1,721,042 research outputs found
Specie rare e di interesse conservazionistico di un settore poco conosciuto dell'Appennino centrale (Cittareale, Rieti).
No full textTHE POWER OF POTENTIAL NATURAL VEGETATION (AND OF SPATIAL TEMPORAL SCALE): A RESPONSE TO CARRION & FERNANDEZ (2009).
No full textA commentary by Carrión & Fernández (Journal of Biogeography, 2009, 36, 2202–2203) compared Holocene pollen records with models of potential natural vegetation (PNV) proposed in the phytosociological literature and concluded that the predicted PNV resulted from anthropogenic disturbance. However, the authors misinterpreted PNV, leading to two serious flaws in their assumptions: (1) PNV is not defined as a pre-anthropic or climax plant community; and (2) PNV is not a concept restricted to the phytosociological method. Therefore we criticize the conclusions expressed in the commentary, and we stress the need for an interdisciplinary approach based on multi-temporal and multi-spatial scales to achieve a modern framework for the study of plant communities
Between global priorities and local urgencies: The important plant areas programme in Italy
No full textGlobal priorities for the conservation of biodiversity assume a key role in determining the national priorities and the research agenda. The "Important Plant Areas in Italy" project, promoted by the Italian Ministry for the Environment, Nature Protection Directorate through a programme aimed at mapping the IPAs, represents an important contribution to the planning of strategies designed to enhance biodiversity conservation. The national working group, co-ordinated by the Inter-university research centre for "Biodiversity, Plant sociology and Landscape ecology" of the "Sapienza" University of Rome and composed of a network of 100 botanical experts was set up to obtain original information and draw up a detailed, nationwide picture of the situation in Italy. Important Plant Areas were identified on the basis of a range of taxonomic groups (such as vascular plants, bryophytes, freshwater algae, lichens and fungi) and habitats in order to promote an integrated model of knowledge for the conservation of plant diversity. Each of the selected vascular plants and habitats was assigned a conservation value on a regional basis. An approach based on the overlapping of the species and habitat maps was used to identify the most important areas for plant diversity and to pinpoint any "hotspots" of richness and diversity. Hence, polygons were defined within the cells of high conservation value and/or containing high vascular species and habitat richness (grid approach). A total of 320 IPAs were identified in Italy (including 8 fresh water algae community sites), covering approximately 15% of the country. Regional results highlighted the extreme heterogeneity of available data and the need for new basic research projects designed to integrate and update the information currently available on the distribution of plant species (vascular plants, bryophytes, freshwater algae, lichens), fungi and habitats in our country. Considering the global emerging issues but acting at local level, the results yielded by this project may be exploited for interventions of various kinds, ranging from the choice of protected areas to urban planning
Rilevanza ecologica delle briofite degli stagni temporanei della Sardegna Congresso della Società Botanica Italiana
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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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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