1,721,101 research outputs found
An interdisciplinary approach for evaluation of temporal-spatial heterogeneity of colour distribution and canopy development on an alpine test site
No full textAuthor Correction: Species richness and beta diversity patterns of multiple taxa along an elevational gradient in pastured grasslands in the European Alps (Scientific Reports, (2020), 10, 1, (12516), 10.1038/s41598-020-69569-9)
No full textCorrection to: Scientific Reportshttps://doi.org/10.1038/s41598-020-69569-9, published online 27 July 2020 The original version of the Article contains an error. The Data Availability section is incomplete. “All species recorded during this study are included in Supplementary Information files of this article.” should read: “The datasets generated and analyzed during this study are not publicly available due to the presence of rare and endangered species at the study sites. However, they are available from the corresponding author upon reasonable request. Site locations and a list of all species recorded in this study are included in the Supplementary Information files of this article.
The consequences of elevated CO² and land use in alpine ecosystems
Full text linkThe consequences of elevated CO2 and land use in alpine ecosystems
This PhD thesis addresses two main aspects of Global Change and their impacts on alpine vegetation and eco-hydrology, (1) the steadily increasing concentration of CO2 in the atmosphere as well as (2) land use and its current decline across the Alps. Current and future rises of atmospheric CO2 concentration are commonly expected to stimulate photosynthesis and to reduce carbon limitation of plant growth. Whether this hypothesis holds for high-elevation pioneer plants in glacier forefields, which were suggested to be particularly responsive, was explored in a CO2 enrichment experiment in the Swiss central Alps. As a second direct biological effect, elevated CO2 often diminishes the water consumption of vegetation by a reduction in stomatal opening. These water savings should translate into temporally increased soil water contents and greater total runoff (the sum of all drainage processes). This question was combined with a second driver of evapotranspiration (ET), the density and height of vegetation. Biomass removal by land use likely reduces water vapour losses in alpine grassland, which should lead to increased runoff as well. Since land use is continuously declining across the Alps, the consequences of the subsequent vegetation transformation on the water balance of alpine grassland and finally, on water yield of alpine catchments were explored over an East to West gradient across the Alpine Arc together with partners in France and Austria.
Three seasons of free-air CO2 enrichment (FACE) at 2440 m a.s.l. revealed that none of the nine glacier forefield species grown in assemblages were stimulated by elevated CO2 throughout the course of the experiment, irrespective of any fertilizer addition, which by itself significantly enhanced growth. With a great robustness across species and growth conditions, our results thus suggest that glacier forefield pioneers, growing under harsh climatic conditions are not carbon limited at current atmospheric CO2 concentration. To quantify the partly opposing effects of elevated CO2 (more runoff) and land use abandonment (less runoff) on the water balance of alpine grassland we used intact monoliths of montane and alpine pastures and meadows in more than 250 weighing and non-weighing lysimeters at three sites in the French, Swiss and Austrian Alps. The experimental CO2 enrichment reduced grassland ET and significantly increased soil moisture but not runoff. Land use simulation by midseason clipping yielded significantly increased runoff sums due to reduced ET, with the highest increases observed in tall grassland of the lower alpine belt in Austria, and the lowest in naturally short vegetation of the upper alpine belt in Switzerland. Future elevated CO2 slightly counteracts the land use effects at canopy level, however, the net effect of declining land use and elevated CO2 is still clearly negative for catchment water yield and thus, for fresh water supply and potential hydroelectric power production. Although these economic costs of water loss due to declining land use are moderate per hectare of alpine grassland, the sums are substantial when scaled to the vast area potentially affected in the Alps. Our results underline the significance of continued land care for catchment value in different alpine regions across the Alps
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
Kapitel 9. Synopsis – Synergien, Zielkonflikte und Umsetzungsbarrieren von Klimaanpassungs- und Klimaschutzmaßnahmen
Full text linkEs existiert eine Fülle von potenziellen Maßnahmen der Klimawandelanpassung und Emissionsminderung im Bereich der Landnutzung. Allerdings stehen Klimawandelanpassung und Emissionsminderung nicht notwendigerweise in einem synergistischen Zusammenhang. Neben der Klimarelevanz sind auch andere Kriterien von Bedeutung, wenn die integrative Leistungsfähigkeit von Maßnahmen bewertet werden soll. Dazu gehören vor allem mögliche und erwartete Auswirkungen auf die Biodiversität und denWasserhaushalt. Dieses Kapitel fasst die Klimawandelanpassungs- und Emissionsminderungsmaßnahmen und ihre Auswirkungen tabellarisch zusammen. Dabei soll eine integrative, übersichtliche Bewertung der im Special Report behandelten Maßnahmen ermöglicht werden
Valutazione della Specific Leaf Area nelle macrofite al fine di una interpretazione funzionale degli ecosistemi acquatici.
No full textThe study investigated the relationship between aquatic macrophytes and the most important leaf traits in functional analysis of terrestrial plants. The final aim was the establishment of scientific bases in the ecological interpretation of water ecosystems. Ten leaves of eight macrophyte species (Magnoliophyta) were randomly collected in each of three different populations. Three soft traits (Leaf Dry Weight, Leaf Dry Matter Content and Specific Leaf Area) were subsequently analysed. Nymphaea alba and Trapa natans showed the highest values of LDW and SLA. Species generally exhibited a variability of the functional traits among the three populations, in particular in the LDW values. However this intraspecific variability did not appear to affect functional characterization of species. In conclusion, the study confirmed the usefulness of leaf traits in the functional analysis of aquatic macrophytes
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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