Logging impact on Amazonian white-sand forests: perspectives from a sustainable development reserve

Overexploitation is one of the main causes of biodiversity loss and local extinction. In the Brazilian Amazon, the intensive use of high-value timber species is leading to a decline in their populations. When in decline, these species can be replaced by less valuable and more common ones that are more feasible to exploit. We conducted interviews with residents of two communities in a sustainable development reserve in central Amazonia, and used free lists and the cognitive salience index (S) to assess the perceptions of residents regarding the occurrence and purpose of timber exploitation, and to identify possible endangered species in white-sand and terra-firme forests. In addition, to infer possible consequences of logging, we assessed the current population status of timber species cited by residents in forest-plot inventories carried out within the reserve. S-index values and interviewee reports suggested an intensive use of terra-firme timber species and an apparently recent increase in the exploitation of white-sand species, which did not use to be exploited because of their relatively low commercial value. The inventories showed that the white-sand timber species have high relative densities and low S values in contrast to the terra-firme species, which mostly have low relative densities and high S values. Our results highlight the need to identify and monitor relevant timber species in both terra-firme and white-sand forests, and to increase the involvement of the local community in the development of logging management practices. (AU)

ASPECTOS MORFOLÓGICOS Y PRIMER REGISTRO DEL DINOFLAGELADO Pronoctiluca spinifera EN EL CARIBE COLOMBIANO

Se registró por primera vez la presencia del dinoflagelado atecado Pronoctiluca spinifera (Lohman) (Schiller, 1933) en el Parque Nacional Natural Corales de Profundidad-PNNCPR del Caribe colombiano. Fueron hallados a uno y 40 m de profundidad, tres ejemplares con tamaño promedio de 54,84 µm de largo y 10,29 (m de ancho; de contorno fusiforme con dos proyecciones, una en forma de tentáculo (13,56 µm) y otra puntiaguda. Los sitios de muestreo se caracterizaron por temperaturas entre 27,7 y 30,3 °C; salinidad entre 35,6 y 36,4 y clorofila a entre 0,0801 y 0,1741 mg/m3; valores típicos de ambientes oceánicos. Con el presente trabajo se amplía la distribución de P. spinifera hallándose por primera vez en el mar Caribe Colombiano en el PNNCPR.

The presence of the unarmored dinoflagellate Pronoctiluca spinifera (Lohman) Schiller (1933) was recorded for the first time in the Parque Nacional Natural Corales de Profundidad-PNNCPR, in the Colombian Caribbean. Three specimens with an average size of 54.84 µm long and 10.29 wide were found at one and 40 m depth; of the fusiform outline with two projections, one in the form of the tentacle (13.56 pm) and another pointed. The sampling sites were characterized by temperatures between 27.7 and 30.3 °C; salinity between 35.6 and 36.4 and Chlorophyll a between 0.0801 and 0.1741 mg / m3; typical values of oceanic environments. With this paper, the distribution of P. spinifera is extended, being found for the first time in the Colombian Caribbean Sea in the PNNCPR.

Floristic composition, structure and soil-vegetation relations in three white-sand soil patches in central Amazonia / Composição florística, estrutura e relação solo-vegetação em três áreas de campinarana na Amazônia central

ABSTRACT The Amazonian white-sand vegetation presents a set of unique features, such as the dominance of a few species, high endemism and low species richness, which differentiate it from other Amazonian forests. Soil parameters have long been recognized as the main drivers of white-sand vegetation (WSV) characteristics. However, how they influence the composition, richness and structure of this vegetation type is still poorly understood. In this study we investigated the variation in floristic composition between patches and the soil-vegetation relations in three central Amazonian WSV patches. We tested whether slight differences in soil properties are linked with differences in floristic composition, species richness and forest structure in adjacent patches. In each patch three plots of 50 x 50 m were sampled (a total of 2.25 ha). Soil samples were collected for each plot. The sampling cutoff for arboreal individuals was DBH ≥ 5 cm. We sampled a total of 3956 individuals belonging to 40 families and 140 species. In each patch only a few species were dominant, but the dominant species varied among patches. Differences among patches were significant, but plots in the same patch tended to have similar species composition. The variable sum of bases (SB) was directly related to species composition, however, species richness and forest structure were not related to soil parameters. Even small variations in soil parameters can change species composition in WSV, although these variations do not necessarily influence the richness and other structural parameters.

RESUMO As campinaranas amazônicas apresentam uma série de características únicas, como a dominância de poucas espécies, alto grau de endemismos e baixa riqueza de espécies, que as diferenciam de outras formações florestais amazônicas. Parâmetros edáficos têm sido apontados como os principais responsáveis pelas características das campinaranas. Contudo, como estes parâmetros influenciam a composição, riqueza e estrutura deste tipo de vegetação ainda é pouco entendido. Neste estudo investigamos a variação estrutural, a composição florística e a relação solo-vegetação em três áreas de campinarana na Amazônia central, com intuito de testar se pequenas diferenças nos parâmetros edáficos do solo estão relacionados com diferenças na composição, riqueza e estrutura do componente arbóreo em áreas de campinarana adjacentes. Em cada área foram amostradas três parcelas de 50 x 50 m (totalizando 2.25 ha), com o critério de inclusão para os indivíduos de DAP ≥ 5 cm. Amostras de solo foram coletadas em cada parcela. O número total de indivíduos amostrados foi 3956, pertencendo a 40 famílias e 140 espécies. Em cada área poucas espécies foram dominantes, mas estas variaram entre as áreas. Diferenças entre as áreas foram significativas, porém parcelas da mesma área tenderam a ter composição florística similar. A variável soma de bases (SB) foi diretamente relacionada à composição de espécies; contudo, riqueza de espécies e estrutura florestal não foram relacionadas a nenhum dos parâmetros do solo amostrados. Concluimos que mesmo pequenas variações nos parâmetros edáficos do solo podem mudar a composição de espécies em campinaranas, embora esta variação não necessariamente influencie a riqueza e outros parâmetros estruturais da vegetação.

Microbial mat ecosystems: structure types, functional diversity, and biotechnological application

Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.

Etiology and Management of Nonunion / 대한정형외과학회잡지

Nonunion is caused by various factors related to fracture characteristics, patient characteristics, treatment, and infection. Aseptic nonunion, is divided into three categories in accordance with the biological activity of the fracture: atrophic nonunion, oligotrophic nonunion, and hypertrophic nonunion. Treatment of nonunion depends on the cause and classification. Here, we report our experiences and review the various causes of nonunion and treatment methods available.

Relaciones suelo-vegetación en una toposecuencia del Escudo Guayanés, Venezuela

The Guayana Shield is one of the oldest territories in the planet and has millions of years subjected to leaching and erosion processes that produce oligotrophic soils. This scarcity of nutrients has not avoided the development of high, diverse and magnificent forests, where plants have adaptations to survive these difficult conditions. The aim of this work was to characterize the physical and chemical parameters of the soils in different forest communities of the Imataca Forest Reserve (IFR), to establish some interpretations on their origin, and some relationships between the edaphic components and the inhabitant species. Terrestrial journeys were carried out and two path-ways were traced for the interpretation of forest communities. In each community, three plots (100m x 100m) for the ecological survey were established. In each plot, all trees, palms, and lianas were measured (dbh≥10cm; dbh: diameter at breast height); four 10m x 10m understory sub-plots were evaluated, and a census of all the spermatophyta species (dbh<10cm) was made. Soils were evaluated by means of a trial pit in each community, and a bore in each one understory sub-plot. The obtained data were analyzed by both a detrended and a canonical correspondence analysis. Results from a total of 15 plots allowed us to identify three communities: a forest dominated by Mora excelsa located in a narrow valley with high content of silt; a swamp forest dominated by Catostemma commune in a sandy broad valley, and a forest in clay hills dominated by Alexa imperatricis. Most of the soils had a pH between 3.1 and 4.5. Nutrients were in very low concentrations (N: 0-0.2%; P: 0-14ppm; K: 0-0.3Cmol/kg) and Al in toxicity quantities. We observed that Ca/Al relationship greater than 1 meant a neutralization of the toxic effect of Al. Besides, basal area ranged from 20.4 to 32.3m²/ha; the highest level (top local forest development) corresponded with the C. commune community with a Ca/Al value of 2.5. This research found an adequate relationship between soil and vegetation, as it was able to identify three communities into three distinct soil conditions. Nevertheless, edaphic constraints indicated that high forest cover must be maintained as an essential element for the conservation of these communities.

El Escudo Guayanés es uno de los territorios más antiguos del planeta; tiene millones de años sometido a procesos de lixiviación y erosión que dejan suelos oligotróficos. El objetivo de este trabajo fue hacer la caracterización de los parámetros físicos y químicos de los suelos, en diferentes comunidades boscosas de la Reserva Forestal Imataca, e identificar ciertas relaciones entre los componentes edáficos y las especies que allí se presentan. Se realizó un inventario de todos los individuos mayores a 10cm dap (diámetro a la altura del pecho) en 15 parcelas (1ha); en cada una de esas parcelas se evaluaron cuatro sub-parcelas de sotobosque (100m²) para contabilizar todas las espermatofitas; los suelos se evaluaron mediante una calicata por comunidad y un barreno en cada sub-parcela de sotobosque. La mayoría de los suelos tienen un pH muy ácido (3.1-4.5), los nutrientes están en concentraciones muy bajas (N: 0-0.2%; P: 0-14ppm; K: 0-0.3Cmol/kg) y el Al en concentraciones tóxicas. Esto coincide con otros estudios realizados en esta región, pero en este trabajo se encontró que la relación Ca/Al con valores superiores a 1, lo que implica una neutralización del efecto tóxico del Al y permite un mejor desarrollo de las comunidades boscosas.

Spatial and temporal fluctuation of phytoplankton functional groups in a tropical reservoir / Variação espacial e temporal dos grupos funcionais do fitoplâncton em um reservatório tropical

Along the horizontal axis of reservoirs are generally recognized three zones (fluvial, transition and lacustrine) with distinct hydrodynamic and physical, chemical and biological properties. Quarterly samplings were conducted in 2002, in the limnetic region from each zone, at different depths of a tropical reservoir. To test the hypothesis that highest biomass (biovolume) of phytoplankton are found in the transition zone, the PERMANOVA analysis was realized. 106 taxa were recorded. Significant differences between biovolume values of the three zones were not verified (pseudo F = 0,89; p = 0,55). Higher values of biomass were obtained in lacustrine and transition zones of the reservoir. The functional group (FG) N (Cosmarium spp.) was dominant in these zones, in rain period, and related to low phosphorus concentration, high transparency and water column stability. Low biovolume values in reservoir characterized oligotrophic conditions in all zones of the reservoir, most of the period. The dominance of FGs Y, Lo, E, P and A, as evidenced by the CCA, was associated with low light availability and higher nutrients concentrations.

Ao longo do eixo horizontal de reservatórios são, em geral, reconhecidas três zonas (fluvial, transição e lacustre) com distinta hidrodinâmica e propriedades físicas, químicas e biológicas. Foram realizadas amostragens trimestrais no ano de 2002, na região limnética de cada zona, em diferentes profundidades, em um reservatório tropical. Para testar a hipótese de que os maiores valores de biovolume fitoplanctônico ocorrem na zona de transição do reservatório, foi realizada a Análise PERMANOVA. Foram registrados 106 táxons. Não foram registradas diferenças significativas entre os valores de biovolume fitoplanctônico das zonas do reservatório (pseudo F = 0,89; p= 0,55). Maiores valores de biovolume foram obtidos na zona lacustre e na zona de transição do reservatório. O grupo funcional N (Cosmarium spp.), dominante nestas zonas, no período chuvoso, esteve relacionado às baixas concentrações de fósforo, alta transparência e estabilidade da coluna de água. Os baixos valores de biovolume caracterizaram condições oligotróficas em todo o reservatório, na maior parte do período de estudo. A dominância dos FGs Y, Lo, E, P e A, como evidenciado por meio da CCA, esteve associada à baixa disponibilidade de luz e concentrações mais altas de nutrientes.

Structure and dynamics of phytoplankton in an Amazon lake, Brazil

Natural lake systems represent important reservoirs for residential water supply, fish production, recreational activities and enjoyment of their natural beauty. Nevertheless, human impacts may affect their health status resulting in degradation and loss of biodiversity. The aim of the present study was to obtain data on the health status of a natural lake located in an indigenous reservation in the Brazilian Amazon, using the phytoplankton community changes along the rainy (June) and dry (November) seasons of 2006. We collected water (temperature, pH, Secchi depth and conductivity) and phytoplankton samples from the subsurface, middle of the water column, and approximately 30cm above the bottom, over 24-hour sampling periods, from a central station in the lake. Samples taken from biotic and abiotic variables were correlated using canonical correspondence analysis (CCA). Results showed that the lake exhibited high temperatures in both seasons, and showed thermal stratification only during the rainy season. Dissolved oxygen exhibited a clinograde pattern in the rainy season and high oxygen in the hypolimnion in the dry season. In the rainy season, the water near the bottom was acidic, turbid and had a greater concentration of phosphorus. Dissolved oxygen, conductivity, pH, nitrite, total phosphorus and total dissolved phosphorus exhibited diel variations in the rainy season, whereas water temperature, dissolved oxygen, total nitrogen and total dissolved phosphorus exhibited significant differences between hours of the day in the dry season. The phytoplankton was represented by 39 taxa, and Chlorophyta showed the greatest species richness, totaling 25 taxa. Among Chlorophyta, desmids were the most diverse, accounting 52%. Bacillariophyta (nine species) was the second most diverse group. Cyanophyta was represented by three species, including Merismopedia tenuissima, the most abundant taxon. Despite the occurrence of taxa that indicate organic pollution, their biomass and frequency indicate that the system is not currently threatened. Lake Caracaranã is an oligotrophic system, with low algal density and isolated blooming episodes due to its shallow depth. Rev. Biol. Trop. 58 (4): 1421-1436. Epub 2010 December 01.

Los sistemas de lagos naturales constituyen reservorios importantes para el abastecimiento de agua residencial, la producción de peces, actividades recreativas y el disfrute de su belleza natural. Sin embargo, el impacto humano puede afectar su estado de salud como resultado de la degradación y la pérdida de biodiversidad. El objetivo del estudio fue determinar el estado de salud de un lago natural en una reserva indígena de la Amazonia brasileña, usando los cambios de la comunidad fitoplanctónica a lo largo de la época lluviosa (junio) y seca (de noviembre) en 2006. Se recogieron muestras de agua (temperatura, pH, conductividad y profundidad de Secchi) y fitoplancton del subsuelo, columna media del agua y a 30cm por encima del fondo, cada 24horas, en una estación central en el lago. Las variables bióticas y abióticas se correlacionaron mediante análisis de correspondencia canónica (CCA). Los resultados mostraron que el lago exhibió altas temperaturas en ambas temporadas, una estratificación térmica solamente durante la época lluviosa así como un patrón vertical de oxígeno disuelto, mientras que en la estación seca se observó una alta cantidad de oxígeno en el hipolimnion. En la época lluviosa, el agua cercana al fondo era ácida, turbia y tenía una mayor concentración de fósforo. Oxígeno disuelto, conductividad, pH, nitritos, fósforo total y disuelto mostraron variaciones diarias en la época lluviosa, mientras que la temperatura del agua, oxígeno disuelto, nitrógeno total y fósforo disuelto mostraron una diferencia significativa en las horas del día durante la estación seca. El fitoplancton estuvo representado por 39 táxones, y Chlorophyta mostró la mayor riqueza de especies, un total de 25 táxones. En Chlorophyta, los desmidios fueron los más diversos, lo que representa el 52%. Bacillariophyta (nueve especies) fue el segundo grupo más diverso. En Cyanophyta se encontraron tres especies, incluyendo Merismopedia tenuissima, el taxon más abundante. A pesar de la ocurrencia de taxones que indican contaminación orgánica, la biomasa y frecuencia sugieren que el sistema actualmente no está en peligro. Lago Caracaranã es un sistema oligotrófico, con baja densidad de algas y aislados episodios de afloramiento debido a su poca profundidad.