WP6. Evaluating the ongoing development of tree communities
© Jean-François Gillet
According to palynological studies, the extension of Central African TMFs started 2000 years BP. This extension may still be going on: present savanna patches within TMFs may be remnants of old savannas rather than recent ones. The distribution of some pioneer species is known to be a result of past shifting cultivation. Evergreen forests may gain ground over semi-deciduous forests at the speed of about 100 m every two or three centuries.
The current mosaic of semi-deciduous forests and sempervirent Gilbertiodendron dewevrei
forests in our study area may be a consequence of this slow progression. The extension of Marantaceae
may also result from combined climate and anthropogenic factors. Improving vegetation description in the transition zones between semi-deciduous and evergreen forests, or closed and Marantaceae
forests, will allow us to better understand the ongoing development of the vegetation.
Activities
Along transects crossing several tree community types, we will:
- Implement complementary forest inventories on all strata, including the regeneration stage.
- Assess light requirements to complement WP5 findings.
- Provide a diagnosis on the ongoing development of the various tree community types.
Expected results
Test if:
- Evergreen forests are still expanding over semi-deciduous forests, and closed forests are expanding over savannas and Marantaceae forests.
- Economically-important light-demanding species are decreasing in TMFs because they originate from a major disturbance that occurred decades or centuries ago (Little Ice Age).