ABSTRACT In the Cerrado, the palm swamps ( veredas ) are characterized by being humid and stable environments that lead to the formation of Histosols ( Organossolos ). and soils with surface horizons of organic constitution, which are fragile and sensitive to anthropic action. This study aimed to evaluate the impact of anthropization (recurrent forest fires and livestock farming) on the chemical, physical and morphological properties of soils in two palm swamps in the Environmental Preservation Area (EPA) of Pandeiros River, Minas Gerais, namely: Água Doce, in preserved condition, and Taboa, in anthropized condition. Four soil profiles were morphologically described, two profiles in each palm swamp, with subsequent chemical and physical analyses, calculations of organic carbon stock and identification of the origin of organic matter. The results were analyzed using descriptive statistics and Pearson’s correlation coefficient. Soil morphological properties were influenced by vegetation cover, drainage and anthropization conditions. As for the physical and chemical properties, adequate values were observed in the preserved palm swamp, including lower bulk density values and higher cation contents. Anthropic actions in the anthropized palm swamp caused degradation of soils, revealed by subsidence, reduction in organic carbon content, increase in bulk density and decrease in fertility. Changes promoted in the soils of the palm swamps compromise ecosystem services, indicating that actions at either local or governmental level should be stimulated for the preservation and conservation of these environments.

ABSTRACT There is a need for greater knowledge about the medium- and long-term effects of prescribed fire management on soil in ecosystems prone to wildfires and more vulnerable to climate change. This study examined the short- and medium-term effects of prescribed fire on soil chemical properties and chemical fractions of soil organic matter (SOM) in two positions of the landscape in a high-elevation grassland environment. The ecosystem is located in the mountain peaks of southeastern Brazil associated with the Atlantic Forest biome. Prescribed fire was conducted in 2017 to reduce understory vegetation and thus prevent potential severe wildfires. Soil samples were collected at the layers of 0.00-0.10, 0.10-0.20, and 0.20-0.40 m, at eight composite sampling. The composite samples were collected on five different occasions: before the prescribed fire, and 10, 30, 90, and 240 days after the prescribed fire. Soil chemical properties, total organic carbon, labile C, and chemical fractionation of SOM were analyzed. All soil properties investigated were affected by the prescribed fire, with variations in landscape position, duration of effect, and soil layer. In the backslope area, the medium-term effect of fire was negative and induced soil degradation and induced soil degradation. In the footslope area, the system showed greater resilience to the effects of fire, as indicated by the recovery of the soil’s chemical properties. These results can help assess the suitability of controlled burning of vegetation for managing risks of fire in mountainous regions, such as high-elevation grasslands.

ABSTRACT State parks are integral protection units created to protect ecosystems. However, anthropic activities may have been previously performed before their creation, forming transitional areas. Studies that evaluate the modifications of edaphic properties in these environments are scarce. The aim of this study was to evaluate the changes in soil properties and litter stock in areas of eucalyptus-forest ecotones. Litter stock (Stocklitter) and total soil organic carbon content and stock (TOCsoil), weighted mean diameter (MWD), origin of aggregates (biogenic or physicogenic) and respective content of total organic carbon (TOCBio and TOCPhy), total organic carbon (TOCAG), soil organic matter chemical fractions [fulvic acid (FAC), humic (HAC), and humin (HUMC)], and particulate, mineral-associated, free light and intra-aggregate light (POC, MAOC, FLFC, and ILFC) soil organic matter, fertility, and glomalin-related soil protein (GRSP) fractions were evaluated in aggregates (layer 0.00-0.10 m) in areas of eucalyptus-forest ecotone (Eco), preserved forest fragment (For), and eucalyptus plantation (Euc), in Nova Baden State Park, Lambari–MG. In the Euc and Eco areas, the highest Stocklitter content was found. Higher values of TOCsoil, TOCAG, GRSP, and MWD were observed in the Euc area. In the biogenic aggregates, the highest content of TOCBio, HAC, HUMC, POC, MAOC, FLFC, and ILFC was determined in detriment of the physicogenic ones. The dynamics of edaphic properties in the Eco area showed greater similarity with the For area than in the Euc area. In general, all vegetation covers contribute to the maintenance of soil quality.

RESUMO A predição da produção florestal requer conhecimento de variáveis dendrométricas e edafoclimáticas. Esse trabalho teve por objetivo ajustar e avaliar a precisão do modelo 3-PG em estimar as variáveis altura, diâmetro a altura do peito (DAP), volume e incremento médio anual (IMA) em plantio comercial de Eucalyptus spp. no norte de Minas Gerais, utilizando dados meteorológicos provenientes de estações automáticas de superfície e de sensoriamento remoto. Para validação do modelo foram estimados os dados de altura, DAP, volume e IMA pelo 3-PG e comparados com dados de inventários florestais, totalizando 335 medições, em 10 talhões, realizadas no período de 2005 a 2011. Foram aplicados os métodos estatísticos correlação linear (Pearson - r), coeficiente de determinação (R²), erro padrão da estimativa (Syx), erro padrão da estimativa em porcentagem (Syx%) e eficiente do modelo (EF). Observou-se que o modelo tende a superestimar as variáveis dendrométricas quando se utiliza a parametrização proposta para região norte de Minas Gerais. Após o ajuste dos parâmetros relativos à idade de fechamento do dossel (fullCanAge), a relação entre stem e DAP (nS) e parametrização das equações alométricas relativas à altura total e ao volume de madeira, incorporado no 3-PG, o modelo obteve resultados satisfatórios com valores de R² = 0,94 e EF = 0,87 para DAP, altura e volume e R² = 0,85 e EF = 0,58 para o IMA, assim como apresentou distribuição dos dados estimados próximo aos valores médios dos dados observados. O 3-PG mostrou eficiência na estimativa do DAP, altura, volume e IMA, tornando-se ferramenta potencial para avaliação de áreas propícias para expansão de novos plantios.

ABSTRACT The prediction of a forest production requires knowledge of the dendrometric and edaphoclimatic variables. This study aimed to adjust and evaluate the accuracy of the 3-PG model in estimating the variables height, diameter at breast height (DBH), volume and mean annual increment (MAI) in commercial plantations of Eucalyptus spp. in northern of Minas Gerais state, using meteorological data from automatic surface stations and remote sensing. To validate the model, data of height, DBH, volume and MAI by 3-PG were estimated and compared with forest inventory data, totaling 335 measurements in 10 plots in the period 2005 to 2011. Linear statistical correlation methods (Pearson - r), the coefficient of determination (R²), the standard error of estimate (Syx), the standard error of the estimate in percentage (Syx%) and the efficient model (EF) were applied. It was observed that the model tends to overestimate the dendrometric variables when using the parameterization proposal for northern region of Minas Gerais state. After adjusting the parameters for the age of canopy closure (fullCanAge), the relationship between stem and DBH (nS) and parameterization of allometric equations for the total height and volume of wood incorporated in the 3-PG, obtained satisfactory results with values of R² = 0.94 and EF = 0.87 for DBH, height and volume and R² = 0.85 and EF = 0.58 for the MAI, as presented distribution of estimated data close to the average values of the observed data. The 3-PG was shown to be effective in estimating the DBH, height, volume and MAI become a potential tool for evaluating suitable areas for the expansion of new crops.

ABSTRACT Incoming longwave radiation was estimated using air temperature data from the output of the regional HadRM3 model in the Intergovernmental Panel on Climate Change’s (IPCC) A2 scenario for projections up to 2070, 2080 and 2090 and using Swinbank’s equation. Spatial distribution was done by Ordinary Kriging through three theoretical mathematical models for the IPCC A2 scenario for the whole Legal Amazon. It was found that the highest averages and outliers occurred in 2090 compared to other years evaluated. The average incoming longwave radiation for 2070, 2080 and 2090 was 394.8, 403.9 and 413.0 Wm-2year-1 , respectively. The coefficients of variation (CV) were higher for 2080 (2.6%) and 2090 (2.8%), similar to the results found by standard deviation. 2070 obtained CV (2.2%) for estimated values of incoming longwave radiation with greater accuracy. Again, 2070 was the only year that could be interpolated because the average degree of spatial dependence found for all models was 12.23%. Lastly, 2080 could only be interpolated using the Gaussian model in the Legal Amazon.

RESUMO Este estudo teve como objetivo espacializar as frações da matéria orgânica do solo em um sistema agroflorestal (SAF) localizado na Mata Atlântica. Foram coletadas trinta e uma amostras de terra nas profundidades de 0-10, 10-20 e 20-40 cm, sendo cada ponto georeferenciado. Foram determinados os teores de carbono orgânico total (COT), carbono particulado (COp), carbono associado a argila e silte (COam), teor de carbono na fração de ácido fúlvico (C-FAF), fração de ácido húmico (C-FAH) e fração de humina (C-HUM). A análise dos semivariogramas e o ajuste do modelo foram realizados utilizando o software ArcGIS 10.2. Posteriormente foi realizada a interpolação espacial através de Krigagem Ordinária. Foi observada dependência espacial para todas as variáveis, com exceção do COT e COp na profundidade de 0-10 cm, visto que apresentaram efeito pepita puro. Foram verificadas modificações na distribuição das substâncias húmicas na área de estudo. Os resultados deste estudo são semelhantes aos de outros realizados em áreas de Mata Atlântica, demonstrando os benefícios do uso do sistema agroflorestal.

ABSTRACT This study aimed to spatialize fractions of organic matter of soil in an agroforestry system (AFS) located in the Atlantic Forest in Brazil. Thirty-one soil samples were collected at depths of 0-10, 10-20 and 20-40 cm from georeferenced collection points. We determined total organic carbon (TOC), particulate carbon (COp), carbon associated with clay and silt (COam), carbon content in the fulvic acid fraction (C-FAF), humic acid fraction (C-HAF) and humin fraction (C-HUM). Semivariogram analysis and model adjustment were carried out using ArcGIS 10.2 software. Subsequently, spatial interpolation was performed using Ordinary Kriging. We observed spatial dependence for all variables except for TOC and COp at the 0-10 cm depth, which presented a pure nugget effect. It was possible to observe modifications in the distribution of humic substances in the study area. The results from this study are similar to those of other studies conducted in naive areas in the Atlantic Forest, demonstrating the benefits of using the agroforestry system.

RESUMO A Floresta Atlântica é o ecossistema brasileiro submetido a processos de degradação ambiental mais acentuado, mesmo assim, em alguns ambientes o processo de regeneração natural pode ser observado. O objetivo deste estudo foi avaliar o padrão da regeneração natural dos fragmentos florestais do Médio Vale Paraíba do Sul quanto aos fatores topográficos e identificar áreas potenciais ao processo de regeneração. O mapeamento dos fragmentos florestais foi obtido a partir de imagens do sensor Thematic Mapper (1994 e 2011). Para os fatores topográficos foram utilizadas as cartas topográficas do IBGE. O processo de regeneração natural na área de estudo é influenciado pelos fatores topográficos e acontece principalmente nos ambientes com superfície plana, declividade variando de ondulada a forte ondulada, orientação da vertente variando de SE (sudeste) a SW (sudoeste) e radiação solar global entre 150000 e 1700000 Watts. Na sub-bacia do ribeirão Cachimbal, os ambientes favoráveis à regeneração natural não são suficientes para que a sub-bacia tenha sua cobertura florestal original restabelecida, por representar apenas 1,2% da área da sub-bacia hidrográfica, o que remete à necessidade de intervenção antrópica.

ABSTRACT The Atlantic Forest is the brazilian ecosystem that is subjected to stronger environmental degradation processes, yet in some environments the natural regeneration process can be observed. Thus, the aim of this study was to evaluate the pattern of natural regeneration of forest fragments in the “Médio Vale Paraíba do Sul” as the topographic factors and to identify potential areas of regeneration. The mapping of forest fragments were obtained from images of the Thematic Mapper sensor (1994 and 2011). For topographical factors, the IBGE topographic maps were used. The natural regeneration process in the study area is influenced by topographical factors and occurs mainly in environments with a flat surface, steepness ranging from wavy corrugated strong, strand orientation ranging from SE (southeast) SW (southwest) and global solar radiation between 1.500.000 and 1.700.000 Watts. In sub-basin Cachimbal stream, favorable environments natural regeneration are not sufficient for sub-basin has restored its original forest cover, it represents only 1.2% of the watershed area, which refers to the need of human intervention.

RESUMO Neste trabalho, objetivou-se espacializar os atributos químicos e físicos do solo em um sistema agroflorestal no município de Seropédica, Rio de Janeiro. Foram coletadas 31 amostras de terra, nas profundidades de 0-10 cm, 10-20 cm e 20-40 cm, sendo cada ponto de coleta georreferenciado. Foram determinados pH (em H2O), acidez potencial (H+Al), cálcio (Ca2+), magnésio (Mg2+), alumínio (Al3+), sódio (Na+), potássio (K+), fósforo (P), carbono orgânico (C), capacidade de troca catiônica do solo (Valor T), saturação por bases (Valor V), argila total, areia total, silte e densidade de raízes finas. O software ArcGIS 10.2 foi utilizado para fazer a análise semivariográfica e o ajuste dos modelos, e posteriormente, foi empregado a interpolação espacial através da Krigagem Ordinária de primeira ordem de três modelos espaciais, esférico, exponencial e gaussiano. De acordo com os resultados, apenas os modelos exponencial e gaussiano foram ajustados para as variáveis, exceto para as variáveis Mg2+ e Valor V, pois não apresentaram dependência espacial, assim expressando efeito pepita puro (EPP). Foram gerados os mapas de distribuição para as variáveis (exceto para aquelas que exibiram EPP), onde ocorreu uma correlação entre as variáveis pH e Al3+, carbono orgânico e cátions, fósforo e argila total, e silte e areia. A geoestatística pode ser aplicada para espacializar os atributos químicos e físicos do solo no sistema agroflorestal, exceto no caso do Mg2+ e Valor V.

ABSTRACT The purpose of this study was to spatialize the chemical and physical attributes of the soil in an agroforestry system in Seropédica, Rio de Janeiro, Brazil. Thirty-one soil samples were collected from 0-10 cm, 10-20 cm, and 20-40 cm depths, and each sampling point was georeferenced. The pH (in H2O), potential acidity (H+Al), calcium (Ca+2), magnesium (Mg+2), aluminum (Al+3), sodium (Na+), potassium (K+), phosphorus (P), organic carbon (C), cation exchange capacity of the soil (T value), base saturation (V value), total clay, total sand, silt, and density of fine roots were measured. The software ArcGIS 10.2 was used to perform the semivariogram analysis and the fitting of the models, and spatial interpolation was performed using a first-order trend ordinary kriging process with spherical, exponential, and Gaussian spatial models. Based on the results, only the exponential and Gaussian models were fitted to the variables, except for the Mg2+ and V value variables, which presented no spatial dependence, thus showing a pure nugget effect (PNE). Distribution maps were generated for the variables (except for those exhibiting PNE), which showed correlation between the variables pH and Al3+, organic carbon and cations, phosphorus and total clay, and silt and sand. Overall, geostatistics could be applied to spatialize the chemical and physical attributes of the soil in the agroforestry system, except in the case of Mg2+ and the V value.

RESUMO Compreender a variabilidade espacial dos atributos químicos e físicos do solo é importante para melhorar as práticas de manejo e conservação do solo. Por sua vez, a variabilidade espacial das propriedades do solo resulta da variação das características morfológicas do relevo. Assim, o objetivo deste estudo foi avaliar a influência da curvatura da superfície na variabilidade espacial dos atributos químicos e físicos do solo na região de Mar de Morros (Pinheiral-Rio de Janeiro, Brasil). Foram selecionadas duas pedoformas adjacentes com curvatura convexa e côncava e coletadas amostras de solo em uma grade com espaçamento fixo de 10 metros entre os pontos. Foram coletadas um total de 56 amostras de solo (0-5 cm de profundidade) nas duas pedoformas e analisados os atributos físicos e químicos do solo. Na análise dos dados foi utilizada estatística descritiva e geoestatísitca. Os atributos químicos do solo apresentaram um padrão aleatório quanto a distribuição espacial em ambas as pedoformas. No entanto, a pedoforma côncava apresentou maiores valores de pH e potássio e valores mais baixos para alumínio quando comparada a pedoforma convexa. Por outro lado, os valores de silte apresentaram dependência espacial em ambas às pedoformas. Já a densidade do solo e o teor de argila apresentaram dependência espacial na pedoforma convexa. Os valores da densidade do solo e silte aumentaram no sentido do terço superior para o terço inferior em ambas as pedoformas. Os resultados mostram que para esta área de estudo, a curvatura da superfície tem maior influência na dependência espacial dos atributos físicos do que para os atributos químicos solo.

ABSTRACT Understanding the spatial variability of soil chemical and physical attributes is important for improving management practices and soil conservation. In turn, the spatial variability of soil properties results from variation in morphological relief characteristics. Thus, the purpose of this study was to evaluate the influence of landform curvature on the spatial variability of soil chemical and physical attributes in the Mar de Morros region (Pinheiral-Rio de Janeiro State, Brazil). Two adjacent landforms were selected with convex and concave curvature and sampled in a regularly spaced grid of 10 meters. A total of 56 soil samples (0-5 cm depth) from the two landforms were collected and analyzed for physical and chemical attributes. The data were analyzed using descriptive statistics and geostatistics. All chemical attributes showed random patterns of spatial variability in both landforms. The concave landform had higher values of pH and potassium and lower values of aluminum than the convex landform. In contrast, silt content showed spatial dependence in both the concave and convex landforms. Bulk density and clay showed spatial dependence in the convex landform. Bulk density and silt content increased from the shoulder to the footslope of both landforms. The results show that, for this study area, landform curvature has more influence on the spatial dependence of soil physical attributes than of soil chemical properties.

RESUMO No Brasil, a Mata Atlântica remanescente é intensamente fragmentada. A conexão de fragmentos florestais através de corredores ecológicos é um passo importante para a conservação da biodiversidade. Determinados locais da paisagem têm maior resiliência e a regeneração natural, por exemplo, pode ser favorecida. Neste trabalho fragmentos florestais remanescentes de Mata Atlântica, no município de Paraíba do Sul, RJ, foram mapeados. Utilizou-se a classificação supervisionada, por máxima verossimilhança, de uma imagem do sensor OLI/Landsat-8; analisou-se a influência de atributos do terreno (face de exposição, radiação solar, declividade e perfil de curvatura) na regeneração natural; e, as áreas com maior potencial para condução da regeneração natural e formação de corredores ecológicos foram indicadas através de pertinência fuzzy. Paraíba do Sul tem 31% do território coberto por vegetação em diferentes estágios de regeneração. Foram contabilizados 1.251 fragmentos florestais em estágio médio ou avançado de regeneração situados, preferencialmente, nas vertentes sudeste, sul e sudoeste, as quais recebem menor quantidade de radiação solar global (Wh.m-2) por ano, e em declividades superiores a 20%. O ajuste de funções fuzzy permitiu identificar 17.327,5 ha de território que tendem a facilitar a recuperação florestal e são, portanto, áreas estratégicas para a formação de corredores ecológicos.

ABSTRACT In Brazil, the remaining areas of Atlantic Forest are intensely fragmented. The connection of forest fragments through ecological corridors is an important step in biodiversity conservation. Certain areas are more resilient, and in those areas, natural forest regeneration, for example, can be encouraged. The aim of this study was to identify areas of greater resilience in order to support the connection of Atlantic Forest fragments with ecological corridors. Forest fragments in the municipality of Paraíba do Sul, in the state of Rio de Janeiro, were mapped using the supervised maximum likelihood classification of an Operational Land Imager (OLI)/Landsat-8 sensor image. Next, we analyzed the influence of terrain attributes (aspect, incident solar radiation, slope, and curvature profile) on natural regeneration. The areas with the greatest potential to achieve natural regeneration and to form ecological corridors were indicated through fuzzy membership functions. Within Paraíba do Sul, 31% of the territory is covered by vegetation in different stages of regeneration. Recordings were made of 1,251 forest fragments in a middle or advanced stage of regeneration. These fragments are usually situated in the southeast, south, and southwest aspects, in areas that receive the least amount of global solar radiation (Wh·m-2) per year, and on slopes with an angle of inclination greater than 20%. The adjustment of fuzzy functions identified 17,327.5 ha with a tendency to recover, and which are therefore strategic areas in the development of ecological corridors.

RESUMO No presente estudo avaliou-se a dinâmica da vegetação de florestas tropicais no período de 2000 a 2010 em áreas desmatadas, utilizando-se os produtos MOD44B, 3B43 e SRTM. Através deles analisou-se, temporal e espacialmente, a ocorrência de regeneração em áreas de desmatamento mapeadas pelo sistema PRODES (Projeto de Estimativa de Desflorestamento da Amazônia) do INPE (Instituto Nacional de Pesquisas Espaciais). Os resultados encontrados mostraram que há regeneração nas áreas desmatadas e que, ao longo do tempo, a densidade da vegetação tende a aumentar. As áreas regeneradas apareceram majoritariamente em áreas mais baixas, seguindo a tendência do desmatamento. O MOD44B mostrou-se eficiente no estudo temporal e espacial da vegetação, indicando haver regeneração ao longo do tempo. O período de maior precipitação coincidiu com o período em que os pixels de menor densidade migraram para classes de maior densidade, sugerindo uma possível relação entre os índices de precipitação e o crescimento da vegetação.

ABSTRACT This article uses data from orbital platforms (MOD44B, 3B43 and SRTM) to evaluate the vegetation dynamics of tropical forests in deforested areas between 2000 and 2010. We analyzed, temporally and spatially, the occurrence of vegetation regeneration in deforested areas mapped by the PRODES system (Programa de Cálculo do Desflorestamento da Amazônia) of the INPE (Instituto Nacional de Pesquisas Espaciais). The results revealed regeneration in deforested areas and also showed that vegetation density tends to increase over time. Areas of regeneration are mainly found in low land areas following the path of deforestation. MOD44B was effective in the vegetation temporal and spatial study, and indicated occurrence of regeneration over time. The higher precipitation period overlapped with the period in which lower density pixels migrated to classes of higher density, which suggests a possible relationship between precipitation indexes and vegetation growth.

RESUMOEste trabalho teve como objetivo ajustar modelos de regressão entre o índice de área foliar (IAF) de plantios de Eucalyptusgrandis x urophylla e índices de vegetação (IVs) de imagens TM - Landsat 5. O estudo foi realizado em plantios com diferentes idades localizados na porção mineira da bacia hidrográfica do rio Doce, entre os anos de 2008 e 2011. O IAF foi medido em campo, de forma não destrutiva, com o equipamento LAI-2000. Os IVs utilizados foram o Normalized Difference Vegetation Index (NDVI), o Soil Adjusted Vegetation Index (SAVI) e o Simple Ratio (SR). O melhor modelo foi ajustado a partir do NDVI, com coeficiente de determinação de 0,73 e erro quadrático médio da raiz de 0,37 m² m–2(19%). Pode-se concluir que os valores de IAF podem ser estimados pelos modelos de regressão ajustados a partir dos IVs derivados do TM - Landsat.

ABSTRACTThe objective of the present study was to fit regression models to the measured leaf area in eucalyptus forests and vegetation indices derived from Landsat-5 TM images. The study was carried out in commercial plantations located in the basin of the Doce River, Minas Gerais state, between 2008 and 2011. Leaf area was measured in the field, non-destructively, with the LAI-2000 device. The following indices were used: Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), and Simple Ratio (SR). The best model was adjusted from the NDVI, with a correlation coefficient of 0.73 and root mean square error of 0.37 m² m–2 (19%). We conclude that the leaf area index can be estimated by the regression models fit to the vegetation indices derived from the Landsat - 5 TM images.

RESUMOPara avaliar os dados de precipitação pluvial via satélite no estado do Amazonas, compararam-se as estimativas do produto 3B43 do satélite TRMM (2004-2008) com dados de sete Estações Meteorológicas Convencionais (EMC). A comparação foi baseada nos seguintes parâmetros estatísticos: Erro Médio (EM), Raiz do Erro Médio Quadrático (REMQ), coeficiente de correlação linear (r) e índice de concordância de Wilmott (d). As estimativas do TRMM foram similares aos dados de superfície e representaram bem a variabilidade sazonal das chuvas. Os dados apresentaram alta correlação linear (r = 0,83), alto índice de concordância (d = 0,85) e REMQ satisfatório (66,6 mm/mês). Dessa forma, as estimativas de precipitação pluvial do produto 3B43 podem ser utilizadas como uma fonte alternativa de dados de qualidade.

ABSTRACTThe aim of this study was to evaluate the rainfall data via satellites in Amazonas state, Brazil. To this end, the estimates from the TRMM-3B43 product (2004-2008) were compared with data from seven Conventional Weather Stations (CWS). The comparison was based on the following statistical parameters: Average Error (AE), Root Mean Square Error (RMSE), linear correlation coefficient (r), and Wilmott’s index of agreement (d). The TRMM-3B43 estimates were similar to the surface data and represent well the seasonal variability of rainfall. The data showed high linear correlation (r = 0.83), high index of agreement (d = 0.85), and satisfactory RMSE (66.6 mm/month). Therefore, rainfall estimates from the TRMM-3B43 product can be used as an alternative source of quality data.

Foram propostos dois cenários futuros para a Amazônia Ocidental, utilizando-se a saída do Modelo de circulação regional HadRM3 para radiação solar global (Rg), para o Estado do Acre. Os cenários A2 (pessimista) e B2 (otimista) são baseados no relatório do IPCC (Intergovernmental Panel on Climate Change). Foram definidas duas estações distintas para ambos os cenários: a estação seca, de abril a setembro, e a estação chuvosa, de outubro a março. O período de 1961 a 1990, "baselines", e para os cenários A2 e B2, a simulação ocorreu entre 2070 e 2100. A conversão da grade pontual do modelo HadRM3 foi baseada no método de Krigagem Ordinária. Os menores valores de R g abrangem a parte oeste do Estado do Acre, na estação seca, em ambos os cenários. Os valores intermediários de R g são na direção norte-sul, seguidos dos maiores valores de R g, que são na porção leste do Estado; houve um aumento significativo de Rg na estação chuvosa no período de 2080 a 2090, em ambos os cenários adotados no estudo. Com base na estatística descritiva e exploratória dos cenários otimista, pessimista e "baseline" mostrou-se que a forçante radiativa (positivo) tende a aquecer a superfície continental e, ao contrário, situação negativa tende a esfriar, sendo identificado tal quadro na formação do gradiente entre as direções leste-oeste do Estado do Acre, para ambas as estações no período de estudo.

Two future climate scenarios have been proposed for the the Western Amazon region - state of Acre, Brazil - using the HadRM3 regional climate model for global solar radiation (Rg). The two climate scenarios, A2 (pessimistic) and B2 (optimistic), are based on findings of the IPCC (Intergovernmental Panel on Climate Change) report. Two distinct seasons were defined for both climate scenarios (dry and rainy): the dry season (from April to September) and the rainy season (from October to March). We chose the time period between 1961 and 1990 as baseline and carried out future simulation from 2070 to 2100 for the A2 and B2 settings. The grid point conversion of the HadRM3 model was based on the Ordinary Kriging method. The smallest values of Rg are found for the western part of Acre state during the dry season in both scenarios. Intermediate values of Rg are observed for the north to south direction, followed by the highest values of Rg for the east side of the state, with significant increase of Rg during the rainy season between 2080 and 2090 for both settings adopted in this study. Based on descriptive and exploratory statistics for the optimistic, pessimistic, and baseline settings, we conclude that the positive radiative forcing tends to warm the land surface, while the negative radiative forcing tends to cool it. This was observed in the formation of the gradient in the east to west direction of the state of Acre in both seasons during the study period.

Dados pluviométricos horários da Estação Meteorológica Automática (EMA) foram preenchidos com dados da normal climatológica do INMET e com os dados do satélite TRMM via produto 3B43. Esses dois conjuntos preencheram as falhas e homogeneizaram os dados do período de 2000-2012, e foram comparados com a ocorrência dos sistemas sinóticos (ZCAS, ZCOU e SF) e com os episódios de El Niño e La Niña, em Seropédica-RJ. A avaliação foi dividida em escalas médias, percentuais sazonais e acumulados anuais. Os dados sinóticos foram obtidos da Climanálise (1996-2012). As características médias mostraram alta variabilidade interanual e intrassazonal dos sistemas sinóticos, seguida da interação dos sistemas de mesoescala e locais. Os meses com maior precipitação (> 120 mm) foram dezembro, janeiro e março, e os meses com menor precipitação (< 60 mm) foram maio, junho, julho e agosto. O verão (42%) e inverno (10%) possuem características bem definidas e distintas em seus padrões de chuva.

Hourly rainfall data from an Automatic Weather Station (AWS) were filled with normal climatology data provided by the National Institute of Meteorology (INMET) and TRMM satellite data via 3B43 product. These two sets filled the gaps and homogenized data from the 2000-2012 period at the Agricultural Ecology station; they were then compared with precipitation occurrence of synoptic systems (SACZ, MCZ and FS) and El Niño and La Niña episodes in the municipality of Seropédica. Evaluation was divided into the following precipitation ranges: average, seasonal percentage, and annual cumulative. Synoptic data from the 1996-2012 period were obtained from 'Climanálise'. The average characteristics identified showed high interannual and intraseasonal variability of synoptic systems, followed by interaction of mesoscale and local systems. December, January and March showed the highest rainfall levels (> 120 mm), while May, June, July and August presented the lowest rainfall levels (< 60 mm). Summer (42%) and winter (10%) seasons have well-defined characteristics and are distinct in their rainfall patterns.