Lesson 32 Mineral Cycling - Alaska Geobotany Center

Estimated current and future carbon fluxes
in the terrestrial biosphere
Sampson et al. (1993)
• Tundra and boreal forests appear to be a
net sink of carbon to the atmosphere
(absorbing carbon in biomass and peat
formation).
• Tropical forests are strong source
(releasing C in respiration and forest
burning).
• Currently, it is unclear whether the
terrestrial biosphere is a net sink or
source of carbon to the atmosphere.
• Doubling of CO 2 will most likely result in
the biosphere being a larger net source.
• The Kyoto accord and other international
efforts are aiming at reducing the flux of
carbon to the atmosphere, partly through
vegetation management or vegetation and
energy management (Columns C and D).