1,721,045 research outputs found
Roberto Bonini, I « libri de cognitionibus » di Callistrato, 1964
No full textHubrecht Georges. Roberto Bonini, I « libri de cognitionibus » di Callistrato, 1964. In: Revue des Études Anciennes. Tome 67, 1965, n°3-4. pp. 554-555
Lichens and mosses as biomonitors of trace elements in areas with thermal springs and fumarole activity (Mt. Amiata, central Italy)
No full textThe contribution of thermal springs and fumaroles to environmental levels of Al, As, B, Cd, Cu, Fe, Hg, Mo, Pb, S, Sb and Zn was evaluated by means of lichens (Parmelia sulcata) and mosses (Hypnum cupressiforme) used as bioaccumulators. Compared to the data reported for unpolluted areas, accumulation of Hg, S and Al was found, with values of Hg and S in the same range as in the vicinity of geothermal power plants. Furthermore, fumaroles turned out to be a significant source of atmospheric arsenic
Is vascular plant species diversity a predictor of bryophyte species diversity in Mediterranean forests?
No full textThis study aimed to (i) investigate the congruence among the species composition and diversity of bryophytes and vascular plants in forests; (ii) test if site prioritization for conservation aims by the maximization of the pooled number of vascular plant species is effective to maximize the pooled number of bryophyte species. The study was performed in six forests in Tuscany, Italy. Four-hundred and twenty vascular plant species (61 of which were woody) and 128 bryophyte species were recorded in 109 plots. Despite the good predictive value of the compositional patterns of both woody plants and total vascular with respect to the compositional pattern of bryophytes, the species richness of the latter was only marginally related to the species richness of the former two. Bryophyte rare species were not spatially related to rare plant species and neither coincided with the sites of highest plant species richness. The species accumulation curves of bryophytes behaved differently with respect to those of woody plants or total vascular plants. Reserve selection analysis based on the maximization of the pooled species richness of either woody plants or total vascular plants were not effective in maximizing the pooled species richness of bryophytes. This study indicates that species diversity of vascular plants is not likely to be a good indicator of the bryophyte species diversity in Mediterranean forests
Epiphytic lichens and bryophytes of forest ecosystems in Tuscany (C. Italy)
No full textThe distribution of epiphytic bryophytes and lichens on three species of trees (Quercus ilex, Quercus cerris and Fagus sylvatica, representing the forest ecosystems of central Italy at low, medium and high elevations, respectively) was examined with respect to host specificity and habitat differences. Although most species were host-specific, the results suggested that habitat characteristics are more important than phorophyte properties in determining the distribution of lichens and bryophytes. Factors affecting the diversity of the epiphytic flora were different for lichens and bryophytes. In the case of lichens, climatic parameters and forest monospecificity were important factors, whereas tree cover (i.e. shade) and to a certain extent the number of available trees seemed more important for bryophytes
Orto Botanico di Siena: centro di biodiversità per la comunità
Full text linkLa storia del Museo Botanico attraverso gli anni conferma l’impronta dell’istituzione universitaria: insegnare, ricercare/coltivare e passare la conoscenza a pubblico/studenti. Un Giardino dei Semplici nel 1684, poi un Orto Botanico dal 1856 e dagli anni 2000 un Centro di conservazione e studio della biodiversità locale. Questa è, nella città del palio, l’immagine dell’Orto Botanico, che sta lavorando con pubblici diversi e vuole trovare una nuova dimensione all’interno della comunità cittadina, per svolgere la sua missione di centro culturale, di spazio verde nella città per svago e piacere, ma allo stesso tempo di luogo di comunicazione scientifica.The history of the Botanical Museum through the years confirms the imprint of the university institution: teaching, researching/cultivating and passing on knowledge to the public/students. A Giardino dei Semplici in 1684, then a Botanical Garden from 1856 and since the 2000s a Centre for the conservation and study of local biodiversity. This is the image of the Botanical Garden in the city of the Palio, which is working with different audiences and wants to find a new dimension within the city community, to carry out its mission as a cultural centre, a green space in the city for recreation and pleasure, but at the same time a place for scientific communication
Quantitative floristics as a tool for the assessment of plant diversity in Tuscan forests
No full textThe results of a floristic survey in six forests owned and managed by the regional administration of Tuscany are reported in this paper. These forests are undergoing a monitoring program, which includes biodiversity as one of the status indicators. Vascular plants are used as indicator species group to quantify biodiversity and they are assessed by means of quantitative floristics. This approach involves the collection of floristic information on the basis of a sampling design. Floristic and structural data were collected in 109 plots, each 400 m2 large, and analysed at both the plot and forest scales. At the plot scale, species richness was found to be unimodally related to elevation and negatively related to tree stem density and total basal area. At the forest scale, the six forests differed in their patterns of species accumulation, with the highest number of species for a given number of sites sampled observed in the intermediate elevation forests. The analysis of the life-form spectrum showed, for both the plot and forest scales, a decreasing importance of the relative abundance of phanerophytes and an increasing importance of the relative abundance of hemicriptophytes in relation to elevation. The use of the approach adopted for future monitoring is also discusse
Effects of nutrient addition on community productivity and structure of serpentine vegetation
No full textThe effects of a nutrient addition experiment on the plant biomass of garigue vegetation on ultramafic (serpentine) soils in Tuscany, Italy, were investigated. Although community composition was not significantly changed, fertilization had a significant positive influence on biomass production. The most affected species groups were woody species (chamaephytes and phanerophytes), annual grasses and annual forbs; the biomass increase of the perennial grasses and perennial forbs was statistically not significant. Soil extractable elements differed for calcium and potassium in the plots where they were added; sodium and nickel extractabilities were reduced by calcium addition due to the increased soil pH. Biomass production was linked more to major nutrient addition than to reduced nickel extractability, confirming that serpentine vegetation of Tuscany is mainly affected by nutritional stress rather than soil heavy metal content. The addition of calcium had a low effect on primary production of these ultramafic soils
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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