Social and Behavioral Sciences | Open Access Articles

Upside-Down Fluxes Down Under: Co2 Net Sink In Winter And Net Source In Summer In A Temperate Evergreen Broadleaf Forest, Alexandre A. Renchon, Anne Griebel, Daniel Metzen, Christopher A. Williams, Belinda Medlyn, Remko A. Duursma, Craig V.M. Barton, Chelsea Maier, Matthias M. Boer, Peter Isaac, David Tissue, Victor Resco De Dios, Elise Pendall

Geography

Predicting the seasonal dynamics of ecosystem carbon fluxes is challenging in broadleaved evergreen forests because of their moderate climates and subtle changes in canopy phenology. We assessed the climatic and biotic drivers of the seasonality of net ecosystem-atmosphere CO2 exchange (NEE) of a eucalyptus-dominated forest near Sydney, Australia, using the eddy covariance method. The climate is characterised by a mean annual precipitation of 800mm and a mean annual temperature of 18°C, hot summers and mild winters, with highly variable precipitation. In the 4-year study, the ecosystem was a sink each year (-225gCm-2yr-1 on average, with a standard deviation of 108gCm-2yr-1); …

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Recent Pause In The Growth Rate Of Atmospheric Co2 Due To Enhanced Terrestrial Carbon Uptake, Trevor F. Keenan, I. Colin Prentice, Josep G. Canadell, Christopher A. Williams, Han Wang, Michael Raupach, G. James Collatz

Geography

Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2 emissions. The terrestrial carbon sink is increasing, yet the mechanisms responsible for its enhancement, and implications for the growth rate of atmospheric CO2, remain unclear. Here using global carbon budget estimates, ground, atmospheric and satellite observations, and multiple global vegetation models, we report a recent pause in the growth rate of atmospheric CO2, and a decline in the fraction of anthropogenic emissions that remain in the atmosphere, despite increasing anthropogenic emissions. We attribute the observed decline to increases in the terrestrial …

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A Full Greenhouse Gases Budget Of Africa: Synthesis, Uncertainties, And Vulnerabilities, R. Valentini, A. Arneth, A. Bombelli, S. Castaldi, R. Cazzolla Gatti, F. Chevallier, P. Ciais, E. Grieco, J. Hartmann, M. Henry, R. A. Houghton, M. Jung, W. L. Kutsch, Y. Malhi, E. Mayorga, L. Merbold, G. Murray-Tortarolo, D. Papale, P. Peylin, B. Poulter, P. A. Raymond, M. Santini, S. Sitch, G. Vaglio Laurin, G. R. Van Der Werf, Christopher A. Williams, R. J. Scholes

Geography

This paper, developed under the framework of the RECCAP initiative, aims at providing improved estimates of the carbon and GHG (CO2, CH4 and N2O) balance of continental Africa. The various components and processes of the African carbon and GHG budget are considered, existing data reviewed, and new data from different methodologies (inventories, ecosystem flux measurements, models, and atmospheric inversions) presented. Uncertainties are quantified and current gaps and weaknesses in knowledge and monitoring systems described in order to guide future requirements. The majority of results agree that Africa is a small sink of carbon on an annual scale, with an average …

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Geography

Recent Pause In The Growth Rate Of Atmospheric Co2 Due To Enhanced Terrestrial Carbon Uptake, Trevor F. Keenan, I. Colin Prentice, Josep G. Canadell, Christopher A. Williams, Han Wang, Michael Raupach, G. James Collatz

Geography

Geography