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Incidence de l’exploitation forestière et fourragère sur la dynamique structurale de Prosopis africana (Gill. & Perr.) Taub., de Ptérocarpus erinaceus Poir., et de Afzelia africana Smith ex Pers., dans la commune de Kéran 1 au Nord -Togo
Get PDFLa déforestation et la dégradation inquiétantes que les ressources forestières et les formations boisées subissent en Afrique de l’ouest, sont dues aux différentes formes d’exploitations irrationnelles, notamment l’exploitation forestière et fourragère. En effet, ces deux formes d’exploitations, constituent les facteurs de pression sur certaines espèces végétales très prisées pour leur bois et fourrage. L’objectif de cette étude est de déterminer l’incidence de ces activités sur la dynamique structurale des peuplements de Prosopis africana, de Ptérocarpus erinaceus, et de Afzelia africana. La méthodologie adoptée est l’inventaire forestier dans les placettes de 1000 m² (100 m x 20 m) installés régulièrement à chaque 200 m le long des transects de 6 km dans chaque zone choisie. Les données floristiques collectées ont été traitées par des techniques d’analyse multivariée. Les résultats montrent que ces activités ont une incidence négative sur la densité, le diamètre moyen, la hauteur moyenne et la surface terrière de ces trois espèces à cause de la densité élevée de coupe, d’émondage et de carbonisation. Ces espèces sont devenues rares et leur régénération atteint rarement la maturité. La structure en classe de diamètre et de hauteur révèle que ces trois espèces sont représentées par les individus de diamètres et hauteurs faibles dans la zone où elles sont exploitées. Cette étude à travers ses résultats, interpelle à une gestion rationnelle de ces trois espèces par des mesures permettant leur protection et conservation durable afin d’éviter leur dégradation irréversible.
The alarming deforestation and degradation of forest resources and woodlands in West Africa are caused by various forms of irrational exploitation, including logging and fodder production. In fact, these two forms of exploitation are the pressure factors on certain plant species that are highly prized for their wood and fodder. The aim of this study is to determine the impact of these activities on the structural dynamics of Prosopis africana, Pterocarpus erinaceus and Afzelia africana stands. The methodology adopted is forest inventory in 1000 m² plots (100 m x 20 m) installed regularly every 200 m along 6 km transects in each selected area. The floristic data collected were processed using multivariate analysis techniques. The results show that these activities have a negative impact on the density, mean diameter, mean height and basal area of these three species, due to the high density of cutting, pruning and charring. These species have become rare, and their regeneration rarely reaches maturity. The structure in terms of diameter and height classes reveals that these three species are represented by individuals with small diameters and heights in the area where they are exploited. The results of this study call for rational management of these three species, with measures for their protection and sustainable conservation to avoid irreversible degradation
Incidence de l’exploitation forestière et fourragère sur la dynamique structurale de Prosopis africana (Gill. & Perr.) Taub., de Ptérocarpus erinaceus Poir., et de Afzelia africana Smith ex Pers., dans la commune de Kéran 1 au Nord -Togo
Get PDFLa déforestation et la dégradation inquiétantes que les ressources forestières et les formations boisées subissent en Afrique de l’ouest, sont dues aux différentes formes d’exploitations irrationnelles, notamment l’exploitation forestière et fourragère. En effet, ces deux formes d’exploitations, constituent les facteurs de pression sur certaines espèces végétales très prisées pour leur bois et fourrage. L’objectif de cette étude est de déterminer l’incidence de ces activités sur la dynamique structurale des peuplements de Prosopis africana, de Ptérocarpus erinaceus, et de Afzelia africana. La méthodologie adoptée est l’inventaire forestier dans les placettes de 1000 m² (100 m x 20 m) installés régulièrement à chaque 200 m le long des transects de 6 km dans chaque zone choisie. Les données floristiques collectées ont été traitées par des techniques d’analyse multivariée. Les résultats montrent que ces activités ont une incidence négative sur la densité, le diamètre moyen, la hauteur moyenne et la surface terrière de ces trois espèces à cause de la densité élevée de coupe, d’émondage et de carbonisation. Ces espèces sont devenues rares et leur régénération atteint rarement la maturité. La structure en classe de diamètre et de hauteur révèle que ces trois espèces sont représentées par les individus de diamètres et hauteurs faibles dans la zone où elles sont exploitées. Cette étude à travers ses résultats, interpelle à une gestion rationnelle de ces trois espèces par des mesures permettant leur protection et conservation durable afin d’éviter leur dégradation irréversible.
The alarming deforestation and degradation of forest resources and woodlands in West Africa are caused by various forms of irrational exploitation, including logging and fodder production. In fact, these two forms of exploitation are the pressure factors on certain plant species that are highly prized for their wood and fodder. The aim of this study is to determine the impact of these activities on the structural dynamics of Prosopis africana, Pterocarpus erinaceus and Afzelia africana stands. The methodology adopted is forest inventory in 1000 m² plots (100 m x 20 m) installed regularly every 200 m along 6 km transects in each selected area. The floristic data collected were processed using multivariate analysis techniques. The results show that these activities have a negative impact on the density, mean diameter, mean height and basal area of these three species, due to the high density of cutting, pruning and charring. These species have become rare, and their regeneration rarely reaches maturity. The structure in terms of diameter and height classes reveals that these three species are represented by individuals with small diameters and heights in the area where they are exploited. The results of this study call for rational management of these three species, with measures for their protection and sustainable conservation to avoid irreversible degradation
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
Analyse de la diversité et de la composition floristique des Massifs montagneux du pays KABYÈ (NORD-TOGO)
Get PDFVariations 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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