1,720,955 research outputs found
Plant diversity dynamics by an extensive chronosequencial approach in the Beech coppices in the Central Apennines (Italy).
No full textIndagine storico catastale e aereofotogrammetrica delle aree di indagine.
No full textRelazione tecnico-scientific
Assessing the effect of landuse in beech forests an example from central Apeninnes, Italy.
No full textIn the mountain belt of the Marches region (Central Apennines, Italy), coppice
management is applied to 70% of beech (Fagus sylvatica) woodlands. This
method has long played an important socio-economic role, providing firewood
and charcoal. Currently 4% of present beech woodlands are being converted to
high forest, while in 21%, silviculture is being abandoned entirely. We aimed to
answer these questions: (1) How does traditional management (short rotation
coppice) affect beech forest plant diversity at different environmental conditions?
(2) How is plant diversity influenced by an extension of the rotation cycle or by
the abandonment of coppicing? Previous investigations on plant diversity relations
in coppice woods focused on limited areas and small numbers of stands, while it
would be much more useful for management applications to have diversity
assessments on the scale of the landscape. After preliminary selection of a number
of forest stands, stratified sampling was conducted according to 200 m elevation
classes (starting from 1000 m a.s.l.), bedrock types (limestone and sandstone), and
stand age (10-year classes, since the last coppicing), to identify 61 sites (0.3 to 35
ha) that would represent the landscape level heterogeneity. Within each stratum a
proportional number of stands were randomly selected among those included in
the forestry registers. Orthophotomaps and related cadastral information were
derived using an Information System. Elevation was used as a proxy variable
accounting for the main beech forest types reported in the regional forest
inventory, which also stated soil and stand conditions. The beech forests belong to
Cardamino kitaibelii-Fagetum and Lathyro veneti-Fagetum associations on
neutro-basic limestone and Solidagini-Fagetum on acidic sandstone. Eighty plots
of 20×20 m were assessed by phytosociological records, within the selected
forests stands. Species were grouped into phytocoenological groups. Our results
suggest that high spatiotemporal variability of forest management accompanied
with high landscape-scale heterogeneity and complexity maintain rich regional
species pool. On both bedrocks, in all elevation classes, the age after coppicing
explained the majority of observed diversity changes at the stand level: forest
specialists increased while non-forest species decreased. A relatively long time
after coppicing (40–60 years), the contribution of the beech specialist species
doubled, while non-forest and species from anthropogenic habitats decreased by
about 50%. On sandstone, gap species also diminished over a long period, and the
beech stands experienced stronger changes over time. We conclude that an
extension of coppice rotation cycle or abandonment would result in lower local
species richness but with higher contribution of beech forest specialists
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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