1,720,995 research outputs found
Effect of tree species and soil properties on nutrient immobilization in the forest floor
No full textForest floor chemistry under seven tree species along a soil fertility gradient
No full text Forest floor chemistry, i.e., C/nutrient ratios, pH, and element contents, were determined in stands of two deciduous species and five conifer species replicated at seven sites along a soil fertility gradient. There were consistent differences between forest floors of the tree species. Lodgepole pine (Pinus contorta Dougl.) forest floors had highest C/nutrient ratios, lowest pH, and the greatest element contents, whereas oak (Quercus robur L.) forest floors had low C/nutrient ratios and the lowest element contents of all species. Differences in forest floor C/nutrient ratios, pH, and element contents between sites of low nutrient status and sites of intermediate to high nutrient status were also great. Forest floor pH was related to mineral soil pH, and C/P, C/Ca, and C/K ratios were related to mineral soil nutrient concentrations. Forest floor C content was negatively related to most mineral soil fertility variables and was closest related to texture, pH, and concentrations of P and Ca. The C content of lodgepole pine and oak forest floors tended to be less affected by the soil fertility gradient. The results suggest that C storage and immobilization of nutrients in forest floors may be managed along an extensive soil gradient by selection of the proper tree species. </jats:p
Effect of tree species and soil properties on nutrient immobilization in the forest floor
No full text
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
- …
