Soil ants.

Between July 1997 and March 1999 ants of soil and litter were taken every three months with core samplers (21cm ø) in a primary rain forest, a secondary forest and two different systems of polycultures in central Amazonia (Brazil) and extracted in Berlese funnels. Greatest generic diversity wasfound in pirmary forest, while in secondary forest and the two polycultures it was about 20% and 30% lower, respectively. Biomass and median density of ants were also highest in primary forest followed by secondary forest and one of the polyculture, whereas the lowest number and biomass of ants was found in the second polyculture. The predatory species of Hypoponera reresented the biggest part of ant biomass in all areas (20%-30%), whereas the very abundant mostly tiny species (<2mm) of Solenopsis made up only 1,4%-3,9% of the ant biomass.Final Report 1996-1999

Tree biomass equations from terrestrial LiDAR : a case study in Guyana

Large uncertainties in tree and forest carbon estimates weaken national efforts to accurately estimate aboveground biomass (AGB) for their national monitoring, measurement, reporting and verification system. Allometric equations to estimate biomass have improved, but remain limited. They rely on destructive sampling; large trees are under-represented in the data used to create them; and they cannot always be applied to different regions. These factors lead to uncertainties and systematic errors in biomass estimations. We developed allometric models to estimate tree AGB in Guyana. These models were based on tree attributes (diameter, height, crown diameter) obtained from terrestrial laser scanning (TLS) point clouds from 72 tropical trees and wood density. We validated our methods and models with data from 26 additional destructively harvested trees. We found that our best TLS-derived allometric models included crown diameter, provided more accurate AGB estimates (R-2 = 0.92-0.93) than traditional pantropical models (R-2 = 0.85-0.89), and were especially accurate for large trees (diameter > 70 cm). The assessed pantropical models underestimated AGB by 4 to 13%. Nevertheless, one pantropical model (Chave et al. 2005 without height) consistently performed best among the pantropical models tested (R-2 = 0.89) and predicted AGB accurately across all size classes-which but for this could not be known without destructive or TLS-derived validation data. Our methods also demonstrate that tree height is difficult to measure in situ, and the inclusion of height in allometric models consistently worsened AGB estimates. We determined that TLS-derived AGB estimates were unbiased. Our approach advances methods to be able to develop, test, and choose allometric models without the need to harvest trees

Uso de ninhos de cupin como fonte de matéria orgânica em sistemas de produção agrosilviculturais na Amazônia

The growth of two annual crops, okra (Abelmoschus escutentus) and egg-plant (Solatium melongena) and one perennial crop, andiroba (Carapa guianensis, a native forest tree of Amazonia) under different treatments with organic manure derived from termite nest material of wood-feeding Nasutitermes species was tested (randomized block design). The use of 25-100 g of nest material gave no significant increase in okra productivity, and 25-200 g gave no significant response in andiroba. The combined use of NPK with 200 g of nest material gave a significant higher production in egg-plant (total number and total fresh weight of fruits) when compared to the control (without fertilizer) and to the treatment with NPK only.The results suggest the possibility to use termite nest material to enhance crop production in Amazonia, particularly in combination with low amounts of mineral fertilizer. Research lines for further investigations are outlined.Foi avaliado crescimento de duas espécies agriculturais anuais, quiabo (Abelmoschus esculentus) e berinjela (Solatium melongena), e de uma espécie perene, andiroba (Carapa guianensis, uma árvore nativa da Amazônia) sob diferentes tratamentos com matéria orgânica derivada de material de cupinzeiro de espécies xilófagas de Nasutitermes (desenho de bloco randomizado). O uso de 25-100 g de material de termiteiro não levou a um incremento significativo da produtividade em quiabo, e 25-200 g não resultou numa resposta significativa em andiroba. O uso combinado de NPK com 200 g de ninho de cupim resultou numa produção significantemente maior em S. melongena (número total e peso fresco total de frutos) se comparado com o controle (sem fertilizante nenhum) e com o tratamento de NPK apenas. Os resultados sugerem a possibilidade de usar material de cupinzeiro para melhorara produção agrossilvicultural na Amazônia, especialmente em combinação com pequenas quantidades de fertilizante mineral Linhas de pesquisa para futuras investigações são apresentadas

Soil fauna and litter decomposition in primary and secondary forests and a mixed culture system in Amazonia.

Este relatório representa um relato das atividades efetuadas no segundo ano do projeto como também dos resultados obtidos dos dados de 1997-1998 e da primeira serie de experimentos de decomposição com sacos de liteira (serrapilheira). Baseado nos resultados ainda preliminares, as áreas de estudo podem ser organizadas numa série, começando da área de floresta primária FLO via um dos locais de plantação, POC, até o local de floresta secundária, SEC, e o segundo local de plantação, POA.bitstream/item/201401/1/Soil-Fauna-And-Litter-Decomposition-in-Primary...-1998.pdfSHIFT ENV 52. Annual Report 1998

Litter production, litter stocks and decomposition coefficients in a central Amazonian rain forest, a secondary forest and agroforestry systems.

Fine litter fall and stocks were determined from July 1997 to March 1999 in an area of primary rain forest (FLO), a 13-year old secondary forest (SEC), and two polyculture systems (agroforestry; POA and POC) in central Amazonia Brazil.Final Report 1996-1999

Microclimate 1997-1999 in primary forest, secondary forest and agroforestry systems in central Amazonia.

Rainfall, average maximum and minimum air temperature, and relative air humidity as measured at the Embrapa weather station all show that 1997 was a strong El Nino (ENSO) year.bitstream/item/181106/1/ID-5199-34-49.pdfFinal Report 1996-1999

Organic matter in termite mounds of an Amazonian rain forest.

This study investigates how termites alter the organic matter in rain forests near Manaus, Brazil. Samples were collected from the outer and inner parts of typical termite nests of Nasutitermes, Termes, Embiratermes, Cornitermes, Anoplotermes, and Constrictotermes genera, as well as from the surrounding topsoil (0cm-10cm) and potential wooden food. The termite nests were signficant sinks for organic matter and its associated nutrients. The organic C contents ranged between 100g kg-1 and 500g kg-1 in the nests, compared to 17g kg-1 to 42g kg-1 in the surrounding topsoils. As lignin contents of the mounds were higher than in wood, lignin may be accumulated in preference to other organic compounds. This findings also sugests that the interior part of the nests is a region of higher organic matter turnover and lignin degradation

Soil termites in a rainforest, a secondary forest and mixed-culture plantation sites in central Amazonia.

Soil termites have been studied in detail in a rain forest, a secondary forest and two agroforestry plantation sites at the Embrapa Amazonia Ocidental, Manaus-AM (Brasil), using soil (0 cm-5 cm) and litter samples taken at random within the study sites, using a soilsampler of 21 cm diameter. As results is presented a list of termite genus diversity, then compare termite biomass and individuals numbers in litter and in soil at the different sites, and discuss possible factors that determine termite distribution in the field

Event selection for dynamical downscaling: a neural network approach for physically-constrained precipitation events

This study presents a new dynamical downscaling strategy for extreme events. It is based on a combination of statistical downscaling of coarsely resolved global model simulations and dynamical downscaling of specific extreme events constrained by the statistical downscaling part. The method is applied to precipitation extremes over the upper Aare catchment, an area in Switzerland which is characterized by complex terrain. The statistical downscaling part consists of an Artificial Neural Network (ANN) framework trained in a reference period. Thereby, dynamically downscaled precipitation over the target area serve as predictands and large-scale variables, received from the global model simulation, as predictors. Applying the ANN to long term global simulations produces a precipitation series that acts as a surrogate of the dynamically downscaled precipitation for a longer climate period, and therefore are used in the selection of events. These events are then dynamically downscaled with a regional climate model to 2 km. The results show that this strategy is suitable to constraint extreme precipitation events, although some limitations remain, e.g., the method has lower efficiency in identifying extreme events in summer and the sensitivity of extreme events to climate change is underestimated