Publicações

A matéria orgânica, conhecida como serapilheira, proveniente da senescência das estruturas vegetais, é de suma importância para manutenção dos ecossistemas florestais visto que, este material, nas florestas tropicais, pode representar até 90% da produtividade primária líquida. Mediante isto, o objetivo deste estudo foi avaliar diferentes métodos de interpolação para espacialização de dados de serapilheira foliar em uma área de floresta primária de terra firme localizada na Reserva Biológica do Jaru, Rondônia, província Ocidental da Amazônia. A coleta de serapilheira foi realizada entre maio de 2016 abril de 2017, em uma parcela permanente de 1 hectare (100 x 100 m), utilizando 25 coletores de 0,25 m2 (0,50 x 0,50 m). A análise espacial foi realizada pelos métodos determinísticos Inverso da Distância ao Quadrado (IDW) e Vizinho Natural (NN). A produção de serapilheira foliar para o período de estudo foi de 8,34 mg.ha-¹ .ano-1 , com maior produtividade entre julho a outubro de 2016, compreendendo o período seco e de transição seco-chuvoso. Observa-se que o melhor ajuste do modelo foi obtido com o método Vizinho Natural (RMSE = 0,0768), com valores mais próximos da média observada, embora, não tenha ocorrido diferença significativa (α = 0,05) entre os dois interpoladores utilizados na espacialização dos dados.

Ao avaliar a dinâmica do desmatamento em 15% dos assentamentos federais do Estado do Pará, durante cinco anos, detectou-se haver proporcionalmente mais desmatamentos no interior dos assentamentos do que na área que os circunscreve. Assim, tem-se o Cadastro Ambiental Rural (CAR) como uma contribuição para a compreensão tanto da expansão da fronteira quanto daquilo que na literatura se denomina Uso e Mudança na Cobertura da Terra, oferecendo um meio eletrônico que permite o cruzamento de informações do desmatamento com o mapa fundiário, apresentando a situação das propriedades ou posses rurais e sua relação com cortes na floresta. Este trabalho tem como objetivo analisar a efetividade do CAR como política ambiental em projetos de assentamentos no município de Novo Repartimento, visando compreender os fatores associados ao avanço do desmatamento e as políticas públicas formuladas para contê-lo. ABSTRACT Assessing the dynamics of deforestation in 15% of the federal settlements in Pará State for five years, it was detected proportionally more deforestation within the settlements than in the area that circumscribes them. Thus, there is the Rural Environmental Registry (CAR) as a contribution to understanding the Frontier expansion and the land-use and land-cover change, offering an electronic document that allows the crossing of deforestation information with the land map, showing the situation of rural properties or possessions and their relation to forest felling. This work aims to analyze the effectiveness of CAR as environmental policy on settlement projects in the city of Novo Repartimento, in order to understand the factors associated with the advance of deforestation and the public policies formulated to contain it.

This study investigates the efficiency of correcting radar rainfall estimates using a stochastic error model in the upper Iguaçu river basin in Southern Brazil for improving streamflow simulations. The 2-Dimensional Satellite Rainfall Error Model (SREM2D) is adopted here and modified to account for topographic complexity, seasonality, and distance from the radar. SREM2D was used to correct the radar rainfall estimates and produce an ensemble of equally probable rainfall fields, that were then used to force a distributed hydrological model. Systematic and random errors in simulated streamflow were evaluated for a cascade of sub-basins of the Iguaçu catchment, with drainage area ranging from 1,808 to 21,536 km2 ). Results showed an improvement in the statistical metrics when the SREM2D ensemble was used as input to the hydrological model in place of the radar rainfall estimates in most sub-basins. Specifically, SREM2D was able to remove the relative bias (up to 50%) in the radar rainfall dataset regardless of the basin dimension, whereas the random error was reduced more prominently in the larger basins (up to 100 m3 s −1 ). An event scale evaluation was also performed for nine selected flood events in three sub-basins. SREM2D reduced the overestimation in the cumulative rainfall and streamflow volumes during these events.

Small changes in the radiation budget at the earths surface can lead to large climatological responses when persistent over time. With the increasing debate on anthropogenic influences on climatic processes during the 1980s the need for accurate radiometric measurements with higher temporal resolution was identified, and it was determined that the existing measurement networks did not have the resolution or accuracy required to meet this need. In 1988 the WMO therefore proposed the estab5 lishment of a new international Baseline Surface Radiation Network (BSRN), which should collect and centrally archive high quality ground-based radiation measurements in 1-minute resolution. BSRN began its work in 1992 with 9 stations, currently (status 2018-01-01), the network comprises 59 stations (with data) and 9 candidates (stations recently accepted into the network with data forthcoming to the archive) distributed over all continents. The BSRN database is the World Radiation Monitoring Center. It is hosted at the Alfred Wegener Institute in Bremerhaven, Germany and now offers more than 10300 months of data from the years 1992 to 2017. All data are available at https://doi.pangaea.de/10.1594/PANGAEA.880000 free of charge.

Episodic multi-year droughts fundamentally alter the dynamics, functioning, and structure of Amazonian forests. However, the capacity of individual plant species to withstand intense drought regimes remains unclear. Here, we evaluated ecophysiological responses from a forest community where we sampled 83 woody plant species during 5 years of experimental drought (throughfall exclusion) in an eastern Amazonian terra firme forest. Overall, the experimental drought resulted in shifts of some, but not all, leaf traits related to photosynthetic carbon uptake and intrinsic water-use efficiency. Leaf delta C-13 values increased by 2-3aEuro degrees within the canopy, consistent with increased diffusional constraints on photosynthesis. Decreased leaf C:N ratios were also observed, consistent with lower investments in leaf structure. However, no statistically significant treatment effects on leaf nitrogen content were observed, consistent with a lack of acclimation in photosynthetic capacity or increased production of nitrogen-based secondary metabolites. The results of our study provide evidence of robust acclimation potential to drought intensification in the diverse flora of an Amazonian forest community. The results reveals considerable ability of several species to respond to intense drought and challenge commonly held perspectives that this flora has attained limited adaptive plasticity because of a long evolutionary history in a favorable and stable climate.

The importance of taking the organic forms of nitrogen (ON) into account when estimating atmospheric nitrogen deposition has been known for a long time. However, there is still only a modest amount of data on organic nitrogen in rainwater worldwide, largely due to the difficulties and uncertainties imposed by the available analytical methods. This work offers a simple, low cost, and reliable method for the determination of ON in rainwater, based on the photo-Fenton process under UV irradiation. The recovery of ON was determined using individual solutions of urea, serine, glycine, and histidine, as well as a mixture of all these compounds plus arginine. Close to 100% organic nitrogen recoveries were obtained for solutions containing 50 μmol N L−1, using addition of 50 μmol L−1 Fe2+ and 2.0 mmol L−1 H2O2, with adjustment of the pH to ∼2.5 and irradiation for 90 min. The average reagent blank was <2.0 μmol N L−1. The homemade reactor employed a 400 W high pressure mercury lamp, from which the external bulb had been manually removed. The reactor ventilation was controlled in order to maintain the temperature at ∼85 °C. The precision of the method ranged from 1.3 to 5.7%, based on ON recovery. Rainwater collected on an event basis in Ribeirão Preto (São Paulo State, Brazil) presented ON concentrations from 4.1 to 34.3 μmol L−1 (n = 18), corresponding to 1345% of the total nitrogen, with an average contribution of 33%. Precision of ≤7.0% was obtained for the analysis of ON in rainwater.

Este trabalho teve por objetivo identificar e quantificar a cobertura vegetal e uso da terra na MNP e comparar com as áreas prioritárias para conservação da biodiversidade. Para tanto, foi realizado o cruzamento de dados vetoriais de uso e cobertura da terra com as APCs e as áreas protegidas na região. Os resultados mostram que apenas 3% das APCs estão sob algum tipo de proteção. As áreas identificadas como de prioridade Extremamente Alta já sofreram perda de 55,6% da sua cobertura florestal original, enquanto que as de prioridade Muito Alta perderam 49%. Portanto, torna-se imprescindível a ampliação do sistema de proteção ambiental na região.

We coupled the hydrologic routing and flood dynamics model Terrestrial Hydrology Model with Biogeochemistry (THMB) to the Integrated LAND Surface Model (INLAND) and compared simulations of the discharge and flood extent area against gauge station and satellite-based information in the Amazon Basin. The coupled model represents well the seasonality of the flooding and discharge, but underestimates both of them. This can be related to an already discussed underestimate of the precipitation in the east of the Andes Mountains. A photosynthesis limitation on the flooded area was also included, showing changes in plant productivity and reduction in vegetation carbon stocks. Despite its limitations, the model proves to be a valuable tool for studies of the hydrological cycle and flood dynamics response to climate change projections, allowing it to be used to represent the feedbacks between continental surface water cycle and vegetation.

Agricultural expansion has caused extensive deforestation throughout the tropics in the last decades, nevertheless, some countries have experienced native forest gains. In the 20th century, the state of São Paulo, Brazil, transitioned from an agricultural frontier to an agro-industrial state, and in parallel, from a high deforestation rate to a net gain in native forest. Here we examine the biophysical and socioeconomic factors that best explain land use and forest cover change in the state, at the municipality scale, over four consecutive intervals between 1960 and 2006. We hypothesized that factors that increase the productivity of agricultural land or reduce pressure on land development would lead to regeneration. Although results differed among intervals, our analyses demonstrate that forest gains were greater in municipalities with high forest cover percentage and steep slopes, and in areas that employed a large number of workers and relied on intensive fertilizer inputs. At the same time, forest loss was higher in municipalities with a large portion of agricultural land and soils with higher water retention capacity. These results reveal that land-use expansion led to forest loss in areas more suitable for agriculture, while forest gains occurred mainly in less suitable areas. Over time, agricultural expansion leveled off and agriculture intensification enabled forest gains, which were most marked in areas with a high percentage of forest remnants. Ultimately, however, these proximate drivers of forest change were driven by governmental policies to modernize agriculture and to protect natural ecosystems.

To effectively implement the Paris Agreement, capacity in carbon accounting must be strengthened in the developing world, and partnerships with local academic institutions can do the accounting for governments and fill the capacity gap. This paper highlights the Brazilian case, focusing on ways in which climate change science information and transparency are being incorporated in national C accounting initiatives, particularly the national inventory of greenhouse gas (GHG) emissions and removals. We report how the third inventory for the sector of land use, land-use change and forestry (LULUCF) was implemented to address scientific challenges involved in the monitoring of carbon stocks and land-use changes of diverse and complex biomes while addressing international and national policy demands (report and decision support) and transparency to various stakeholders. GHG emissions and removals associated with 2002-2010 carbon changes in aboveground, belowground biomass, necromass and soil carbon by land use and land cover changes were estimated for all Brazilian biomes, and for the Amazon estimates were also presented for the periods of 2002-2005 and 2005-2010. The inventory improved regional estimates for carbon stock and national emission factors with the support and engagement of the scientific community. Incorporation of local context is essential to reduce uncertainties and properly monitor efforts to contribute to GHG emission/reduction targets. To promote transparency and make information more accessible, the national inventory results were made available by the National Emissions Registry System (SIRENE). This system was built to support climate change policies as an important legal apparatus and by increasing access to emissions and land-use change data.

A oferta de energia é condição básica para o desenvolvimento socioeconômico de uma nação. O mundo tem passado por um intenso crescimento populacional e o aprimoramento da qualidade de vida e do bem-estar humano está acarretando um forte crescimento na demanda de energia, principalmente nos países em desenvolvimento, o que traz consigo uma crescente preocupação com os impactos socioambientais decorrentes. A demanda de energia crescente vem conduzindo profundas mudanças no meio ambiente, colocando a humanidade diante de novos desafios em um planeta com recursos naturais finitos. Além disso, o crescimento da demanda energética, somado à perspectiva de redução dos suprimentos de fontes convencionais de energia, tem sido motivo de preocupação com implicações na economia global. Qualquer país que busque alcançar indicadores de desenvolvimento humano mais elevados, necessita de segurança em seu sistema energético. Em relatório, a Agência Internacional de Energia (IEA, 2014) afirma que a demanda mundial de energia crescerá mais de um terço até 2035. No entanto, apesar do esforço realizado em diversos países, sobretudo na Comunidade Europeia, com a adoção de políticas energéticas focadas no incentivo do uso de fontes renováveis de energia, o mundo não tem conseguido colocar o sistema global de energia numa trajetória mais sustentável. Diversos fatores influem no consumo de eletricidade de um país, como o produto interno bruto e a taxa de crescimento econômico. O Brasil vem apresentando consumo inferior ao consumo médio mundial nos últimos anos, mas o governo brasileiro tem executado programas e ações que visam promover o acesso a eletricidade em todo o território nacional de modo que um aumento no consumo per capita de eletricidade é esperado para os próximos anos. Os parâmetros econômicos e sociais em conjunto com valores da série histórica do consumo de energia possibilitam estudar e prever valores da demanda futura de energia. O Plano Decenal de Expansão de Energia (PDE 2026), prevê o consumo per capita de eletricidade de 3370kWh/hab. para 2026.

From a business perspective, climate change mitigation offers certain opportunities that drive the market for new business, and presents an opportunity to engage in Corporate Social Responsibility (CSR). In this study, we examine the motivation for companies in Latin America to implement Clean Development Mechanism (CDM) projects, whether CDM encourages the adoption of CSR practices, and the benefits companies gain from adopting such practices. The data are taken from a survey of project developer companies in Brazil, Mexico and Peru. The results show that government influence and/or incentives have been very low. The benefits of participating in such projects include being viewed as industry leaders in the country and improving corporate reputation.