1,720,983 research outputs found
Uganda and REDD+: Is it worth getting involved from a socio-economic perspective?
No full textAnthropogenic (human caused) climate change is a major global issue because of the effects of climate change, which include increased frequency of drought, floods, erratic and/or insufficient rainfall, waterborne diseases; as well as related consequences such as water shortages, forest fires and loss of biodiversity. It is therefore imperative that there be a global effort to mitigate climate change in order to limit these potentially disastrous effects. Deforestation and forest degradation, principally in the tropics, cause approximately 12 percent of anthropogenic greenhouse gas (GHG) emissions. Therefore, one method to mitigate climate change is to address reducing GHG emissions from deforestation and forest degradation. "Reducing Emissions from Deforestation and Forest Degradation, conservation, sustainable management of forests, and enhancement of forest carbon stocks in developing countries," also known as REDD+, is, at its core, a financial incentives based strategy that aims to compensate national governments, sub-national actors, private project developers and/or local communities, in return for demonstrable reductions in carbon emissions from deforestation and forest degradation and enhancements of terrestrial carbon stocks. REDD+ also focuses on building capacity for developing countries to reduce emissions from deforestation and forest degradation and invest in low-carbon paths to sustainable development. Uganda is one of the developing countries that has shown enthusiasm for REDD+ and has actively engaged in REDD+ readiness activities. However, REDD+ readiness activities are costly due to various institutional capacity requirements that may pose a significant challenge to Uganda. The question posed by the study is whether Uganda's involvement in REDD+ is likely to result in net economic benefits for the country. The study aims to determine whether, in the absence of direct evidence of the success of the REDD+ mechanism in any country, Uganda's economic benefits from REDD+ are still expected to exceed the costs of implementation. Social benefits are an additional incentive however, even a combination of both economic and social benefits may not be reason enough for a country to become a REDD+ country, especially if alternative land uses are more lucrative or costs are too high. The methodology used is largely qualitative and theoretical, except for the economic analysis which is quantitative. The outcome of the study is that while there is insufficient evidence to suggest that Uganda will not benefit overall from being involved with REDD+, the feasibility study of the potential REDD+ project in the Murchison-Semkili landscape showed that, at least in that project area, the economic benefits were unlikely to cover both the implementation and opportunity costs in the long term. This does raise a legitimate concern that REDD+ might not result in net economic benefits for Uganda. Even though the economic benefits of Uganda's involvement in REDD+ are uncertain, the mechanism is still expected to result in social benefits, such as improved livelihoods in terms of service delivery; increased efficiency and accountability of government and governmental institutions; and increased public consultation and participation. There are, however, risks to Uganda's successful implementation of REDD+ such as unspecified donor funding, which may not be forthcoming, and the lack of clarity surrounding global compliance carbon markets. Uganda still has much to do in order to build the required institutional capacity for REDD+ to be successful, especially with regard to increasing the effectiveness of the institutions that manage the country's forests. Uganda also needs to reduce some of the drivers of deforestation in the country through programmes that target poverty alleviation and improve agricultural practices. In terms of REDD+ specifically, Uganda needs to complete the development of a National REDD+ Strategy, secure adequate funding for the mechanism, and accelerate the development of REDD+ pilot activities, which are currently in the planning phase. Further research is needed on determining the total value of Uganda's forests, taking into account economic, environmental and social considerations. Research is also needed on the impact successful REDD+ pilot activities have had in other comparable countries
Long-term vegetation change in the Succulent Karoo, South Africa following 67 years of rest from grazing
Full text linkChanges in species richness and vegetation composition in the diverse semi arid Succulent Karoo vegetation of South Africa were investigated after 67 • (1937-2004) years of rest from grazing at the Worcester Veld Reserve. Vegetation change in 70 plots at this 75 ha site was assessed using multi variate ordination techniques. Changes in plant communities on termitaria sites were consistently greater than for adjacent off-termitaria sites and the north-facing slopes changed more than the south-facing slopes. There was a higher increase in diversity on off-termitaria than termitaria sites. On termitaria sites there was a general decrease in stem succulents, particularly Euphorbia mauretanica and an increase in long-lived evegreen shrubs such as Pteronia incana and Asparagus suaveo/ens. Most sites changed in a similar direction primarily determined by their association with termitaria and secondarily with .. aspect. These findings suggest a predictable and directional replacement sequence under changing disturbance (grazing) regimes in a semi-arid region
Long-term vegetation change in the Succulent Karoo, South Africa following 67 years of rest from grazing
Full text linkChanges in species richness and vegetation composition in the diverse semi arid Succulent Karoo vegetation of South Africa were investigated after 67 • (1937-2004) years of rest from grazing at the Worcester Veld Reserve. Vegetation change in 70 plots at this 75 ha site was assessed using multi variate ordination techniques. Changes in plant communities on termitaria sites were consistently greater than for adjacent off-termitaria sites and the north-facing slopes changed more than the south-facing slopes. There was a higher increase in diversity on off-termitaria than termitaria sites. On termitaria sites there was a general decrease in stem succulents, particularly Euphorbia mauretanica and an increase in long-lived evegreen shrubs such as Pteronia incana and Asparagus suaveo/ens. Most sites changed in a similar direction primarily determined by their association with termitaria and secondarily with .. aspect. These findings suggest a predictable and directional replacement sequence under changing disturbance (grazing) regimes in a semi-arid regio
An assessment of land degradation and alien plants invasion in the Waterberg Biosphere Reserve, Limpopo Province
Full text linkLand degradation and invasion by alien plants are interconnecting issues that span both natural and socio-economic systems. As a result, addressing the complexity and severity of these pressures requires the use of a multidisciplinary approach. This study aims to assess land degradation and invasive alien plants distribution and their impacts on the ecosystem services within the WBR. An area outside the reserve was designated as a control to compare how degradation processes have evolved over the last few decades. Landsat images captured in 1989, 2000, 2013, and 2017 were used to analyse and map the land use/cover change. The images were classified into the following classes: water bodies, woody vegetation, grasslands, cultivated fields, bare lands, and settlements. Change detection performed between the years showed that the area outside the WBR has been losing grasslands and woody vegetation and gained more bare lands, cultivated fields, and settlements. On the contrary, the area within the WBR lost a significant amount of bare land and gained grasslands, woody vegetation, and a small amount of cultivated fields and settlements. The roadside survey was used to assess the distribution of invasive alien plants along the main roads in the selected areas. A single observer drive-by method was used to record the alien plants present at an interval of 5 km. To understand how the communities are being influenced by land degradation and alien plants invasion, focus group discussions were held to understand how their livelihoods are affected. Four important indicators, namely vegetation loss, land-use intensity, alien plants distribution, and population pressure, were overlaid using ArcMap 10.1 to determine the land degradation severity in both study areas. The results revealed that land degradation was severe outside the WBR, where most human activities occur, regardless of population pressure and alien plant distribution. These issues were intensifying with profound, severe implications for people's livelihoods, as land is the leading resource from which communities, both within and outside the WBR, eke their living. The WBR experienced land recovery following the proclamation of the area as a formal biosphere reserve by UNESCO, which has constrained the harmful impact of human activities. Reversing degradation and invasion by alien plant species requires sustainable land use and planning based on the current land-use practices and landscape attributes. Therefore, integrating local and scientific knowledge is helpful in the planning of sustainable and efficient land management
Current and future vulnerability of South African ecosystems to perennial grass invasion under global change scenarios
Full text linkThesis (PhD (Conservation Ecology and Entomology))--University of Stellenbosch, 2010.ENGLISH SUMMARY: Climate change and biological invasions are major components of global change induced by human activity and are considered major drivers of global biodiversity decline in terrestrial ecosystems. These drivers interact synergistically and render ecosystems vulnerable to invasion by invasive alien species. Grasses are a group of invasive plants that easily respond to global changes and alter native plant community structure and ecosystem processes, such as fire frequency. To date there have been few studies that assess the ecological drivers and effects of invasive grass species on arid and semi-arid ecosystems of South Africa. Fountain grass (Pennisetum setaceum) is a widely distributed invasive alien perennial grass from North Africa and the Middle East, valued by horticulturalists worldwide. It spreads along the edges of roads on the outskirts of most towns, and is common on mine spoil in many areas throughout South Africa. Occasionally, it escapes into natural vegetation along drainage lines or after fires. This grass can be a costly problem for agriculture and biodiversity conservation as it is unpalatable and increases fire risk. Understanding its distribution and invasive dynamics will contribute to better management and control practices. The main objective of this study was to understand the ecology and invasion processes of P. setaceum across South African environmental gradients, and use it as a model to understand the synergistic relationships between biological invasions and other global change (climate and land use) scenarios. This study provides the first assessment of how P. setaceum overcomes different invasion barriers in South Africa as an emerging invader, in comparison with other parts of the world where it has already become problematic. A number of management and control options for this grass and other similar perennial grasses result from this study. Specifically, the study provides comprehensive understanding of: 1) the distribution and habitat preferences of P. setaceum in arid and semi-arid parts of South Africa, 2) environmental resources and habitat conditions that promote its invasive potential, 3) growth and reproductive performance across environmental gradients, 5) the response of an arid ecosystem to P. setaceum invasion and fire promotion, and 6) the predicted future distribution of this grass in South Africa under scenarios of climate change and spread. The study has found that road-river interchanges are ideal sites for P. setaceum growth and that these sites should be targeted for management and control of this species. P. setaceum was found to persist under diverse biome environments, which is attributed to local adaptation. Disturbance was found to be a major factor promoting fountain grass invasion into semi-natural areas away from roadsides. Major clean-ups of this grass should focus on disturbed areas, especially in the fertile parts of the fynbos region where the grass has high climatic suitability. Management and control should also focus on areas with high nutrients and extra water, as these areas facilitate growth and reproduction. The dynamics of P. setaceum invasion and spread makes it a good model for management of similar emerging invasive perennial grasses in similar ecosystems.AFRIKAANSE OPSOMMING: Klimaatsverandering en biologiese indringing is grootskaalse komponente van mensgedrewe globale veranderinge, en kan ook gesien word as prominente drywers van die huidige afname in globale biodiversiteit van terrestriële ekosisteme. Hierdie drywers werk saam in sinergie, en laat sodoende ekosisteme kwesbaar vir indringing deur uitheemse indringerplante. Grasse is ‘n groep indringerplante wat maklik reageer ten opsigte van globale veranderinge en verander inheemse plantgemeenskapstruktuur en ekosisteem prosesse, soos byvoorbeeld veldbrand frekwensie. Tot op hede is daar wynig studies gedoen wat die ekologiese drywers en effekte van indringergras spesies in droë en semi-droë ekosisteme van Suid-Afrika assesseer. Pronkgras (Pennisetum setaceum) is ‘n wyd verspreide meerjarige uitheemse indringergras, oorspronklik vanaf Noord-Afrika en die Midde-Ooste, en word waardeer deur tuinboukundiges wêreldwyd. Dit versprei al langs padrande aan die buitewyke van meeste dorpe, en is algemeen op ou mynhope in verskeie dele van Suid-Afrika. Somtyds ontsnap hierdie gras langs dreineringskanale of na veldbrande, en beland so in die omringende natuurlike plantegroei. Hierdie gras kan ‘n duur probleem word vir landbou asook biodiversiteit bewaring omdat dit onsmaaklik is vir diere, en dit verhoog veldbrand risiko. ‘n Beter begrip van pronkgras verspreiding en indringingdinamika sal bydra tot verbeterde bestuur en kontrole praktyke.
Die hoofdoel van hierdie studie was om die ekologie en indringing prosesse van P. setaceum regoor Suid-Afrikaanse omgewingsgradiente te begryp, en dit dan te gebruik as ‘n model om die sinergistiese verhoudings tussen biologiese indringing en ander globale veranderinge (klimaat en grondgebruik) te verstaan. Die studie verskaf die eerste assessering van hoe P. setaceum verskillende indringing hindernisse in Suid-Afrika oormeester as ‘n opkomende indringer, in vergelyking met ander dele van die wêreld waar dit al klaar problematies is. Hierdie studie verskaf uiteindelik ‘n aantal bestuur en kontrole opsies vir hierdie en ander soortgelyke meerjarige grasse. Die studie verskaf spesifiek ‘n deeglike verstaan van: 1) die verspreiding en habitat voorkeure van P. setaceum in droë en semi-droë areas in Suid-Afrika, 2) omgewingshulpbronne en habitat toestande wat hierdie plant se indringing potensiaal verhoog, 3) groei- en voortplantingsvertoning oor verskillende omgewingsgradiente,
4) die reaksie wat ‘n droë ekosisteem toon teenoor P. setaceum indringing en veldbrand verhoging, en 5) die toekomstige verspreiding van hierdie gras in Suid-Afrika onder voorspellings van klimaatsverandering en verspreiding. Die studie het gevind dat pad-rivier tussengange ideale liggings is vir P. setaceum vestiging, en dat hierdie liggings dus geteiken moet word vir bestuur en kontrole doeleindes. P. setaceum toon volharding onder diverse bioom omgewings, wat toegeskryf word aan plaaslike aanpassing. Daar is gevind dat versteuring ‘n groot faktor is in die verhoging van pronkgras indringing in semi-natuurlike areas weg van padskouers. Grootskaalse pronkgras uitroeiing projekte moet fokus op versteurde gebiede, veral in die vrugbare dele van die fynbos streek, waar hierdie gras hoë klimaatsgeskiktheid toon. Bestuur en kontrole programme moet ook fokus op areas met hoë nutriente inhoud en ekstra water, aangesien hierdie areas groei en voortplanting vergemaklik. Die dinamika van P. setaceum indringing en verspreiding maak dit ‘n goeie model vir die bestuur van soortgelyke opkomende meerjarige indringergrasse in soortgelyke ekosisteme.Doctora
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
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
- …
