Can we define leaf exchange functional groups in ever wet rainforest trees? A test using leaf temporal traits

Abstract

Phenology studies the life cycle events in the life of plants. Over the last years, attention to phenological studies has increased, specially due to the need to understand the response of plant communities to climate change. This is particular relevant in tropical ecosystem, such as the Amazon, due to its biodiversity and influence on the global climate. Tropical forest exhibit a hig diversity of phenological patterns, reflecting evolutionary adaptations to abiotic and biotic factors. The regulation of phenology in tropical tree is manily recognized to be influenced by radiation and water availability, specially during the dry season. The leaf flushing during this period can increase photosynthesis rates and reduce water loss through transpiration. Nonetheless, biotic interactions, such as herbivory, can also play a key role in the phenology of tropical plants. The production of new leaves during the dry season, combined with leaf traits defense, may be an escape strategy against herbivores, reducing herbivory pressure. The green-up phenomenon in the Amazon during the dry season is mainly seem from the perspective of sesasonal variation in abiotic factors. However, this behavior may be a response to herbivory, a knowledge that remains poorly understood in tropical ecosystems. Understanding the patterns of leaf flushing and their relationship with proximal and distal causes is importante for understanding plant adaptations in this environment. To this end, we will use near-remote phenology monitoring (phenocams), which provide accurate phenological temporal data. This project aims to integrate leaf flushing pattern in Central Amazon, the leaf traits of these species, and their relationship with herbivory. The hypothesis is that leaf flushing during the dry season acts as an escape strategy against herbivores, and that tree species with more susceptible traits produce their leaves during thi season. On the other hand, species with traits that confer resistance produce their leaves during the rainy season, which characterizes the highest insect activity.