1,720,957 research outputs found
Moving toward the north: A country-level classification of land sensitivity to degradation in Czech Republic
No full textLand sensitivity to degradation is a spatially varying attribute of local systems that experience rapid changes in socio-ecological conditions. To answer the increasing demand of quantitative risk assessment of land degradation and desertification - taken as a final stage of land degradation - in non-affected countries, our study estimates land sensitivity to degradation in the Czech Republic at 1:10,000 scale using the Environmental Sensitive Area (ESA) framework. Czech land was classified into four sensitivity levels (‘insensitive’, ‘potentially sensitive’, ‘fragile’, and ‘critical’). ‘Fragile’ and ‘critical’ land concentrated in accessible lowlands with intensive agriculture. Climate and vegetation quality contributed the most to land sensitivity to degradation in the country. Low soil quality and land management quality were causes of land sensitivity in few, sparse agricultural districts. A comparison with Mediterranean and South-Eastern European countries indicates that land sensitivity to degradation in the Czech Republic is only slightly lower than in neighbouring, affected countries (sensu UNCCD, Annex IV), with the same acting drivers (agriculture intensification and urban sprawl). In light of climate change, national and regional policies are required to face with the increase of land sensitivity in ‘formally non-affected’ countries of Central-Eastern Europe, taking stock of the ‘Mediterranean’ experience in assessing and managing land sensitivity to degradation
Are valuable and representative natural habitats sufficiently protected? Application of marxan model in the Czech Republic
Full text linkThe joint impact of human activities and climate change on natural resources lead to biodiversity loss. Therefore, it is important to select protected areas through systematic conservation planning. The present study assessed how representative natural habitats are protected under the nature conservation network, and to identify new-but so far insufficiently-protected areas containing these habitats for sustainable management. We used the Marxan model to select the most valuable insufficiently protected natural habitats in the Czech Republic as a representative example for a conservation strategy for Central-Eastern European environments. We set three conservation targets (25%, 50%, and 75%), defining how much percent area of valuable representative natural habitats should be added to the area of the habitats already included in the Nature Protection Network. To implement these conservation targets it is necessary to preserve 22,932 ha, 72,429, ha and 124,363 ha respectively of the conservation targets occurring in the insufficiently protected areas, and 17,255 ha, 51,620 ha, and 84,993 ha respectively of the conservation features in the areas without protection status. Marxan was revealed to be an appropriate tool to select the most valuable and insufficiently protected natural habitats for sustainable management
Latent drivers of landscape transformation in eastern Europe. Past, present and future
Full text linkLand-use changes in Europe have been influenced by social forces including economic, demographic, political, technological and cultural factors. Contributing to a refined conceptualization of multifaceted processes of landscape transformation in the European continent, the present study proposes an extensive review of land-use trends in Eastern Europe, focusing on past, present and future conditions that may characterize latent drivers of change. Three time periods with a specific institutional, political and socioeconomic context reflecting distinct processes of land-use change were identified including: (i) the rapid transition to a centralized political system since the early 1950s (up to the late 1980s); (ii) a progressive transition from communist regimes to parliamentary democracy in 1989-1990 (up to the early 2000s); and (iii) the subsequent accession of individual countries to the European Union (2004-2007) up to nowadays. The most recent land-use trends are increasingly influenced by European directives on the environment, while national policies continue to shape economic development in member states
Envisioning present and future land-use change under varying ecological regimes and their influence on landscape stability
Full text linkClimate change plays an important role in shaping ecological stability of landscape systems. Increasing weather fluctuations such as droughts threaten the ecological stability of natural and anthropogenic landscapes. Uncertainty exists regarding the validity of traditional landscape assessment schemes under climate change. This commentary debates the main factors that threaten ecological stability, discussing basic approaches to interpret landscape functioning. To address this pivotal issue, the intimate linkage between ecological stability and landscape diversity is explored, considering different approaches to landscape stability assessment. The impact of land-use changes on landscape stability is finally discussed. Assessment methodologies and indicators are reviewed and grouped into homogeneous classes based on a specific nomenclature of stability aspects which include landscape composition, fragmentation and connectivity, thermodynamic and functional issues, biodiversity, soil degradation, and ecological disturbance. By considering land-use change as one of the most important factors underlying climate change, individual components of landscape stability are finally delineated and commented upon. In this regard, specific trajectories of land-use change (including agricultural intensification, land abandonment, and urbanization) are investigated for their effects on ecological stability. A better understanding of land-use impacts on landscape stability is crucial for a better knowledge of processes leading to land degradation
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
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