For her doctoral research, Cecilia spent two years climbing canopy trees up to 65m tall at two Amazonian sites in Peru and French Guiana to study tropical leaf phenology (timing of leaf emergence and abscission). Natural leaf aging/phenology is a fundamental driver of change in morphological, biochemical and spectral leaf traits, thereby, regulating both ecosystem processes (plant growth, energy and nutrient cycling) and remotely-sensed canopy dynamics. Recent remote sensing studies have reported seasonal variation in the phenology of the Amazon rainforest, with enhanced "greenness" (expressed through vegetation indices such as NDVI or EVI or vegetation leaf area index estimates) in the dry season. These studies have mostly been satellite-based and suggest that leaf phenology is a major driver of seasonal productivity in carbon-rich tropical evergreen forests. However, these studies have had little corroboration with on-the-ground observations of the phenology of tropical forests which is still poorly understood.