Role of Fire in Nutrient Cycling in Brazil

+Role of Fire in Nutrient Cycling in Brazil and the Pine Barrens Hedin Laboratory Princeton University Summer 2013 Amy Tourgee Symposium of Learning October 4, 2013

+ Hedin Laboratory n Organization of Hedin Lab n Location: EEB Department, Princeton University n Research Interests: nutrient cycling n Summer Internship Work: n Meta-analysis n Experiment/Fieldwork

+ Project Origins n n Nutrient cycling n Nutrient-vegetation feedbacks shape landscape n Role of fire in these feedbacks n Questions about linking above and belowground cycling and soil fertility Site Applications n Brazil: savanna vs. forest n Pine Barrens: pygmy pines vs. forest

+ Project 1: Meta-Analysis n Goal: study the differences in community composition of nitrogen-fixing species and individuals between savanna and forest in Brazil n Methods n Meta-analysis: combining data from many different studies n Advantages: precision and accuracy for a heterogeneous and spatially large area.

+ Project 1: Meta-Analysis n My Role n n Search for scientific papers with relevant data Compile data into an Excel database Analyze data using statistics and graphs Conclusions n n Deduce something about the role of fire in shaping savanna/forest niches Test evolutionary strategy of nitrogen-fixers

+ Project 2: Pine Barrens n “Pinelands” n Central and Southern NJ n Forest vs. Pygmy Pines n Goal: determine the role of soil fertility and fire in shaping the above and belowground biomass. n Methods n Experimental design n Fieldwork in the Pine Barrens

+ Project 2: Pine Barrens n n My role n Fieldwork: vegetation surveys and measurements, soil samples above and belowground biomass, soil fertility n 3 plots: hold soil fertility & fire frequency constant through different plot combinations Conclusion n Infer whether fire or soil fertility or combination drives nutrient cycling feedbacks Poor soil fertility & Low frequency of fire Poor soil fertility & High frequency of fire Very poor soil fertility & High frequency of fire

+ Internship Experience n n Research Experience n Data compilation vs. fieldwork n Insight into working in a lab Skills n Tackling problems and revision in the scientific process n Collaboration with other scientists n Confidence in my work

+ Thank You! n Adam Pellegrini, Graduate Student, Princeton University n Hedin Laboratory n Princeton Environmental Institute