ABSTRACT MOS (soil organic matter) is a natural carbon reservoir, and divided into different stages of decomposition according to its solubility and structural complexity. In view of this context, this work aimed to quantify the carbon content in the humic fractions of the soil organic matter under an agroforestry system in three toposequences in the swamp of altitude in Pernambuco, Brazil. The study was carried out on the Yaguara farm, and the studied areas were native forest and three toposequences of agroforestry system. Soil samples were collected in trenches 1.5 x 1.5 m, at depths 0-20, 20-40 and 40-60 cm, with four replications. The carbon concentrations in the humic fractions of the soil decreased with increasing depth. The area with agroforestry system had the highest concentrations of carbon in the humic fractions. The stocks of humic fractions found in the agroforestry system area showed higher average values in the top area 5.62, 9.72 and 22.53 Mg ha-1 in relation to native forest 4.84, 8.28 and 19.20 Mg ha-1, respectively for fulvic acid, humic acid and humine. Among the evaluated areas, the soil with agroforestry system top area has great potential to increase the carbon storage in the humic fractions of the soil. reservoir complexity context Pernambuco Brazil farm 15 1 5 1. m 020, 020 0 20, 20 0-20 2040 40 20-4 4060 60 40-6 cm replications depth 562 62 5.62 972 9 72 9.7 2253 22 53 22.5 ha1 ha ha- 484 4 84 4.84 828 8 28 8.2 1920 19 19.2 ha1, 1, humine 02 2 0-2 204 20- 406 6 40- 56 5.6 97 7 9. 225 22. 48 4.8 82 8. 192 19. 0- 5. 4.

RESUMO A MOS (matéria orgânica do solo) é um reservatório natural de carbono e dividida em diferentes estágios de decomposição conforme sua solubilidade e complexidade estrutural. Diante desse contexto, este trabalho teve como objetivo quantificar os teores de carbono nas frações húmicas da matéria orgânica do solo sob sistema agroflorestal em três topossequências no brejo de altitude de Pernambuco, Brasil. O estudo foi desenvolvido na fazenda Yaguara, e as áreas estudadas foram mata nativa e três topossequências de sistema agroflorestal. As amostras de solos foram coletadas em trincheiras 1,5 x 1,5 m, nas profundidades 0-20, 20-40 e 40-60 cm, com quatro replicações. As concentrações de carbono nas frações húmicas do solo diminuíram com o aumento da profundidade. A área com sistema agroflorestal teve as maiores concentrações de carbono nas frações húmicas. Os estoques das frações húmicas encontradas em área de sistema agroflorestal apresentaram maiores valores médios em área de topo 5,62, 9,72 e 22,53 Mg ha-1 em relação à mata nativa 4,84, 8,28 e 19,20 Mg ha-1, respectivamente para ácido fúlvico, ácido húmico e humina. Dentre as áreas avaliadas, o solo com sistema agroflorestal área de topo tem grande potencial para aumentar o armazenamento de carbono nas frações húmicas do solo. estrutural contexto Pernambuco Brasil Yaguara 15 1 5 1, m 020, 020 0 20, 20 0-20 2040 40 20-4 4060 60 40-6 cm replicações profundidade 562 62 5,62 972 9 72 9,7 2253 22 53 22,5 ha1 ha ha- 484 4 84 4,84 828 8 28 8,2 1920 19 19,2 ha1, fúlvico humina avaliadas 02 2 0-2 204 20- 406 6 40- 56 5,6 97 7 9, 225 22, 48 4,8 82 8, 192 19, 0- 5, 4,

ABSTRACT Amazonian soils have been suffering severe changes resulting from human activities in the region, causing significant changes in soil attributes that can contribute to greater susceptibility to erosion processes. Therefore, the present work aimed to estimate the erodibility in natural and anthropic environments in the southern region of the Amazon. Eight areas in the region were selected, including areas of native forest, savannah, cerradão, pasture and reforestation, delimiting 32 sampling points per area, with collections at a depth of 0.00-0.20 m, totaling 256 samples. Next, texture analysis and quantification of soil organic carbon were performed, and then erodibility was estimated by indirect prediction methods, Tukey’s test, Pearson’s correlation and factorial analysis of principal components. According to the results obtained, it was observed that the evaluated areas of native forest 1 and 2, cerradão and pasture present high susceptibility to erosion in relation to the cerrado, reforestation with genipap, teak and mixed areas. Therefore, it was noted that the high level of erodibility is associated with a greater predominance of sand fraction, K factor, Ki Kr and low clay content, as well as with the management employed in the areas. processes Therefore Amazon selected savannah 3 area 0.000.20 000020 0.00 0.20 0 00 20 0.00-0.2 m 25 samples Next performed methods Tukeys Tukey s test Pearsons Pearson components obtained 2 cerrado genipap fraction factor content 000 0.000.2 00002 0.0 020 0.2 0.00-0. 0.000. 0000 0. 02 0.00-0 0.000 0.00-

Abstract Intense soil preparation and disturbance in crops, over time, reduces the quantity and quality of soil organic matter. Given this context, this work aimed to determine soil carbon stocks and labile fractions under agroforestry system (AFS) and toposequences in an altitude marsh, Taquaritinga do Norte, Pernambuco, Brazil. The study was carried out at the Yaguara farm, and the areas studied were native forest with 4.57 ha and coffee plantation in shade with native forest with 25.59 ha. Soil samples were collected in four trenches measuring 1.5 x 1.5 x 0.60 m, with a distance of 50 meters. Soils were collected at depths of 0-20, 20-40 and 40-60 cm, followed by chemical, physical and density analyzes to determine soil carbon stocks and labile fractions. The area with shaded coffee showed higher values of soil carbon stocks at depths of 0-20 cm and 20-40 cm. At a depth of 40-60 cm, the AFS top toposequence showed the highest carbon stock with 11.73 Mg ha-1, followed by the area with native vegetation with 10.6 Mg ha-1, slope with 9.23 Mg ha-1 and pediment with 7.00 Mg ha-1. It was found that the top toposequence with shaded coffee exhibited a greater stock of labile carbon at depth 0-20 cm with a value of 1.06 Mg ha-1, followed by the bedding areas (SAF) with 0.88 Mg ha-1, native forest with 0.79 Mg ha-1 and slope with 0.67 g kg-1. However, the area of native vegetation showed the highest value of labile carbon at a depth of 40-60 cm. It was concluded that the area with shaded coffee in the top toposequence showed great capacity to increase total carbon stocks and labile carbon stocks of soil organic matter. crops time matter context (AFS marsh Norte Pernambuco Brazil farm 457 4 57 4.5 2559 25 59 25.5 15 1 5 1. 060 0 60 0.6 m meters 020, 020 20, 20 2040 40 20-4 4060 40-6 chemical 0-2 1173 11 73 11.7 ha1, ha1 1, 106 10 6 10. 923 9 23 9.2 ha- 700 7 00 7.0 ha1. 06 1.0 SAF (SAF 088 88 0.8 079 79 0.7 067 67 kg1. kg1 kg kg-1 However 45 4. 255 2 25. 0. 02 204 20- 406 40- 0- 117 11. 92 9. 70 7. 08 8 07 kg-

Resumo O intenso preparo e revolvimento do solo em cultivos, com o tempo, reduz a quantidade e a qualidade da matéria orgânica do solo. Diante desse contexto, este trabalho teve como objetivo determinar os estoques de carbono do solo e frações lábeis sob sistema agroflorestal (SAF) e topossequências em brejo de altitude, em Taquaritinga do Norte, Pernambuco, Brasil. O estudo foi desenvolvido na fazenda Yaguara, e as áreas estudadas foram mata nativa com 4,57 ha e plantio de café sombreado com mata nativa com 25,59 ha. As amostras de solos foram coletadas em quatro trincheiras 1,5 x 1,5 x 0,60 m, com distância de 50 metros. Foram coletados solos nas profundidades de 0-20, 20-40 e 40-60 cm, seguido de análises químicas, físicas e densidade para determinação dos estoques de carbono no solo e frações lábeis. A área com café sombreado apresentou maiores valores de estoques de carbono no solo nas profundidades de 0-20 cm e 20-40 cm. Na profundidade de 40-60 cm, a topossequência de topo do SAF apresentou maior estoque de carbono com 11,73 Mg ha-1, seguido da área com vegetação nativa com 10,6 Mg ha-1 , encosta com 9,23 Mg ha-1 e pedimento com 7,00 Mg ha-1. Verificou-se que a topossequência de topo com café sombreado exibiu maior estoque de carbono lábil na profundidade 0-20 cm com o valor de 1,06 Mg ha-1, sucedido das áreas de pedimento (SAF) com 0,88 Mg ha-1, mata nativa com 0,79 Mg ha-1e encosta com 0,67 Mg ha-1. No entanto, a área de vegetação nativa apresentou o maior valor de carbono lábil na profundidade de 40-60 cm. Concluiu-se que a área com café sombreado na topossequência topo mostrou grande capacidade para elevar os estoques de carbono total e estoques de carbono lábil da matéria orgânica do solo. cultivos tempo contexto (SAF altitude Norte Pernambuco Brasil Yaguara 457 4 57 4,5 2559 25 59 25,5 15 1 5 1, 060 0 60 0,6 m metros 020, 020 20, 20 2040 40 20-4 4060 40-6 químicas 0-2 1173 11 73 11,7 ha1, ha1 106 10 6 10, ha- 923 9 23 9,2 700 7 00 7,0 ha1. 1. Verificouse Verificou se 06 1,0 088 88 0,8 079 79 0,7 ha1e hae 1e 067 67 entanto Concluiuse Concluiu 45 4, 255 2 25, 0, 02 204 20- 406 40- 0- 117 11, 92 9, 70 7, 08 8 07

ABSTRACT The objective of this work was to evaluate soil attributes and root distribution in areas under forest conversion to cultivated environments. The study was carried out in four areas: forest, cupuaçu, guarana and annatto, located in the municipality of Canutama, state of Amazonas. Soils and volumetric rings were collected in the layers 0.00 – 0.10; 0.10 – 0.20; 0.20 – 0.30; 0.30 – 0.40; and 0.40 – 0.50 m for analyses of physical and chemical attributes and root distribution. Univariate statistical analyses were carried out, the means were compared with the Tukey’s test (p < 0.05) and Pearson’s correlation (p < 0.05 and < 0.01). The forest area and the cultivated environments present soil chemical limitations for agricultural production, whereas the physical attributes presented satisfactory values. The chemical attributes underwent major changes and degradations upon conversion to agriculture. Major changes were observed in the layers of 0.00 – 0.10 and 0.10 – 0.20 m for the studied areas. Cupuaçu cultivation showed higher values of roots dry weight (RDW) and roots distribution (RD), with the highest values found in the 0.00 – 0.10 and 0.10 – 0.20 m layers.

ABSTRACT In the Amazon region, soil patches with an anthropic A horizon are found, called Indian black earths (IBEs). Indian black earths are highly fertile and, therefore, are deforested by small local farmers to cultivate without basic management that maintains soil and crop sustainability. Therefore, in order to evaluate the effect of using different cultures on the spatial variability of soil chemical attributes, three cultivated IBEs and one IBE under natural forest were selected for georeferencing and sample collection. The collection was made with a mesh system with 88 points per IBE, stratified in three layers: 0–0.05, 0.05–0.10 and 0.10–0.20 m. The soil was sampled, dried in the shade and sieved to obtain the fine earth fraction for analysis of chemical attributes. Descriptive statistical and geostatistical analyses were applied to the results. The use and management of soil influenced the spatial behavior of the chemical attributes of IBEs. The cultivation of Brachiaria over many years favored the reduction of the spatial variability of chemical attributes. The use of cacao and coffee crops also favored the homogeneity of the IBEs in relation to the natural forest, but not as much as for Brachiaria, likely due to the succession of crops that preceded these crops. The IBE in the forest contains a high natural spatial correlation in the first 0.1 m of the surface; however, more than 70% of this correlation is linked to a random variation.

Resumo A erodibilidade é uma característica do solo que representa a susceptibilidade com que suas partículas da camada mais superficial são levadas e transportadas para locais mais baixos por agentes erosivos, causando danos ambientais e econômicos. O objetivo deste trabalho foi estimar a erodibilidade do solo em áreas de pastagens e florestas no município de Porto Velho-Rondônia. Em campo, foram selecionadas três áreas com diferentes tipos de vegetação, uma com braquiária, outra com capim mombaça e uma terceira em floresta nativa. Nas áreas com pastagens, foi delineada uma malha amostral de tamanhos iguais (90 m x 60 m), e na área de floresta uma malha amostral aproximada (90 m x 50 m), com espaçamento regular de 10 m entre os pontos amostrais para ambas as áreas. A amostragem foi realizada nos pontos de cruzamento da malha na profundidade de 0,0-0,2 m, compondo 70 pontos amostrais nas áreas com pastagens e 60 pontos amostrais na área de floresta, totalizando 200 amostras. Em seguida, foram realizadas análises laboratoriais para determinação da textura seguida do fracionamento da areia, e do carbono orgânico seguida da estimativa da matéria orgânica do solo. Os fatores de erodibilidade foram calculados por meio de modelos de predição indireta e, em seguida, foram aplicadas técnicas univariadas, geoestatísticas e multivariadas. Os ambientes de pastagem diferiram do ambiente de floresta. No entanto, a área de capim mombaça funciona como um ambiente intermediário entre a floresta e a braquiária, estando mais próxima do ambiente de floresta.

Abstract “Erodibility” is a characteristic of the soil that represents the susceptibility with which its particles from the most superficial layer are taken and transported to lower places by erosive agents, causing environmental and economic damages. This work estimated soil erodibility in pastures and forest areas in the municipality of Porto Velho-Rondônia. In the field, three areas with different types of vegetation were selected, one with brachiaria, another with mombaça grass, and a third in native forest. In areas with pastures, a sampling mesh of equal sizes was outlined (90 m x 60 m), and in the forested area an approximate sampling mesh (90 m x 50 m), with a regular spacing of 10 m between the samples points for both areas. The sampling was done at the crossing points of the mesh at a depth of 0.0-0.2 m, composing 70 sample points in the areas with pastures and 60 sample points in the forest area, totaling 200 samples. Then, laboratory analyzes were carried out to determine the texture followed by the fractionation of the sand, and the organic carbon followed by the estimate of the organic matter of the soil. The erodibility factors were calculated using indirect prediction models, and then, univariate, geostatistical and multivariate techniques were applied. The pastures’ environments differed from the forest environment. However, the mombaça grass area functions as an intermediate environment between the forest and the brachiaria, being closer to the forest environment.

Resumo O reconhecimento da influência das práticas de manejo nas condições físicas e químicas do solo é substancial para a agricultura sustentável. Por essa razão, o estudo foi desenvolvido com o objetivo de avaliar o comportamento de atributos do solo sob diferentes usos na região de Humaitá, AM, utilizando métodos estatísticos multivariados. O estudo foi desenvolvido em 8 propriedades rurais produtoras de banana, pastagem, milho, café, mandioca, hortaliças, sistema agroflorestal e fragmento florestal. Amostras de solos com estrutura preservada nas camadas de 0,0 - 0,10 e 0,10 - 0,20 m foram coletadas aleatoriamente em 5 pequenas trincheiras por área, totalizando 32 amostras nos sistemas de manejo, para determinar os atributos físicos e químicos. Os dados foram então submetidos à análise estatística univariada e multivariada. Análises exploratórias de dados (componentes principais e dendrogramas) e frequência de covariáveis ambientais foram eficientes em distinguir ambientes de produção, portanto a classificação multivariada baseada em atributos físicos e químicos do solo pode auxiliar no planejamento adequado do uso da terra. A análise dos componentes principais indica que a DS apresenta dependência direta com o RSP, sinalizando o uso do solo com pastagem o único no processo de compactação. A acidez do solo é o principal fator limitante para o desenvolvimento da cultura, exigindo a adoção de práticas corretivas de pH do solo com melhorias na oferta de nutrientes. A conversão da floresta para pastagem manteve a característica estrutural do solo, enquanto os demais usos incrementaram melhorias na qualidade física e fertilidade do solo.

Abstract The recognition of the influence of management practices on soil physical and chemical conditions is substantial for sustainable agriculture. For this reason, this study was developed for the purpose of evaluating the behavior of soil attributes under different uses in the region of Humaitá, AM, using multivariate statistical methods. The study was developed in 8 rural properties producing bananas, grassland, maize, coffee, cassava, vegetables, agroforestry system and a forest fragment. Samples of soils with preserved structure in the 0.0 - 0.10 and 0.10 - 0.20 m layers were randomly collected in 5 small trenches per area, totaling 32 samples in the management systems, to determine the physical and chemical attributes. The data were then submitted to univariate and multivariate statistical analysis. Exploratory data analysis (principal components and dendrogram) and frequency of environmental covariates was efficient in distinguishing production environments, so multivariate classification based on physical and chemical attributes of the soil can help in the proper planning of land use. The analysis of the principal components indicates that the BD presents direct dependence with the SPR, signaling the use of the soil with grassland the only one in the process of compaction. Soil acidity is the main limiting factor for crop development, requiring the adoption of pH corrective practices with improvements in nutrient supply. The conversion of the forest to grassland maintained the structural characteristics of the soil, while the other uses increased improvements in physical quality and soil fertility.

RESUMO Objetivou-se avaliar a regeneração natural pós-fogo em uma área de campo sujo. Foram selecionados três ambientes; I e II, com ocorrência de fogo, e III, sem ocorrência. Em cada local foi instalado um transecto com 20 parcelas de 5 × 5 m (25 m2). Foram mensurados o diâmetro ao nível do solo (DNS), altura total e rebrota de todos os indivíduos com altura ≥ 0,10 m e DNS ≤ 5,0 cm. Nos ambientes I e II foram amostrados 436 e 387 indivíduos e 29 e 24 espécies, respectivamente. Já no ambiente III foram amostrados 741 indivíduos e 29 espécies. Houve diferença significativa no número de perfilhos, número de indivíduos e na área basal. Nos ambientes I e II, 72% e 88%, respectivamente, apresentaram indícios de rebrotamento. O incêndio modificou a estrutura da vegetação e a rebrota foi a principal estratégia utilizada pelas espécies nos locais com ocorrência de incêndio.

ABSTRACT This study aimed to evaluate the natural post-fire regeneration in dry grassland. We selected three sites: I and II, with occurrence of fire and III with no occurrence. Each site received one transect with 20 plots of 5 × 5m (25m 2). Diameter at ground level (DNS), total height and regrowth of all individuals with height ≥ 0.10 m and DNS ≤ 5.0 cm were measured. Sites I and II, respectively, had 436 and 387 sampled individuals, and 29 and 24 species. Site III had 741 individuals and 29 species sampled. There was a significant difference in the number of tiller, individuals and basal area. In sites I and II, 72% and 88%, respectively, showed signs of regrowth. The fire changed the structure of vegetation, and regrowth was the main strategy used by species in sites with fire occurrence.

Relata-se a freqüência de vegetais Bromeliaceae e de outros criadouros com plantas positivos para Aedes aegypti durante dois ciclos operacionais (tratamento focal) consecutivos no Município do Rio de Janeiro, RJ, cujos períodos foram de 12 de novembro de 2000 a 9 de março de 2001 e 12 de março de 2001 a 15 de junho de 2001. O trabalho destaca as implicações epidemiológicas oriundas da crescente utilização dessas plantas para fins decorativos.

The frequency of Bromeliaceae and other plant breeding places where Aedes aegypti can be found is reported during two consecutive operational cycles (focal treatment) in the city of Rio de Janeiro. These cycles took place from November 12 2000 to March 9 2001 and from March 12 2001 to June 15 2001. This study concentrates on the epidemiological implications resulting from the growing use of these plants as decorative living objects.

Relata-se a freqüência de vegetais Bromeliaceae e de outros criadouros com plantas positivos para Aedes aegypti durante dois ciclos operacionais (tratamento focal) consecutivos no Município do Rio de Janeiro, RJ, cujos períodos foram de 12 de novembro de 2000 a 9 de março de 2001 e 12 de março de 2001 a 15 de junho de 2001. O trabalho destaca as implicações epidemiológicas oriundas da crescente utilização dessas plantas para fins decorativos.

The frequency of Bromeliaceae and other plant breeding places where Aedes aegypti can be found is reported during two consecutive operational cycles (focal treatment) in the city of Rio de Janeiro. These cycles took place from November 12 2000 to March 9 2001 and from March 12 2001 to June 15 2001. This study concentrates on the epidemiological implications resulting from the growing use of these plants as decorative living objects.