Terrestrial ecosystems play an important role in the global carbon (C) cycle. Tropical
forests in Southeast Asia are constantly changing as a result of harvesting and conversion to other
land cover. As a result of these changes, research on C budgets of forest ecosystems has intensified
in the region over the last few years. This paper reviews and synthesizes the available information.
Natural forests in SE Asia typically contain a high C density (up to 500 Mg/ha). Logging
activities are responsible for at least 50% decline in forest C density. Complete deforestation
(conversion from forest to grassland or annual crops) results in C density of less than 40 Mg/ha.
Conversion to tree plantations and other woody perennial crops also reduces C density to less
than 50% of the original C forest stocks. While much information has been generated recently,
there are still large gaps of information on C budgets of tropical forests and its conversion to other
land uses in SE Asia. There is therefore a need to intensify research in this area.