Concern about the future of tropical rain forests has largely focused on threats to the survival of the extraordinary biological diversity that characterizes these ecosystems. Another perspective emphasizes the role that tropical rain forests play in the global carbon cycle. Despite covering only about 8% of the land surface, tropical rain forests are thought to contain about 40% of the terrestrial biomass and account for over 50% of the annual net primary productivity of the biosphere (Williams et al., 1998). Furthermore, recent evidence suggests that unlogged tropical rain forests act as a sink of anthropogenic carbon emissions (Grace et al., 1995). Conversely, the destruction of rain forests by land clearance and forest fires is a significant source of CO2, a point dramatically highlighted by the recent massive fires that have occurred in tropical rain forests worldwide (Malingreau et al., 1985; Brown, 1998). The purpose of this review is to report current research concerning the factors that influence carbon dynamics in tropical rain forests.
