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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.
451

Appropriate Forest Management in Biha Resort and its Buffer Areas, Bukit Barisan Selatan National Park, Indonesia / インドネシア、ブキット・バリサン・セラタン国立公園ビハ・リゾートとその緩衝地域における適切な森林管理

Anggi, Mardiyanto 25 March 2024 (has links)
京都大学 / 新制・課程博士 / 博士(地球環境学) / 甲第25470号 / 地環博第256号 / 新制||地環||52(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 柴田 昌三, 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 / DGAM
452

Intrapreneurial ecosystems in academia and their overlooked outputs: Graduate employability and wellbeing

Abreu, M., Grinevich, Vadim 12 March 2024 (has links)
Yes / The aim of this paper is dual: a) to elaborate a systemic concept of intrapreneurship in academia which will be reflective of complexities and idiosyncrasies of the University as a multi-mission multi-function organisation; and b) to empirically test this concept in the context of relatively neglected outputs of academic intrapreneurship such as graduate employability and graduate wellbeing. Guided by an intrapreneurial ecosystem framework, our analysis is based on a combination of administrative and survey panel data for 141 UK higher education institutions. We arrive at several contributing findings. These suggest that the intrapreneurial ecosystem within academia is increasingly predisposed towards enhancing the quality of graduate outcomes rather than simply promoting raw measures such as graduate jobs or the number of graduate start-ups. Furthermore, we reveal the critical role of University national stakeholder networks for graduate career satisfaction, start-up generation, and undergraduate employment. Finally, our empirical exercise and its results demonstrate the practical value of the proposed concept of the intrapreneurial ecosystem for University management and practitioners, not least because it systematically identifies areas for an immediate, medium- and long-term action.
453

The Effectiveness of Constructed Treatment Wetland Systems at Removing Microplastic Pollution

Johnsen, Katherine L 01 January 2024 (has links) (PDF)
Plastics are a highly utilized material in modem society, leading to environmental concerns surrounding plastic pollution. Microplastics, which are defined as plastic particles less than 5mm in size, have additionally become increasingly recognized as a harmful pollutant in aquatic systems. Constructed treatment wetland systems (CTWSs) are highly effective at removal and mitigation of pollutants, including anthropogenic nutrient inputs. This study aims to understand the potential of a CTWS to remove microplastic pollution from tertiary-treated municipal wastewater before discharge into a local natural water body. Microplastic percent removal was determined through the manual quantification of microplastics in triplicate 500mL surface water samples, taken at both an influent and effluent site. Samples were vacuum filtered and particles within the sample were caught on the 0.45μm pore size nitrocellulose filter paper, dried, and transported to a microscope station where microplastics could be identified and quantified according to visual characteristics. Results indicate the CTWS studied is removing, on average, 93 % of microplastic particles across 11 months of data collection, demonstrating an additional ecosystem service provided by treatment wetlands.
454

Characterization of wet and dry deposition to the nitrogen sensitive alpine ecosystems in the Colorado Rocky Mountains

Oldani, Kaley Michelle January 1900 (has links)
Master of Science / Department of Civil Engineering / Natalie Mladenov / The Colorado Front Range of the Rocky Mountains contains undeveloped, barren soils, yet in this environment there is strong evidence for a microbial role in increased nitrogen (N) export. Barren soils in alpine environments are severely carbon-limited, and organic carbon (OC) is the main energy source for heterotrophic microbial activity and sustenance of life. Atmospheric deposition can contain high amounts of OC. Atmospheric pollutants, dust events, and biological aerosols, such as bacteria, may be important contributors to the atmospheric OC load. In this stage of the research we evaluated seasonal trends and annual loadings in the chemical composition and optical spectroscopic (fluorescence and UV-vis absorbance) signatures of wet deposition and dry deposition in an alpine environment, at Niwot Ridge in the Rocky Mountains of Colorado to better understand the sources and chemical characteristics of atmospheric deposition. Dry deposition was found to be an important source of OC to the alpine. Wet deposition contributed substantially greater amounts of dissolved ammonium, nitrate, and sulfate. There were also positive relationships between dissolved organic carbon (DOC) concentrations and ammonium, nitrate and sulfate concentrations in wet deposition, which may be derived from such sources as dust and urban air pollution. We also observed the presence of seasonally-variable fluorescent components in atmospheric samples that are different from aquatic dissolved organic matter (DOM). Finally, the quality of atmospheric organic compounds reflects photodegradation during transport through the atmosphere. These results are relevant because atmospheric inputs of carbon and other nutrients may influence nitrification in barren, alpine soils and, ultimately, the export of nitrate from alpine watersheds.
455

Structure fonctionnelle des assemblages ichtyologiques le long de gradients environnementaux (système lagunaire de Patos-Mirim, Brésil) / Functional structure of fish assemblages along environmental gradients (Patos-Mirim lagoon complex, Brazil)

Mouchet, Maud 13 December 2010 (has links)
Les écosystèmes procurent de nombreux services essentiels aux sociétés humaines à travers les effets positifs de la biodiversité des communautés d'espèces. Par conséquent, identifier le rôle des organismes vivants et les facteurs influençant la diversité de leurs fonctions (ou diversité fonctionnelle), est indispensable pour prédire efficacement l'évolution des écosystèmes soumis aux pressions locales et globales.Cette thèse s'articule donc autour de deux axes: (i) établir un cadre méthodologique pour décrire la structure fonctionnelle locale et régionale des communautés, et (ii) améliorer la connaissance de l'impact des poissons sur la dégradation de la matière organique.Dans un premier temps, nous avons consolidé les outils méthodologiques permettant (i) d'améliorer la fiabilité des dendrogrammes fonctionnels, (ii) l'étude comparative des principaux indices de diversité fonctionnelle à l'échelle locale, et (iii) le développement d'une nouvelle décomposition de la diversité fonctionnelle en composantes locale (α), régionale (γ) et turnover (β). Appliqué aux communautés ichthyologiques échantillonnés le long d'un gradient de salinité, dans le système lagunaire de Patos-Mirim (Brésil), ce socle méthodologique nous a permis de révéler une structure fonctionnelle stable le long du gradient, en dépit d'une forte variabilité en composition d'espèces, ces communautés étant structurées majoritairement par un filtre environnemental agissant sur les capacités de locomotion des poissons.Dans un second temps, nous avons étudié l'impact des communautés ichthyologiques sur le cycle des nutriments. Plus précisément, nous avons estimé le potentiel de dégradation de la matière organique de plusieurs espèces de poissons, en étudiant la diversité fonctionnelle et génétique de leur flore bactérienne intestinale. Nous avons montré que les communautés ichthyologiques pouvaient influencer le recyclage des nutriments de façon non négligeable en raison d'un important potentiel de dégradation commun à la plupart des espèces étudiées, ce potentiel étant peu affecté par la diversité génétique ou les facteurs environnementaux. / Ecosystems provide many services essential to Human societies through the positive effects of biodiversity exhibited by species communities. Therefore, identifying the role of living organisms and the factors influencing the diversity of their functions (i.e. functional diversity) is fundamental to accurately predict the evolution of ecosystems undergoing local and global pressures.This thesis is organized around two axes: (i) establishing a methodological framework to describe the functional structure of local and regional communities, and (ii) improving our knowledge of the impact of fish on the degradation of organic matter.First, we have consolidated the methodological tools through (i) the improvement of functional dendrograms reliability, (ii) the comparative study of the main indices estimating local functional diversity, and (iii) the development of a new decomposition of functional diversity into local (α) and regional (γ) components, and functional turnover (β). Applied to fish assemblages sampled along a salinity gradient in Patos-Mirim lagoons complex (Brazil), this methodological framework allowed us to reveal a steady functional structure, despite a high variability in species composition, these communities being primarily structured by environmental filtering acting on fish locomotion abilities.   In a second step, we studied the impact of fish communities on nutrient cycling. More specifically, we estimated degradation of organic matter potential of several fish species by studying the genetic and functional diversity of their intestinal bacterial flora. We showed that the fish community could significantly influence nutrient cycling through an important degradation potential, common to most species studied, which is weakly affected by genetic diversity or environmental factors.
456

Ecosystem Services and Disservices in an Agriculture–Forest Mosaic : A Study of Forest and Tree Management and Landscape Transformation in Southwestern Ethiopia

Ango, Tola Gemechu January 2016 (has links)
The intertwined challenges of food insecurity, deforestation, and biodiversity loss remain perennial challenges in Ethiopia, despite increasing policy interventions. This thesis investigates smallholding farmers’ tree- and forest-based livelihoods and management practices, in the context of national development and conservation policies, and examines how these local management practices and policies transform the agriculture–forest mosaic landscapes of southwestern Ethiopia. The thesis is guided by a political ecology perspective, and focuses on an analytical framework of ecosystem services (ESs) and disservices (EDs). It uses a mixed research design with data from participatory field mapping, a tree ‘inventory’, interviews, focus group discussions, population censuses, and analysis of satellite images and aerial photos. The thesis presents four papers. Paper I investigates how smallholding farmers in an agriculture–forest mosaic landscape manage trees and forests in relation to a few selected ESs and EDs that they consider particularly beneficial or problematic. The farmers’ management practices were geared towards mitigating tree- and forest-related EDs such as wild mammal crop raiders, while at the same time augmenting ESs such as shaded coffee production, resulting in a restructuring of the agriculture–forest mosaic. Paper II builds further on the EDs introduced in paper I, to assess the effects of crop raids by forest-dwelling wild mammals on farmers’ livelihoods. The EDs of wild mammals and human–wildlife conflict are shown to constitute a problem that goes well beyond a narrow focus on yield loss. The paper illustrates the broader impacts of crop-raiding wild mammals on local agricultural and livelihood development (e.g. the effects on food security and children’s schooling), and how state forest and wildlife control and related conservation policy undermined farmers’ coping strategies. Paper III examines local forest-based livelihood sources and how smallholders’ access to forests is reduced by state transfer of forestland to private companies for coffee investment. This paper highlights how relatively small land areas appropriated for investment in relatively densely inhabited areas can harm the livelihoods of many farmers, and also negatively affect forest conservation. Paper IV investigates the patterns and drivers of forest cover change from 1958 to 2010. Between 1973 and 2010, 25% of the total forest was lost, and forest cover changes varied both spatially and temporally. State development and conservation policies spanning various political economies (feudal, socialist, and ‘free market-oriented’) directly or indirectly affected local ecosystem use, ecosystem management practices, and migration processes. These factors (policies, local practices, and migration) have thus together shaped the spatial patterns of forest cover change in the last 50 years. The thesis concludes that national development and conservation policies and the associated power relations and inequality have often undermined local livelihood security and forest conservation efforts. It also highlights how a conceptualization of a local ecosystem as a provider of both ESs and EDs can generate an understanding of local practices and decisions that shape development and conservation trajectories in mosaic landscapes. The thesis draws attention to the need to make development and conservation policies relevant and adaptable to local conditions as a means to promote local livelihood and food security, forest and biodiversity conservation, and ESs generated by agricultural mosaic landscapes. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 3: Submitted. Paper 4: Manuscript.</p>
457

Function follows Form : Trait-based approaches to climate change effects on wetland vegetation and functioning

Moor, Helen January 2016 (has links)
Climate change and habitat fragmentation are altering the structure and functioning of plant communities world-wide. Understanding how, why and with what consequences are major challenges of ecology today. Trait-based approaches focus on functional rather than taxonomic identity to facilitate process-based explanation and prediction. This thesis develops new ways of operationalising traits to understand plant community responses to the environment and community effects on ecosystem functioning and services. Wetlands, distinct in nature and patchy in their distribution, serve as a natural laboratory to extend plant trait theory and as inspiration for metacommunity modelling. The first part of the thesis (Papers 1 and 2) focuses on wetland plant traits in relation to current and future environmental conditions, ecosystem functioning and ecosystem services. Paper 1 surveys the state of knowledge regarding (i) ultimate and proximate drivers of wetland plant community functional composition, trait covariation and responses of individual traits along gradients, as well as (ii) trait effects on the sets of ecosystem properties and processes that underlie the generation of three key wetland ecosystem services (regulation of water flow, water quality, and climate). Paper 2 modifies species distribution modelling to predict future changes in plant community trait distributions due to climate change in central Sweden, which allows a qualitative estimate of changes in ecosystem service potential. Climate change induced functional changes may benefit water quality and flow regulation provided by fens and riparian wetlands, but compromise carbon sequestration capacity in bogs. The second part of the thesis (Papers 3 and 4) develops trait-based metacommunity models to study the interplay of local and regional dynamics on species, community and whole-metacommunity responses to climate change. Paper 3 finds model assumptions about species dispersal capacity to strongly influence predictions of diversity loss following climate change. While differences in species dispersal capacity drastically increase predicted extinction risk, more realistic models based on an empirically derived seed mass – seed number trade-off strongly moderate these predictions. Without considering fitness effects of covarying traits, models that include variable dispersal capacities thus might overestimate extinction risk from climate change. Paper 4 studies the development and recovery of the regional average trait-lag of response trait distributions, as a direct measure of the instantaneous realised metacommunity response to temperature change with implications for levels of ecosystem functioning. The dynamical response jointly depended on local response capacity and regional adaptive re-organisation via species range shifts. Where habitat was scarce, connectivity network properties mediated response capacity and may guide conservation priorities. This thesis makes contributions to plant trait ecology, wetland functional ecology, ecosystem service science and metacommunity theory. As a whole it furthers progress towards a predictive ecology that can bridge scales from individual physiology to ecosystem dynamics and anticipate global change effects on biodiversity and ecosystem functioning. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.</p><p> </p>
458

Greening Soweto : calculating above-ground tree biomass, stored carbon and net economic value

Lembani, Reuben Lungu 19 January 2016 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, in partial fulfillment of the requirement for the degree of Master in Environmental Science Johannesburg, 2015 / Quantifying ecosystem services of urban forests has become an important subject for the national and international ecological economics agenda. This is in the wake of offsetting anthropogenic emissions of CO2, while promoting urban habitability and sustainability. This study estimates above-ground tree biomass, carbon stored and the associated economic value and net economic value of carbon sequestrated by the tree planting project in Soweto, Johannesburg, South Africa. Measurements of diameter at breast height (1.3 m) and tree height were done on all the individual trees that were recently planted (estimated to be about seven years) and other trees estimated to be over 25 years old in Petrus Molefe Park and Thokoza Park. A general allometric equation by Tietema (1993) was used to estimate above-ground biomass which was converted to carbon stocks. The economic value of carbon sequestrated was calculated at an equivalent price of R440.40 per tonne of carbon. The total above-ground biomass, carbon stored and economic value, and net economic value of the trees in Petrus Molefe Park was 7.45 tonnes, 3.35 tonnes, R1,475 and R-495,325, while the trees in Thokoza Park had 205.76 tonnes, 92.59 tonnes, R40,777 and R-312,023, respectively. The results indicated that the older trees in Thokoza Park had larger amounts of above-ground tree biomass, greater carbon storage and net economic value than the younger trees in Petrus Molefe Park. The economic values of carbon sequestrated were less than the cost of planting the trees, therefore the net economic value of carbon sequestrated were negative. The project is at an early, but promising stage, since the Greening Soweto Project provided a number of ecosystem services (i.e. beautifying the landscape, filtering air, recreation and amenity etc.), the performance of the project was evaluated by the extent to which it integrates the environmental and social benefits into the economic benefits and opportunities. Key words: Above-ground biomass, allometric equation, carbon stored, diameter at breast height, net economic value.
459

Sojans roll i världen / Soy’s Role in the World

Andersson, Anton, Berg, Astrid, Rådkvist, Emil, Wennberg, Sara, von Zweigbergk, Jacob January 2019 (has links)
The soybean has become one of the world's largest agricultural commodities, with growth in soybean production being driven by two prime demands, animal feed and food products. The purpose of this report is to analyze the role of the soybean in the world and study its consumption in order to make a projection of future demand. The report is based on literature and data from previous studies and public databases, and the main way of analyzing the role of soybean production is through valuation of the ecosystem services lost in conversion to cropland. Argentina, Brazil and the USA are the main producers of soybean, and as such they were the focus of the production segment. In all these countries the conversion rate of natural ecosystems was found to be high, with losses of ecosystem services as a result. Demand showed steady growth and the projection indicated that it would continue to grow, creating the question of where to convert natural habitat to new cropland. The result shows there is a lack of such suitable land, and hence a reduced demand is the only viable solution. As animal feed is the main driver of demand, the conclusion is that the main way of reducing demand is to change our eating habits and reducing animal products in our diets. / Syftet med denna rapport är att analysera sojans roll i världen. Detta genom att redogöra för hur produktionen ser ut och vilka ekologiska konsekvenser denna medför. Vidare har konsumtion och konsumtionstrender studerats för att slutligen ta fram en trolig framtidsprognos. Studien utgår ifrån två användningsområden; djurfoder och mänsklig konsumtion, samt de tre främsta produktionsländerna; Brasilien, Argentina och USA.   Rapporten är en litteraturstudie och grundar sig i resultat från tidigare gjorda undersökningar, studier och artiklar. Syftet har besvarats genom ekonomiska värderingar av påverkade ekosystem och dess ekosystemtjänster till förmån för produktionen av sojabönan. Vidare har data från officiella databaser insamlats för att redogöra för den historiska och nutida konsumtionen av sojabönor och påvisa en stigande trend kring konsumtionen världen över, som inte visar några tecken i dagsläget att stagnera.  Resultat visar på en ökad global efterfråga av sojabönan som till största del grundar sig i en ökad levnadsstandard och där av förändrade kostvanor. Det blir allt vanligare att inkludera kött och andra animaliska produkter i den mänskliga kosten vilket leder till en ökad efterfrågan på djurfoder och följaktligen konsumtionen av sojabönan.   Det har konstaterats att de olika ekosystemen har varierande ekonomiskt värde i de olika länderna. Några av de som är värderade högst är våtmarkerna i Brasilien och USA samt Amazonas regnskog. Baserat på detta konstateras att det skulle vara fördelaktigt att odla upp de ekosystem som ger mindre ekosystemtjänster till samhället, men det är problematiskt då de i många fall redan exploaterats till mycket stor andel. Detta leder till att marginella områden måste konverteras för fortsatt expansion, med större risker för både ekosystem och jordbrukare, alternativt att de högre värderade ekosystemen kommer konverteras i större utsträckning.   Att bemöta den ökade efterfrågan av sojabönan anses därför problematisk, i synnerhet på grund av dess stora omfattning. Det enda hållbara alternativet på lång sikt måste därför bli att minska behovet. Detta innebär att världens konsumtionsmönster måste ändras så att den genomsyras av mer hållbart tänkande och att kosten är mer baserat mer på vegetabiliska produkter.
460

Studies of specific gene expression of phosphate transporters in sawgrass (Cladium jamaicense crantz) and cattail (Typha domingensis pers.)

Unknown Date (has links)
In the Florida Everglades, sawgrass has been displaced by cattail, predominantly resulting from phosphate enrichment. It has been found that phosphate transporters and arbuscular mycorrhizal (AM) fungi play an important role in phosphate uptake in the plants. This study aimed to reveal the symbiosis between AM fungi and sawgrass and cattail and identify the phosphate transporters, especially AM-specific phosphate transporters in these two species. AM colonization was only found in sawgrass roots, not cattail, at low phosphate concentrations in lab and field samples by trypan blue staining. AM fungi could increase sawgrass growth and had little effect on cattail growth. Four phosphate transporters were identified in sawgrass. CjPT1, CjPT2 and CjPT3 were expressed in roots and shoots independent of AM fungi and phosphate availability, while CjPT4 appeared to be an AM regulated phosphate transporter gene and its expression was induced by AM fungi. / by Li Lin. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

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