Carbon in Amazon Forests: Unexpected Seasonal Fluxes and Disturbance-Induced Losses

  title={Carbon in Amazon Forests: Unexpected Seasonal Fluxes and Disturbance-Induced Losses},
  author={Scott R. Saleska and Scott D. Miller and Daniel Michael Matross and Michael L. Goulden and Steven C. Wofsy and Humberto R. da Rocha and Pl{\'i}nio Barbosa de Camargo and Patrick M. Crill and Bruce C. Daube and Helber C de Freitas and Lucy R. Hutyra and Michael Keller and Volker Kirchhoff and Mary Menton and J. William Munger and Elizabeth Hammond Pyle and Amy H Rice and Hudson Silva},
  pages={1554 - 1557}
The net ecosystem exchange of carbon dioxide was measured by eddy covariance methods for 3 years in two old-growth forest sites near Santarém, Brazil. Carbon was lost in the wet season and gained in the dry season, which was opposite to the seasonal cycles of both tree growth and model predictions. The 3-year average carbon loss was 1.3 (confidence interval: 0.0 to 2.0) megagrams of carbon per hectare per year. Biometric observations confirmed the net loss but imply that it is a transient… 
Seasonal controls on the exchange of carbon and water in an Amazonian rain forest
[1] The long-term resilience of Amazonian forests to climate changes and the fate of their large stores of organic carbon depend on the ecosystem response to climate and weather. This study presents
Modeling the carbon balance of Amazonian rain forests: resolving ecological controls on net ecosystem productivity
There is still much uncertainty about ecological controls on the rate and direction of net CO2 exchange by tropical rain forests, in spite of their importance to global C cycling. These controls are
Variability of Carbon and Water Fluxes Following Climate Extremes over a Tropical Forest in Southwestern Amazonia
The carbon and water cycles for a southwestern Amazonian forest site were investigated using the longest time series of fluxes of CO2 and water vapor ever reported for this site, found to have a net carbon uptake of ≈5 t C ha−1 year−1, but the effects of the drought of 2005 were still noticed in 2006, when the climate disturbance caused the site to become a net source of carbon to the atmosphere.
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[1] Annual precipitation in the central and southern warm-desert region of North America is distributed climatologically between summer and winter periods with two prominent dry periods between them.
Respiration controls the unexpected seasonal pattern of carbon flux in an Asian tropical rain forest
Tropical rain forests play important roles in the global carbon cycle. We report a six-year eddy covariance carbon flux campaign in a primary tropical seasonal rain forest in southwest China. An
Carbon balance of a primary tropical seasonal rain forest
The role of primary tropical rain forests in the global carbon cycle is under active debate. By combining long-term forest inventory data with physiological measurement data in a 1 ha permanent
Evidence for strong seasonality in the carbon storage and carbon use efficiency of an Amazonian forest
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Substantial amounts of carbon are sequestered during dry periods in an old-growth subtropical forest in South China
A number of continuous eddy covariance measurements and long-term biomass inventories had proved that old-growth forests are carbon sinks worldwide. The present study estimated the net ecosystem
Carbon dioxide exchange in a semidesert grassland through drought‐induced vegetation change
[1] Global warming may intensify the hydrological cycle and lead to increased drought severity and duration, which could alter plant community structure and subsequent ecosystem water and carbon
Drought sensitivity of Amazonian carbon balance revealed by atmospheric measurements
The results suggest that moisture has an important role in determining the Amazonian carbon balance, and the Amazon may become an increasing carbon source as a result of both emissions from fires and the suppression of net biome exchange by drought.


Changes in the carbon balance of tropical forests: evidence from long-term plots
Long-term monitoring of plots in mature humid tropical forests concentrated in South America revealed that biomass gain by tree growth exceeded losses from tree death in 38 of 50 Neotropical sites, suggesting that Neotropic forests may be a significant carbon sink.
Carbon Dioxide Uptake by an Undisturbed Tropical Rain Forest in Southwest Amazonia, 1992 to 1993
Measurements of carbon dioxide flux over undisturbed tropical rain forest in Brazil for 55 days in the wet and dry seasons of 1992 to 1993 show that this ecosystem is a net absorber of carbon
Carbon dioxide transfer over a Central Amazonian rain forest
Tropical rain forests are among the most important and least monitored of terrestrial ecosystems. In recent years, their influence on atmospheric concentrations of carbon dioxide and water vapor has
Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2
It is suggested that the overall carbon budget of rainforests, summed across terrestrial and aquatic environments, appears closer to being in balance than would be inferred from studies of uplands alone.
The effects of partial throughfall exclusion on canopy processes, aboveground production, and biogeochemistry of an Amazon forest
(1) Moist tropical forests in Amazonia and elsewhere are subjected to increasingly severe drought episodes through the El Nino-Southern Oscillation (ENSO) and possibly through deforestation-driven
Effect of interannual climate variability on carbon storage in Amazonian ecosystems
The Amazon Basin contains almost one-half of the world's undisturbed tropical evergreen forest as well as large areas of tropical savanna,. The forests account for about 10 per cent of the world's
Slow in, Rapid out--Carbon Flux Studies and Kyoto Targets
Many researchers currently attempt to measure the detailed carbon balance of forests, because net release or uptake of carbon by forests could have a large impact on the atmosphere9s COconcentration.
Amazonian Tree Mortality During the 1997 El Niño Drought
Results suggest that intact Amazonian rainforests are relatively resistant to severe El Nino events, and there was no detectable effect of soil texture on mortality rates.
The role of deep roots in the hydrological and carbon cycles of Amazonian forests and pastures
DEFORESTATION and logging transform more forest in eastern and southern Amazonia than in any other region of the world1–3. This forest alteration affects regional hydrology4–11 and the global carbon
Influence of soil texture on carbon dynamics and storage potential in tropical forest soils of Amazonia
[1] Stable and radiocarbon isotopes were used to investigate the role of soil clay content in the storage and dynamics of soil carbon in tropical forest soils. Organic matter in clay-rich Oxisols and