Maria de Lourdes Pinheiro Ruivo

Biogeochemical cycling of carbon, water, energy, trace gases, and aerosols in Amazonia: The LBA-EUSTACH experiments

The biogeochemical cycling of carbon, water, energy, aerosols, and trace gases in the Amazon Basin was investigated in the project European Studies on Trace Gases and Atmospheric Chemistry as a Contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA-EUSTACH). We present an overview of the design of the project, the measurement sites and methods, and the meteorological conditions during the experiment. The main results from LBA-EUSTACH are: Eddy correlation studies in three regions of the Amazon Basin consistently show a large net carbon sink in the undisturbed rain forest. Nitrogen emitted by forest soils is subject to chemical cycling within the canopy space, which results in re-uptake of a large fraction of soil-derived NOx by the vegetation. The forest vegetation is both a sink and a source of volatile organic compounds, with net deposition being particularly important for partially oxidized organics. Concentrations of aerosol and cloud condensation nuclei (CCN) are highly seasonal, with a pronounced maximum in the dry (burning) season. High CCN concentrations from biomass burning have a pronounced impact on cloud microphysics, rainfall production mechanisms, and probably on large-scale climate dynamics.

MICROBIAL BIOMASS AND SOIL CHEMICAL PROPERTIES UNDER DIFFERENT LAND USE SYSTEMS IN NORTHEASTERN PARÁ

O aumento da producao agricola na Amazonia brasileira tem ocorrido devido, em grande parte, a expansao da fronteira agricola, utilizando areas ja antropizadas ou avancando sobre a vegetacao primaria. Ao mesmo tempo, os sistemas agricolas, na pequena producao, continuam utilizando o fogo no preparo da area, o que leva a perda da capacidade produtiva dos solos em curto espaco de tempo, forcando a abertura de novas areas. Este trabalho avaliou o efeito de metodos de preparo do solo e tempo de pousio que envolvem queima e trituracao da vegetacao, com permanencia na superficie ou incorporada ao solo, com ou sem adubacao mineral, em duas epocas do ano sobre os atributos quimicos e biologicos do solo. O experimento foi instalado em 1995 em um Latossolo Amarelo do campo experimental da Embrapa Amazonia Oriental, no nordeste do Estado do Para. O delineamento experimental foi em blocos casualizados, arranjados em esquema fatorial 2 x 6, sendo dois sistemas de manejo e seis tratamentos, estudados em duas epocas de coleta. Os sistemas de manejo envolveram as culturas de arroz (Oriza sativa), seguido de feijao-caupi (Vigna unguiculata) e mandioca (Manihot esculenta). Um sistema constou de dois ciclos de cultivo seguidos, deixando em pousio por tres anos; e o outro, de um ciclo de cultivo, deixando em pousio por tres anos. Os tratamentos foram: corte e queima da vegetacao, com adubacao NPK (Q+NPK); corte e queima da vegetacao, sem adubacao NPK (Q-NPK); corte e trituracao da vegetacao, deixando-a na superficie do solo, com adubacao NPK (C+NPK); corte e trituracao da vegetacao, deixando-a na superficie do solo, sem adubacao NPK (C-NPK); corte e trituracao da vegetacao, com incorporacao e com adubacao NPK (I+NPK); e corte e trituracao da vegetacao, com incorporacao e sem adubacao NPK (I-NPK). As coletas de solo foram realizadas na estacao mais chuvosa (abril de 2006) e na menos chuvosa (setembro de 2006), na profundidade de 0,0-0,1 m. Em cada parcela, foram coletadas 10 amostras simples para compor uma amostra composta. O sistema de manejo mais intensivo apresentou maiores teores de C microbiano (Cmic) e N microbiano (Nmic), ao passo que o sistema menos intensivo mostrou maio teor de C orgânico. Os tratamentos que apresentaram maior teor de Cmic e Nmic foram aqueles em que houve corte, trituracao e deposicao da biomassa na superficie do solo. Os atributos quimicos nos dois sistemas de manejo encontram-se em faixas que enquadram os solos como de baixa fertilidade; no entanto, P e K (no periodo chuvoso) foram mais elevados no sistema de manejo menos intensivo.

The use of micromorphology for the study of the formation and properties of Amazonian Dark Earths

A blood sampling device includes an expansible, flexible container which, when unfilled, lies flat with its opposed sides together. The container is connected to a support having a passage for connecting the container with a needle cannula. A manually operable valve is disposed between the passage and the container. A gas vent communicates with the passage and has a hydrophobic filter for allowing air in the needle and passage to escape without entering the collection chamber of the container. The container has an isolation chamber at the proximal end for isolating air or air bubbles that might enter the collection chamber as a result of error in sampling technique. By hand manipulation of the container, such air bubbles can be moved from the collection chamber into the isolation chamber to isolate the air bubbles and prevent further absorption of oxygen from such air bubbles into the blood sample in the collection chamber. A closure cap is provided which substantially avoids the introduction of air into a filled container when employed to close the container.

Variação temporal e vertical de atributos químicos de um gleissolo do Rio Guamá cultivado com Canaranas

Sediments carried away by the muddy waters of the Guama River and the heterogeneity of these substances are responsible for the soil formation and diversity of chemical characteristics in the periodically flooded areas. This study aimed at determining the physical and chemical attributes of a low floodplain (varzea) soil of the Guama river, in different periods, cultivated with Paramaribo canarana (Echinochloa polystachya H.B.K) or canarana erecta lisa (Echinochloa pyramidales Lam). The experimental design was entirely randomized, in a 4 x 4 factorial scheme (4 depths and 4 sampling periods) with 6 replications. Composite soil samples were collected at six equidistant points from a transection, at depths of 0-10, 10-20, 20-30, and 30-40 cm in May, August and November/2002 and February/2003. Soil texture, organic matter, pH in H2O, pH in KCl, extractable P, exchangeable K, Al, Ca, and Mg and the micronutrients Cu, Mn, Zn, and Fe were determined. The soil of the area under study is classified as Gleysol, i.e., little developement, poorly drained, normally acid, with a silt- clay-loam horizon. The soil chemistry composition was affected by seasonality. During the rainy season and when the most intense flooding occurred in the floodplain, in February, the pH, Cu and soluble iron concentrations increased and Mg and exchangeable aluminum decreased. During lower soil humidity periods base saturation and CTC were higher. Iron was the nutrient that showed the greatest variation in the flooded soil; the increases exceeded 1000 % during the period of more pronounced flooding (February).

Características químicas de um Gleissolo sob diferentes sistemas de uso, nas margens do rio Guamá, Belém, Pará

Foram estudados os efeitos do uso do solo sobre a fertilidade, em Gleissolo sob tres diferentes sistemas de manejo. As coletas foram feitas antes do periodo chuvoso nos seguintes sistemas de manejo: area cultivada com arroz (Oriza sativa L.) ha aproximadamente 40 anos, com algumas interrupcoes ao longo deste periodo, com o cultivo algumas vezes mecanizado e uso de aracao e gradagem; area sob pastagem de canarana erecta lisa (Echinochloa pyramidalis Hitch.), formada ha cerca de 20 anos sem uso de adubacoes ou calagens; e area sob vegetacao natural de floresta tipica das areas de varzea alta. As amostras de solo foram coletadas em dez pontos a partir de um transecto nas areas, em quatro profundidades 0-10, 10-20, 20-30 e 30-40 cm. Os resultados demonstraram que o solo em condicoes naturais, de modo geral, apresentou atributos quimicos que variaram de bons a muito bons, o que demonstra um grande potencial para o uso agricola. O cultivo agricola dos solos das varzeas do rio Guama provocou uma reducao da concentracao de P e de K. O sistema de uso com pastagem apresentou maior sustentabilidade da fertilidade do que o sistema sob cultivo com arroz, visto que, alem da melhoria das caracteristicas quimicas, a materia orgânica elevou-se, tambem, em relacao ao sistema natural.

Neogene sharks and rays from the Brazilian ‘Blue Amazon’

The lower Miocene Pirabas Formation in the North of Brazil was deposited under influence of the proto-Amazon River and is characterized by large changes in the ecological niches from the early Miocene onwards. To evaluate these ecological changes, the elasmobranch fauna of the fully marine, carbonate-rich beds was investigated. A diverse fauna with 24 taxa of sharks and rays was identified with the dominant groups being carcharhiniforms and myliobatiforms. This faunal composition is similar to other early Miocene assemblages from the proto-Carribbean bioprovince. However, the Pirabas Formation has unique features compared to the other localities; being the only Neogene fossil fish assemblage described from the Atlantic coast of Tropical Americas. Phosphate oxygen isotope composition of elasmobranch teeth served as proxies for paleotemperatures and paleoecology. The data are compatible with a predominantly tropical marine setting with recognized inshore and offshore habitats with some probable depth preferences (e.g., Aetomylaeus groups). Paleohabitat of taxa particularly found in the Neogene of the Americas (†Carcharhinus ackermannii, †Aetomylaeus cubensis) are estimated to have been principally coastal and shallow waters. Larger variation among the few analyzed modern selachians reflects a larger range for the isotopic composition of recent seawater compared to the early Miocene. This probably links to an increased influence of the Amazon River in the coastal regions during the Holocene.

Efeito do cálcio no controle da Hypsipila grandella em mudas de mogno cultivadas em hidroponia

The objective of this research was to evaluate the leaf level of calcium and the effect attack by caterpillar H. grandella to young mahogany (S. macrophylla) plants cultivated in a nutritive solution. This solution was that proposed by Hoagland and Arnon modified by Epstein (1975). The experiment was carried out in the greenhouse of the Federal Rural University of Amazonas (UFRA), at Belem, Para, from September 2004 to February 2005. A split plot experimental desing with five replicates was used. The plots were five doses of calcium (0, 80, 160, 240, 320 mg Ca.L -1 ) and the subplots two times of harvesting the plants (189 e 211 days after planting) for the variables sensitivity of mahogany seedlings to attack of the drill, gallery length and stem level of calcium. Results showed the calcium decreased gallery length of infection suggesting that it was efficient to control the attact of plague to mahogany seedlings.

LBA-ESECAFLOR Artificially Induced Drought in Caxiuanã Reserve, Eastern Amazonia: Soil Properties and Litter Spider Fauna

Abstract A review is presented of soil properties and litter fauna of an experimental site in the Caxiuana forest, eastern Amazonia, as a contribution to the Large-Scale Biosphere–Atmosphere Experiment in Amazonia (LBA). This study’s main scientific goal is to compare some biogeochemical soil properties of an undisturbed forest ecosystem with those of an experimental (1 ha) plot in which rainfall was artificially excluded to simulate drought [the Efeitos da Seca da Floresta (ESECAFLOR) experiment]. A second scientific objective is to investigate the space variability of soil profile characteristics in the experimental sites, particularly organic carbon concentration, moisture, and texture. It is expected that such soil property variability influences greatly the distribution of several biological species such as spiders. To investigate such effects in the litter spider community, we applied percentual complementarity and Simpson diversity index to available data. Our results suggest that a faunal transiti...

Organic Matter in Archaeological Black Earths and Yellow Latosol in the Caxivanã, Amazonia, Brazil

The National Reserve of Caxivana, located in the Lower Amazon region, is a place where environmental preservation is still possible even though its surroundings are densely inhabited. The Ferreira Penna Scientific Station (ECFPn) is a building in the reserve and belongs to the Museu Paraense Emilio Goeldi (MPEG), supporting multidisciplinary research in terms of species, communities, and ecosystems.

Fertility, Microbial Biomass and Edaphic Fauna Under Forestry and Agroforestry Systems in the Eastern Amazon

In many countries the rate of deforestation is accelerating. For example, many forest areas of Bangladesh, India, Philippines, Sri Lanka and parts of the rainforest in Brazil could disappear by the end of the century (GLOBAL CHANGE, 2010). The primary forest, especially in the tropics like the Philippines, Malaysia and Thailand such as in Brazil began to be destroyed, because the growth of the agricultural expansion caused a significant decrease in natural resources. Over the past 50 years, the Philippines, there was a loss of 2.4 acres of vegetation every minute, which is attributed to two factors: growth of agriculture and illegal logging