CAREER: Drivers of tropical tree seedling dynamics and species coexistence along environmental gradients

Yale University, New Haven CT

Investigators

Abstract

The tropics contain the highest diversity of plants on earth, with hundreds of tree species existing within a single forest. Understanding how such a diversity of plants can exist in these areas, without a handful of species taking over, remains a long-standing issue in ecology. Processes acting on seedlings may be particularly important for determining the number and types of plants found in these forests. The present study will examine how factors such as light and water availability, and the types and number of neighboring plants influence seedling survival and help maintain plant diversity. Understanding how diversity is maintained is important for conserving and managing forests and preserving the services they provide. This project will integrate research with educational activities, including classroom-based and field trip courses on tropical forest ecology and conservation. Videos for online training programs targeting environmental decision makers will also be developed. The project will take advantage of a strong rainfall gradient in central Panama to investigate how the relative importance of different drivers of seedling growth and survival shift with changes in rainfall and dry season severity. In addition, the project will examine how species characteristics -traits like wood density and leaf area- determine seedling responses to their local environment. Data collected at field sites in Panama will be used to develop new computer models that simulate forest dynamics over multiple generations in order to assess the relative contribution of abiotic and biotic drivers of seedling performance to tree species coexistence. This integration of field data and novel forest simulation models will significantly advance understanding of the key mechanisms shaping tropical tree communities and will provide a framework for predicting changes in tropical forest diversity and species composition in response to shifts in climate. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.