GC/HWR/GEOS 572: Global Biogeochemical Cycles

Instructors: Steve Leavitt

TuTh 11-12:15, Bannister Tree-Ring Bldg. 424

3 credits


Global Biogeochemical Cycles (GBCs) have been critical to development of Earth systems over the past 4.5 billion years, and they are fundamental to many ongoing global change issues that will affect our planet far into the future.  This class will look at biogeochemical cycling on both ends of this time spectrum, with greater emphasis on current disturbances in GBCs and their important consequences to the atmosphere, hydrosphere, pedosphere, ecosystems, and humans. The final organization of the class will depend on number and interests of the students enrolled.

This is an inquiry-based forum for students in global change-related fields to study major processes affecting global fluxes and transformation of chemical species among reservoirs at the Earth's surface, including measurement and modeling issues.  The role of biosystems and hydrology is central to many of the topics, particularly as related to modern and ancient global change in the Earth system.


Readings: No textbook; article readings will be assigned.  Texts will be recommended for background material as needed.

Purpose: To provide a forum for students in global change-related fields to study processes affecting fluxes of chemical species within and among atmosphere, biosphere, lithosphere and ocean pools at various spatial and temporal scales. Because of the multi-disciplinary nature of understanding global biogeochemical cycles (GBC), students will be exposed to scientific fields and investigations outside of their core major.

Topics: Coverage will emphasize active fluxes of chemical constituents among reservoirs near the Earth's surface particularly those related to biosystems, and to processes involved in chemical transfers and transformations.  Topics will include local, regional and global perturbations that are important to ecosystems, including the human components and cycle imbalances.  Central threads will be the water, carbon and nitrogen cycles.

Format:  Class will meet to discuss topics and readings (discussion variously led by instructor and students) and direct students to a few campus-wide relevant seminars by visitors to UA as they become available.  The classes will include expert guest speakers from around campus who will provide insights into their GBC-related specialties.  There may be opportunities to visit some labs on campus and a Biosphere 2 field trip.

Credit: 3 units

Grading:  Course grading is based on student performance with specific options to be discussed during the first week. Course grade of incomplete will be given only by prior arrangement and under valid circumstances. Attendance is expected at each class period.