1,720,968 research outputs found
Malcolmia littorea: The isolated Italian population in the European context
No full textWe compared the coenological information of the only Italian population of Malcolmia littorea (L.) R.
Br. with published phytosociological relevés, including ones of this species, throughout its European
range. With the aim of highlighting the main climatic features influencing the distribution patterns of
M. littorea, we integrated coenological data with some climatic variables and considered major drivers
for plant distribution at the European scale. Finally, we analysed the population extent of M. littorea
in Italy, in order to assess its conservation status at regional level. The DCA analysis, performed on a
matrix 139 relevés
×183 species, separated the relevés according to their floristic composition, showing
a geographic gradient from Portugal to Mediterranean coasts, until Italy; with Mediterranean relevés
clearly separated from Atlantic ones as well. Along the beach-inland gradient, the analysis highlights
that the species is typical of fixed dunes habitats (more inland, mainly stabilised dunes), although in the
Atlantic it can also be found in mobile dunes. The analysis of climatic variables in relation to M. littorea
distribution, suggested that the species is sensitive to low winter temperature and to summer drought.
The only Italian population of M. littorea is subjected to many threats, due to its small dimensions (<1 ha),
isolation from the rest of its distribution area, that ranges from Portugal to France (until the Camargue
region) and intensive human disturbances. Using both field and remote sensing information, we showed a
considerable decrease of the occupied surface in Italy, leading us to suggest that the IUCN threat category
of M. littorea in Italy should be reassessed from endangered to critically endangered
Rediscovering the scientific and didactic value of minor herbarium collections: the seeds and fruits collection by Gustavo Bonaventura
Full text linkSeeds and fruits collections are very important from a systematic point of view and represent useful references in several disciplines and research fields. The Herbarium of Sapienza University of Rome (RO) hosts a Spermoteque/Carpoteque, which was organized by Gustavo Bonaventura (1902-1976). The purpose of this paper is to describe the heritage of Bonaventura's collection. It consists of 42 wooden boxes, globally hosting 3411 glass tubes containing seeds, fruits, and other materials. The collection was first of all catalogued; then, analysis were conducted regarding taxonomic composition, temporal and geographic coverage, institutions of provenience, collectors, content, and preservation status. The specimens refer to 2740 taxa, belonging to 890 genera and 135 families. Many genera of agricultural interest are present, each one with different cultivars. The collection spans across 130 years (1843-1975) and hosts specimens coming from all over the world. Materials were provided by several herbaria, botanical gardens and agrarian institutes, and by 50 collectors. The Bonaventura's collection is still a useful reference collection, testifying biodiversity over times and thus being useful for diachronic studies; moreover, it documents the interests of collectors and the past network activity between institutions
Woody flora as a predictor of vascular plant richness. An insight in Italy
No full textA key problem in quantifying biodiversity is whether it is possible to infer the overall diversity using suitable data subsets. The aim of this article, based on the updated data on the native woody flora of Italy, is to evaluate the reliability of such data as a predictor of vascular plant richness at a medium scale represented by the 20 administrative regions. Woody taxa were divided in trees, shrubs and lianas. We used stepwise multiple regression and principal component analysis to analyse the correlation between environmental heterogeneity, vascular plant units (species and subspecies) richness and woody units' richness. Woody flora of Italy consists of 61 families, 133 genera, 469 species and 509 units. Shrubs constitute 74% of the woody flora, trees and lianas of 23% and 3%, respectively. Both stepwise multiple regression analysis and two principal component analyses strongly suggest that woody units, and trees in particular, are correlated with total vascular plant richness, at all hierarchical taxonomical levels. The environmental heterogeneity has been demonstrated to be much more important than the area for the biodiversity of Italian regions. Woody flora, as a surrogate of total flora, is extremely useful for rapid assessments of overall vascular plant diversity that may be exploited for monitoring purposes
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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