Structural and compositional dimensions of phytochemical diversity in the genus Piper reflect distinct ecological modes of action

Context: An increasing number of ecological studies have used chemical diversity as a functionally relevant, scalable measure of phytochemical mixtures, demanding more rigorous attention to how chemical diversity is estimated. Most studies have focused on the composition of phytochemical mixtures and have largely ignored structural concerns, which may have greater importance for ecological function. Here we explore the development of structural complexity and compositional diversity resulting from different biotic and abiotic interactions in Piper kelleyi Tepe (Piperaceae). We also describe how variation in structural complexity and compositional diversity differ between two congeners, P. kelleyi and Piper reticulatum. To better interpret these results, we have developed a hypothesis-driven framework for interpreting these dimensions of chemical diversity in phytochemical mixtures.

Approach: We used the tropical shrub, P. kelleyi, as a model system to examine interactions between eco...