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Maintenance of genetic diversity in Cordia africana Lam., a declining forest tree species in Ethiopia
Get PDFWe assessed genetic variation in a total of 22 populations of the tree species Cordia africana Lam. in Ethiopia and analyzed the country-wide impact of population history, forest disturbance and alteration of land use on extant intraspecific diversity. Amplified Fragment Length Polymorphisms (AFLPs) and chloroplast microsatellite markers were investigated. The analyses of the AFLP data revealed high diversity in all investigated populations: the percentage of polymorphic loci (PPL) ranged from 62.2% to 92.2% and Nei\u27s gene diversity from 0.220 to 0.320 within the populations. The mean PPL and the mean diversity within populations were 85.7% and 0.287, respectively. The analysis of molecular variance revealed a moderate level of differentiation (ΦST = 0.07, p \u3c 0.001) among the populations. The Mantel test proved a significant but low correlation (r = 0.31, p \u3c 0.001) between the geographic distance and the genetic differentiation matrices. Only three different cpDNA haplotypes were observed; no more than two haplotypes were found in any population. The dominant haplotype with an overall frequency of 81% was observed in all populations. The level of differentiation among the populations was comparatively low at chloroplast DNA (GST = 0.18, RST, NST = 0.22). The observed patterns and levels of genetic variation within and among the populations indicate that efficient gene flow via pollen and seed is likely to be the main factor contributing to the maintenance of genetic diversity in natural and disturbed conditions
Assessment of tree species diversity patterns and socioeconomic uses on agricultural landscapes a case of Western Oromia, Ethiopia
No full textThis dataset was moved to: https://doi.org/10.34725/DVN/Q7W3JEDeforestation is one of the prominent problems in developing countries. Forest destruction, land degradation and loss of biodiversity are major environmental problems in Ethiopia. A study was conducted to assess study was to characterize on-farm tree diversity, their patterns and socioeconomic uses in the study area. Four sites representing drier and moist agroecology in the sub-humid agroecology were selected. A total of 100 households, 25 from each sites, were randomly selected and assess tree and shrub species diversity and understand their socioeconomic importance. Data on tree species diversity in the homestead, crop fields and grazing/pasture land use system were collected from 100, 18 and 11 households, respectively. The result showed that a total of 82 tree species were recorded from crop fields, homegardens and grazing/pasture land use system in the study sites. The total number of tree species in the homegardens, crop fields and grazing land was 67, 52 and 29 respectively. The Shannon diversity index in the entire land use system varied from 2.11 at Uke Badiya to 2.28 at Ongobo Bakanisa, and species evenness of the entire land use system varied from 0.565 at Oda Haro to 0.593 at Ongobo Bakanisa. The Shannon diversity index in the homestead land use system varied from 1.80 at Wayu Kumba to 2.13 at Oda Haro, and species evenness of the homestead land use system varied from 0.519 at Wayu Kumba to 0.596 at Oda Haro. The Shannon diversity index in the crop fields use system varied from 1.06 at at Oda Haro to 2.44 at Ongobo Bakanisa, and species evenness of the crop fields land use system varied from 0.450 at Wayu Kumba to 0.879 at Ongobo Bakanisa. The Shannon diversity index in the grazing land use system varied from 1.53 at Ongobo Bakanisa to 1.82 at Oda Haro, and species evenness of the grazing land use system varied from 0.487 at Ongobo Bakanisa to 0.709 at Oda Haro. The density of woody species recoreded in entire land use system varied from 133 at Oda Haro to 476 at Wayu Kumba. Structurally, Eucalyptus camaldulensis was the most important tree species among the common species to the three land use system in the study sites. Homestead size area influenced the species diversity, and coversly wealth status did not influence it. From the total surveyed of tree species abundance in the study sites 85.6% estabilished through plantation and 18.4% established through natural regenerated (retention). The purposes of tree retaining/planting were 38% for live fence, 30% for firewood, 13% for income, 13% for fodder, 4% for timber and 2% for fruit production. Generally, the study showed that agricultural landscapes harbour high diversity of trees and shrubs, to which farmers attach various values to the different utilities acrued from the system
Assessment of tree species diversity patterns and socioeconomic uses on agricultural landscapes a case of Western Oromia, Ethiopia
No full textThis dataset was moved to: https://doi.org/10.34725/DVN/Q7W3JEDeforestation is one of the prominent problems in developing countries. Forest destruction, land degradation and loss of biodiversity are major environmental problems in Ethiopia. A study was conducted to assess study was to characterize on-farm tree diversity, their patterns and socioeconomic uses in the study area. Four sites representing drier and moist agroecology in the sub-humid agroecology were selected. A total of 100 households, 25 from each sites, were randomly selected and assess tree and shrub species diversity and understand their socioeconomic importance. Data on tree species diversity in the homestead, crop fields and grazing/pasture land use system were collected from 100, 18 and 11 households, respectively. The result showed that a total of 82 tree species were recorded from crop fields, homegardens and grazing/pasture land use system in the study sites. The total number of tree species in the homegardens, crop fields and grazing land was 67, 52 and 29 respectively. The Shannon diversity index in the entire land use system varied from 2.11 at Uke Badiya to 2.28 at Ongobo Bakanisa, and species evenness of the entire land use system varied from 0.565 at Oda Haro to 0.593 at Ongobo Bakanisa. The Shannon diversity index in the homestead land use system varied from 1.80 at Wayu Kumba to 2.13 at Oda Haro, and species evenness of the homestead land use system varied from 0.519 at Wayu Kumba to 0.596 at Oda Haro. The Shannon diversity index in the crop fields use system varied from 1.06 at at Oda Haro to 2.44 at Ongobo Bakanisa, and species evenness of the crop fields land use system varied from 0.450 at Wayu Kumba to 0.879 at Ongobo Bakanisa. The Shannon diversity index in the grazing land use system varied from 1.53 at Ongobo Bakanisa to 1.82 at Oda Haro, and species evenness of the grazing land use system varied from 0.487 at Ongobo Bakanisa to 0.709 at Oda Haro. The density of woody species recoreded in entire land use system varied from 133 at Oda Haro to 476 at Wayu Kumba. Structurally, Eucalyptus camaldulensis was the most important tree species among the common species to the three land use system in the study sites. Homestead size area influenced the species diversity, and coversly wealth status did not influence it. From the total surveyed of tree species abundance in the study sites 85.6% estabilished through plantation and 18.4% established through natural regenerated (retention). The purposes of tree retaining/planting were 38% for live fence, 30% for firewood, 13% for income, 13% for fodder, 4% for timber and 2% for fruit production. Generally, the study showed that agricultural landscapes harbour high diversity of trees and shrubs, to which farmers attach various values to the different utilities acrued from the system
Assessment of tree species diversity patterns and socioeconomic uses on agricultural landscapes a case of Western Oromia, Ethiopia
No full textDeforestation is one of the prominent problems in developing countries. Forest destruction, land degradation and loss of biodiversity are major environmental problems in Ethiopia. A study was conducted to assess study was to characterize on-farm tree diversity, their patterns and socioeconomic uses in the study area. Four sites representing drier and moist agroecology in the sub-humid agroecology were selected. A total of 100 households, 25 from each sites, were randomly selected and assess tree and shrub species diversity and understand their socioeconomic importance. Data on tree species diversity in the homestead, crop fields and grazing/pasture land use system were collected from 100, 18 and 11 households, respectively. The result showed that a total of 82 tree species were recorded from crop fields, homegardens and grazing/pasture land use system in the study sites. The total number of tree species in the homegardens, crop fields and grazing land was 67, 52 and 29 respectively. The Shannon diversity index in the entire land use system varied from 2.11 at Uke Badiya to 2.28 at Ongobo Bakanisa, and species evenness of the entire land use system varied from 0.565 at Oda Haro to 0.593 at Ongobo Bakanisa. The Shannon diversity index in the homestead land use system varied from 1.80 at Wayu Kumba to 2.13 at Oda Haro, and species evenness of the homestead land use system varied from 0.519 at Wayu Kumba to 0.596 at Oda Haro. The Shannon diversity index in the crop fields use system varied from 1.06 at at Oda Haro to 2.44 at Ongobo Bakanisa, and species evenness of the crop fields land use system varied from 0.450 at Wayu Kumba to 0.879 at Ongobo Bakanisa. The Shannon diversity index in the grazing land use system varied from 1.53 at Ongobo Bakanisa to 1.82 at Oda Haro, and species evenness of the grazing land use system varied from 0.487 at Ongobo Bakanisa to 0.709 at Oda Haro. The density of woody species recoreded in entire land use system varied from 133 at Oda Haro to 476 at Wayu Kumba. Structurally, Eucalyptus camaldulensis was the most important tree species among the common species to the three land use system in the study sites. Homestead size area influenced the species diversity, and coversly wealth status did not influence it. From the total surveyed of tree species abundance in the study sites 85.6% estabilished through plantation and 18.4% established through natural regenerated (retention). The purposes of tree retaining/planting were 38% for live fence, 30% for firewood, 13% for income, 13% for fodder, 4% for timber and 2% for fruit production. Generally, the study showed that agricultural landscapes harbour high diversity of trees and shrubs, to which farmers attach various values to the different utilities acrued from the system
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
Assessment of tree species, diversity distribution pattern and socioeconomic uses on farmland in Oromia regional state: the case of East Shewa zone
No full textThe study presents analysis of farmland tree species composition diversity, distribution pattern and socioeconomic uses in East Shewa Zone of Oromia National Regional State. With the intention of well characterizing tree diversity in terms of crop/tree management systems five Kebeles were selected from five purposively selected Woredas of East Shewa Zone and 20 HHs in each Kebele were selected randomly. From the selected 20 households 4 of them were selected randomly to survey all plots owned by them and for the remaining 16 households, plots investigated were those with the main homestead. All trees and shrubs for all the farms owned by the selected households were surveyed. A total of 172 farm plots were surveyed in the study area and 76 woody plant species, representing 63 genera and 23 families were recorded. The Family Fabaceae with twenty species had the highest number of species. Homestead planting, boundary planting, mixed with crop, grazing land, small scale woodlot and hedge row planting were land use practices that were observed in the study sites. Maximum richness and abundance were recorded in homesteads followed by boundary plantings and on-farms having Shannon diversity index value of 3.05, 3.02 and 2.43 respectively. There were significance relationship between land holding and number of individual trees however; land holding with species richness, Shannon diversity and evenness index didn’t show significant relationship. Better management strategies and approaches would improve the existing agroforestry system
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
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