1,720,970 research outputs found
Simulating diverse forest management options in a changing climate on a Pinus nigra subsp. laricio plantation in Southern Italy
Full text linkMediterranean pine plantations provide several ecosystem services but are vulnerable to climate change. Forest management might play a strategic role in the adaptation of Mediterranean forests, but the joint effect of climate change and diverse management options have seldom been investigated together. Here, we simulated the development of a Laricio pine (Pinus nigra subsp. laricio) stand in the Bonis watershed (southern Italy) from its establishment in 1958 up to 2095 using a state-of-the-science process-based forest model. The model was run under three climate scenarios corresponding to increasing levels of atmospheric CO2 concentration and warming, and six management options with different goals, including wood production and renaturalization. We analysed the effect of climate change on annual carbon fluxes (i.e., gross and net primary production) and stocks (i.e., basal area, standing and harvested carbon woody stocks) of the autotrophic compartment, as well as the impact of different management options compared to a no management baseline. Results show that higher temperatures (+3 to +5 °C) and lower precipitation (-20 % to -22 %) will trigger a decrease in net primary productivity in the second half of the century. Compared to no management, the other options had a moderate effect on carbon fluxes over the whole simulation (between -14 % and +11 %). While standing woody biomass was reduced by thinning interventions and the shelterwood system (between -5 % and -41 %), overall carbon stocks including the harvested wood were maximized (between +41 % and +56 %). Results highlight that management exerts greater effects on the carbon budget of Laricio pine plantations than climate change alone, and that climate change and management are largely independent (i.e., no strong interaction effects). Therefore, appropriate silvicultural strategies might enhance potential carbon stocks and improve forest conditions, with cascading positive effects on the provision of ecosystem services in Mediterranean pine plantations
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
On the Increasing Occurrence of a Green Christmas: A Perspective from Long-Term Eddy Covariance Observations on Winter Dormancy Interruptions in a Subalpine Forest
Full text linkSeasonal dormancy in temperate and boreal forests is an adaptive trait that guarantees tree survival during the winter season. This phenomenon is mainly affected by temperature and photoperiod (Heide 1974). However, increasing evidence suggests that winter dormancy is not a static state but rather a dynamic period influenced by intermittent warm spells that can temporarily reactivate ecosystem processes. These dormancy interruptions, particularly during "Green Christmas" events — characterized by reduced snow cover and anomalous winter temperatures — have the potential to alter seasonal carbon fluxes, shift forest phenology, and alter physiological cycles. As climate change intensifies, understanding the frequency and implications of these interruptions becomes crucial for predicting long-term shifts in ecosystem carbon dynamics and energy fluxes.Recent studies have reported that evergreen forests can initiate photosynthesis well before complete snowmelt (Bowling 2024), while deciduous forests exhibit a delayed response to warming trends. Additionally, Körner (2023) challenges conventional meteorological definitions of growing seasons, emphasizing that photosynthetic activity does not always align with temperature-based phenological markers. While there is strong evidence that climate warming influences seasonal carbon fluxes, long-term Eddy Covariance (EC) records reveal mixed trends in photosynthetic activity, suggesting that additional research is needed to uncover the underlying ecological and physiological mechanisms driving these shifts.As multiple EC flux tower sites established under the EUROFLUX project approach three decades of continuous observations, they offer a valuable opportunity to assess the long-term effects of climate variability on forest dormancy and carbon cycling. These extensive datasets allow for detailed trend analyses of winter dormancy interruptions, providing insights into their frequency, intensity, and potential impact on annual carbon sequestration.For this study, we selected the Renon-Selvaverde site (ICOS ID: IT-Ren, eLTER ID: BOL1), a subalpine forest with a long-term EC measurement record. To enhance the completeness of our dataset, we incorporated locally processed EC data, extending the NEE record from the Warm Winter Dataset (Gharun 2024) up to the present (1997-2024). Additionally, we ensured continuity in meteorological observations for the whole time span of our analysis.Leveraging this long-term dataset, we investigated how winter dormancy interruptions influence seasonal carbon dynamics. By integrating EC observations with environmental drivers, we aimed to refine our understanding of subalpine ecosystem responses to mid-winter warming events and evaluate their broader implications for carbon balance in the context of climate change.Winter dormancy interruptions were identified based on periods when NEE fluxes were significantly different from zero during the winter months. We then examined the relationships between NEE, shortwave radiation, soil temperature, and air temperature from the vertical profile during these interruptions. To quantify these interactions, we conducted a correlation analysis to assess the strength and significance of environmental drivers influencing ecosystem-level fluxes.Our analysis revealed an increase in the frequency of warm spells beginning in 2020. However, we did not detect a significant pattern in the duration of these events. Currently, warm spells appear to be isolated occurrences, allowing the forest stand to return to its dormant state after each event. Additionally, we observed that dormancy interruptions correspond to periods when soil temperatures remain above freezing and snow cover is absent, supporting the hypothesis that soil conditions play a critical role in determining ecosystem activity during winter. Anyhow, it is important to distinguish between warm spells characterized by non-freezing soil temperature (with or without snow cover) and photosynthetic activation driven by solar radiation but occurring under soil freezing conditions. In the latter case, photosynthesis may be initiated but remains constrained by water availability, with unclear effects on NEE.At present, these dormancy interruptions do not significantly impact the winter carbon budget of the observed ecosystem. However, we hypothesize that a continued increase in both the frequency and duration of warm spells could lead to fundamental shifts in seasonal or even annual carbon dynamics. An extended period of mid-winter photosynthetic reactivation could alter the seasonal carbon budget and potentially reduce the ability of subalpine forests to function as a long-term carbon sink, affecting their contribution to carbon neutrality.Future research should focus on mechanistic modelling approaches to predict long-term changes in carbon sequestration capacity under scenarios of increased winter warming and reduced snow cover
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Accuracy, realism and general applicability of European forest models
No full textForest models are instrumental for understanding and projecting the impact of climate change on forests. A considerable number of forest models have been developed in the last decades. However, few systematic and comprehensive model comparisons have been performed in Europe that combine an evaluation of modelled carbon and water fluxes and forest structure. We evaluate 13 widely used, state-of-the-art, stand-scale forest models against field measurements of forest structure and eddy-covariance data of carbon and water fluxes over multiple decades across an environmental gradient at nine typical European forest stands. We test the models' performance in three dimensions: accuracy of local predictions (agreement of modelled and observed annual data), realism of environmental responses (agreement of modelled and observed responses of daily gross primary productivity to temperature, radiation and vapour pressure deficit) and general applicability (proportion of European tree species covered). We find that multiple models are available that excel according to our three dimensions of model performance. For the accuracy of local predictions, variables related to forest structure have lower random and systematic errors than annual carbon and water flux variables. Moreover, the multi-model ensemble mean provided overall more realistic daily productivity responses to environmental drivers across all sites than any single individual model. The general applicability of the models is high, as almost all models are currently able to cover Europe's common tree species. We show that forest models complement each other in their response to environmental drivers and that there are several cases in which individual models outperform the model ensemble. Our framework provides a first step to capturing essential differences between forest models that go beyond the most commonly used accuracy of predictions. Overall, this study provides a point of reference for future model work aimed at predicting climate impacts and supporting climate mitigation and adaptation measures in forests.European Regional Development Fund https://doi.org/10.13039/50110000853
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