1,721,424 research outputs found
Available wood in small forest patches and its links with plant diversity and ecosystem services
No full textSmall forest patches, smaller than 10 ha, are very common in many European landscapes and may represent a significant amount of wood available for logging, but also a support of important parts of biodiversity and of many ecosystem services. Few is known about the status of these quantities, because of the difficulty to sample such small habitats. In this presentation, we measured the amount of wood available, according to several classes of quality, in a sample of very small forest patches in southwestern France. In the same places, plant diversity and a set of related ecosystem services were also measured. The results showed a huge variability between patches regarding the amount of available wood, with some of them with a very dense stock of wood, comparatively with national references. Plant diversity was higher in patches with intermediate level of wood stocks, the lowest richness was in the densest patches, but the plant species were then more typical of large forest flora. It seems that allowing older and bigger trees in small patches could reduce the negative impact of the small size of the patch on plant composition. Few of the other ecosystem services were related to the amount of wood but these complex relationships need more detailed analyses. These preliminary results showed that small forest patches represent a significant amount of wood that may be harvested in the future is the demand continue to increase, but this may have consequences on their conservation value for plants, but apparently not for many other ecosystem services. Management practices are also a factor that need to be considered in the future as it may modify strongly the structure of these forests
Micro-topography associated to forest edges
No full textForest edges are often defined as the discontinuity between the forest habitat and an adjacent open habitat, thus they are based on a clear difference in the structure of the dominant vegetation. However, beside this very general definition, in the field we can observe a large diversity of edges, with often different kinds of micro-topography features: bank, ditch, stone wall, path, etc. As these elements are rather common in many temperate forest edges, it seems important to start to characterize them more clearly and with consistency. From a set of observations in south-western France, we build a first typology of the micro-topographic elements associated to forest edges.
For each of them we describe the process, natural or human induced, at their origin, and according to the literature available, we identify some of their key ecological roles. Banks, generated by the differential erosion between forest and crops along slopes, are especially analyzed since they are the most common micro-topographic element in our region. It offers many micro-habitat conditions in the soil used by a wide range of species, notably by several bee species. More research is required to study in details the importance of such micro-topographic elements
Forests for agriculture: new perspectives in European landscapes
No full textDuring the last centuries, most of the European landscapes have been strongly impacted by the increasing disconnection between farming and forestry. When agriculture developed, it was to the detriment of the forest, and even in regulations, forest and agriculture were rarely considered as linked issues. This disconnection is also true for scientific research, as agronomy and forest sciences followed parallel routes for decades. However, landscape ecology is one of the few disciplines where both were almost equally considered as components of a same complex system. In this presentation, we argue that in the future, stronger links between forest and agriculture will become more important and that we need to engage our research towards a better understanding of how these two landscape components interact. We identified 4 types of links between agriculture and forests. The first one is that classical forest wood-based products (timber, firewood) could become parts of farming activities. The demand for wood-based energy is forecasted to increase in the near future, as it is a renewable source of energy easily available. Farmers can benefit from additional economic resources provided by wood product sale, and they have also the need for energy. They have and access to this scattered resource, and they have the relevant skills to use the equipment for logging. Thus, the role of farmers in the increase of forest harvesting, and its consequences, must be anticipated. The second one is the ability of forests to produce useful resources for agriculture. There are several examples, such as the use of fence posts, of wood chips as litter for living stocks, or of charcoal in crops. With a better knowledge of these resources, farmers may reduce their dependency to external sources and contribute to local markets. Ecosystems services is the third, and very important, interaction. There is a growing literature that shows how many very important ecosystem services for agriculture are related to the surrounding natural habitats, and especially forests. They are shelters for organisms who help pest regulation in crops, or for pollinators, or for local climate buffering. Landscape ecology has a lot to say about these ecosystemic interactions and should focus more on how forest management may be modified to provide better services to nearby agriculture. Finally, many of the agroecological recommendations are basically inspired by the functioning of forests and how these ecosystems are able to stay productive and resilient. Agriculture has a lot to learn from forest science, and these scientific links must be supported. These perspectives open up new questions for landscape ecology and they are arguments for a more systemic understanding of the complexity of landscapes, including equally forest and agriculture (and other land uses), towards a better management of the full range of available natural resources
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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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