The Terrestrial Biogeochemistry Laboratory in the Department of Earth and Environmental Science of the University of Pennsylvania invites applicants for competitive Ph.D. fellowships in one of two research areas: Soil carbon biogeochemistry: Projects seek to quantify and characterize the recalcitrant pools of pyrogenic and geogenic carbon in soils. We’ll examine chemical transformations and dissolution as mechanisms controlling their fate in the critical zone. Urban biogeochemistry: New and evolving research projects to study the biogeochemical functioning of urban ecosystems with emphasis on cycling and storage of carbon and nutrients. Positions are ideal for candidates who have completed an MSc in soil science, geosciences, environmental chemistry, ecosystem science or related fields, but outstanding BSc graduates in such programs will be considered. For further information, please contact Dr. Alain Plante by email (aplante@sas.upenn.edu) or consult the department website (www.sas.upenn.edu/earth). Applications can be submitted directly online (https://www.applyweb.com/upenng/) before December 15.