124,713 research outputs found
Impact of Target Diameter Harvesting on Spatial and Temporal Pattern of Drought Risk in Forest Ecosystems Under Climate Change Conditions
No full textForests are influenced by many disturbances, especially drought, windthrow, pest attacks, air pollution, and forest management. The climate change results in increasing frequency of weather extremes which will probably cause drought stresses in European forest ecosystems. By integrating several new features within the BROOK90 model, smallscale coupled process-based modeling was carried out for different climate and target diameter harvesting scenarios in the region of Solling, Germany. The results show considerable increment of drought risks towards 2100 compared to “present climate conditions”, caused by changes in precipitation and increase of mean air temperature. Beyond this it is shown that for the Solling site the changes of structure and microclimate produced by target diameter harvesting result in a decrease of drought stress and could be implemented to mitigate drought events
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
Changes of forest stands vulnerability to future wind damage resulting from different management methods
No full textThe structure of forests stands changes continuously as a result of forest growth and both natural and anthropogenic disturbances like windthrow or management activities – planting/cutting of trees. These structure changes can stabilize or destabilize forest stands in terms of their resistance to wind damage. The driving force behind the damage is the climate, but the magnitude and sign of resulting effect depend on tree species, management method and soil conditions. The projected increasing frequency of weather extremes in the whole and severe storms in particular might produce wide area damage in European forest ecosystems during the 21st century. To assess the possible wind damage and stabilization/destabilization effects of forest management a number of numeric experiments are carried out for the region of Solling, Germany. The coupled small-scale process-based model combining Brook90 [1] and SCAlar DIStribuiton turbulence model [2-4] is implemented. The SRES climate scenarios A1B and B1 dynamically downscaled by Climate Local Model CLM [5] are used to project the future climate conditions in the area. The experiments are performed for two tree species (spruce and beech) and a mixed stand and for two target diameter harvesting scenarios. The results show considerable increment of wind damage risks towards 2100 compared to “present climate conditions”, caused by the combination of weak increase of wind speed and precipitation and strong increase of air and soil temperature. The effect is stronger for coniferous species than for deciduous ones. It is shown that management activities have a strong destabilizing effect on forests due to joint influence of climatic factors and decrease of stand density
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
Feedbacks of windthrow for Norway spruce and Scots pine stands under changing climate
No full textWind damage is one of the major natural disturbances that can occur worldwide in most types of forests. Enhanced management using adequate decision support systems (DSS) can considerably reduce the risk of windthrow. The decision support system 'Forest and Climate Change' (DSS-WuK) which is currently being developed at Gottingen University aims at providing a tool for the quantitative assessment of biotic and abiotic risks for forest ecosystems under the conditions of changing climate. In order to assess the future risks of wind damage the system employs a coupled modelling approach combining the turbulence model SCAlar DIStribution (SCADIS) with the soil-vegetation-atmosphere-transfer (SVAT) model BROOK 90. The present study investigates projections of wind damage in Solling, Germany under climate scenarios A1B and B1, taking into account the windthrow feedbacks-changes of microclimate as a result of tree fall and consequent stabilization or destabilization of a forest stand. The results of the study indicate that in Solling the risk of windthrow for spruce and pine forest stands is likely to increase considerably during the 21st century. The general tendencies indicate that under A1B the probability of damage would be higher than under B1 and that under the same climate and soil conditions the risk for spruce stands would be higher than for pine stands of equal age. The degree of damage and feedback contribution as well as a sign of feedback in each particular case will strongly depend on the particular local or regional combination of climatic and soil factors with tree species, age and structure. For Solling the positive feedback to local climatic forcing is found. The feedback contributes considerably (up to 6% under given conditions) to the projected forest damage and cannot be neglected. Therefore, the adequate projection of future damage probabilities can be performed only with a process-based coupled soil-atmosphere model with corresponding high spatial and temporal resolution
“Anpassungstrategien für eine nachhaltige Waldbewirtschaftung unter sich wandelnden Klimabedingungen - Entwicklung eines Entscheidungsunterstützungssystems "Wald und Klimawandel" (DSS-WuK)
No full text“Anpassungstrategien für eine nachhaltige Waldbewirtschaftung unter sich wandelnden Klimabedingungen - Entwicklung eines Entscheidungsunterstützungssystems "Wald und Klimawandel" (DSS-WuK)
No full textQualitative Inhaltsanalyse von Interviews mit Hilfe von MAXQDA
No full textCapova D, Kastrup V. Qualitative Inhaltsanalyse von Interviews mit Hilfe von MAXQDA. In: Wilde M, Basten M, Fries S, Gröben B, Meyer-Ahrends I, Kleindienst-Cachay C, eds. Forschen für den Unterricht : junge Experten zeigen wie's geht!. Baltmannsweiler: Schneider Verlag Hohengehren; 2013: 12-29
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
- …
