversification. These insects which have a low dispersal capacity are recently becoming important model systems in evolutionary studies. We conducted an extensive sampling of species belonging to the Cataglyphis albicans group in the Iberian Peninsula (IP) and the northern Morocco (North Africa; NA). We then combined genetic, chemical and morphological analyses. The results suggest the existence of at least three and five clades in the IP and NA, respectively, whose…
Eco-geomorphological connectivity and coupling interactions at hillslope scale in drylands: Concepts and critical examples
2020
The diagnosis of land degradation requires a deep understanding of ecosystem functioning and evolution. In dryland systems, in particular, research efforts must address the redistribution of scarce resources for vegetation, in a context of high spatial heterogeneity and non-linear response. This fact explains the prevalence of eco-hydrological perspectives interested in runoff processes and, the more recent, focused on connectivity as an indicator of system resource optimisation. From a geomorphological perspective and reviewing the concepts of eco-hydro-geomorphological interactions operating in ecosystems, this paper explores the effects of erosion on vegetation configuration through two …
Multilocus phylogenetics of smooth clam shrimps (Branchiopoda, Laevicaudata)
2021
International audience; Laevicaudatan branchiopods, also called ‘smooth clam shrimps’ or ’pea shrimps’, are rare crustaceans found exclusively in temporary, small freshwater bodies, which stay dry most of the year. Only 42 laevicaudatan species have been described so far, 90% of which belong to the genus Lynceus. The first multilocus phylogeny of the group is provided here, based on 15 Lynceus species from North and South America, Europe, Africa, Asia, Australia and New Caledonia and using nine molecular markers (two mitochondrial and seven nuclear genes, including newly designed primers). Genetic data suggest populations of Lynceus brachyurus from Europe and North America to represent a co…
Cave-adapted campodeids (Hexapoda, Diplura, Campodeidae) from the Dinarides and adjacent karst regions
2021
Five new species are described, Plusiocampa (Didymocampa) cvijici Sendra & Antić, sp. nov., Plusiocampa (Plusiocampa) atom Sendra & Antić, sp. nov., Plusiocampa (Stygiocampa) barethae Sendra & Rađa, sp. nov., Plusiocampa (Stygiocampa) dulcici Sendra & Rađa, sp. nov. and Plusiocampa (Venetocampa) pirnati Sendra & Borko, sp. nov. This brings the number of cave-adapted species of campodeids known from the Dinarides, Eastern Alps, Balkan System and Rodope Massif to 28 (one species in the genus Campodea and 27 in Plusiocampa). Among Plusiocampa, four out of five subgenera are present (Pentachaetocampa is not present in the region studied): Didymocampa (one species), Plusiocampa s. str. (15 speci…
Exploring relationships between grid cell size and accuracy for debris-flow susceptibility models: a test in the Giampilieri catchment (Sicily, Italy)
2016
Debris flows are among the most hazardous phenomena in nature, requiring the preparation of suscep- tibility models in order to cope with this severe threat. The aim of this research was to verify whether a grid cell-based susceptibility model was capable of predicting the debris- flow initiation sites in the Giampilieri catchment (10 km2), which was hit by a storm on the 1st October 2009, resulting in more than one thousand landslides. This kind of event is to be considered as recurrent in the area as attested by historical data. Therefore, predictive models have been prepared by using forward stepwise binary logistic regression (BLR), a landslide inventory and a set of geo- environmental …
Outlook from the soil perspective of urban expansion and food security
2021
The use of soil as support for built-up areas represents only one of its several functions. Farmlands at the fringe of conurbations have more chance of being converted into built-up areas due to the favourable topography and the accessibility to existing infrastructure, being in the vicinity of urban areas. We analysed the global land-take during the period 2000–2014. The data are based on a global dataset describing the spatial evolution of human settlements using the Global Human Settlement Layer, which was derived from Landsat images collected in 1975, 1990, 2000 and 2014. Although the global land-take represents roughly 0.1% of the global terrestrial Earth, it affects 1% of the naturall…
Una segregazione paradossale e multi-scalare: il caso del quartiere ZEN di Palermo
2016
L’articolo affronta la questione della segregazione nel quartiere ZEN di Palermo (Sicilia). L’impianto teorico dialoga con la letteratura anglosassone, ma ne prende le distanze nel tentativo di individuare alcune specificità locali del caso. L’obiettivo è duplice: intanto indentificare alcuni “movimenti geostorici” che hanno caratterizzato il quartiere, collegando a ciascuno di questi una fase del processo segregativo; inoltre, rappresentare la segregazione del quartiere in forma cartografica, mediante l’uso di alcuni ideogrammi e mappe mentali. This article deals with the issue of segregation in the ZEN district of Palermo, Sicily. The theoretical framework is built around Anglo-Saxon refe…
Environmental problems and Geographic education. A case study: Learning about the climate and landscape in Ontinyent (Spain)
2021
AbstractCultural perceptions of the environment bring us back to elements and factors guided by “natural” cause-effect principles. It seems that academic education has had little effect on the manner and results of learning about changes in the local landscape, especially as regards rational explanations. There is considerable difficulty relating academic concepts about the climate to transformations in the environmental landscape. Teaching tasks are mediatized due to the use of rigorous and precise concepts which facilitate functional and satisfactory learning. This is the objective of the research this article aims to undertake, for which we have chosen the case of Ontinyent (Spain). This…
Migración residencial y urbanismo expansivo en el mediterráneo español
2015
Este artículo investiga la migración internacional de jubilados noreuropeos hacia España y su influencia en el desarrollo del urbanismo expansivo en nuestro país. Los temas clave que en este artículo se analizan son la expansión del urbanismo expansivo durante la burbuja inmobiliaria española, la cantidad y distribución de los jubilados noreuropeos residentes en España, y la relación entre la llegada de dichos migrantes residenciales y la difusión del urbanismo expansivo. Este artículo explica los motivos de esta migración residencial, que están principalmente relacionados con el clima y el estilo de vida mediterráneos. También describe los beneficios y los inconvenientes de dicha migración…