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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.
1

Die Entwicklung der standörtlichen Nährstoffvorräte bei naturnaher Waldbewirtschaftung und im Plantagenbetrieb, Ostkalimantan (Indonesien) /

Ruhiyat, Daddy. January 1989 (has links)
Thesis--Georg-August-Universität. / Includes bibliographical references (p. 180-195).
2

Skogsstrukturer och dess betydelse för biodiversitet : visat i en gradient av mänsklig påverkan / Forest structures and their importance for biodiversity : studied along a gradient of human impact

Brynjarsdotter, Hilda January 2020 (has links)
This study was conducted to find out if there are forest structural differences along a gradient of human impact: tree plantation, semi-natural forest, and natural forest. Two, forest areas in the north of Sweden were selected; Kulbäcksliden, which is dominated by mesic to moist spruce forest with gap dynamics, and a forest in the  Eco park Skatan, which due to dry soils historically have been dominated by pine forest and fire dynamics. An assessment was made from the sampled areas to test if they, according to the Swedish Forest Agency checklist, could be counted as woodland key habitats. The study areas are located in the Vindeln municipality, Sweden. Boreal forests in the region historically had structures controlled by either forest fires or gap dynamics. However, due to today’s forestry oriented for maximize productivity, the former large variation in forest structures have largely decreased, and with them a large part of the diversity of flora and fauna. Policy wise, Sweden have both a production goal and an environmental goal concerning the forests. However, today, one can argue that in practice the production goal weighs heavier, and with that follows an intense conversion of forests to plantations. This leads to diminishing populations of species of various forest organisms, mostly due to habitat loss. This study showed that in Kulbäcksliden there was a significant difference in structure among plantations, semi-natural forests, and natural forests, concerning occurrence of high biodiversity value trees of spruce, and fallen dead wood. In Eco park Skatan, this study showed a significant difference in the number of high biodiversity value trees of spruce and standing dead wood between a natural forest and a semi-natural forest. Furthermore, of the five areas that were investigated, only the two natural forests in each area could be counted as a woodland key habitat. This indicates that our modern-day forestry destroys structures that are essential for many species, which can lead to declining populations. If we want to conserve our flora and fauna, we need to change our policies regarding our forestry and make the environmental goal equally important to the production goal, not only in theory, but also in practice. To do this we need to spread awareness to the public about the situation in our forests.
3

Forest resources and forestry in Vietnam / Tài nguyên rừng và lâm nghiệp ở Việt Nam

Luong, Thi Hoan 09 December 2015 (has links) (PDF)
Forest and forestland are important roles and sources of livelihood for the population living in or near forests and in mountainous areas of Vietnam. The objectives of this paper analysed the change in forest resource, and policy of forestry in Vietnam. In recent several years, forest area rapidly covered an average rate of 240,000 ha/year and had about 13.39 million hectares in 2010. It has contributed to the use of bare land, job creation and improvement of livelihoods for 25% of Vietnam’s population living in mountainous areas. Those results were the purpose of reforestation program and the production of wood industry in Vietnam. In this addition, government policies and regulations have provided a solid foundation for development of the forest plantations and conservation of forest ecosystems though forest land allocation and lease to organizations, households, and individuals. Therefore, the forest utilization has motivated by both environmental and commercial factors in Vietnam based on dividing into three forest categories special use, protection and production forests. However, the development strategy of forest management plan is the difficulties associated with conflicting land claims and boundary disputes due to the value of the established forest. / Rừng và đất rừng đóng vai trò quan trọng và là nguồn sinh kế cho người dân sống trong hoặc gần rừng ở các khu vực miền núi của Việt Nam. Mục tiêu của nghiên cứu này phân tích sự thay đổi về tài nguyên rừng và chính sách về lâm nghiệp. Trong một vài năm gần đây, diện tích rừng bao phủ nhanh với tốc độ trung bình 240.000 ha/năm và có khoảng 13,39 triệu ha trong năm 2010 này đã góp phần vào việc sử dụng đất trống, tạo việc làm và cải thiện đời sống cho 25% dân số sống ở khu vực miền núi của Việt Nam. Kết quả này là mục đích của chương trình trồng rừng và sản xuất gỗ công nghiệp tại Việt Nam. Bên cạnh đó, chính sách và các quy định của chính phủ đã cung cấp một nền tảng vững chắc cho việc phát triển diện tích trồng rừng và bảo tồn hệ sinh thái rừng mặc dù rừng và đất rừng đã được giao và khoán cho các tổ chức, hộ gia đình, cá nhân. Vì vậy, việc sử dụng rừng đã thúc đẩy bởi hai yếu tố môi trường và thương mại ở Việt Nam, dựa trên phân loại rừng: rừng đặc dụng, rừng sản xuất và rừng phòng hộ. Tuy nhiên, chiến lược kế hoạch quản lý phát triển rừng có những khó khăn liên quan đến xung đột khiếu nại đất và tranh chấp biên giới do giá trị của rừng được thành lập.
4

Producing tea coolies?

Varma, Nitin 05 December 2013 (has links)
Als "Coolie" gilt gemeinhin der "ungelernte" Arbeiter. Das Anbieten von Leiharbeit hatte diverse präkoloniale Vorläufer. Im 19. Jahrhundert wurde der Versuch unternommen, den Begriff des "Coolies" durch diskursive Auslegungen und die Methoden einer "flexiblen-inflexiblen" Arbeit neu zu prägen. "Coolie"-Arbeit galt meist als ein Kompromiss zwischen der Vergangenheit (Sklavenarbeit) und der Zukunft (freie Arbeit/Lohnarbeit) und als Spagat zwischen beiden Systemen. Sie wurde als ein Übergangsstadium und Teil eines versprochenen Wandels dargestellt. Die Teeplantagen Assams nahmen wie viele andere tropische Plantagen in Südasien auch im 19. Jahrhundert offiziell ihren Betrieb auf. Ursprünglich wurden sie von lokalen Arbeitern betrieben. Erst in den späten 1850er-Jahren wurden die lokalen Arbeiter durch von außerhalb der Provinz importierten Arbeitskräften ersetzt, die in der historischen Literatur gemeinhin unproblematisch mit dem Begriff "Coolies" belegt werden. Durch eine Analyse des Übergangs von der lokal rekrutiert für "Kuli" Arbeit und durch eine Analyse seiner Einführung die Studie argumentiert, dass "Kuli" Arbeit wurde "produziert" in den Kolonialkapitalistischen Plantagen in Assam. Mein Anliegen besteht dabei ausdrücklich nicht darin, einen zügellosen kolonialen Kapitalismus nahezulegen, dessen Strategie es ist, "Coolies" zu definieren und hervorzubringen oder die historischen Umstände, Verhandlungen, Streitfragen und Krisen zu betonen. Ich versuche vielmehr, die Erzählungen vom plötzlichen Auftauchen des archetypischen Teeplantagen-"Coolies" (d.i. als importierter und unfreier Lohnarbeiter) zu hinterfragen und sein Erscheinen, sein Bestehen und seine Verlagerungen mehr im Sinne grundlegender und diskursiver Prozesse auszulegen. / “Coolie” is a generic category for the “unskilled” manual labour. The offering of services for hire had various pre-colonial lineages. In the nineteenth century there was an attempt to recast the term in discursive constructions and material practices for “mobilized-immobilized” labour. Coolie labour was often proclaimed as a deliberate compromise straddling the regimes of the past (slave labour) and the future (free labour). It was portrayed as a stage in a promised transition. The tea plantations of Assam, like many other tropical plantations in South Asia, were inaugurated and formalized during this period. They were initially worked by the locals. In the late 1850s, the locals were replaced by labourers imported from outside the province who were unquestioningly designated “coolies” in the historical literature. Qualifying this framework of transition (local to coolie labour) and introduction (of coolie labour), this study makes a case for the “production” of coolie labour in the history of the colonial-capitalist plantations in Assam. The intention of the research is not to suggest an unfettered agency of colonial-capitalism in defining and “producing” coolies, with an emphasis on the attendant contingencies, negotiations, contestations and crises. The study intervenes in the narratives of an abrupt appearance of the archetypical coolie of the tea gardens (i.e., imported and indentured) and situates this archetype’s emergence, sustenance and shifts in the context of material and discursive processes.
5

The immoderate past the image of the Southern gentleman in history and fiction, 1860-1980 /

Leenhouts, Anna Jacoba, January 1900 (has links)
Thesis (Ph. D.)--Rijuksuniversiteit te Utrecht, 1982. / Summary in Dutch. Includes bibliographical references.
6

Land availability for sustainable agricultural tree crops

Weber, Norbert, Meyer, Matthias 22 February 2021 (has links)
Prof Dr Norbert Weber from TU Dresden argues that land availability for sustainable agricultural tree crops and a positive perception of this by the official administration both remain challenging hurdles.
7

Forest resources and forestry in Vietnam: Review paper

Luong, Thi Hoan 09 December 2015 (has links)
Forest and forestland are important roles and sources of livelihood for the population living in or near forests and in mountainous areas of Vietnam. The objectives of this paper analysed the change in forest resource, and policy of forestry in Vietnam. In recent several years, forest area rapidly covered an average rate of 240,000 ha/year and had about 13.39 million hectares in 2010. It has contributed to the use of bare land, job creation and improvement of livelihoods for 25% of Vietnam’s population living in mountainous areas. Those results were the purpose of reforestation program and the production of wood industry in Vietnam. In this addition, government policies and regulations have provided a solid foundation for development of the forest plantations and conservation of forest ecosystems though forest land allocation and lease to organizations, households, and individuals. Therefore, the forest utilization has motivated by both environmental and commercial factors in Vietnam based on dividing into three forest categories special use, protection and production forests. However, the development strategy of forest management plan is the difficulties associated with conflicting land claims and boundary disputes due to the value of the established forest. / Rừng và đất rừng đóng vai trò quan trọng và là nguồn sinh kế cho người dân sống trong hoặc gần rừng ở các khu vực miền núi của Việt Nam. Mục tiêu của nghiên cứu này phân tích sự thay đổi về tài nguyên rừng và chính sách về lâm nghiệp. Trong một vài năm gần đây, diện tích rừng bao phủ nhanh với tốc độ trung bình 240.000 ha/năm và có khoảng 13,39 triệu ha trong năm 2010 này đã góp phần vào việc sử dụng đất trống, tạo việc làm và cải thiện đời sống cho 25% dân số sống ở khu vực miền núi của Việt Nam. Kết quả này là mục đích của chương trình trồng rừng và sản xuất gỗ công nghiệp tại Việt Nam. Bên cạnh đó, chính sách và các quy định của chính phủ đã cung cấp một nền tảng vững chắc cho việc phát triển diện tích trồng rừng và bảo tồn hệ sinh thái rừng mặc dù rừng và đất rừng đã được giao và khoán cho các tổ chức, hộ gia đình, cá nhân. Vì vậy, việc sử dụng rừng đã thúc đẩy bởi hai yếu tố môi trường và thương mại ở Việt Nam, dựa trên phân loại rừng: rừng đặc dụng, rừng sản xuất và rừng phòng hộ. Tuy nhiên, chiến lược kế hoạch quản lý phát triển rừng có những khó khăn liên quan đến xung đột khiếu nại đất và tranh chấp biên giới do giá trị của rừng được thành lập.
8

Is short rotation forestry biomass sustainable?

Zurba, Kamal 27 October 2016 (has links) (PDF)
Despite the negative effects of fossil fuels on the environment, these remain as the primary contributors to the energy sector. In order to mitigate global warming risks, many countries aim at reducing greenhouse gas emissions. Bioenergy crops are being used as a substitute for fossil fuels and short rotation forestry is a prime example. In order to examine the sustainability of energy crops for fuel, typical European short rotation forestry (SRF) biomass, willow (Salix spp.) and poplar (Populus spp.) are examined and compared to rapeseed (Brassica napus L.) in respect to various aspects of soil respiration and combustion heat obtained from the extracted products per hectare. Various approaches are used to look at an As-contaminated site not only in the field but also in a soil-column experiment that examines the fate of trace elements in SRF soils, and in an analysis using MICMAC to describe the driving factors for SRF crop production. Based on the cause-effect chain, the impacts of land-use change and occupation on ecosystem quality are assessed when land-use is changed from degraded land (grassland) to willow and poplar SRF. A manual opaque dynamic closed chamber system (SEMACH-FG) was utilized to measure CO2 emissions at a willow/poplar short rotation forest in Krummenhennersdorf, Germany during the years 2013 and 2014, and at a rapeseed site in 2014. Short rotation forest soils showed higher CO2 emission rates during the growing season than the dormant season – with a CO2 release of 5.62±1.81 m-2 s-1 for willows and 5.08±1.37 µmol CO2 m-2 s-1 for poplars in the growing season. However, during the dormant season the soil sites with willow emitted 2.54±0.81 µmol CO2 m-2 s-1 and with poplar 2.07±0.56 µmol CO2 m-2 s-1. The highest emission rates for the studied plantations were observed in July for both years 2013 and 2014, during which the highest air and soil temperatures were recorded. Correlations between soil emission of CO2 and some meteorological parameters and leaf characteristics were investigated for the years 2013 and 2014. For example, for the willow clone (Jorr) and poplar clone (Max 3), high correlations were found for each between their soil emission of CO2 and both soil temperature and moisture content. Fitted models can explain about 77 and 75% of the results for Jorr and Max 3 clones, respectively. Moreover, a model of leaf area (LA) can explain about 68.6% of soil CO2 emission for H275. Estimated models can be used as a gap-filling method, when field data is not available. The ratio between soil respiration and the combustion heat calculated from the extracted products per hectare was evaluated and compared for the study’s willow, poplar and rapeseed crops. The results show that poplar and willow SRF has a very low ratio of 183 kg CO2 GJ 1 compared to rapeseed, 738 kg CO2 GJ 1. The soil-column experiment showed that by continuing the SRF plantation at the As-contaminated site, remediation would need only about 3% of the time needed if the site was left as a fallow field. In order to understand the complex willow and poplar short rotation forestry production system, 50 key variables were identified and prioritized to describe the system as a step to enhance the success of such potentially sustainable projects. The MICMAC approach was used in order to find the direct and the indirect relationships between those parameters and to classify them into different clusters depending on their driving force and interdependency. From this, it can be summarized that in order to enhance the success of a SRF system, decision makers should be focussing on: ensuring a developed wood-fuel market, increasing farmers’ experience/training, improving subsidy regulations and recommending a proper harvesting year cycle. Finally, the impacts of land-use change and occupation on the ecosystem quality were assessed. Results show that establishing SRF plantations on degraded lands improved the ecosystem structural quality (ESQ) by about 43% and ecosystem functional quality (EFQ) by about 12%. Based on overall results, poplar and willow SRF biomass can be recommended as renewable and sustainable sources for bioenergy.
9

Is short rotation forestry biomass sustainable?

Zurba, Kamal 12 October 2016 (has links)
Despite the negative effects of fossil fuels on the environment, these remain as the primary contributors to the energy sector. In order to mitigate global warming risks, many countries aim at reducing greenhouse gas emissions. Bioenergy crops are being used as a substitute for fossil fuels and short rotation forestry is a prime example. In order to examine the sustainability of energy crops for fuel, typical European short rotation forestry (SRF) biomass, willow (Salix spp.) and poplar (Populus spp.) are examined and compared to rapeseed (Brassica napus L.) in respect to various aspects of soil respiration and combustion heat obtained from the extracted products per hectare. Various approaches are used to look at an As-contaminated site not only in the field but also in a soil-column experiment that examines the fate of trace elements in SRF soils, and in an analysis using MICMAC to describe the driving factors for SRF crop production. Based on the cause-effect chain, the impacts of land-use change and occupation on ecosystem quality are assessed when land-use is changed from degraded land (grassland) to willow and poplar SRF. A manual opaque dynamic closed chamber system (SEMACH-FG) was utilized to measure CO2 emissions at a willow/poplar short rotation forest in Krummenhennersdorf, Germany during the years 2013 and 2014, and at a rapeseed site in 2014. Short rotation forest soils showed higher CO2 emission rates during the growing season than the dormant season – with a CO2 release of 5.62±1.81 m-2 s-1 for willows and 5.08±1.37 µmol CO2 m-2 s-1 for poplars in the growing season. However, during the dormant season the soil sites with willow emitted 2.54±0.81 µmol CO2 m-2 s-1 and with poplar 2.07±0.56 µmol CO2 m-2 s-1. The highest emission rates for the studied plantations were observed in July for both years 2013 and 2014, during which the highest air and soil temperatures were recorded. Correlations between soil emission of CO2 and some meteorological parameters and leaf characteristics were investigated for the years 2013 and 2014. For example, for the willow clone (Jorr) and poplar clone (Max 3), high correlations were found for each between their soil emission of CO2 and both soil temperature and moisture content. Fitted models can explain about 77 and 75% of the results for Jorr and Max 3 clones, respectively. Moreover, a model of leaf area (LA) can explain about 68.6% of soil CO2 emission for H275. Estimated models can be used as a gap-filling method, when field data is not available. The ratio between soil respiration and the combustion heat calculated from the extracted products per hectare was evaluated and compared for the study’s willow, poplar and rapeseed crops. The results show that poplar and willow SRF has a very low ratio of 183 kg CO2 GJ 1 compared to rapeseed, 738 kg CO2 GJ 1. The soil-column experiment showed that by continuing the SRF plantation at the As-contaminated site, remediation would need only about 3% of the time needed if the site was left as a fallow field. In order to understand the complex willow and poplar short rotation forestry production system, 50 key variables were identified and prioritized to describe the system as a step to enhance the success of such potentially sustainable projects. The MICMAC approach was used in order to find the direct and the indirect relationships between those parameters and to classify them into different clusters depending on their driving force and interdependency. From this, it can be summarized that in order to enhance the success of a SRF system, decision makers should be focussing on: ensuring a developed wood-fuel market, increasing farmers’ experience/training, improving subsidy regulations and recommending a proper harvesting year cycle. Finally, the impacts of land-use change and occupation on the ecosystem quality were assessed. Results show that establishing SRF plantations on degraded lands improved the ecosystem structural quality (ESQ) by about 43% and ecosystem functional quality (EFQ) by about 12%. Based on overall results, poplar and willow SRF biomass can be recommended as renewable and sustainable sources for bioenergy.:Table of Contents Acknowledgements VI Abstract VII List of Figures IX List of Tables XI List of Appendix Tables XII List of Abbreviations XIII List of Abbreviations ...continued XIV 1. Background 1 1.1. General introduction 1 1.2. Soil organic carbon (SOC) 2 1.3. Soil respiration 4 1.4. Energy and bioenergy crops 5 1.5. Willow and poplar short rotation forestry 8 1.6. Degraded lands 10 1.8. Challenges 17 1.9. Objectives of this study 18 2. Methodology 19 2.1. Site Description 19 2.2. Environmental variables 22 2.3. Measuring CO2 emissions 23 2.3.1. Soil emission of CO2 23 2.3.2. Sensitivity of soil respiration to temperature (Q10) 25 2.4. Willow and poplar leaf traits 26 2.4.1. Measuring leaf area 26 2.4.2. Leaf Area Index (LAI) 27 2.4.3. Leaf sensitivity to high and low temperatures 28 2.5. Soil characteristics 30 2.5.1. Soil sampling 30 2.5.2. Soil Moisture Content % (SMC) by gravimetric method 31 2.5.3. Soil pH 31 2.5.4. Soil Cation Exchange Capacity (CEC) 31 2.5.5. Soil content of C, N, S, heavy metals and trace elements 31 2.5.6. Soil porosity 31 2.5.7. Soil pore water 32 2.5.8. Soil hydraulic conductivity (Kf) 32 2.6. Soil-column experiment 34 2.6.1. Experiment set-up 35 2.6.2. Distribution coefficients (Kd) 35 2.7. MICMAC approach 36 2.7.1. Selection of variables 36 2.7.2. Description of direct relationships 36 2.7.3. Classification of variables 37 2.8. Impacts of land-use change on the ecosystem quality 38 2.9. Computer software 40 3. Results and Discussion 41 3.1. Environmental conditions 41 3.1.1. Photosynthetically active radiation (PAR) 41 3.1.2. Soil temperature 42 3.1.3. Soil moisture content 43 3.2. Soil emission of CO2 46 3.2.1. CO2 emission from soil at the short rotation forestry site 46 3.2.2. Soil emission of CO2 during the day and the night 48 3.2.3. Cumulative emission of CO2 49 3.2.4. Comparison with other bioenergy crops 50 3.3. Q10 52 3.4. Willow and poplar Leaf Characteristics 54 3.4.1. Leaf Area Index (LAI) 54 3.4.2. Specific leaf area (SLA) 56 3.4.3. Leaf sensitivity to temperature 57 3.5. Correlations of soil CO2 emission with soil temperature and moisture content 59 3.6. Correlations of soil CO2 emission with plant parameters 65 3.7. Insights into soil respiration and combustion heat per area 67 3.7.1. Cumulative seasonal CO2 emission (CE) 68 3.7.2. Output energy 69 3.7.3. CO2(soil respiration) / Energy ratio 70 3.7.4. Global-warming potential (GWP) 72 3.8. Trace elements in soil 73 3.8.1. Solid-liquid partition coefficients (Kd) 74 3.8.2. Estimating time of remediation 78 3.9. Identification and Prioritization of Key Parameters for Willow and Poplar Short Rotation Forestry (SRF) Production System 82 3.9.1. Based on direct influence/dependence map: 85 3.9.2. Based on indirect influence/dependence map: 87 3.10. Impacts of Land-use Change on the Ecosystem Quality 93 4. Conclusions and Recommendations 101 5. References 102 Appendix 118

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