There is much confidence in the global temperature change and its attribution to human activities. Global climate models have attained unprecedented complexity in representing the climate system and its response to external forcings. However, climate prediction remains a serious challenge and carries large uncertainty, particularly when the scale of interest becomes small. With the increasing interest in regional impact studies for decision-making, one of the urgent tasks is to make a systematic, quantitative evaluation of the expected skill of climate models over a range of spatiotemporal scales. The first part of this dissertation was devoted to this task, with focus on the predictive skill in the linear trend of surface air temperature. By evaluating the hindcasts for the last 120 year period in the form of deterministic and probabilistic predictions, it was found that the hindcasts can reproduce broad-scale changes in the surface air temperature, showing reliable skill at spatial scales larger than or equal to a few thousand kilometers (30° x 30°) and at temporal scales of 30 years or longer. However, their skill remains limited at smaller spatiotemporal scales, where we saw no significant improvement over climatology or a random guess. Over longer temporal scales, the feedbacks from the carbon cycle to atmospheric CO₂ concentration become important. Therefore the rest of the dissertation attempts to find key processes in the climate-carbon cycle feedback using one of the leading land-climate models, the National Center for Atmospheric Research Community Land Model. Evaluation of site-level simulations using field observations from the Amazon forest revealed that the current formulation for drought-related mortality, which lacks the ecophysiological link between short- and long-term drought stress, prevent the model from simulating realistic forest response. Global simulations showed that such dynamics of vegetation strongly influences the control of the nitrogen cycle on vegetation productivity, which then alters the sensitivity of the terrestrial biosphere to surface air temperature. This implies that if the state of the terrestrial biosphere is inconsistent with the simulated climate, either biased or prescribed, then its feedback to anthropogenic forcing could be also inconsistent.

The Amazon rain forest plays an important role in regional and global biogeochemical cycling, but the region may undergo an increase in the frequency and severity of drought conditions driven by global climate change, regional deforestation and fire. The effects of this drought on carbon cycling in the Amazon, particularly below-ground, are potentially large but remain poorly understood. This thesis examines the impacts of seasonal and longer-term drought upon ecosystem carbon allocation and cycling at an Amazon rain forest site with a particular focus upon below-ground processes. Measurements are made at three one-hectare forest plots with contrasting soil type and vegetation structure, to observe responses across a range of Amazon primary forest types. A fourth plot is subjected to partial rainfall exclusion to permit measurement of forest responses to a wider range of soil moisture levels than currently exists naturally. An analysis of the number of samples required to accurately quantify important ecosystem carbon stocks and fluxes is used to guide the sampling strategy at the field site. Quantifying root dynamics, in particular, presents methodological challenges. Thus, I critically review existing methods, and develop techniques to accurately measure root standing biomass and production. Subsequently, these techniques are used to record root responses, in terms of standing biomass, production, morphology, turnover and nutrient content, to variation in soil moisture across the four rain forest plots. There is substantial environmental variation in root characteristics. However, several responses remain consistent across plots: root production of biomass, length, and surface area, is lower where soil is dry, while root length and surface area per unit mass show the opposite pattern. The other major component of the below-ground carbon cycle is soil carbon dioxide efflux. I partition this efflux, on each plot, into contributions from organic ground surface litter, roots and soil organic matter, and investigate abiotic and biotic causes for observed differences within and between plots. On average, the percentage contribution of soil organic matter respiration to total soil carbon dioxide efflux declines during the dry season, while root respiration contribution displays the opposite trend. However, spatial patterns in soil respiration are not directly attributable to variation in either soil moisture or temperature. Instead, ground surface organic litter mass and root mass account for 44 % of observed spatial heterogeneity in soil carbon dioxide efflux. Finally, information on below-ground carbon cycling is combined with aboveround data, of canopy dynamics and stem wood production and mortality, to analyze the potential effects of drought upon carbon cycling in an Amazon forest ecosystem. Comparison of the rainfall exclusion plot with a similar, but unmodified, control plot reveals potentially important differences in tree carbon allocation, mortality, reproduction, soil respiration and root dynamics. The apparent net consequence of these changes is that, under drier conditions, the amount of CO2 moving out of the forest and into the atmosphere is diminished. This synthesis of above-ground and below-ground data advances understanding of carbon cycling in rain forests, and provides information which should allow more accurate modelling of the response of the Amazon region to future drought. Additional measurements at other sites, and of other ecosystem carbon fluxes, should further refine modelling predictions.

No description available.

The importance of tropical forests for global diversity and ecosystem function is well established in scientific literature, but is undermined by gaps in our knowledge of tropical ecosystems and species. Primates play important functional roles in these ecosystems, and despite constituting one of the most well-recognised taxa in the world, many species remain poorly studied. The Area de Conservación Regional Communal Tamshiyacu-Tahuayo (ACRCTT), located in the northeastern Peruvian Amazon, harbours one of the most diverse primate assemblages in the world and presents an ideal opportunity for the study of primate communities and mechanisms of their coexistence. Previous research has recorded the presence of an atypically coloured morph of monk saki monkeys (Pithecia monachus, sensu Marsh 2014) living in sympatry with a population of burnished sakis (Pithecia inusta, sensu Marsh 2014) in the reserve. In this study, the behavioural ecology of this potentially undescribed morph of saki monkey is described, using continuous focal data collected during the early wet season in the ACRCTT. The sakis were most often encountered in multi-adult groups and in the upper forest strata. The observed feeding strategies suggest that fruits and/or seeds constitute the sakis' primary food source in the wet season, although arthropods were also ingested during a large proportion of feeding records. Sex differences in behavioural patterns provide support for a difference in male and female investment in group defence. As only the monk saki morph was encountered during the study, the potential for seasonal habitat differentiation between the saki populations at the ACRCTT is discussed. A survey of primates in flooded and non-flooded forest areas at the ACRCTT was also conducted, in which nine of the 14 primate species recorded at the ACRCTT were encountered. Significant differences in the vertical distribution of primate groups provide evidence for vertical stratification in the ACRCTT primate community. This study contributes to previous research on the poorly-studied Pithecia genus, and provides insights into the mechanisms of niche differentiation between Pithecia and other primates.

The success of Amazon Mechanical Turk (MTurk) as an online research platform has come at a price: MTurk has suffered from slowing rates of population replenishment, and growing participant non-naivety. Recently, a number of alternative platforms have emerged, offering capabilities similar to MTurk but providing access to new and more naïve populations. After surveying several options, we empirically examined two such platforms, CrowdFlower (CF) and Prolific Academic (ProA). In two studies, we found that participants on both platforms were more naïve and less dishonest compared to MTurk participants. Across the three platforms, CF provided the best response rate, but CF participants failed more attention-check questions and did not reproduce known effects replicated on ProA and MTurk. Moreover, ProA participants produced data quality that was higher than CF's and comparable to MTurk's. ProA and CF participants were also much more diverse than participants from MTurk.

The economic modernization of the Amazon fostered by the Brazilian military government during the 1960s and 1970s was largely realized without taking into consideration the presence of local households which lived from the extraction of forest products (mainly non-timber). When they began to be expulsed, a political resistance, often guided by the Catholic Church, appeared as well as the creation of unions based on traditional identities, especially that of rubber tappers. During the 1980s, these unions made a strategic alliance with the ecologist movement which started to consider traditional populations, whose lifestyle depended on the forest, as allies for the protection of the Amazon rainforest. The movement gained a decisive momentum at the end of the decade by putting forward new proposals of land tenure for traditional populations, grounded on collective land rights. This strategy has been very efficient during the 1990s and 2000s, during which about 1,300,000 km(2) of rainforest were set apart and reserved for the use of "traditional communities" under a variety of legal status. But it has also led to mix under the same "collective" etiquette and principles a number of different ways of using and managing land and natural resources. This assumption however should be nuanced by a careful analysis of the resource management systems existing in each case, for they are in general complex and mix varying proportions of individual and collective decisions. The aim of this paper is to explore this question using the example of the Chico Mendes agroextractive settlement (PAE-CM), inhabited by about 100 rubber tapper families and symbolic of the political struggle of traditional populations in the Amazon for being the home of the rubber tapper leader Chico Mendes assassinated in 1988. Applying Ostrom "design principles", we try to catch what are the local institutional arrangements and to see if they suggest collective or individual management, and what the boundaries between both categories are. As a conclusion, we find that the PAE-CM's system is much less collective than expected, and also very much controlled by external authorities, in a logic pretty much away from the idea of a CPR system. This finding is useful to understand the shortcomings in the actual management of the PAE but also to foresee difficulties which will probably arise in the management of many of the areas which have gained collective land rights or collective management statutes in the Amazon.

Master of Arts / Department of Geography / Marcellus M. Caldas / The democratization of Brazil in 1985 brought hope and impetus for agrarian reform, especially after the proposal of a series of new settlement projects by many Presidents to expropriate and redistribute lands to the Brazil’s landless. The landless poor, however, took this new state-sanctioned program into their own hands and started occupying lands to build land reform settlements. Social Movement Organizations (SMOs) that were established and working illegally gradually emerged and invaded large private landholdings near urban areas with a specific political agenda, while far rural landless people targeted unclaimed open public forest for land occupation to build spontaneous land reform settlements. Both types of land occupation actions constituted the Direct Action Land Reform (DALR). Recent literature has outlined the socio-economic circumstance that affected DALR, DALR settlement formation process and its implication to deforestation; however, no research considers forest fragmentation in these land reform settlements and its relationship with demographic factors. In order to fill this gap in the literature, this thesis first compared the temporal and spatial dynamics of deforestation fragment patterns in spontaneous DALR settlements around the municipality of Uruará along the Transamazon Highway, and in SMO-led DALR settlements in Southern Pará region using satellite imagery from 1986 to 2010 and three landscape metrics (patch mean area, area-weighted mean shape index and patch cohesion index). Metrics results were then respectively analyzed with selected field survey data to discover the impacts of demographic factors on forest fragmentation in DALR settlements. Results showed that SMO-led DALR settlements in Southern Pará primarily exhibited larger, more irregularly shaped and more physically connected deforestation fragments than spontaneous DALR settlements in the Uruará region over the whole study period. Demographic factors that influenced forest fragmentation in DALR settlements included the number of people and children per household, family lot size, percentage of families receiving credit and the distance between the family lot and the nearest city. At last, constructive policy recommendations were provided based on research findings.

The PHP: Hypertext Preprocessor language (PHP) has evolved to a sophisticated mainstream programming language for rapid development of significant Web applications at major sites including Facebook.com, Wikipedia.org and Yahoo.com. Leading software vendors such as Oracle and IBM are rushing in providing tools that bridge their products to PHP. However, we have observed a gap in facilitating PHP to utilize Web services efficiently. This thesis reports our efforts in design and implementation of PHP applications that consume Web services. In doing so, I have proposed a framework facilitating PHP programs to utilize Web services with high performance capability. In addition, a number of Web service standards including WS-Addressing and those in WS-Security are integrated into my PHP implementation. Examples of using various Amazon Web Services are provided with details.

The master's thesis Extractive reserves in the brazilian Amazon analyzes the contemporary economic and social development in the region of brazilian Amazon and the position of the concept of extractive reserves inside this process. The main goal is to determine whether the extractive reserves are the ideal strategy for this region and a path to sustainable development while trying to describe the structure of their production and the possibility of placement of their product on the world market.

Orientador: Ricardo Cardoso Benine / Resumo: O gênero Stichonodon Eigenmann (1910) foi proposto para alocar Lutkenia insignis Steindachner (1876), uma espécie conhecida de rios da bacia Amazônica. Até o presente momento, Stichonodon insignis não havia sido redescrita. Além disso, pouco era conhecido sobre a sua osteologia e ecologia. Neste trabalho, nós revisamos o material disponível de S. insignis a fim de se fornecer uma redescrição detalhada da espécie. Ademais, é apresentada uma descrição detalhada da sua osteologia e informações sobre a sua ecologia. Apresentamos também dados de análises morfométricas de regressões lineares que devem ser consideradas em análises comparativas com demais membros em Characidae. Uma discussão sobre a alocação de Stichonodon insignis ao nível de subfamília é apresentada. / Abstract: The genus Stichonodon Eigenmann (1910) was proposed to allocate Lutkenia insignis Steindachner (1876), a species known from Amazon basin. To date, Stichonodon insignis was not redescribed. In addition, little was known about its osteology and ecology. In this work, we review the available material of S insignis In order to provide a detailed redescription of the species. Besides of that, and presents a detailed description of its osteology and provide information about its ecology. We also present data Morphometric analysis of linear regressions that should be considered in comparative analyzes with other members in Characidae. A discussion on the allocation of Stichonodon insignis at the subfamily level is presented. / Mestre