Search results for " ECOLOGY"
showing 10 items of 2331 documents
Qanāts and historical irrigated landscapes in Palermo’s suburban area (Sicily)
2020
La città di Palermo e la sua valle circostante sono un importante paesaggio storico irriguo, caratterizzato da strutture idrauliche sotterranee e da una lunga tradizione di sistemi di irrigazione ereditati dalla presenza islamica in Sicilia nel medioevo (IX-XI secolo). La “rivo- luzione verde” islamica ha radicalmente innovato i sistemi di irrigazione siciliani e questo portò all’introduzione e alla diffusione di nuove specie coltivate. Nell’area suburbana di Pa- lermo sono stati indagati 63 infrastrutture idrauliche e tunnel di scolo, classificati in 4 ca- tegorie: 1) qanāts; 2) qanāts ciechi; 3) pozzi collegati; 4) gallerie di scolo emergenti. Que- ste strutture, nonostante alcuni dubbi c…
Vegetation series as a marker of interactions between rural settlements and landscape: new insights from the archaeological record in Western Sicily
2020
[EN] Plant communities are complex and dynamic elements of the landscape, intertwined with both natural factors and human activities. Vegetation series reflect the environmental characteristics of the landscape, but also the anthropic impact, one of the exogenous forces that most profoundly affects the landscape formation process. This paper aims to investigate the interactions between long-term human settlement catchment areas and vegetation series. The case study area of the Sicani Mountains (Central-Western Sicily) proved to be an ideal place to perform GIS-based spatial analysis in order to compare a data set of rural archaeological sites and land units created through the mapping of ve…
La terre : un bien hors du commun. De l'utopie à la révolution foncière
2018
International audience; La terre manque toujours cruellement d'un droit à sa démesure. Indispensable à la plupart des activités humaines, cette ressource naturelle est saisie par un ensemble disparate de règles au prix, trop souvent, d'une négation de ses qualités. « À vouloir "forcer" la terre, écrivait Pisani, nous prenons, en effet, le risque de la voir se dérober »2. De là, un mal bien terrestre de notre société, qui affecte aussi bien la chose elle-même que ses habitants. Les symptômes portent les noms d'accaparement, d'artificialisation, de surexploitation, de dégradation. Ils sont suffisamment graves pour justifier la création d'un authentique système foncier, projet politique encore…
Global urban environmental change drives adaptation in white clover
2022
Made available in DSpace on 2022-04-28T19:52:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-18 Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied am…
La pluralità dello spazio pubblico: una analisi ricognitiva nel centro storico di Palermo
2011
La letteratura inerente allo sviluppo urbano moderno e postmoderno, da Michel Foucault a Henri Lefebvre, ha aperto un dibattito in merito alla concezione classica di apertura/accessibilità dello spazio pubblico, evidenziando aspetti quali la esclusione spaziale, la sorveglianza e il controllo sociale, la questione del “diritto alla città”. Si assiste ad una progressiva riduzione o sostituzione dello spazio pubblico – privatizzato, fortificato, commercializzato – di cui risentono in primis i soggetti più deboli e marginali. Talvolta emergono nuove forme di produzione sociale dello spazio, ad esempio tramite riappropriazione informale di “luoghi di scarto”. Il lavoro di ricerca ha focalizzato…
Understanding the microbial biogeography of ancient human dentitions to guide study design and interpretation
2021
AbstractThe oral cavity is a heterogeneous environment, varying in factors such as pH, oxygen levels, and salivary flow. These factors affect the microbial community composition and distribution of species in dental plaque, but it is not known how well these patterns are reflected in archaeological dental calculus. In most archaeological studies, a single sample of dental calculus is studied per individual and is assumed to represent the entire oral cavity. However, it is not known if this sampling strategy introduces biases into studies of the ancient oral microbiome. Here, we present the results of a shotgun metagenomic study of a dense sampling of dental calculus from four Chalcolithic i…
Changement climatique et suivi de la biodiversité marine côtière aux Iles Kerguelen
2018
Nearshore marine habitats of the French sub-Antarctic islands concentrate a rich and unique biodiversity that is currently facing climate change and its still not well-understood and multifaceted effects. Understanding the impact of these changes and predicting the potential response of ecosystems requires advanced knowledge of marine life and the achievement of uninterrupted and long-term observing programs. The Proteker program, no. 1044 of the French Polar Institute Paul-Émile Victor, has been developped in partnership with the National Nature Reserve of French Southern Territories in order to establish an observatory of coastal marine biodiversity in the Kerguelen Islands and evaluate t…
Living Coccolithophores from the Gulf of Sirte (Southern Mediterranean Sea) during the summer of 2008
2012
The Gulf of Sirte is a largely unexplored area in the southernmost Mediterranean Sea.We are presenting here 2008 summer data on the distribution pattern of living coccolithophores, a main phytoplankton calcifying group, in 105 samples from 20 stations. The survey includes coastal and offshore stations, enabling us to provide indications on the dynamics of phytoplankton productivity in relation to oceanographic processes. The total coccosphere concentrations show higher values in the offshore stations and lower ones for coastal sites. Umbellosphaera tenuis, Emiliania huxleyi, Florisphaera profunda, Syracosphaera pulchra HOL (Calyptrosphaera oblonga) and Rhabdosphaera spp. dominate the assemb…
The giant panda is cryptic
2021
The giant panda (Ailuropoda melanoleuca) is an iconic mammal, but the function of its black-and-white coloration is mysterious. Using photographs of giant pandas taken in the wild and state-of-the-art image analysis, we confirm the counterintuitive hypothesis that their coloration provides camouflage in their natural environment. The black fur blends into dark shades and tree trunks, whereas white fur matches foliage and snow when present, and intermediate pelage tones match rocks and ground. At longer viewing distances giant pandas show high edge disruption that breaks up their outline, and up close they rely more on background matching. The results are consistent across acuity-corrected c…
Improved camouflage through ontogenetic colour change confers reduced detection risk in shore crabs
2019
Abstract Animals from many taxa, from snakes and crabs to caterpillars and lobsters, change appearance with age, but the reasons why this occurs are rarely tested.We show the importance that ontogenetic changes in coloration have on the camouflage of the green shore crabs (Carcinus maenas), known for their remarkable phenotypic variation and plasticity in colour and pattern.In controlled conditions, we reared juvenile crabs of two shades, pale or dark, on two background types simulating different habitats for 10 weeks.In contrast to expectations for reversible colour change, crabs did not tune their background match to specific microhabitats, but instead, and regardless of treatment, all de…