Title: The Importance of Leaf Phenology in Plant Economic Strategies in Tropical Dry Ecosystems

Abstract: Evaluating phenology is fundamental to understanding the ecological strategies of trees in tropical dry ecosystems (TDEs), yet most previous work simply places species in coarse categories, such as evergreen versus deciduous. Here, we use data from phenocameras to quantify the phenological strategies of 43 tree species across tropical dry forests and savannas in Brazil, represented by sampling in the Caatinga and Cerrado respectively. Further, we compare phenological metrics to measures of conventional functional traits such as leaf size, leaf nitrogen and wood density. We find wide variation across species in the length of the growing season, growing season start and end dates, in the level of intraspecific phenological coordination among individuals and in species’ interannual variability in start and end of season dates. These various measures distill down to two main axes of phenological variation, one related to prolongation of the end of the growing season after the rainy season ends and to the total length of the growing season and another related to the start of the season relative to rainfall onset (so-called pre-rain green-up) and intraspecific and interannual variability in start of season. The first axis aligns with the acquisitive-conservative economics spectrum, with acquisitive species possessing small, short-lived leaves with high N and P and conservative species possessing larger, longer-lived leaves with lower N and P. Acquisitive species predominate in the Caatinga dry forests and conservative species in the Cerrado savannas. The second axis varies independently of conventional functional traits and may represent an additional axis of ecological diversification in trees of TDEs. The first axis shows high phylogenetic signal, commensurate with that for conventional functional traits, while the second axis shows less phylogenetic signal and greater divergence among closely related species. Our study provides the first insights into how phenological strategies align and diverge from the acquisitive to conservative economics spectrum in trees of the dry tropics.

Speaker Bio: Nattália Neves holds a degree in Biological Sciences and is currently a Master’s student in Ecology, Evolution and Biodiversity at São Paulo State University (UNESP), Brazil. She is affiliated with the Center for Research on Biodiversity Dynamics and Climate Change (CBioClima) and the Phenology Lab at UNESP. Her research investigates phenological strategies of trees in tropical dry ecosystems, based on phenocamera data from dry forests and savannas in Brazil. She examines how species differ in their phenological strategies and how these patterns relate to functional traits and phylogeny.

In-person location: SEEC S228 (Sievers room).

Zoom option available.