The impact of repeated droughts on the stability of the Amazon forest

Although tropical forests only cover around 10% of the Earth’s land surface, they host at least 2/3 of the world’s flora and fauna diversity, 96% of global tree species and deliver a range of essential ecosystem services. However, an increase in drought frequency and intensity over the Amazon forest has been predicted due to anthropogenic greenhouse gas emissions. Such an increase in drought events is expected to cause an increase in fire activity, tree mortality and carbon emissions to the atmosphere within large areas of the Amazon. It is thus of utmost importance to understand how tropical forests respond to drought and what environmental factors mediate tropical forest stability. The general objective of this research is to gain insight in the drought resistance and resilience mechanisms of tropical forests. By using remote sensing technology we will be able to study how tropical forest canopy traits and trait diversity interact with stability in the face of drought, and this in a spatial explicit way crossing different spatial scales; from local to regional. The main hypothesis is that trait profiles exist that can be associated with increased stability and that stability in the face of droughts increases with higher α and β canopy trait diversity. To study the tree canopy trait diversity and stability to drought interactions, we will focus on the Peruvian Andes-Amazon region, which is a biodiversity hotspot covering 76 million ha of tropical forests; and since the region also suffered from a drought in 2010 and 2015-2016, this study region is highly suitable for our drought stability study.