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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Stocks de carbone du sol dans les zones de reboisement : bases pour projets de mécanisme pour un développement propre / Soil carbon stocks in reforestation areas : bases for Clean Development Projects

Silva Moreira, Cindy 09 November 2010 (has links)
Malgré l'importance de la séquestration du carbone (C) dans les sols forestiers, il existe actuellement peu de projets Mécanisme pour un Développement Propore (MDP) qui tiennent compte de la gestion de ce compartiment dans l'atténuation du réchauffement climatique. La cause principale est que l'accréditation du carbone séquestré dans le sol représente de plus grands défis et des risques par rapport aux autres composantes des écosystèmes forestiers.Connaissant les difficultés économiques et les problèmes environnementaux impliqués dans l'adoption d'un tel projet et l'importance des forêts dans l'atténuation du changement climatique, l'objectif de cette étude était d'évaluer les performances des méthodes dedétermination des stocks de carbone du sol dans deux projets de reboisement, ainsi que pour leurs situations de références (c'est-à-dire utilisation des terres avant la plantation, des pâturages naturels, ainsi que la végétation native) comme base pour diminuer le rapport coût bénéfice des projets MDP dans le secteur forestier. Pour atteindre l'objectif principal, cestravaux de recherches ont consisté à l'étude de: (i) la variabilité spatiale du C du sol dans une zone de reboisement avec des espèces indigènes, établi dans le bassin amazonien dans le MatoGrosso à Cotriguaçu (Zone I) et une chronoséquence de plantations d'Eucalyptus, située dansl'état de São Paulo à Avare (zone II); (ii) la taille des parcelles et la distance idéale de séparation des échantillons à partir de l'étude de la dépendance spatiale du C, (iii)l'estimation de la teneur en C et la densité du sol (Ds) par spectroscopie dans le proche(NIRS) et moyen (MIRS) infrarouge, afin de réduire les coûts sans affecter la qualité des résultats analytiques : et (iv) du calcul des stocks de C du sol pour ces deux projets et l'estimation du bilan C du projet MDP menées dans la zone II, en utilisant l'outil EX-ACT («EX-Ante Carbon-balance Tool»). Les résultats ont confirmé l'existence d'une variabilité spatiale importante du C du sol, ainsi qu'une forte dépendance spatiale pour tous les traitements étudiés. L'analyse du nombre optimal d'échantillons de sol a montré que la collecte de cinq points par parcelle est aussi précise qu'un échantillonnage plus dense. La taille optimale des parcelles a été estimée de 361 à 841 m2 dans les plantations de la zone I et de 900 à 3721 m2 pour la Zone II. La performance de la spectroscopie MIRS et NIRS pourestimer la teneur en C des sols a été jugée très satisfaisante, surtout quand les modèles ont été étalonnés à partir de sous populations constituées de 10 à 50% de l'ensemble des données.Les résultats de l'estimation de Ds ont été légèrement moins satisfaisants que ceux pour le Cdu sol. Les stocks de C dans le sol calculés pour la zone I étaient supérieurs à ceux de la zone II. Si on ne considère que le compartiment du sol, il apparaît que le potentiel de génération de crédits C est plus important dans le reboisement à partir d'espèces indigènes dans un sol argileux que pour un reboisement d'eucalyptus dans un sol sableux. Le bilan C du projet de la zone I a montré un potentiel de séquestration de près de trois millions de tonnes d'équivalentCO2 en 40 ans. Il est espéré que cette étude qui montre des possibilités de réduction des coûts liés aux calculs des stocks de C du sol contribuera à une meilleure prise en compte de ce compartiment dans les projets MDP forestiers. / Considering the great importance of carbon sequestration (C) in forest soils, there are fewCDM projects that include this compartment as an agent of global warming mitigation. Thisoccurs because the quantification of soil C stocks represents a bigger challenge whencompared to other components of forest ecosystems. Considering the economic difficultiesand environmental issues involved in adopting this type of project and the importance offorests in mitigating climate change, the objective of this study was to evaluate theperformance of methods for obtaining soil C stocks in two forestry areas and their respectivebaselines (land use prior to planting, i.e. pastures and native vegetation) as a basis forreducing the cost-benefit ratio of CDM projects. To achieve the main objective, this researchwas composed of the following steps: (i) estimating the spatial variability of soil C in an areareforested with native species, established in Cotriguaçú, MT (Area I) and a Eucalyptuschronosequence, located in Avaré, SP (Area II), (ii) determining the optimal amount of soilsamples and the plot size from the soil C spatial dependence range in the reforestation areas,(iii) estimating soil C content and bulk density (BD) by Near and Mid Infrared ReflectanceSpectroscopy (NIRS and MIRS, respectively) to reduce analytical costs without affecting thequality of the results, and (iv) calculating soil C stocks in both areas and estimating the carbonbalance of a CDM Project conducted in Area II, using EX-ACT ("Ex-Ante Carbon BalanceTool"). The results confirmed the existence of significant soil C spatial variability in bothareas and a strong spatial dependence at all plots. The analysis of the optimal number of soilsamples indicated that the sampling procedure with five points per plot is as accurate asintensive sampling. The optimum size of plots ranged from 361-841 m2 at Area I plantationsand from 900-3721 m2 at Area II. The performance of MIRS and NIRS to estimate the soilcarbon content was very satisfactory, especially when the models were calibrated withamounts between 5-10% of the total data set. The estimations of BD were slightly less precisethan those of soil C content. The soil C stocks obtained at Area I were higher than Area II.Considering only the soil compartment, it is clear that the potential for C credit generation in areforestation with native species on a clayey soil is higher than in a reforestation witheucalyptus on a sandy soil. The C balance of the CDM project conducted in Area I is expectedto sequester almost three million tones of CO2 eq in 40 years. We hope this study contributesto the increased inclusion of soil in CDM projects, by confirming the feasibility of reducingthe costs associated with both sampling and analytical procedures.
132

Wood resources management : A case study of the Aral region, Kazakhstan / カザフスタン国アラル地域における森林資源管理

Matsui, Kayo 24 September 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第22101号 / 地環博第187号 / 新制||地環||37(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 舟川 晋也, 教授 西前 出, 准教授 真常 仁志 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM
133

Waldmehrungspolitik in der Region Leipzig

Schneider, Hans Hermann 20 December 2012 (has links)
Die Gegend um Leipzig stellt sachsenweit die waldärmste Region dar. Vor diesem Hintergrund verwundert es nicht, dass landesweite Pläne und Programme den Schwerpunkt der Waldvermehrung in Sachsen strikt in diese Region lenken, in der mittlerweile seit über 30 Jahren um mehr Wald gerungen wird. Auch die aktuellste Fassung des Landesentwicklungs-plans 2012, gegenwärtig noch als Entwurf vorliegend, verweist auf die Leipziger Region, wenn es darum geht, den im Bundesvergleich unterdurchschnittlichen Waldanteil Sachsens von gegenwärtig 28,5 % auf 30 % der Landesfläche zu erhöhen. Potential wird hierbei vor allem in der sich immer noch in Rekultivierung befindlichen Bergbaufolgelandschaft des Leipziger Südens sowie in der ausgeräumten Agrarlandschaft des ländlich geprägten Raums gesehen. Initiativen und Bestrebungen, den Waldanteil der Region langfristig zu erhöhen, sind tief in der Geschichte verankert und werden von den verschiedensten Akteuren getragen. In den 1970er Jahren waren es die Staatlichen Forstbetriebe, die im Zuge der Sanierung einer devastierten Tagebaulandschaft ausgedehnte Waldgebiete neu entstehen ließen und der Bevölkerung im Ballungsraum Leipzig damit wieder eine attraktive Erholungslandschaft schaffen wollten. Ab Mitte der 90er Jahre ging der Zuwachs neuer Waldgebiete spürbar zurück und beschränkt sich seit dem auf die Aufforstung kleinerer Flächen in Streulagen. Aus der Sicht vieler Forstfachleute wird diese Tatsache als äußerst unbefriedigend eingeschätzt. Mittlerweile besteht dagegen die Vermutung, dass sich der jährliche Waldflächenzuwachs in der Waage mit einem zunehmenden Waldflächenverlust hält und dass das ursprüngliche Ziel der Waldmehrung dem der Erhaltung des vorhandenen Waldes gewichen ist. Aus diesem Grunde haftet der Region um Leipzig zunehmend das Charakteristikum einer planungs-dynamischen Region an, in der in kurzer Zeit Flächennutzungsarten wechseln und Pläne geändert werden. Erschwert wird die Waldvermehrung aber nicht nur durch wirtschaftliche und Gemeinwohlinteressen, sondern vor allem durch naturschutzrechtliche Vorgaben der Europäischen Union, die "runtergebrochen" auf die Regionalebene zu erheblichen Konflikten im Bestreben um mehr Wald führen. Hinzu kommt ein enorm wachsender Flächenverlust, so dass Landwirte der Region zunehmend nicht mehr bereit sind, ihr wertvolles Ackerland für eine Aufforstung bereit zu stellen. Ein eigens dafür konstruiertes, agrarpolitisches Förderinstrument der Europäischen Union, das landwirtschaftliche Flächennutzer zu einer Aufforstung auf ihrem Grund und Boden bewegen und die Waldvermehrung in Sachsen vorantreiben soll, wird kaum in Anspruch genommen.
134

[pt] DO DESMATAMENTO AO REFLORESTAMENTO: O PAPEL DA DISSUASÃO GERAL NA MUDANÇA DE COMPORTAMENTO DOS FAZENDEIROS / [en] FROM DEFORESTATION TO REFORESTATION: THE ROLE OF GENERAL DETERRENCE IN CHANGING FARMERS BEHAVIOR

JOAO PEDRO GRACA MELO VIEIRA 29 June 2023 (has links)
[pt] Esta dissertação investiga o impacto de sanções ambientais sobre mudanças florestais na Amazônia brasileira. Examinamos o papel da dissuasão geral na mudança do comportamento dos agricultores, alterando suas percepções sobre o risco de violar as leis florestais após serem punidos ou testemunharem a punição de fazendas adjacentes. Usando a estratégia de diferença em diferenças e novos dados espaciais, mostramos que as sanções reduzem o desmatamento em 48 por cento nas fazendas punidas e em 21 por cento nas fazendas adjacentes, enquanto aumentam o reflorestamento em 15 por cento e 6,5 por cento, respectivamente. Análises de heterogeneidade revelam que mesmo sanções sem componentes de incapacitação levam a mudanças comportamentais substanciais e que a responsividade dos fazendeiros às sanções coincide com o compromisso geral à aplicação das leis florestais. Não há evidências de deslocamento espacial ou tentativas de fugir do monitoramento. Em um cenário contrafactual sem sanções, o desmatamento dos fazendeiros aumentaria 29 por cento. Esses resultados sugerem que a dissuasão geral pode tornar as sanções ambientais uma ferramenta poderosa para combater o desmatamento e promover o reflorestamento em escala. / [en] This dissertation investigates the impact of environmental sanctions on forest changes in the Brazilian Amazon. We examine the role of general deterrence in changing farmers behavior by altering their perceived risk of violating forest laws after being punished or witnessing the punishment of adjacent farms. Using a difference-in-differences strategy and novel spatial data, we show that sanctions decrease deforestation by 48 percent in punished farms and 21 percent in adjacent farms while increasing reforestation by 15 percent and 6.5 percent, respectively. Heterogeneity analyses reveal that even sanctions lacking incapacitation components lead to substantial behavioral changes and that farmers responsiveness to sanctions coincides with the overall commitment to forest law enforcement. There is no evidence of spatial displacement or attempts to elude monitoring. In a counterfactual scenario without sanctions, farmers deforestation would increase by 29 percent. These findings suggest that general deterrence can make environmental sanctions a powerful tool for combating deforestation and promoting reforestation at scale.
135

Nonindustrial private forest landowner participation in incentive programs and regeneration behavior

Sun, Xing 15 December 2007 (has links)
Nonindustrial private forest (NIPF) landowners have been major players in increasing forest productivity and improving forest health. Understanding what factors influence landowner participation in government programs, and furthermore, what factors determinate how quickly after harvest landowners regenerate, is critical for developing policies to improve landowner participation in government assistance programs and timely regeneration of harvested lands. Two studies were conducted to investigate these issues. The necessary data were obtained through a 2006 telephone survey of randomly selected Mississippi NIPF landowners. Factors considered included an array of land, ownership, management, and demographic characteristics. In the first study, a two-step landowner behavior model was constructed to explain NIPF landowner participation in government incentive programs, conditional on their awareness of these programs. The second study used duration analysis to analyze the time elapsed between harvest and regeneration. Interest in timber production, past regeneration experience, education, and membership in forestry organization influenced NIPF landowner knowledge of incentive programs and were significant predictors of participation. Those NIPF landownersn who regenerated, did so on average, 11 months after harvest. After the 16th month following harvest, the probability of regenerating harvested lands decreased rapidly. The interval between harvest and reforestation was reduced by maintaining an interest in timber production, consulting a forester to coordinate the harvest, residing on the forest land, having planted pines, and increasing timber prices.
136

Optimizing loblolly pine management with stochastic dynamic programming

Häring, Thomas W. 02 October 2007 (has links)
This study examines effects of unpredictable price fluctuations and possible catastrophic losses on the optimal site preparation intensity of un thinned loblolly pine plantations under the assumption of lisk aversion. It concentrates exclusively on financial motives and does not take non-market values and portfolio considerations into account. The results should be interpreted with these limitations in mind. Two approaches are taken to compare site preparation intensities: a quasideterministic approach, where expected cash flows are discounted with risk-adjusted discount rates, and a stochastic approach, where probability functions of cash flows are used to maximize expected utility from net present values. The stochastic approach is further divided into non-adaptive scenarios and adaptive scenarios, where the investor can gather additional price information during the life of a stand to optimize the harvest decision. The adaptive management problem is solved with stochastic dynamic programming. For each possible harvest age, an optimal reservation price below which the forest landowner should not sell the stumpage is calculated. The study shows that the use of a single risk-adjusted discount rate is generally inadequate to compare different management intensities. The stochastic approaches reveal that the optimal management intensity depends on the degree of risk aversion, with increasing risk aversion leading to a lower intensity level. Given the possibility of catastrophic losses, the adoption of a feedback harvesting policy strengthens the already dominant influence of risk aversion and does not generally lead to an increase in management intensity. The study's results suggest that even if the landowner is managing the forest solely for financial reasons, some of the reluctance to invest in intensive forestry may not indicate a lack of interest or information but simply an economic reaction to risk, especially in regions with a high potential danger of catastrophic losses. / Ph. D.
137

Woody Species Diversity, Forest and Site Productivity, Stumpage Value, and Carbon Sequestration of Forests on Mined Lands Reclaimed Prior to the Passage of the Surface Mining Control and Reclamation Act of 1977

Rodrigue, Jason Adam 26 November 2001 (has links)
The present state of forestry post mining land uses has prompted concern among researchers, landowners, and the public. Surface mines reclaimed to forests under the provision of the Surface Mining Control and Reclamation Act (SMCRA) may not achieve site productivity levels required by the law. Anecdotal evidence suggests that many pre-law reforested mined sites are growing productive forests. The purpose of this study was to characterize these forests and the mine soils in which they are growing, and use them to benchmark forest development on mined land. Using 14 mined and 8 non-mined sites in the midwestern and eastern coalfields research to address the following objectives was undertaken: (i) characterize the development, composition, and diversity of woody species on pre-SMCRA, forested surface mined land; (ii) estimate forest and site productivity on surface mined land and determine the soil and site properties most influencing forest growth; (iii) estimate projected rotation-age timber product value; (iv) quantify current carbon sequestration pools associated with the developing woody plant biomass, the forest floor, and developing soil medium; (v) compare the diversity, forest and site productivity, commercial value, and carbon capture of reclaimed mined sites to that of regional non-mined forest systems. Species richness between non-mined and mined sites was about the same within each region with 14 to 15 tree species in the canopy. Canopy richness of eastern mined sites was less than that on midwestern mined sites (12 species compared to 17 species, respectively). Species richness of the understory and woody ground layer were similar between sites planted to pines versus hardwoods. White pine (Pinus strobus) monocultures, planted on many sites in the eastern region, caused species unevenness throughout all forest strata. Midwestern mined sites and eastern sites planted to hardwoods closely approximated non-mined sites in commercial species composition. Planted species represented the majority of canopy layer dominance and abundance (82% relative dominance and 56% relative abundance). Site productivity between non-mined sites and 12 of the 14 mined sites was similar. Regression analysis identified the five most influential soil properties affecting site quality, which included soil profile base saturation, total coarse fragments, total available water, C horizon total porosity, and soil profile electrical conductivity. These five properties explained 52 % of the variation in tree growth. Forest productivity of these mined sites was equal to or greater than that of non-mined forests, ranging between 3.3 m3ha-1yr-1 and 12.1 m3ha-1yr-1. Management activities such as planting pine and valuable hardwood species increased the stumpage value of forests on reclaimed mine sites. Rotation-age stumpage values on mined study sites ranged between $3,064 ha-1 and $19,528 ha-1 and were commonly greater than stumpage values on non-mined reference sites. After 20 to 55 years, total site carbon levels on mined study sites averaged 217 Mg ha-1, while total carbon amounts on natural sites averaged 285 Mg ha-1. The amounts of carbon captured within the plant biomass and litter layer were the same on mined and natural sites. However, the soil carbon content of mined sites averaged 39 % lower than natural soils. The amount of carbon captured across mined sites was largely a function of forest stand age. Pre-SMCRA forests growing on mined sites with productivity levels similar to non-mined sites are capable of developing forest attributes comparable to or greater than those found on non-mined land within a period of 60 years, the length of a commercial hardwood rotation. These mature forests can serve as benchmarks for forest development on mined lands being reclaimed under current state and federal regulations. / Master of Science
138

Improving domestic markets for the wood products of reforestation programs: a case study of eucalyptus in northwestern Senegal

Merry, Frank 04 August 2009 (has links)
There is a drastic need for reforestation in the Sahel region of Africa. International donors and local governments invest large sums of money for the purpose of planting trees. Unfortunately, the majority of reforestation efforts last only as long as the projects. Presently there is a push in the donor community to have more sustainable projects, increasing local participation and creating a situation in which reforestation efforts will continue beyond the scope of any one project. This thesis examines the potential opportunity for the use of eucalyptus in the domestic sawn wood markets of Senegal. It is hoped that with increased economic incentives the local population will become more inclined to plant trees. It is therefore important to identify the market opportunities for the products of reforestation. In this research it has been noted that more emphasis should be placed on determining the barriers to market entry for the goods to be produced from the reforestation and providing assistance to lower those barriers. In Senegal it is generally accepted that planting for fuel wood and housepoles does not provide enough of an economic incentive for increased local involvement in reforestation. This thesis finds that the domestic sawn wood market for eucalyptus in Senegal holds potential but will not provide tangible benefits until there are further improvements in the market infrastructure and communication to the farmer. To increase the participation in this market the people of Senegal need to see for themselves that reforestation can be financially beneficial. Reforestation projects rust have a longer-term vision and provide assistance throughout the productive cycle of the tree. / Master of Science
139

Development of Ecosystem Structure and Function on Reforested Surface-Mined Lands

Avera, Bethany Noel 30 January 2015 (has links)
Surface mining in the central Appalachian coalfield disturbs landscapes. Post-mining reforestation efforts now achieve successful reestablishment and growth; however, it is unclear whether reforestation efforts also restore the native forest ecosystem functions. We quantified rates of return of key ecosystem functions and structural attributes of the post-mining forested ecosystem. A chronosequence of four reforested mine sites and an unmined reference stand were studied in southwestern Virginia. Total soil nitrogen (N) and component (mineral soil, forest floor, root, and aboveground biomass) ecosystem carbon (C) pools were quantified. Throughout the growing season, soil gas fluxes [i.e., carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4)], soil inorganic-N [nitrate (NO3-) and ammonium (NH4+)], and total and active microbial biomass were measured. Soil organic C (SOC) and total ecosystem C are returning to the mined landscape. Ecosystem C was correlated with N (r= 0.80; p= 0.0003) and with total and active microbial biomass (r= 0.92; p=<.0001 and r= 0.86; p=<.0001). Available soil inorganic-N and CO2 and N2O fluxes showed no significant differences among study sites; however, the reforested mine soils showed a diminished capacity for CH4 uptake. Although some ecosystem components and functions rapidly returned to the mined landscape, others did not. Our results indicate that reforestation on surface mined lands is largely successful at restoring many ecosystem functions, yet certain functions are decoupled from the redeveloping ecosystem structure. Improved understanding of relationships between ecosystem functions and structural measures in this context can aid development of ecosystem restoration science and mine reclamation practice. / Master of Science
140

Realising REDD in Africa : risk, feasibility and supporting policy

Knowles, Tony 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Responding appropriately to anthropogenic climate change presents a considerable challenge to humankind. Projected changes in climate are anticipated to affect the world's natural systems, human health and economies in many ways. Consequently, there is an urgent need to implement climate change mitigation and adaptation measures that are appropriate and efficient. This dissertation focuses on aspects of risk and feasibility associated with land use based climate change mitigation. First, it reviews policy, implementation and incentive issues that are key to promoting permanence and reducing the risk of leakage associated with reducing emissions from deforestation and forest deforestation (REDD1) in sub-Saharan Africa. Secondly, it assesses the transaction costs associated with the implementation of avoided deforestation and reforestation activities and their effect on the financial feasibility of ventures located in woodland and rangeland systems. Thirdly, it explores the potential impact of biophysical risk factors (such as fire) on the outcome of REDD activities in two chapters. The first risk chapter introduces the notion of biophysical risk and reviews the risk of fire to REDD activities located in important African vegetation types. The second chapter on risk uses the Century Ecosystem Program and published climate projection data to assess the effect of projected changes in temperature, rainfall and atmospheric carbon dioxide on the outcome of REDD activities. The results indicate that, among the biophysical risk variables assessed, fire may not present a major risk to REDD activities located in African woodland, savanna and grassland systems. In contrast, fire may present a significant risk in moist forests where unprecedented dry periods may allow fire to occur in a system where it has previously been absent. The analysis of the affect of climate change found that changes in climate are generally predicted to lead to an increase in carbon stocks and sequestration rates for the vegetation types assessed. Exceptions do occur, such as the modeled effect on nutrient-rich savannas, which require further investigation. The analysis of transaction costs associated with REDD activities illustrated that such costs may inhibit the feasibility of smaller-scale activities, especially in ecosystems outside of moist forests with relatively low carbon stocks and associated revenues. Whereas the proposed creation of national-scale capacity may reduce some transaction costs to a certain extent, there is a clear need to better understand the true cost of REDD activities. In terms of required supporting policy and implementation capacity, it is noted 1) that multi-criteria land use planning is particularly important in reducing permanence risk, 2) that the scope of recognized land use activities that reduce atmospheric GHG needs to be expanded if the benefits of REDD are to be fully realised and 3) that informal land tenure may not require transformation prior to successful, sustainable implementation. A review of the appropriateness of community-based forest carbon monitoring found that such an approach presents significant cost savings while providing local employment and incentive opportunities. Exposure to such initiatives to date indicated that the quality of data collected is adequate and sufficiently robust to fulfill project and national-scale reporting and verification requirements. / AFRIKAANSE OPSOMMING: Antropogeniese klimaatsverandering hou daadwerklike uitdagings vir die mensdom in. Huidige voorspellings dui daarop dat klimaatsverandering natuurlike sisteme, gesondheid en die ekonomie op 'n verskeidenheid van vlakke gaan beinvloed. Daar is dus 'n dringende nood aan korrekte en effektiewe aanpassings- en mitigasie maatstawwe wat geimplementeer kan word. Hierdie proefskrif fokus op die risiko en lewensvatbaarheid van grondgebruiksgebaseerde klimaatsverandering mitigasie. Eerstens gee dit 'n oorsig van die beleids en implementasie dryfvere wat noodsaaklik is vir die bevordering van permanentheid en die verlaging van die risiko van lekkasie wat geassosieer word met verlaagde emissies vanwee degradasie en ontbossing (VEDO2) in sub-Sahara Afrika. Tweedens analiseer dit die transaksiekoste wat geassosieer word met die vermyding van ontbossing en herbebossing en die effek daarvan op die finansiele lewensvatbaarheid van sulke aktiwiteite in bosveld en weiveld. Derdens ondersoek die proefskrif die biofisiese risiko faktore (soos vuur) op die uitslag van VEDO aktiwiteite in twee hoofstukke. Die eerste hoofstuk word ingelei deur 'n ontleding en verklaring van biofisiese risiko en gee dan 'n oorsig oor die risiko van vuur op VEDO projekte in belangrike plantegroei-tipes in Afrika. Die tweede hoofstuk maak gebruik van die Century Ekostelsel Program om die impak van voorspelde veranderings in temperatuur, reenval en atmosferiese koolstofdioksied op VEDO aktiwiteite te evalueer. Die resultate dui aan dat onder die biofisiese risiko faktore wat ondersoek is, vuur nie so „n belangrike risiko inhou vir VEDO projekte in die bosveld, savanna en grasveld plantegroeitipes in Afrika nie. In teenstelling hou vuur 'n groot risiko in vir nat woude waar ongekende droeë tydperke kan veroorsaak dat vuur wel mag voorkom in „n stelsel waar dit voorheen afwesig was. Die analise op die effek van klimaatsverandering het bevind dat veranderinge in klimaat tipies sal lei tot a toename in koolstof voorrade en verhoogde sekwestrasie tempos vir die plantegroeitipes wat geevalueer is. Daar was egter uitsonderings, soos byvoorbeeld die gemodeleerde impakte op nutrientryke savannas wat verdere ondersoek benodig. Die analise ten opsigte van die transaksiekoste wat gepaardgaan met VEDO aktiwiteite illustreer dat sulke kostes dalk die lewensvatbaarheid van kleinerskaal projekte mag benadeel, veral in ekostelsels anders as nat woude met relatief lae koolstof voorrade en geassosieerde inkomste. Die voorgestelde skepping van kapasiteit op 'n nasionale vlak mag dalk transaksie koste verlaag tot 'n mate, maar daar is duidelik 'n behoefte om beter insigte te verkry oor die ware kostes van VEDO aktiwiteite. Wat betref die vereiste ondersteunende beleid en implimentasie kapasiteit is daar bevind dat 1) multi-kriteria grondgebruik beplanning uiters belangrik is in die verlaging van permanentheidsrisiko, 2) die omvang van erkende grondgebruiks aktiwiteite moet uitgebrei word om ten volle voordeel te trek uit VEDO, 3) dat informele grondbesit dalk nie transformasie vereis voor suksesvolle, volhoubare implementasie nie. „n Oorsig oor die aanvaarbaarheid van gemeenskapsgebaseerde woudkoolstofmonitering het gevind dat so 'n benadering tot groot kostebesparings lei terwyl dit ook plaaslike werkskepping bevorder en dien as dryfveer vir projekte. Blootstelling aan sulke inisiatiewe tot op hede dui aan dat die kwaliteit van die data wat ingesamel is voldoen aan projek- sowel as nasionale vlak verslaggewingsvereistes.

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