Katie Heineman

Ph.D. student
Program in Ecology and Evolutionary Biology

The availability of soil-derived nutrients, such as nitrogen, phosphorus, and potassium, limits plant growth and influences the spatial distribution of tropical tree species in tropical forests. While tree species composition changes considerably over soil fertility gradients, the role of plant nutrient allocation in species habitat preference and the forces that maintain variation in allocation strategies among co-existing trees are poorly understood. My dissertation explores how allocation of limiting elements responds to variation in soil nutrient availability in tropical tree species and to what extent these responses influence ecosystem nutrient cycles. Field work for this project was designed to exploit extreme natural availability of soil nutrients in two forest ecotypes: 1) a wet montane forest in western Panama (Fortuna Forest Reserve), and 2) a seasonally dry lowland forest in the Panama Canal Zone. I have performed inventories of foliar and woody tissue chemistry across these two soil gradients to evaluate the constraint of nutrient stoichiometry within and among soil habitats. I am also using an experimental approach to determine how allocational responses to defoliation and nutrient addition differ among species and soil habitats.  

Dept. of Plant Biology School of Integrative Biology
Program in Ecology & Evolutionary Biology University of Illinois