1,721,022 research outputs found

    An approach to the identification of indicators for forest biodiversity The Solling mountains (NW Germany) as an example

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    In this study, we present an approach for the identification of indicators for biodiversity within forest ecosystems. We analyze the data of stands of pure Norway spruce (Picea abies (L.) Karst) and European beech (Fagus sylvatica L.), as well as mixed P. abies-F. sylvatica forests in the Solling mountains (NW Germany). The analysis is based on 683 vegetation samples in total. For different plant groups, that is, vascular plants, bryophytes, Red List species, we investigate species numbers as a parameter of biodiversity. Species numbers are differentiated into three classes to describe low to high diversity. Plots are separately examined for the three different forest types. In order to take the species-area relationship into account, we only use releves with a plot size of 100 m(2). Our approach focuses on the probability to be in a defined range of species numbers, that is, class, if a certain species occurs. For the purpose of facilitating the differentiation of the classes, we use the presence values of species in the classes for further characterization of indicators. Few indicators were found for the low ranges of species numbers. In addition, there were only a small number of species groups and stand types having indicators for all three classes. Various species have multiple indicator functions, e.g., with regard to the investigated species groups. The focus on a few of these multi-indicators allows a rapid assessment of forest biodiversity. The catalog of indicators resulting from the investigation helps to facilitate and accelerate biodiversity evaluations of forest stands, in particular with regard to nature conservation and the restoration of natural forests

    Conservation with local people: Medicinal plants as cultural keystone species in the Southern Alps

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    The concept of “cultural keystone species” (CKS) combines ecological and socioeconomic aspects and has a great potential for improving the overall success of conservation and restoration of ecosystems. In our study, we combined an ecological analysis of traditional medicinal plant species with an explorative analysis of the stakeholder landscape to understand the importance of plants for local communities. We investigate the feasibility of the CKS concept for traditional medicinal plants using the Southern Alps (Northern Italy) as a case study. Based on a comprehensive survey of traditional medicinal plants, we analyzed the habitats where they occur and their significance as CKS candidates. We applied the index of identified cultural influence (ICI). We identified some of the relevant stakeholders and their potential interest in traditional medicinal plants. From a total of 273 native medicinal species, we ranked the 10 most important CKS candidates. These comprised species with different ecology such as the herbs Achillea millefolium agg., Alchemilla xanthochlora, Arnica montana, Hypericum perforatum, Matricaria chamomilla, Peucedanum ostruthium, Urtica dioica, the shrub Juniperus communis, and the tree species Betula pendula. By merging their importance for the local communities with their occurrences in the habitats of South Tyrol, the concept of CKS can stimulate species and habitat conservation, and ecosystem restoration

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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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