1,720,966 research outputs found
Body size - abundance relationships in Collembola vary among forest habitats along an altitudinal gradient
No full textDrivers of Centipede and Spider Diversity and Biomass Along an Elevation Gradient on Changbai Mountain, China
No full textABSTRACT In the context of global change, mountain ecosystems are facing more threats than ever. Therefore, understanding spatial distribution patterns of diversity and their driving factors on mountains is gaining increasing attention. Although comprising an essential component of terrestrial ecosystems, the structure of soil fauna communities in mountain ecosystems and their driving factors have been little studied. Changbai Mountain harbors one of the most well‐preserved forest ecosystems in the temperate zone. Its high biodiversity provides an ideal setting for investigating biodiversity patterns along elevation gradients. We investigated the diversity, biomass, and community composition of two key soil predator taxa—centipedes and spiders—across eight elevations ranging from 800 to 1850 m a.s.l. Furthermore, we explored correlations between community characteristics and environmental factors. A total of 26 centipede species were identified among 2796 individuals, while 76 spider species were recorded from 2327 individuals. Both centipede and spider richness, biomass, as well as spider density, decreased with increasing elevation. Climatic variables and litter quality were identified as the primary drivers influencing the richness, biomass, and community composition of both taxa. Specifically, changes in temperature and precipitation associated with elevation were identified as the main drivers of changes in diversity, biomass, and community composition. Litter quality, including litter pH, total phosphorus, total carbon, total nitrogen, and N/P ratio, was of secondary importance. Overall, the results provide critical insights into the vulnerability of soil fauna to global climate change and highlight the need for conservation strategies that account for the complex interactions between biodiversity and environmental change.National Natural Science Foundation of China https://doi.org/10.13039/501100001809Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
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
Correction to: Elevational changes in canopy Collembola community composition are primarily driven by species turnover on Changbai Mountain, northeastern China
No full textIntraspecific trait variation of carrion beetle species and communities across elevations
No full textAbstract Filtering processes across environmental gradients can structure patterns of trait variation within communities. The community‐weighted mean (CWM) is a metric that is commonly used to indicate the directionality of such filtering processes and the optimal adaptive strategy of taxa within community. Proximity to the CWM indicates higher fitness, and deviations from this optimal value result in changes in the relative abundances of coexisting species. We investigated patterns of intraspecific trait variation in four coexisting carrion beetle species (Coleoptera: Silphidae) across elevational gradients. The study was conducted in temperate forest ecosystems with distinct natural vegetation zones ranging from 950 m to 1700 m above sea level. Of the 12 traits measured, we found that intraspecific variation ranged from 34% (body length) to 100% (ratio of elytra length, head length and head width to body length) and accounted for a larger proportion of variation than interspecific variation in 7 traits. For most traits, trait range, which indicates the niche breadth of species at a given elevation, was positively correlated with relative abundance. The CWMs of traits associated with long‐distance dispersal decreased with elevation, whereas those associated with microhabitat use showed the opposite trend. Soil temperature influenced tibia length after controlling for the effects of species identity, but soil water content had no effect on trait variation. Patterns of variation in body width and thorax width of two beetle species supported the CWM‐optimality hypothesis; however, patterns of trait variation in body width and thorax length of another species showed an opposite trend. Our study identifies several traits that can be highly variable within carrion beetle species. Such high levels of intraspecific trait variation may enable populations to adapt across a wide range of elevations and vegetation types.National Natural Science Foundation of China https://doi.org/10.13039/501100001809China Scholarship Council https://doi.org/10.13039/50110000454
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
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