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This paper aims to describe the spatial-temporal variability in catch of the main fishery resources of the Amazon River and floodplain lakes of the Lower Amazon, as well as relating the Catch per Unit of Effort with anomalies of some of the Amazon River, atmosphere and Atlantic Ocean system variables, determining the influence of the environment on the Amazonian fishery resources. Finfish landings data from the towns and villages of the Lower Amazon for the fisheries of three sites (Óbidos, Santarém and Monte Alegre), were obtained for the period between January 1993 and December 2004. Analysis of variance, detrended correspondence analysis, redundancy analysis and multiple regression techniques were used for the statistical analysis of the distinct time series. Fisheries production in the Lower Amazon presents differences between the Amazon River and the floodplain lakes. Production in the Amazon River is approximately half of the one of the floodplain lakes. This variability occurs both along the Lower Amazon River region (longitudinal gradient) and laterally (latitudinal gradient) for every fishing ground studied here. The distinct environmental variables alone or in association act differently on the fishery stocks and the success of catches in each fishery group studied here. Important variables are the flooding events; the soil the sea surface temperatures; the humidity; the wind and the occurence of El Niño-Southern Oscillation events. Fishery productivity presents a large difference in quantity and distribution patterns between the river and floodplain lakes. This variability occurs in the region of the Lower Amazon as well as laterally for each fishery group studied, being dependent on the ecological characteristics and life strategies of each fish group considered here. [ABSTRACT FROM AUTHOR]

Studies of tropical soil organic carbon (SOC) response to deforestation present conflicting results, confounding estimates of the regional effects of land-cover change on carbon storage. We calculated the change in Soc stocks due to deforestation through 1996 for the state of Rondônia, Brazil, in the southwestern Amazon basin. Whereas the net change in SOC for the state as a whole was slightly negative (-0.5% or -5012 Gg), spatially explicit maps suggest dramatic local changes, ranging from -76% to +74%, with outliers as high as +330%. The direction and magnitude of change in SOC following forest clearing is related to original forest soil carbon and pH, which in turn provides a general measure for overall nutrient availability and possible toxicities. When native soil carbon is high, SOC decreases in response to land-cover conversion from forest to pasture; conversely, low soil carbon and low soil fertility lead to gains in carbon under pasture. Mapping variability, rather than relying on large-area averages, illustrates why results from individual field sites have been contradictory. [ABSTRACT FROM AUTHOR]