Search results for " HABITAT"
showing 10 items of 267 documents
Grouping facilitates avoidance of parasites by fish
2013
Background. Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods. Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish co…
Invasive Aliens in Italy: Enumeration, History, Biology and Their Impact
2021
Italy includes two large islands, Sardinia and Sicily, and a peninsula separated from the European continent by the Alpine Arch. At national level ISPRA (Instituto Superiore per la Protezione e la Ricerca Ambientale, Higher Institute for Environmental protection and research) is the instrument of the Ministry of Environment and for the Protection of the Territory and the Sea to carry out its mission, including the study, monitoring, and control of invasive alien species. Universities, Scientific Societies, and ONGs play a vital role in basic research. The interest in the study of alien plants is of a theoretical nature, as regards the migrations of living beings and interactions with native…
Regime shifts and alternative stable states in intertidal rocky habitats: State of the art and new trends of research
2018
Abstract The existence of regime shifts and alternative stable states in ecosystems is well known and has very large effects on their structure and dynamics. Since shifts between alternative stable states have significant implications for the ecosystems conservation, their prevention should be an aim of primary interest, and for this reason a particular attention has been paid to their study. Regarding marine ecosystems, rocky intertidal habitats, in particular, represent an ideal system for the study of alternative stable states because of their characteristics: they exhibit strong environmental gradients, are easy to manipulate, and most of the inhabiting species grow rapidly. Given the s…
L’habitat perché du Malpas à Soyons (Ardèche) durant l’Antiquité tardive : état des données
2023
International audience; Recent excavations carried out between 2011-2016 in the ancient and medieval town of Soyons (Ardèche), located in the middle Rhône valley, in the territory of the roman colony of Valence, provide us new data on the occupation of the hilltop of Le Malpas.The study of the fortification of the Iron age has revealed the existence of a rampart built during the 3rd century AD. At this time, the lower city, under the actual village, is gradually abandoned. After a probable hiatus during the 4th century AD, the hilltop and the lower city grew again during the 5th and the 6th century AD. The late antique artefacts discovered in all the trenches dug on the Malpas let us assume…
Comunidad, consolidación urbana y políticas de vivienda social. Una mirada desde Colombia y la ciudad de Tunja, Boyacá / / / \ \ \ Community policies…
2020
Resumen: Las ciudades latinoamericanas presentan múltiples problemáticas urbanas, entre ellas el crecimiento a saltos y los vacíos urbanos que deja la autoconstrucción de viviendas, todo en un marco de desigualdad en la distribución del suelo, con soluciones de planeación insuficientes, alejadas de la realidad de las comunidades, y poco eficaces en la mitigación del déficit de calidad de las viviendas y del hábitat urbano. Se estudia el caso de esta ciudad mediana, el análisis a su política urbana y de vivienda social, la mirada de los gestores públicos y la perspectiva que tiene la comunidad, todo con el fin de encontrar propuestas de mejora que procuren una consolidación del entorno urban…
First record of Lindenia tetraphylla (Vander Linden, 1825) and rediscovery of Orthetrum nitidinerve (Selys, 1841) in Sicily (Insecta: Odonata)
2017
The first Sicilian record of Lindenia tetraphylla and a new regional record of Orthetrum nitidinerve, species not recorded since 1975 in mainland Sicily, are here reported. All individuals of L. tetraphylla and O. nitidinerve were observed in the same site in the province of Trapani.
Infrastructura Naturans. Architetture di trasformazione della circonvallazione di Palermo
2022
The article discusses the theoretical system that supports design themes and processes of recycling large urban road infrastructures, referring to an international research that frames them among the sustainable regeneration processes of the contemporary city, and further evoking the project for the transformation of Palermo's ring road that has been elaborated within this research. Witnesses of past urban seasons, these infrastructures are marked by a peculiar morphology that deserves to be maintained, while they must emancipate themselves from asphalt and adapt to new urban mobilities. By hybridizing vegetation and buildings as never before, the longest roadways in our urban contexts may …
No room for males in caves: Female-biased sex ratio in subterranean amphipods of the genus Niphargus.
2021
Sex allocation theory predicts that the proportion of daughters to sons will evolve in response to ecological conditions that determine the costs and benefits of producing each sex. All else being equal, the adult sex ratio (ASR) should also vary with ecological conditions. Many studies of subterranean species reported female-biased ASR, but no systematic study has yet been conducted. We test the hypothesis that the ASR becomes more female-biased with increased isolation from the surface. We compiled a data set of ASRs of 35 species in the subterranean amphipod Niphargus, each living in one of three distinct habitats (surface-subterranean boundary, cave streams, phreatic lakes) representing…
Il litorale di Manfria (Gela) -
2010
Questo studio illustra il notevole patrimonio ambientale del Sito d'Interesse Comunitario "Torre Manfria", area tutelata ai sensi della Direttiva 92/43 CEE. Poiché l'area si trova nel comune di Gela, caratterizzato da una densità abitativa tra le più alte della Sicilia, l'occasione è buona anche per riflettere sui temi centrali del rapporto uomo-ambiente, prendendo spunto dagli innumerevoli esempi offerti dalla realtà locale. Ciò è stato fatto con la speranza di suscitare interesse verso un vivere "altro", che riconosca il valore della cultura, della conoscenza, dell'interazione virtuosa, facendosi ispirare dalla bellezza sobria ed essenziale degli ecosistemi.
A geo-statistical predictive approach to the Habitat mapping of Vulnerable Marine Ecosystems along the northern Sicily inner continental shelf (south…
2016
The main aim of this work is to statistically predict the distribution of Vulnerable Marine Ecosystems (VMEs) along the continental shelf regions of the northern Sicilian margin (southern Mediterranean). The considered habitats, already mapped in the area on a qualitative base, are the Posidonia oceanica and Cymodocea nodosa seagrasses and the Coralligenous biocenosis. Posidonia oceanica and Coralligenous are considered as VMEs owing to their value as environmental indicators and biodiversity hotspots in coastal marine areas. For this reason, several actions were aimed in recent years to their complete characterization and mapping. The study area is located in the continental shelf of the n…