11 research outputs found

    Deforestation and Carbon Stock Loss in Brazil’s Amazonian Settlements

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    We estimate deforestation and the carbon stock in 2740 (82 %) of the 3325 settlements in Brazil’s Legal Amazonia region. Estimates are made both using available satellite data and a carbon map for the “pre-modern” period (prior to 1970). We used data from Brazil’s Project for Monitoring Deforestation in Amazonia updated through 2013 and from the Brazilian Biomes Deforestation Monitoring Project (PMDBBS) updated through 2010. To obtain the pre-modern and recent carbon stocks we performed an intersection between a carbon map and a map derived from settlement boundaries and deforestation data. Although the settlements analyzed occupied only 8 % of Legal Amazonia, our results indicate that these settlements contributed 17 % (160,410 km2) of total clearing (forest + non-forest) in Legal Amazonia (967,003 km2). This represents a clear-cutting of 41 % of the original vegetation in the settlements. Out of this total, 72 % (115,634 km2) was in the “Federal Settlement Project” (PA) category. Deforestation in settlements represents 20 % (2.6 Pg C) of the total carbon loss in Legal Amazonia (13.1 Pg C). The carbon stock in remaining vegetation represents 3.8 Pg C, or 6 % of the total remaining carbon stock in Legal Amazonia (58.6 Pg C) in the periods analyzed. The carbon reductions in settlements are caused both by the settlers and by external actors. Our findings suggest that agrarian reform policies contributed directly to carbon loss. Thus, the implementation of new settlements should consider potential carbon stock losses, especially if settlements are created in areas with high carbon stocks. © 2016, The Author(s)

    Synthesis and Structural Properties of Niobium Pentoxide Powders: A Comparative Study of the Growth Process

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    Powders Nb2 O5 were prepared by two different synthesis method, Sol-Gel and polymeric precursors (Pechini). In the Pechini method before adding the citric acid in the process, four different solutions were used to get the samples. For Sol-gel method, two different processes were also used in obtaining powders. The precursor was completely solubilized in ethanol and then hydrolyzed with ammonia and water. The calcination of the samples was between 500 and 750°C. The resulting powders were characterized by Scanning Electron Microscopy (SEM), Brunauer, Emmett and Teller (BET) surface area measurements, UV-visible and Raman spectroscopy. The formation of T−Nb2 O5 orthorhombic took place upon calcination at 7500C. Crystallite sizes were determined using the Scherrer method which resulted in an uniformed size of about 25 − 65nm. Ultraviolet-Visible diffuse reflectance spectroscopy indicated a variation in the optical band gap values (3.32-3.40 eV) in crystal growth process. The Raman vibrational modes indicate the presence of the orthorhombic phase of the material

    Environmental impact assessment in Brazilian Amazonia: Challenges and prospects to assess biodiversity

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    Environmental Impact Assessment (EIA) has the goal of providing decision makers with an indication of the likely environmental consequences of planned actions risking environmental changes and, when necessary, allowing revision of these actions to mitigate adverse impacts. Here we provide an overview of the efficiency of EIA with emphasis on Brazilian Amazonia and discuss the problems and challenges with this type of assessment in highly diverse ecosystems. We concentrate on the methodology and performance of EIAs for three of the most recent and largest infrastructure projects in Amazonia: the Belo Monte hydroelectric dam, the BR-319 Highway, and the Juruti bauxite mine. We conclude that all of these EIAs fall short of properly assessing the expected impact of infrastructure development in situ, and that their results had little or no effect on policy decisions. To improve the reliability and usefulness of EIAs in biologically diverse ecosystems, we suggest three relatively fast and cost-effective complementary approaches for assessing biodiversity: remote sensing, reflectance spectroscopy, and DNA meta-barcoding. We discuss how these emerging cutting-edge techniques can help in identifying environmental threats and the consequences of different activities in Amazonia. The ability to monitor the state of the environment and the likely impacts of human activities on natural resources is fundamental to evidence-based decisions on development choices, to the design of appropriate management strategies, and to mitigate biological and ecological consequences. © 2017 The Author
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