Legacies of Amazonian Dark Earths on Forest Composition, Structure and Dynamics
SummaryAmazonian Dark Earths (ADE) or ‘terra preta’, are anthropogenic soils, originated since pre-Columbus times. These soils contain higher levels of phosphorous, calcium (mainly originated from bone residuals), and nitrogen that increase fertility of the naturally poor soils in the Amazon basin. In this thesis I evaluated if the increase in nutrients affected positively the Amazonian forest. I found that higher soil pH and nutrient addition associated with ADE caused changes in understory species composition, decreased fern species richness and had a modest effects on forest structure and dynamics. Increases in nutrients, specifically Ca, caused different responses on tree species: some positive and some negative, resulting in potentially long term effects on the tree species composition of the forest.