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 Sandy texture soils have a great expression in agricultural areas worldwide. In the Baixada Fluminense, soils with a sandy texture on the surface horizons are striking, and a good part of these areas is destined for producing vegetables using conventional cultivation methods. The sandy texture is one of the great challenges for agriculture due to the low water retention capacity provided to the soil, the rapid decomposition of organic matter, and the intense loss of nutrients by leaching. In these areas, the action of erosive processes is sometimes observed, whether water or wind erosion. The practices carried out in conventional agriculture can accentuate these processes. This study aimed to evaluate the influence of different soil management systems, with different vegetation covers, on the pathways of aggregate formation, the nutrient contents contained therein, and the organic matter fractions, with the objective of using these properties as indicators of soil quality. The study was carried out in an organic production unit, with no-till system (NT) and conventional system (CT), three vegetal covers were evaluated, namely; seed cocktail 1 (C1) (Crotalaria (Crotalaria juncea) (20 kg ha-1), Jack Bean (Canavalia ensiformis) (150 kg ha-1) and millet (Pennisetum glaucum) (60 kg ha-1)), and seed cocktail 2 (C2) (with 50 % of the amount of seeds used in C1), and spontaneous plants (S. P). Undisturbed samples were collected at the layers of 0.00-0.05 and 0.05-0.10 m, and, from these samples, aggregates with a diameter between 9.7 and 8.0 mm were classified according to the formation route (Biogenic or Physicogenic). From these, the chemical properties were quantified (pH, Ca2+, Mg2+, Al3+, P, Na+, K+), and also the carbon fractions (total organic carbon – TOC, mineral-associated organic carbon – MAOC), particulate organic carbon – POC, and free light fraction carbon – LFC). Based on the results, it was verified that the percentage of biogenic aggregates was higher than the physicogenic one in the layer of 0.00-0.05 m, not being verified influences of the vegetal coverage or the management system. Chemical properties did not differ significantly between training pathways. The CT, for the most part, was the system in which the highest values of chemical properties were observed, and in general, the C2 and S.P coatings were the ones that provided the greatest improvements for chemical properties and carbon content.

Abstract The study evaluated the ecology of soil invertebrate faunal communities in periodically flooded forest (CF) fragments and anthropic fields (AF) in the Atlantic Forest. The sampling occurred in the rainy and dry seasons using pitfall traps. We estimated the total activity, richness, diversity, and evenness as well as the activity of the taxonomic and functional groups. Total activity and richness varied as a function of seasonality. Entomobryomorpha, Poduromorpha, and Symphypleona were the most representative taxonomic groups. Enchytraeidae and Blattaria were exclusive to CF. Auchenorrhyncha, Chilopoda, Heteroptera, and Thysanoptera were exclusive to AF. The functional group of microphagous/saprophagous (M/S) showed the highest activity, independent of the environment and season. Greater dissimilarity was observed among the invertebrate fauna in AF when compared to CF. Periodically flooded areas favored groups from the saprophagous trophic guild, while AF areas favored predator and herbivore groups. Soil fauna present in forest environments presented less seasonal variability.

Resumo Nos ecossistemas florestais, a dinâmica da serapilheira está relacionada à tipologia vegetal e as condições climáticas dos ambientes, as quais são influenciadas pela heterogeneidade topográfica da paisagem. Assim, o objetivo deste estudo foi avaliar se diferentes condições de relevo (pedoformas convexa e côncava) alteram a dinâmica da serapilheira em Floresta Estacional Semidecidual na sub-bacia do ribeirão Cachimbal, Pinheiral-RJ. Foram selecionadas duas pedoformas adjacentes com relevo do tipo convexa (convexa-divergente) e côncava (côncava-convergente), sendo essas divididas em minissítios (MS) I, II, e III na pedoforma convexa e IV, V e VI na pedoforma côncava. Nos diferentes ambientes foram avaliados o estoque e a decomposição da serapilheira em duas estações do ano (chuvosa e seca). Para avaliar o estoque foram coletadas dez amostras de serapilheira de cada um dos MS, utilizando um gabarito quadrado com 25 cm de lado. Para avaliar a taxa de decomposição da serapilheira, foram selecionadas 10 g de folhas, as quais foram acondicionadas em litterbags, instalados no campo e coletadas em diferentes intervalos de tempo. O estoque e os teores de nutrientes da serapilheira foram influenciados em função do tipo da pedoforma, variação do gradiente topográfico e estação do ano, maiores estoques foram observados na pedoforma convexa, em estação seca e os maiores teores de K+ e Mg+2 foram observados nos MS inferiores das pedoformas. Por outro lado, os teores de carbono foram influenciados apenas pela estação do ano como maiores teores na estação chuvosa. A decomposição da serapilheira ocorre de maneira diferenciada em função da pedoforma, do gradiente topográfico e da estação do ano, cujos maiores valores foram observados na pedoforma convexa e na estação chuvosa.

Abstract In forest ecosystems the dynamics of burlap is related to the plant typology and to the climatic conditions of environments, which are influenced by the topographic heterogeneity of the landscape. The objective of this study was to evaluate whether different relief conditions (convex and concave pedoforms) alter the burlap dynamics in a semi-deciduous seasonal forest in the sub-basin of Cachimbal, Pinheiral - RJ state. Two adjacent landforms with relief convex type (convex-divergent) and concave (concave-convergent) were selected, and these ones were divided into mini sites (MS) I, II, and III in the convex landform and IV, V and VI in the concave landform. The stock and the decomposition of the burlap in two seasons (rainy and dry) were rated in different environments. To evaluate the stock, ten samples of litter from each MS were collected using a square template with 25-cm side. To evaluate the burlap decomposition rate, 10 g of leaves were selected, which were placed in litterbags, installed in the field and collected at different time intervals. Litter stock and nutrient contents were influenced by the pedoform type, topographic gradient variation and season, larger stocks were observed in convex pedoform in dry season and higher K+ and Mg+2 contents. in the lower pedoform MS. On the other hand, the carbon contents were influenced only by the season of the year like higher contents in the rainy season. The decomposition of burlap forming material occurs differently depending on the landform, topographic gradient and on the season, where the highest values were observed in the convex landform and in the rainy season.

Abstract The stage of natural forest regeneration may influence soil fauna. This study aimed to test the hypothesis that there are differences in the structure and composition of the soil fauna communities between areas undergoing less advanced (LAS) and more advanced (MAS) stages of natural regeneration of Seasonal Semideciduous Forest at Pinheiral, RJ. Soil fauna was sampled using pitfall traps, during dry and rainy seasons. Total abundance, abundance of the saprophagous/predator group, mainly Formicidae, and the relative participation of Orthoptera were higher in MAS, while the relative participation of Acari, Araneae, Coleoptera, Diptera and the herbivorous group were higher in LAS, during both climatic seasons. Some taxonomic groups were restricted to one of the areas. Richness, evenness and diversity tended to present higher values in LAS (dry season). The higher complexity of the soil fauna community was correlated to the higher leaf litter standing stock in LAS.

ABSTRACT We characterized soil physical and chemical properties and soil organic matter in epigeal termite mounds in pastures to evaluate the changes promoted by termites in comparison to an adjacent area. We selected seven active epigeal termite mounds in the municipality of Seropédica, state of Rio de Janeiro, Brazil. Soil samples were collected from top, center and base positions of each mound, at 0.50 and 1.50 m distance from the base of the mound. We identified individuals of the genus Embiratermes, Velocitermes, and Orthognathotermes. The humin fraction predominated over the humic and fulvic acid fractions both in mounds and adjacent soil. The amount of organic matter and the mineral fractions (mineral-associated organic carbon - MOC) varied among builder species. The studied chemical attributes point to a higher concentration of nutrients in the mounds than in the adjacent soil.

RESUMO A composição e qualidade do banco de sementes são alguns dos fatores responsáveis pela estrutura e composição florística dos ambientes florestais. O objetivo deste estudo foi avaliar o banco de sementes de um fragmento de Floresta Estacional Semidecidual, com influência das características topográficas da paisagem. Foram selecionadas duas pedoformas adjacentes com relevo do tipo convexa e côncava, sendo essas divididas em minissítios (MS) I, II, e III na pedoforma convexa, e IV, V, VI na pedoforma côncava. Foram amostrados 10 pontos de cada MS, distribuídos assistematicamente, com uma área superficial de 0,0625 m² e profundidade de 3 cm. Foi registrado um total de 4.862 sementes.m-1 germinadas no período de 90 dias, sendo na pedoforma convexa observado o maior número de sementes.m-1 germinadas. Em ambas as pedoformas, foram identificadas 35 famílias e 88 espécies; dentre as espécies, 37% têm hábito herbáceo; 24%, arbóreo; 18%, arbustivo; 12%, trepador; e 2%, epifítico. Quanto ao tipo de pedoforma, foram registradas 44% das espécies encontradas em ambas, 31% foram exclusivas da convexa e 25%, da côncava. Para aos parâmetros florísticos e fitossociológicos, a pedoforma convexa apresentou maior número de sementes, famílias, espécies e riqueza, enquanto a côncava teve maiores índices de diversidade. As condições topográficas foram determinantes na composição florística e fitossociológica do banco de sementes, sendo os maiores valores de riqueza verificados na pedoforma convexa e de diversidade, na côncava, com maior índice de valor de importância para as famílias Asteraceae, Melastomataceae e Urticaceae.

ABSTRACT The composition and quality of the seed bank are some of the factors responsible for the structure and floristic composition of forest environments. The aim of this study was to evaluate the seed bank of a semideciduous forest patch, taking into account the influence of the landscape’s topographical features. Two adjacent landforms, of convex and concave shapes, were selected. They were divided into mini sites (MS) I, II, and III in the convex landform and IV, V and VI in the concave one. Ten sample points on each MS were randomly distributed with a surface area of 0.0625 m² and 3 cm deep. A total of 4,862 germinated seeds.m-1 was registered in 90 days, with the convex landform presenting the highest frequency of germinated seeds.m-1. A total of 35 families and 88 species were identified in both landforms, of which 37% were of herbaceous habit, 24% arboreal, 18% shrubs, 12% lianas and 2% epiphytic. Regarding the landform’s shape, 44% of the species were found in both convex and concave ones, 31% were found exclusively on the convex landform and 25% exclusively on the concave one. Regarding floristic and phytosociological parameters, the convex landform accounted for a higher number of seeds, families, and species richness, while the concave landform accounted for higher diversity. Topography was a determinant factor for the floristic and phytosociological composition of the seed bank. The highest species richness was recorded in the convex landform and highest diversity in the concave landform, with Asteraceae, Melastomataceae and Urticaceae families presenting the highest importance indexes of value.

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 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.