Search results for "Terra"
showing 10 items of 4214 documents
Typification of the name Statice calcarae (Plumbaginaceae), basionym of the threatened endemic Limonium calcarae
2018
Limonium calcarae (basionym Statice calcarae), a rare diploid species endemic to Sicily, is one of the few members of the genus that occurs in the inland areas of the island. According to IUCN criteria, it has been assessed as critically endangered but recent data on its distribution, demography and threats affecting its populations are lacking. A lectotype is designated, preserved at PAL, and isolectotypes have been traced and verified in other European herbaria.
The Messinian stromatolites of the Sierra del Colmenar (Western Mediterranean): facies characterization and sedimentological interpretation
2018
A representative outcrop of the Messinian stromatolites belonging to the Terminal Carbonate Complex unit, from the northern sector of the Bajo Segura basin (Caja de Ahorros del Mediterraneo section, Sierra del Colmenar, SE Spain) has been studied. Here, we present a detailed analysis of the architecture, external morphology, and internal morphology in order to reconstruct the environmental and palaeoecological conditions for their growth. The stromatolites macrostructure consists of a continuously doming type morphology (build up and sheets areas).These developed close to the coast and acted as a palaeogeographic barrier, reducing physical stress, channeling the erosive effect of water and …
Karyology of Limonium (Plumbaginaceae) species from the Balearic Islands and the western Iberian Peninsula
2007
Somatic chromosome numbers, conventional karyotype features and idiograms are reported for 27 Limonium species inhabiting the Western Mediterranean basin (Iberian Peninsula and the Balearic Islands). The chromosome numbers of Limonium barceloi (2n = 36), L. ejulabilis (2n = 24), L. inexpectans (2n = 26), L. interjectum (2n = 24), and L. scopulorum (2n = 25) were determined for the first time. In addition, new aneuploid and/or polyploid cytotypes are reported in L. alcudianum (2n = 26), L. bonafei (2n = 26), L. camposanum (2n = 26), L. companyonis (2n = 26), L. dufourii (2n = 26), L. geronense (2n = 36), L. marisolii (2n = 54), L. migjornense (2n = 50), and L. pseudodictyocladon (2n = 16). A…
Unusually large magmatic CO2gas emissions prior to a basaltic paroxysm
2010
[1] The low-intensity activity of basaltic volcanoes is occasionally interrupted by short-lived but energetic explosions which, whilst frequently observed, are amongst the most enigmatic volcanic events in Nature. The combination of poorly understood and deep, challenging to measure, source processes make such events currently impossible to forecast. Here we report increases in quiescent degassing CO2 emissions (>10,000 t/day) prior to a powerful explosive event on Stromboli volcano on 15 March 2007. We interpret such large CO2 flux as being sourced by passive gas leakage from a deeply (>4 km) stored magma, whose depressurization, possibly caused by the onset of an effusive eruption on 28 F…
Mitochondrial DNA Regionalism and Historical Demography in the Extant Populations of Chirocephalus kerkyrensis (Branchiopoda: Anostraca)
2012
BackgroundMediterranean temporary water bodies are important reservoirs of biodiversity and host a unique assemblage of diapausing aquatic invertebrates. These environments are currently vanishing because of increasing human pressure. Chirocephalus kerkyrensis is a fairy shrimp typical of temporary water bodies in Mediterranean plain forests and has undergone a substantial decline in number of populations in recent years due to habitat loss. We assessed patterns of genetic connectivity and phylogeographic history in the seven extant populations of the species from Albania, Corfu Is. (Greece), Southern and Central Italy.Methodology/principal findingsWe analyzed sequence variation at two mito…
Background levels and baseline values of available heavy metals in Mediterranean greenhouse soils (Spain)
2011
Abstract This study determines extractable levels of Cd, Cu, Pb, Zn, Ni and Co in western Almeria (Spain) greenhouse surface soil horizons using EDTA solution, which is identified as the fraction available for organisms and plants. It also establishes background levels, geochemical baseline concentration and reference values (RV), and investigates the possible relationships between soil properties and elemental concentrations. The results show that the soil concentration of these extractable heavy metals was high as those reported by other authors for Spanish agricultural soils. The available RV concentrations obtained (mg kg −1 ) were: Cd 0.17, Cu 1.6, Pb 13.8, Zn 5.0 Ni 1.7 and Co 2.9. Us…
A New Framework for the Extraction of Contour Lines in Scanned Topographic Maps
2010
3D simulations requested in various applications had led to the development of fast and accurate terrain topography measurement techniques. In this paper, we are presenting a novel framework dedicated to the semiautomatic processing of scanned maps, extracting the contour lines vectors and building a digital elevation model on their basis, fulfilled by a number of stages discussed in detail throughout the work. Despite the good results obtained on a large amount of scanned maps, a completely automatic map processing technique is unrealistic and remains an open problem.
Holistic Approach to the Mediterranean Architectural Heritage at risk of abandonment: the case study of Montalbano Elicona (Italy)
2022
A conceptual and methodological renewal is needed in the field of formation, transformation and management of the built environment. This need also concerns the architectural heritage, a non-renewable resource threatened by various types of risk factors, including abandonment. A similar phenomenon (intended as a lack of usage, which leaves room for improper or harmful utilization) is juxtaposed with overuse (intended as too intense and continuous a usage), which today is even more unacceptable, due to the need for social distancing as part of the containment measures of COVID-19. There is a wide and varied case history regarding abandonment, with reference to possible causes and consequence…
Do small marinas drive habitat specific impacts? A case study from Mediterranean Sea
2011
Many human activities add new structures to the marine landscape. Despite the fact that human structures cause some inevitable impacts, surprisingly little information exists on the effects of marina on natural marine assemblages. The aim of this paper is to assess habitat-specific response of benthic sessile organisms of rocky shores in relation to the presence of a small marina. Sampling was carried out at three coastal habitats (midshore, lowshore and subtidal) by means of visual censuses adopting an after-control-impact (ACI) experimental design. It appears that the marina affects the structure and composition of benthic communities of both the midshore and the lowshore. Little effect w…
A SMALL INVADER CONQUERS SICILY: AMPHISTEGINA LOBIFERA (FORAMINIFERA: AMPHISTEGINIDAE)
2018
The highly invasive Amphistegina lobifera (Larsen, 1976), a benthic foraminiferal species native to the Red Sea, has colonized the Eastern Mediterranean through the Suez Canal and altered the native community structure. More recently, it has been reported from Malta and the Pelagian Islands within the Sicily channel. Here, we report new records from the southern coasts of Sicily, where we found it abundant both in the soft-bottom sediment and as epiphyt on algae. The occurrence of A. lobifera in Pantelleria and Favignana islands represents the Mediterranean westernmost record of this non-indigenous species.