IRES US-Botswana: Research Opportunities to Investigate Carbon Cycling in the Okavango River Delta, Botswana for US Undergraduate & Graduate Geoscience Students

Oklahoma State University, Stillwater OK

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Professor Eliot Atekwana of Oklahoma State University will conduct an International Research and Experience for Students (IRES) program to support research and educational activities over 3 years for 6 undergraduate and 3 MS students to investigate carbon cycling in the Okavango River delta, Botswana, Africa. The University of Botswana (UB) and the UB Harry Oppenheimer Okavango Research Center (HOORC) will be partners, and 3 undergraduate and 3 graduate students from UB will participate in the project. The student activities will be supervised by PIs from OSU (Atekwana - Aqueous geochemistry, stable isotopes; Cruse - Organic geochemistry, trace elements), and collaborators from UB (Molwalefhe - Hydrogeology), and HOORC (Ringrose - Soils; Masamba - Hydrology, water quality) with complimentary expertise. The work plan ensures effective mentoring of all students, and full and equal participation of Botswanan collaborators and students. The proposed research and educational activities will engage students in field-oriented, hypotheses-driven research on carbon cycling. The Okavango River delta is the ideal setting for this project because (1) river water transit time through the delta is 5-6 months and (2) the delta is in a semi-arid climate where >96% of the water is lost through evapotranspiration. The Okavango River is unique in that it is the only river system in the world where long water transit time and evapotranspiration enhance solute mass transfer from the river to sediments via evapo-concentration driven by terrestrial vegetation. On a global scale, the Okavango River delta is one of the largest riverine wetland systems, yet its role in carbon cycling is unknown. Students will conduct field experiments to test three hypotheses: (1) Vegetative evapo-concentration plays a critical role in carbon mass transfer of riverine dissolved inorganic carbon; (2) Carbon sequestered as carbonate minerals in sediment and surfaces of islands and floodplain by evapoconcentration of groundwater is cycled to the river during flooding; and (3) Carbon in groundwater in the Okavango delta is derived from river water. Intellectual Merit: Quantifying carbon cycling in large riverine systems such as the Okavango is critical for assessing the role of biogeochemical and physical processes on CO2 evasion to the atmosphere. Evapotranspiration and evapo-concentration in the Okavango delta likely plays an important role in coupled solute and carbon cycling. How evapo-concentration affects the cycling of carbon between river water, sediments, and groundwater is not well documented nor understood. Therefore the results of the student research activities will fulfill fundamental knowledge gaps in overall understanding of the role of vegetation on carbon cycling. In addition, this research experience will provide students the opportunity to explore answers to other basic science questions related to the important topic of carbon cycling. The research activity proposed is potentially transformative because it will be shown for the first time that vegetative evapotranspiration affects carbon cycling. This concept has not been previously associated with the role of vegetation in carbon cycling. Broader Impact: The proposed research and educational activities have three broader impacts: (1) Reciprocal understanding of academic and social culture between US and Botswanan students and scientists. US students will gain an international perspective to their education and an enriching cultural experience. They will also acquire personal contacts to build relationships that will form a core for future international collaborations and learn the logistics associated with international research. This international collaboration will contribute to the continued development of a diverse, globally-engaged, science and engineering workforce. Two early career faculty (Cruse and Molwalefhe) will be mentored on international collaboration by senior PI?s as part of this program. (2) Broaden participation of underrepresented groups by targeting students in the Oklahoma Louis Stokes Alliance for Minority Participation for this project. (3) Results from the proposed research will be widely disseminated to enhance scientific and technological understanding by scientists and policy-makers. Students participating in this project will make several presentations at scientific meetings, as well as prepare manuscripts to be published in peer-reviewed journals. Additionally, data from the proposed research will be used for teaching several geochemistry courses at OSU and UB.