1. Terra Preta, forest composition and forest dynamics
Forests in the Amazon area have often been considered as pristine, but many of these forests are less than a few hundred years old and bear traces of former human interventions. The human legacy can be seen in both the soils (Terra Preta) and in the vegetation (enrichment with fruit-bearing and other useful species such as palms for housing). This legacy has most likely resulted in different forest composition, structure and dynamics which are caused by and feed back to soil properties. Understanding these feedbacks will determine management and use potential of such forests. In this project we aim to (1) establish soil maps to correlate forest properties with soil properties, with special emphasis on effects of Terra Preta on water availability; (2) test for differential abundance and population structure in Terra Preta and non-Terra Preta sites for 20-40 tree species that are known to have been used or cultivated by the Amerindians; (3) test for differential abundance of light-demanding tree species at both sites as a basis for improved forestry practices; (4) unravel the mechanisms through greenhouse experiments to determine which factors of soil improvement are most important for future forest management practices; (5) use models to assess future uses of these forests under different forms of management on Terra Preta and non-Terra Preta sites; (6) relate general theories of maintenance of species richness to human interventions in soils and vegetation (intermediate disturbance hypothesis; paradox of enrichment, Grime’s humped back model).