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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

Community-based conservation in Peruvian Amazon. Attempts to save the red uakari of Loreto

Berglund, Amanda January 2016 (has links)
Abstract. In Peru, the population of a very rare monkey species called the red uakari (Cacajao calvus ucayalii) lives in the Amazon rainforest in an area called Loreto. The natural resources of Loreto have been exploited due to large anthropogenic pressure which has affected the biodiversity. This thesis focuses on two areas that are now protected; one conservation concession and one community-based conservation reserve, each led by two biologists and researchers. The theory of the tragedy of the commons – a concept first described by Garrett Hardin in an article in the scientific journal Science in 1968 – will be taken into consideration and analysed when studying the common gains to protect the forest, as well as the over usage of resources. This thesis investigates in a qualitative way the risks of overexploiting the rainforest and the actions taken to preserve it, and hence saving the red uakari from becoming extinct. A combination of semi-structured interviews with the two biologists and content analysis of some of their work, amongst others, will assist in the outcome of this thesis, which is intended to be used for future protection of inhabited lands in rainforests that run the risk of being overexploited due to external commercial interests. The supposition of my study was to get a better understanding of community-based action to protect a specific space in an area that is under a great deal of external pressure and it shows that collective action and involvement of local community often has positive outcome.
2

Early warning signals of environmental tipping points

Boulton, Christopher Andrew January 2015 (has links)
This thesis examines how early warning signals perform when tested on climate systems thought to exhibit future tipping point behaviour. A tipping point in a dynamical system is a large and sudden change to the state of the system, usually caused by changes in external forcing. This is due to the state the system occupies becoming unstable, causing the system to settle to a new stable state. In many cases, there is a degree of irreversibility once the tipping point has been passed, preventing the system from reverting back to its original state without a large reversal in forcing. Passing tipping points in climate systems, such as the Amazon rainforest or the Atlantic Meridional Overturning Circulation, is particularly dangerous as the effects of this will be globally felt. Fortunately there is potential for early warning signals, designed to warn that the system is approaching a tipping point. Generally, these early warning signals are based on analysis of the time series of the system, such as searching for ‘critical slowing down’, usually estimated by an increasing lag-1 autocorrelation (AR(1)). The idea here is that as a system’s state becomes less stable, it will start to react more sluggishly to short term perturbations. While early warning signals have been tested extensively in simple models and on palaeoclimate data, there has been very little research into how these behave in complex models and observed data. Here, early warning signals are tested on climate systems that show tipping point behaviour in general circulation models. Furthermore, it examines why early warning signals might fail in certain cases and provides prospect for more ‘system specific indicators’ based on properties of individual tipping elements. The thesis also examines how slowing down in a system might affect ecosystems that are being driven by it.
3

As políticas de biodiversidade e de mudanças climáticas: (des) articulações e reflexos sobre o mosaico de conservação do Cristalino/ MT / Biodiversity and climate change policies: link and reflex on the conservation mosaic of Cristalino / MT.

Paulo, Carla Moura de 03 May 2016 (has links)
As modificações do clima se apresentam como um dos maiores desafios da sociedade contemporânea, principalmente no que se refere aos seus efeitos no meio natural e na biodiversidade. Os riscos das alterações climáticas ainda não são totalmente conhecidos, e suas consequências para a diversidade biológica estão sendo descobertas no momento atual. Porém, seus impactos vão além das modificações no ambiente natural e se refletem também nas políticas e relações mundiais. Neste sentido, o presente trabalho analisa as inter-relações entre as políticas públicas de biodiversidade e de mudanças climáticas, nas diferentes escalas de atuação. O interesse é identificar como um problema de ordem mundial se desdobra em âmbito local. Para isso, avalia a situação das políticas que incidem na Amazônia brasileira, tendo como estudo de caso o mosaico formado pelo Parque Estadual e RPPN do Cristalino, localizados no Estado de Mato Grosso. / The climate change is one of the major challenges of contemporary society, especially regarding its effects on the nature environment and biodiversity. The risks of climate change is not well known yet, and its consequences for biodiversity are being discovered at the moment. However, its impacts are beyond the changes in the natural environment and are also reflected at the policies and global relations. So, this paper analyzes the interrelationships between public policies on biodiversity and on climate change, considering the different scales of operation. It aims to identify how a world order problem unfolds at the local level. Thus, it verifies the situation of the public policies that impact on the brazilian Amazon, which the case study is the mosaic formed by the Parque Estadual e RPPN do Cristalino, located in Mato Grosso.
4

Con esta papa, yo como: shifting food landscapes in peri-urban amazonia

January 2013 (has links)
acase@tulane.edu
5

Predation, Palatability and the Distribution of Tadpoles in the Amazon Rainforest

Hero, Jean-Marc, n/a January 1991 (has links)
A variety of aquatic habitats with different levels of potential predators are available to larval amphibians in Central Amazon rainforest. The anuran community at Reserva Florestal Adolfo Ducke, 25 km east of Manaus, Amazonas, Brasil, was studied to determine which species have eggs and/or larvae in water and how those larvae are distributed in time and space. The temporal and spatial distribution of potential predators as well as abiotic characteristics of these waterbodies were determined simultaneously to test for correlations with the distribution of tadpoles. The distribution of tadpoles was strongly related to fish predation pressure. Several tadpole species were found only in waterbodies with high fish abundance and thus have the ability to survive with fish. Most of these tadpoles were found to be unpalatable in controlled experiments. Unpalatability is the major adaptation allowing the coexistence of tadpoles and fish and is thus a major factor affecting tadpole community composition in this system. Controlled experiments showed that fish do not eat anuran eggs while the tadpoles of Leptodacrylus knudseni and Osteocephalus taurinus ate all types of eggs offered. The percentage of anurans with aquatic oviposition was positively related to fish abundance and negatively related to the occurrence of species of tadpole that ate eggs in experiments. These findings suggest that the present patterns of anuran distribution represent an evolutionary response to predation on the eggs and larvae. Contrary to the models of Heyer et al. (1975) and Wilbur (1984), desiccation and predation-pressure were not the major factors affecting species richness within waterbodies of the RFAD rainforest. In support of the model of Heyer et al. (1975), anuran species richness was correlated with the size of the waterbody. This could be because the size of the waterbody is related to increased complexity and availability of microhabitats. The range of volumes of waterbodies was also found to directly affect species richness of the RFAD community. While predation appeared to have a limited effect on species richness of individual ponds, predation-pressure was found to have a major influence on species composition. Anuran eggs and larvae survived with specific predators by possessing particular survival-traits (e.g. unpalatability and oviposition strategies). However, survival-traits were not effective against all predators in all habitats. The distribution of different predators among ponds provides a patchy environment on a local scale (i.e. within ponds). When combined with the variety of survival-traits exhibited by the anuran species, this spatial patchiness in predation contributes towards species richness within the anuran community of the RFAD rainforest.
6

Geological Control of Floristic Composition in Amazonian Forests

Higgins, Mark Alexander January 2010 (has links)
<p>Amazonia contains the largest remaining tracts of undisturbed tropical forest on earth, and is thus critical to international nature conservation and carbon sequestration efforts. Amazonian forests are notoriously difficult to study, however, due to their species richness and inaccessibility. This has limited efforts to produce the accurate, high-resolution biodiversity maps needed for conservation and development. The aims of the research described here were to identify efficient solutions to the problems of tropical forest inventory; to use these methods to identify floristic patterns and their causes in western Amazonia; and propose new means to map floristic patterns in these forests.</p><p> Using tree inventories in the vicinity of Iquitos, Peru, I and a colleague systematically evaluated methods for rapid tropical forest inventory. Of these, inventory of particular taxonomic groups, or taxonomic scope inventory, was the most efficient, and was able to capture a majority of the pattern observed by traditional inventory techniques with one-fifth to one-twentieth the number of stems and species. Based on the success of this approach, I and colleagues specifically evaluated two plant groups, the Pteridophytes (ferns and fern allies) and the Melastomataceae (a family of shrubs and small trees), for use in rapid inventory. Floristic patterns based on inventories from either group were significantly associated with those based on the tree flora, and inventories of Pteridophytes in particular were in most cases able to capture the majority of floristic patterns identified by tree inventories. These findings indicate that Pteridophyte and Melastomataceae inventories are useful tools for rapid tropical forest inventory.</p><p> Using Pteridophyte and Melastomataceae inventories from 138 sites in northwestern Amazonia, combined with satellite data and soil sampling, I and colleagues studied the causes of vegetation patterns in western Amazonian forests. On the basis of these data, we identified a floristic discontinuity of at least 300km in northern Peru, corresponding to a 15-fold difference in soil cation concentrations and an erosion-generated geological boundary. On the basis of this finding, we assembled continent-scale satellite image mosaics, and used these to search for additional discontinuities in western Amazonia. These mosaics indicate a floristic and geological discontinuity of at least 1500km western Brasil, driven by similar erosional processes identified in our study area. We suggest that this represents a chemical and ecological boundary between western and central Amazonia.</p><p> Using a second network of 52 pteridophyte and soil inventories in northwestern Amazonia, we further studied the role of geology in generating floristic pattern. Consistent with earlier findings, we found that two widespread geological formations in western Amazonia differ eight-fold difference in soil cation concentrations and in a majority of their species. Difference in elevation, used as a surrogate for geological formation, furthermore explained up to one-third of the variation in plant species composition between these formations. Significant correlations between elevation, and cation concentrations and soil texture, confirmed that differences in species composition between these formations are driven by differences in soil properties. On the basis of these findings, we were able to use SRTM elevation data to accurately model species composition throughout our study area.</p><p> I argue that Amazonian forests are partitioned into large-area units on the basis of geological formations and their edaphic properties. This finding has implications for both the ecology and evolution of these forests, and suggests that conservation strategies be implemented on a region-by-region basis. Fortunately, the methods described here provide a means for generating accurate and detailed maps of floristic patterns in these vast and remote forests.</p> / Dissertation
7

Behavior and Ecology of Neotropical Tree Squirrels in Seasonally Flooded Forests in the Peruvian Amazon

Jessen, Rosa Raquel January 2013 (has links)
Tree squirrels play an important role in the maintenance of forest ecosystems by functioning as seed and fungal spore dispersers, forest regenerators, and prey for forest predators. The highest species richness for tree squirrels occurs in tropical forests and these species are also the least studied. We conducted distance sampling to estimate population density, measured habitat variables to investigate forest characteristics that influence habitat selection and feeding site selection at three different scales, and conducted observations to obtain knowledge about activity pattern and behavior of Neotropical pygmy squirrels and Amazon red squirrels in the Peruvian Amazon. Density of Neotropical pygmy squirrels was 0.10 and 0.14 individuals/ha for 2009 and 2010. Activity peaked in early morning, squirrels were found mainly in the canopy but never on the ground, and frequency of behaviors differed by time and story level. Neotropical pygmy squirrels used mainly high and low restinga and areas that had more large trees. Squirrels also used species of trees disproportionately to availability. Neotropical pygmy squirrels seem to be associated with features related to mature forests. Amazon red squirrels use mainly high and low restinga and selected Astrocaryum and Attalea palm trees that were taller and larger as foraging sites compared to random locations. Amazon red squirrels used all vertical strata of the forest and the main behaviors observed were travel and forage. Behaviors were similar among time periods but differed in frequency by vertical strata. Although Amazon red squirrels used vegetation communities differently than their availability and selected for tree characteristics, they did not select for site characteristics and this is different from other tree squirrel species. We also conducted surveys during a wet and a dry year to investigate and estimate diversity of diurnal mammals. We assessed the vertical strata of the forest to determine if diversity index varied by story level, and estimated alpha, beta, and gamma diversity. Overall mammal diversity did not differ between wet and dry years. Diversity index differed by story level between years, but was the highest in the canopy for both years. Alpha diversity was higher in the dry year, and gamma and beta diversity were higher in the wet year. Frequency of sightings of species was influenced by time of day and varied by story level. Protection of continuous, mature forests with large canopies has important conservation implications as these areas most likely protect the greatest diversity of mammals while also providing shelter and food for other taxa.
8

Pleistocene and Holocene environmental changes in the Brazilian Amazon region

Hermanowski, Barbara 25 February 2013 (has links)
No description available.
9

Avaliação da atividade antimicrobiana, antioxidante e análise fitoquímica preliminar de plantas medicinais utilizadas pelas populações da região do Vale do Juruena e microrregião no Norte Araguaia, Mato Grosso, Brasil

Silva, Larissa Irene da 27 August 2015 (has links)
Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-19T19:02:18Z No. of bitstreams: 1 DISS_2015_Larissa Irene da Silva.pdf: 3830512 bytes, checksum: effa1f609c60aad498f2c09c31af4590 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-27T17:50:29Z (GMT) No. of bitstreams: 1 DISS_2015_Larissa Irene da Silva.pdf: 3830512 bytes, checksum: effa1f609c60aad498f2c09c31af4590 (MD5) / Made available in DSpace on 2018-04-27T17:50:29Z (GMT). No. of bitstreams: 1 DISS_2015_Larissa Irene da Silva.pdf: 3830512 bytes, checksum: effa1f609c60aad498f2c09c31af4590 (MD5) Previous issue date: 2015-08-27 / CNPq / As doenças infecciosas estão entre as dez principais causas de óbitos no mundo. Os produtos naturais são fontes importantes de antibióticos. Sendo assim este trabalho se propõe a avaliar a atividade antibacteriana, antioxidante e bioprospectar alguns metabólitos secundários de plantas de uso popular na região do Vale do Juruena, e microrregião do Norte Araguaia, Mato Grosso, Brasil. Uma amostra de cada planta foi depositada no depositadas no Herbário da UFMT e no HERBAM. Os extratos das 99 espécies foram obtidos por maceração em solução hidroetanólica a 70%. A atividade antimicrobiana foi avaliada pelo método microdiluição em caldo, pelo qual se determinou a concentração inibitória mínima (CIM). Claritromicina e anfotericina (0,39 - 50 μg/mL), foram utilizadas como padrões, bacterianos e fúngicos, respectivamente. A capacidade antioxidante foi determinada pelos ensaios de DPPH, FRAP e NO usando-se ácido ascórbico como padrão, e, para este último quercetina. Dois extratos hidroetanólicos destacaram-se pelo amplo espectro de atividade antibacteriana: Bauhinia glabra (EHBg) e Terminalia argentea (EHTa). O EHBg apresentou boa atividade antibacteriana frente à Klebsiella pneumoniae (CIM = 25 μg/mL), moderada frente a Enterococcus faecalis (CIM = 200 μg/mL) e Streptococcus pyogenes (CIM = 400 μg/mL) e fraca atividade contra Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella flexneri, Staphylococcus epidermidis e Bacillus subtilis (CIM = 800 μg/mL). O EHTa apresentou moderada atividade contra Staphylococcus aureus (CIM = 200 μg/mL), Enterococcus faecalis, Streptococcus pyogenes, Staphylococcus epidermidis e Bacillus subtilis (CIM = 400 μg/mL). Dois extratos hidroetanólicos destacaram-se pelo amplo espectro de atividade antifúngico: Bertholletia excelsa (EHBe), Cochlospermum regium (EHCch)e Qualea grandiflora (EHQg). O EHBe apresentou moderada atividade contra Aspergillus terreus (CIM = 100 μg/mL), Aspergillus fumigatus (CIM = 200 μg/mL), Candida glabrata e Cryptococcus neoformans (CIM = 400 μg/mL), e fraca atividade contra Candida albicans e Candida tropicalis (CIM = 800 μg/mL).O EHCch apresentou boa atividade contra Penicillium verrucosum, Trichophyton mentagrophytes e Microsporum gypseum (CIM = 6,25 μg/mL), moderada contra Candida albicans, Candida albicans fluconazol-resistente, Aspergillus fumigatus (CIM = 400 μg/mL) e fraca contra Aspergillus niger, Aspergillus parasiticus e Aspergillus terreus (CIM = 800 μg/mL). O EHQg demonstrou boa atividade frente a Trichophyton rubrum (CIM = 12,5 μg/mL) e fraca atividade contra Candida albicans, Candida albicans fluconazol-resistente, Candida tropicalis e Cryptococcus neoformans, Aspergillus fumigatus, Aspergillus niger, Aspergillus parasiticus, e Aspergillus terreus (CIM = 800 μg/mL). Se destacaram pela sua atividade antioxidante, nos modelos de DPPH e FRAP, respectivamente, EHBe (CI50 = 0,39 ± 0,08 e 65,00 ± 8,67 μg/mL), Cariniana rubra (CI50 = 0,44 ± 016 E 64,00 ± 4,43 μg/mL) e Cedrela odorata (IC50 = 0,56 ± 0,08 and 56,37 ± 0,75μg/mL), nenhum extrato hidroetanólico testado exibiu CI no modelo de NO. Os teores de fenois totais nos extratos hidroetanólicos variaram de 0,06 a 10,91 mgEAt/g, os de flavonoides totais de 0,01 a 4,40 mgER/g e os de cumarinas, apresentarajm variação de 0,011 a 2,09 mgEC/g. Os resultados apontam a existência de componentes biológicamente ativos nas plantas medicinais da região do Vale do Juruena e microrregião no Norte Araguaia, ratificando seu o uso popular para o tratamento de infecções. Essas propriedades revelaram um grande potencial antimicrobiano e antioxidante dos extratos que poderiam ser aplicados futuramente na indústria farmacêutica, alimentar e cosmética. / Infectious diseases are among the ten leading causes of deaths worldwide. Natural products are important sources of antibiotics. Thus, this study aims to evaluate the antibacterial activity, antioxidant and bioprospect some secondary metabolites of popular use of plants in the region of the Juruena Valley and micro-region in North Araguaia, Mato Grosso, Brazil. A sample of each was deposited in deposited in the Herbarium of UFMT and HERBAM. The extracts of the 99 species were obtained by maceration in hydroethanol 70% solution. The antimicrobial activity was evaluated by the microdilution broth method by which it was determined the minimum inhibitory concentration (MIC), clarithromycin and amphotericin (0,39 - 50 μg/mL), were used as standards, bacterial and fungal, respectively. The antioxidant capacity was determined by DPPH, FRAP and NO using ascorbic acid as a standard, and for the latter quercetin. Two hydroethanolic statements highlighted by the broad spectrum of antibacterial activity: Bauhinia glabra (EHBg) and Terminalia argentea (EHTa). The EHBg showed good antibacterial activity against Klebsiella pneumoniae (MIC = 25 μg/mL), moderate against Enterococcus faecalis (MIC = 200 μg/mL) and Streptococcus pyogenes (MIC = 400 μg/mL) and weak activity against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella flexneri, Staphylococcus epidermidis e Bacillus subtilis (MIC = 800 μg/mL). The EHTa showed moderate activity against Staphylococcus aureus (MIC = 200 μg/mL), Enterococcus faecalis, Streptococcus pyogenes, Staphylococcus epidermidis e Bacillus subtilis (MIC = 400 μg/mL). Two hydroethanolic extracts highlighted by the broad spectrum of antifungal activity: Bertholletia excelsa (EHBe), Cochlospermum regium (EHCch) andd Qualea grandiflora (EHQg). The EHBe showed moderate activity against Aspergillus terreus (MIC = 100 μg/mL), Aspergillus fumigatus (MIC = 200 μg/mL), Candida glabrata and Cryptococcus neoformans (MIC = 400 μg/mL), and weak activity against Candida albicans and Candida tropicalis (MIC = 800 μg/mL). The EHCch showed good activity against Penicillium verrucosum, Trichophyton mentagrophytes and Microsporum gypseum (MIC = 6,25 μg/mL), moderate against Candida albicans, Candida albicans fluconazole-resistent, Aspergillus fumigatus (MIC = 400 μg/mL) and weak against Aspergillus niger, Aspergillus parasiticus and Aspergillus terreus (MIC = 800 μg/mL). The EHQg showed good activity against Trichophyton rubrum (MIC = 12,5 μg/mL) and weak against Candida albicans, Candida albicans fluconazole-resistent, Candida tropicalis and Cryptococcus neoformans, Aspergillus fumigatus, Aspergillus niger, Aspergillus parasiticus, and Aspergillus terreus (MIC = 800 μg/mL). Stood out for their antioxidant activity in models of DPPH and FRAP, respectively, EHBe (IC50 = 0,39 ± 0,08 e 65,00 ± 8,67 μg/mL), Cariniana rubra (IC50 = 0,44 ± 016 E 64,00 ± 4,43 μg/mL) and Cedrela odorata (IC50 = 0,56 ± 0,08 and 56,37 ± 0,75μg/mL), no hydroethanolic extract tested exhibited IC in the model. The total phenols content in hydroethanolic extracts ranged from 0,06 - 10,91 mgEAt/g, the total flavonoids 0,01 a 4,40 mgER/g and the coumarins showed variation from 0,011 - 2,09 mgEC/g. The results show the existence of biologically active components in medicinal plants Juruena Valley region and micro region in North Araguaia, confirming its popular use for the treatment of infections. These properties showed strong antimicrobial and antioxidant potential of extracts that could be applied in the future in the pharmaceutical, food and cosmetics.
10

As políticas de biodiversidade e de mudanças climáticas: (des) articulações e reflexos sobre o mosaico de conservação do Cristalino/ MT / Biodiversity and climate change policies: link and reflex on the conservation mosaic of Cristalino / MT.

Carla Moura de Paulo 03 May 2016 (has links)
As modificações do clima se apresentam como um dos maiores desafios da sociedade contemporânea, principalmente no que se refere aos seus efeitos no meio natural e na biodiversidade. Os riscos das alterações climáticas ainda não são totalmente conhecidos, e suas consequências para a diversidade biológica estão sendo descobertas no momento atual. Porém, seus impactos vão além das modificações no ambiente natural e se refletem também nas políticas e relações mundiais. Neste sentido, o presente trabalho analisa as inter-relações entre as políticas públicas de biodiversidade e de mudanças climáticas, nas diferentes escalas de atuação. O interesse é identificar como um problema de ordem mundial se desdobra em âmbito local. Para isso, avalia a situação das políticas que incidem na Amazônia brasileira, tendo como estudo de caso o mosaico formado pelo Parque Estadual e RPPN do Cristalino, localizados no Estado de Mato Grosso. / The climate change is one of the major challenges of contemporary society, especially regarding its effects on the nature environment and biodiversity. The risks of climate change is not well known yet, and its consequences for biodiversity are being discovered at the moment. However, its impacts are beyond the changes in the natural environment and are also reflected at the policies and global relations. So, this paper analyzes the interrelationships between public policies on biodiversity and on climate change, considering the different scales of operation. It aims to identify how a world order problem unfolds at the local level. Thus, it verifies the situation of the public policies that impact on the brazilian Amazon, which the case study is the mosaic formed by the Parque Estadual e RPPN do Cristalino, located in Mato Grosso.

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