Methane emission from tropical savanna Trachypogon sp. grasses

E. Sanhueza (1) , L. Donoso (1)

1 IVIC - Instituto Venezolano de Investigaciones Cientificas = Venezuelan Institute for Scientific Research

Methane flux measurements from the soil-grass system were made during the wet season in unperturbed plots and plots where standing dry and green Trachypogon sp. grasses were clipped to just above the soil surface. Results support the surprising discovery that vegetation emits methane. The dry/green mixture of grasses produce methane at a rate of ~10 ng m^?2 s^?1, which extrapolated to the global savanna would produce an annual emission of ~5 Tg, much lower than the production recently suggested in the literature. On the other hand, during the wet season savanna soil consume CH₄ at a rate of ~4.7 ng m^?2 s^?1, producing a global sink of ~1.3 Tg yr^?1. Therefore, the tropical savanna soil-grass system would make a modest contribution to the global budget of methane.

Domaines: Océan, Atmosphère

E. Sanhueza, L. Donoso. Methane emission from tropical savanna Trachypogon sp. grasses. Atmospheric Chemistry and Physics Discussions, 2006, 6 (4), pp.6841-6852. ⟨hal-00302008⟩