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

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。俄克拉荷马州立大学的Eliot Atekwana教授将为6名本科生和3名硕士学生开展为期3年的国际学生研究和经验（IRES）项目，以支持研究和教育活动，调查非洲博茨瓦纳奥卡万戈河三角洲的碳循环。博茨瓦纳大学（UB）和UB哈里奥本海默奥卡万戈研究中心（HOORC）将成为合作伙伴，UB的3名本科生和3名研究生将参与该项目。学生活动将由俄勒冈州立大学（Atekwana -水地球化学，稳定同位素；克鲁斯-有机地球化学，微量元素）的私人导师和来自UB （Molwalefhe -水文地质）和HOORC （Ringrose -土壤；Masamba -水文，水质）的合作者进行监督，并提供免费的专业知识。该工作计划确保对所有学生进行有效指导，并确保博茨瓦纳合作者和学生充分和平等参与。拟议的研究和教育活动将使学生参与以实地为导向、假设驱动的碳循环研究。奥卡万戈河三角洲是这个项目的理想环境，因为(1)河水通过三角洲的时间为5-6个月，(2)三角洲处于半干旱气候，96%的水通过蒸发蒸发而流失。奥卡万戈河的独特之处在于，它是世界上唯一的河流系统，长时间的水输送和蒸散作用通过陆地植被驱动的蒸散浓度增强了溶质质量从河流向沉积物的转移。在全球范围内，奥卡万戈河三角洲是最大的河流湿地系统之一，但它在碳循环中的作用尚不清楚。学生将通过实地实验验证三个假设：(1)植物蒸发浓度在河流溶解无机碳的碳质传递中起关键作用；(2)地下水蒸发在沉积物、岛屿和漫滩表面以碳酸盐矿物形式封存的碳在洪水期间循环到河流中；③奥卡万戈三角洲地下水中的碳主要来源于河水。知识价值：量化奥卡万戈河等大型河流系统的碳循环对于评估生物地球化学和物理过程对二氧化碳逃逸到大气中的作用至关重要。奥卡万戈三角洲的蒸散发和蒸散浓度可能在溶质和碳的耦合循环中起重要作用。蒸发浓度如何影响河水、沉积物和地下水之间的碳循环，目前还没有很好的文献记载，也没有得到很好的理解。因此，学生研究活动的结果将填补对植被在碳循环中的作用的全面理解的基础知识空白。此外，这项研究经验将为学生提供机会探索与碳循环这一重要主题相关的其他基础科学问题的答案。提出的研究活动具有潜在的变革性，因为它将首次证明植物蒸散作用影响碳循环。这个概念以前没有与植被在碳循环中的作用联系起来。更广泛的影响：拟议的研究和教育活动有三个更广泛的影响：(1)美国和博茨瓦纳学生和科学家之间的学术和社会文化的相互理解。美国学生将获得国际视野的教育和丰富的文化体验。他们还将获得个人联系，建立关系，形成未来国际合作的核心，并学习与国际研究相关的物流。这种国际合作将有助于持续发展一支多元化的、全球参与的科学和工程劳动力队伍。两位早期职业教师（Cruse和Molwalefhe）将由高级PI？作为这个项目的一部分。(2)通过针对俄克拉何马州路易斯·斯托克斯少数民族参与联盟的学生，扩大代表性不足群体的参与。(3)建议的研究结果将广泛传播，以提高科学家和决策者对科学技术的理解。参与该项目的学生将在科学会议上做几次报告，并准备在同行评审期刊上发表的手稿。此外，拟议研究的数据将用于俄勒冈州立大学和UB的几门地球化学课程的教学。

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.