We have created this Blog and the database to provide a place where the scientific community can share and update the fast growing knowledge and data on the study of greenhouse gas CO2, CH4, and N2O fluxes in Africa.

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Marsden et al., 2008. Relating coarse root respiration to root diameter in clonal Eucalyptus stands in the Republic of the Congo.

Marsden, C., Nouvellon, Y., Epron, D., 2008. Relating coarse root respiration to root diameter in clonal Eucalyptus stands in the Republic of the Congo. Tree Physiology 28, 1245-1254.

Abstract

Root respiration is an important component of the carbon balance of a forest ecosystem. We measured CO2 efflux of excised fine roots and intact coarse roots in 3-, 4- and 13-year-old Eucalyptus stands in the region of Pointe-Noire, Republic of the Congo. A transportable and adaptable closed chamber gas exchange system directly measured CO2 efflux of roots from 0.5 to 32 mm in diameter. Fluxes were corrected for measurement system leaks and normalized to a reference temperature of 30 °C. Mean fine root respiration rates at the reference temperature varied between 8.5 and 10.8 ╬╝mol CO2 kg−1 s−1 depending on the stand. Coarse root respiration was strongly negatively correlated to root diameter. We propose a model based on a radial gradient of respiratory activity within the root to simulate the exponential decrease in respiration with diameter. Although many sources of uncertainty in the measurements remain, as discussed in this paper, these results provide a basis for scaling up organ-level root respiration measurements to the tree and stand levels.

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